Malattia di alzheimer i pro e i contro delle terapie farmaceutiche, nutraceutiche, botaniche e stimolatorie


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Malattia di Alzheimer: i pro e i contro delle terapie farmaceutiche, nutraceutiche, botaniche e stimolatorie

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Malattia di alzheimer i pro e i contro delle terapie farmaceutiche, nutraceutiche, botaniche e stimolatorie

  1. 1. Review Article amr Alzheimer’s Disease: The Pros and Cons of Pharmaceutical, Nutritional, Botanical, and Stimulatory Therapies, with a Discussion of Treatment Strategies from the Perspective of Patients and Practitioners Keith A. Wollen, PhD Abstract emphasis has been on single-target approaches, AD Alzheimer’s disease (AD) is characterized by dysfunctional is characterized by many different cellular dysfunc- intracellular and extracellular biochemical processes that tions, suggesting that a multi-target approach may result in neuron death. This article summarizes hypotheses provide more therapeutic value. regarding cell dysfunction in AD and discusses the effective- The goal of this article is to present a current ness of, and problems with, different therapies. Pharma- review of pharmaceutical, nutritional, botanical, ceutical therapies discussed include cholinesterase inhibitors, and stimulatory therapies. Stimulatory therapies, memantine, antihypertensive drugs, anti-inflammatory drugs, which include physical exercise, music, and secretase inhibitors, insulin resistance drugs, etanercept, cognitive training, have received very little brain-derived neurotrophic factor, and immunization. attention but may prove to be important adjuncts Nutritional/botanical therapies included are huperzine A, to more traditional approaches. Since FDA- polyphenols, Ginkgo, Panax ginseng, Withania somnifera, approved pharmaceuticals offer only modest phosphatidylserine, alpha-lipoic acid, omega-3 fatty acids, short-term benefits, serious side effects, and high acetyl L-carnitine, coenzyme Q10, various vitamins and cost, and nutrients and botanicals often have less minerals, and melatonin. Stimulatory therapies discussed are research backing, practitioners must weigh the physical exercise, cognitive training, music, and socialization. potential drawbacks of all therapies against the Finally, treatment strategies are discussed in light of the certain consequences of AD progression. benefits and drawbacks of different therapeutic approaches. It is concluded that potential risks of both approved and AD Pathology non-approved therapies should be weighed against the At the most basic level, AD results from cellKeith A. Wollen, PhD – potential benefits and certain consequences of disease death that can result from many different factors.Professor Emeritus, progression. Approaches that target several dysfunctions Alzheimer brains have low levels of acetylcholinePsychology Department ofWashington State University; simultaneously and that emphasize nutritional, botanical, and (ACh), which can arise from the accumulation ofresearch area in learning stimulatory therapies may offer the most benefit at this time. beta amyloid (βA) protein fragments that formand memory. (Altern Med Rev 2010;15(3):223-244) hard plaques that can in turn interfere with theCorrespondence address:3203 South Maple Street, ability of ACh to effect synaptic transmission andPort Angeles, WA 98362 Introduction initiate inflammatory processes that produceEmail: Although there have been numerous reviews of reactive oxygen species. Research suggests that βA therapies for Alzheimer’s disease (AD), most have opens channels in cell membranes, permitting concentrated on either pharmaceuticals or natural calcium ions (Ca2+) to enter the cell and triggering therapies, with only a few covering elements of several processes leading to mitochondrial dysfunc- both. Many papers are oriented toward researchers tion, inflammation, and cell death.1 Some research rather than practitioners. Although usually the suggests that, in the early stages of AD, βA has an223 Alternative Medicine Review Volume 15, Number 3 Copyright © 2010 Alternative Medicine Review, LLC. All Rights Reserved. No Reprint Without Written Permission.
  2. 2. amr Review Article Key words: Alzheimer,antioxidant function so that efforts to reduce it Administration (FDA) for treating AD. Meta- huperzine, hupA, Ginkgo,might be counterproductive. Other research has analyses have repeatedly found that AChEIs have a Virtiva, ginseng, Withania,found only a weak relationship between the modest beneficial effect on cognition and memory.5 ashwagandha, lipoic, phosphatidylserine,amounts of βA and the severity of AD. βA may be Donepezil and rivastigmine are often regarded as omega, fish oil, EPA, DHA, ALA,the end result of a destructive chain of events and providing only symptomatic relief without provid- acetyl-L-carnitine, ALC, ALCAR,hence more symptomatic than problematic. ing neuroprotective effects. However, in vitro coenzyme, CoQ10, memory, cognition, cognitive, brain, Another possible cause of cell death in AD is a studies show that donepezil offers neuroprotection curcumin, resveratrol,chemical change in a protein (tau) that keeps by reducing glutamate excitotoxicity, diminishing idebenone, lithium,microtubules stable. This causes a neuron’s βA toxicity, and consequently increasing cell melatoninmicrotubules to pair with other tubules producing longevity.6,7 Donepezil slowed atrophy of thetau (neurofibrillary) tangles that result in tubule hippocampus in humans, which suggests a neuro-disintegration and block neurotransmitters, protective effect.8 Data also suggest that cognitiveleading to cell death. benefits from donepezil after three years are Reactive oxygen species (oxygen ions, peroxides, greater when treatment is started early rather thanand free radicals) can result in cell death by delayed one year.9initiating a chain reaction that leads to damage of Galantamine, a natural AChEI (originally derivedcell membranes, mitochondria, lipids, and proteins. from the common snowdrop and other plants, but Damage from toxic excitatory amino acid now synthesized), protects neurons and reducesneurotransmitters, especially glutamate, can cell death by modulating nicotinic receptors, whichproduce excitotoxicity and cell death. Excitotoxicity are significantly reduced in AD brains.10,11 In ancan occur even with normal glutamate levels if animal model, galantamine also increased dopami-glutamate receptor sites become overstimulated.2 nergic neurotransmission in the hippocampus,10 aThe receptor most involved in excitotoxicity is brain area particularly important in memory.N-methyl-D-aspartic acid (NMDA). If NMDA sites Galantamine does not result in tolerance andare overactivated, high levels of Ca2+ can enter the only short-term efficacy characteristic of donepezilcell, causing a permanent depolarization of the and rivastigmine.11 A meta-analysis of 10 random-post-synaptic neuron and creating reactive oxygen ized, placebo-controlled, double-blind studiesspecies and other substances that cause cell death. concluded that galantamine either improved orPotential mechanisms have also linked excitotoxic- prevented decline of cognition and activities ofity to βA and tau tangles.2 daily living.12 Since galantamine can produce Damage from toxins, chemicals, and trauma can gastrointestinal upset, researchers recommendproduce inflammation, another factor in AD. starting with a low dose and gradually increasing toInflammation often results from persistent 16-24 mg daily. The beneficial effects of galan-oxidative stress, but other determinants include tamine have been found to persist for 36 months,βA, protease inhibitors, pentraxins, inflammatory with 50-percent improvement over expected scorescytokines, and prostaglandin-generating cyclooxy- of untreated mild-to-moderate AD subjects.13 Thegenases. Unhealthy neurons contain low levels of magnitude of the benefit increases over time.N-acetyl-aspartate (NAA), which may also be an Rivastigmine, which inhibits both butyrylcholin-issue. Exposure to pollutants can make the esterase and AChE, provides two pathways forblood-brain barrier permeable to toxins, thus prolonging ACh and so might be expected to becausing oxidative stress, inflammation, and βA more effective than donepezil or galantamine. Suchaccumulation.3,4 an outcome, along with less cortical atrophy in the temporal parietal area, was observed in mild ADPharmaceutical Therapies patients over a 20-week period.14 A post hocAcetylcholinesterase Inhibitors (AChEIs) analysis of several studies suggests that rivastig- AChEIs inhibit the action of acetylcholinesterase mine slows the rate of decline as long as five(AChE), thereby enabling ACh to work for a longer years.15period of time, interact with cholinergic receptors AChEIs have several limitations; they areand potassium ion channels, and affect the uptake, expensive, provide modest benefits, and usuallysynthesis, and release of neurotransmitters. have a brief period of effectiveness (sometimesAChEIs include donepezil (Aricept®), rivastigmine partially resolved by switching to a different(Exelon®), galantamine (Razadyne®), and tacrine AChEI). AChEIs have short half-lives and may have(Cognex®) – all approved by the U.S. Food and Drug considerable side effects (especially tacrine), Volume 15, Number 3 Alternative Medicine Review 224Copyright © 2010 Alternative Medicine Review, LLC. All Rights Reserved. No Reprint Without Written Permission.
  3. 3. Review Article amr resulting from activation of peripheral cholinergic less cognitive decline when given an ACE inhibitor systems.16 More emphasis is needed on clinical that crossed the blood-brain barrier (perindopril or significance rather than statistical significance. captopril) than when given an ACE inhibitor that did not (enalapril or imidapril) or a calcium NMDA Antagonists channel blocker (nifedipine or nilvadipine).30 A Memantine is thought to reduce cell damage by recent study confirmed that ACE inhibitors slow decreasing excitotoxicity resulting from overactiva- the progression of AD.31 A potential downside of tion of NMDA glutamate receptors during synaptic ACE inhibitors is that they may block ACE from transmission. Memantine stops overstimulation by converting βA1-42 to less damaging βA1-40, thereby binding to NMDA receptors, which inhibits the reducing its protective function.32 influx of Ca2+ and results in a small improvement in Possible mechanisms by which ACE inhibitors cognition and behavior.17 Although memantine has work include reducing angiotensin II (a substance been FDA approved only for more severe AD, it has that interferes with memory formation by reducing been found effective in phase III trials for both ACh),33 increasing an enzyme that breaks down βA, moderate-to-severe18,19 and mild-to-moderate and increasing acetylcholine. Another possibility is cases.20,21 Nevertheless, the overall data suggest that angiotensin II is converted to angiotensin III that clinically significant effects on cognition, and then to angiotensin IV. Angiotensin IV binds at mood, and performance of daily activities are seen AT4 receptor sites, which are most prevalent in the primarily with more severe cases of AD.22 neocortex, hippocampus, and other areas impor- It is important not to completely block all tant in cognition and memory. This counteracts a glutamate-mediated synaptic transmission since dysfunctional cholinergic system, resulting in more cells must have some NMDA activity to function ACh and improved learning and memory.34 properly. Memantine meets this criterion since it Angiotensin receptor blockers are antihyperten- selectively blocks only excessive stimulation.2,23 sive drugs that block the action of angiotensin II by In a small study of 11 AD patients, memantine binding at AT1 receptor sites. They have been was shown to reduce tau phosphorylation, which reported to reduce AD risk and slow its progres- would be expected to reduce tau tangles.24 Other sion.35,36 These drugs include telmisartan, valsartan, neuroprotective effects have been summarized in a losartan, and candesartan. Potential mechanisms recent review.25 Memantine appears to be well of action include reducing angiotensin II and tolerated.26 increasing the activation of AT4 receptors. NMDA antagonists, such as memantine, have Calcium channel blockers are another category generally been regarded as neuroprotective,2 but of antihypertensive drugs. It may be that βA, they have also demonstrated neurotoxic properties mutations in presenilin proteins, or other factors that diminish memory, incite neuron death, and open channels that permit Ca2+ to enter and even produce psychotic episodes in humans.27 damage cells.37 If so, calcium channel blockers Memantine’s neurotoxicity may be increased by might be expected to benefit AD patients. AChEIs. Such an effect has been demonstrated in Although some research has shown that people an animal model where the concurrent use of taking calcium channel blockers were less likely to donepezil and memantine produced a substantial develop dementia,38 other studies have been increase in neurotoxic reactions.27 Although the negative.39 Since most research has been on clinical relevance of this in humans is unknown, hypertensive individuals, the effects of calcium the simultaneous use of both drugs merits caution. channel blockers on nonhypertensive subjects are On the other hand, recent research shows that such unknown. combinations slow cognitive decline more than memantine or AChEIs alone and that the benefit of Anti-Inflammatory Drugs combination therapy increases over time and Most research on nonsteroidal anti-inflamma- persists for years.28 tory drugs (NSAIDs) has focused on prevention rather than treatment of AD. One study that Antihypertensive Drugs examined 49,349 NSAID users for five years found Antihypertensive drugs have potential for AD the risk of acquiring AD was clearly reduced by therapy. Angiotensin converting enzyme (ACE) ibuprofen and less so by indomethacin, while inhibitors reduced inflammation and mental celecoxib and the salicylates offered no protec- decline in AD patients by 50 percent.29 Mild-to- tion.40 It was not possible to determine AD risk for moderate AD subjects with high blood pressure had many NSAIDs because of small numbers of users.225 Alternative Medicine Review Volume 15, Number 3 Copyright © 2010 Alternative Medicine Review, LLC. All Rights Reserved. No Reprint Without Written Permission.
  4. 4. amr Review ArticleNSAIDs that reduced βA1-42 were no more likely to Insulinbe effective than those that did not. Studies of risk Insulin has many roles in normal cell function-have been inconsistent and correlational in nature, ing. Nasal administration of insulin improvedmaking it impossible to conclude causation. several cognitive measures in subjects with earlyMoreover, other studies have reported that NSAID AD or mild cognitive impairment.51 Nasal adminis-use can actually increase the risk of developing tration allows insulin to reach the brain quicklydementia.41 NSAIDs are well known for producing without affecting insulin levels elsewhere in thegastrointestinal symptoms as well as liver and body. Nasal administration has also improvedkidney toxicity. verbal memory but only for persons with a specific Research on the use of NSAIDs for the treatment genetic makeup (the apolipoprotein E4 [APOE ε4]of AD patients has also been disappointing.42 A allele).52 The latter study used only three doses ofrandomized, placebo-controlled study of people insulin (versus 42 in the previous study) and testedwith mild-to-moderate AD found no cognitive 15 minutes after administration (versus after 21benefit from NSAIDs.43 days). Animal models have demonstrated that anti- Insulin resistance can affect the brain as well asinflammatory cyclooxygenase-2 (COX-2) inhibitors other organs, making it difficult for the brain cells(rofecoxib) reduced oxidative stress but non-spe- to acquire energy for cell maintenance and synapticcific COX inhibitors (flurbiprofen and ibuprofen) connections; thus, cell death can occur.53 Also,did not.44 An animal model revealed that ibuprofen, hyperinsulinemia has been found to increasenaproxen, and a COX-2 inhibitor (MF-tricyclic) inflammation and βA1-42 in healthy adults.54each restored memory, but only MF-tricyclic A possible mechanism underlying insulinblocked the suppressive effects of βA on synaptic resistance in the central nervous system is theplasticity.45 In an 18-month human trial, celecoxib, formation of toxic protein fragments calleda COX-2 inhibitor, improved memory and cogni- beta-amyloid derived diffusible ligands (ADDLs).tion in individuals with mild cognitive According to this view, ADDLs bind to synapticimpairment.46 receptor sites, where they prevent insulin from working, causing synaptic dysfunction andSecretase Inhibitors eventual dementia. Other possible mechanisms of Secretases are enzymes that break amyloid action are described elsewhere.55precursor protein (APP), found in cell membranes,into βA fragments that form plaques. Consequently, Etanercept (Enbrel®)secretase inhibitors should slow the production of Etanercept has recently generated interestβA. Human research is very limited, but a gamma- because it produced dramatic cognitive improve-secretase inhibitor has been shown to reduce ment. AD brains have elevated levels of theplasma βA by about 60 percent in a small 14-week cytokine tumor necrosis factor-alpha (TNF-α).study of mild-to-moderate AD patients; however, Since TNF-α regulates neural transmission,no significant differences in cognition were found.47 lowering it by spinal injections of etanercept mightConclusions that the treatment was well tolerated restore the brain to more normal functioning. Aseem false, given hair color changes, skin rashes, a dramatic cognitive improvement was evidenced inbowel obstruction, nausea, vomiting, diarrhea, and one moderate-to-severe AD subject within min-more in just 36 treated subjects. utes.56 The author reported this finding was Beta-secretase inhibitors have been shown to commonly observed on multiple patients overreduce βA in animal models and may have fewer three years of clinical practice. An open-label pilotadverse effects.48,49 Memoquin is a beta-secretase study with mild-to-severe AD found once weeklyinhibitor that also inhibits AChE, reduces βA treatments of 25-50 mg etanercept producedproduction, limits tau hyperphosphorylation, and improvement over a six-month period.57 Etanerceptfights oxidation, but it is early in the developmen- is FDA approved for immune disorders but not for 50tal stage. Presently, most research involves develop- secretase inhibitor molecules that will pen-etrate the blood-brain barrier, produce beneficial Brain Derived Neurotrophic Factor (BDNF)results, and not produce adverse effects. BDNF is a protein produced in the brain that helps existing neurons survive, facilitates the growth of new neurons and synapses, and reverses neuronal atrophy and behavior deficits; Volume 15, Number 3 Alternative Medicine Review 226Copyright © 2010 Alternative Medicine Review, LLC. All Rights Reserved. No Reprint Without Written Permission.
  5. 5. Review Article amr intracellular signaling is also facilitated. BDNF is Flavonoids and other Novel Plant active in the hippocampus and cortex and low Constituents levels of it are associated with poor memory. In HuperzineA (HupA) some areas of the brain, BDNF stimulates neuro- HupA is an extract from the Chinese moss genesis. BDNF levels decline with age and are lower Huperzia serrata that has been used for centuries in in AD brains than in those without dementia.58 Chinese folk medicine to treat a wide range of In various mouse, rat, and primate models, diseases. A review of in vitro and animal studies BDNF has reversed synaptic damage, partially found HupA preserves ACh longer than tacrine, normalized genetic errors, improved cell signaling, galantamine, or donepezil.69 HupA reduces reversed learning and memory deficits, reversed βA-induced neuronal degeneration in the hippo- cognitive decline, and reduced oxidative stress and campus and cortex, decreases oxidative damage cell death.59 These changes did not result from from free-radical induced βA plaques, protects changes in βA. neurons from cytotoxins and apoptosis induced by A major problem is that the BDNF molecule is βA and free radicals, and inhibits glutamate too large to penetrate the blood-brain barrier. toxicity. The research and potential mechanisms of Human trials, mostly investigating Parkinson’s action underlying these effects have been reviewed disease, have used a micro pump to directly infuse in detail.69,70 BDNF into the brain through a cannula inserted Acetylcholinesterase exists in different molecular into the skull. This risky procedure accounts for the forms referred to as G1, G2, G3, and G4. Human lack of human trials.60 In addition, too large a dose brains have mostly the G4 form with a smaller can produce serious side effects. Although in vitro amount of G1. Hence, inhibition of G4 is more and animal data are promising, it is unlikely that germane in terms of prolonging ACh and facilitat- BDNF therapy will be in use anytime soon. ing synaptic transmission in humans. In the However, physical exercise and diets rich in striatum and hippocampus (areas important in omega-3 fatty acids have been found to normalize learning and memory), HupA primarily inhibits G4, BDNF without the difficulties associated with brain whereas donepezil primarily inhibits G1. HupA infusions.61,62 penetrates the blood-brain barrier better than donepezil, rivastigmine, or tacrine.70 Immunization Two Chinese randomized, double-blind, placebo- βA has been reduced by injecting AD patients controlled trials with 103 AD patients for eight with a synthetic form of βA called AN1792. weeks71 and 202 mild-to-moderate AD patients for Although this reduces βA, the effect on AD is 12 weeks72 used 400 mcg HupA daily. In both cases, unclear. Some people respond to immunization there was statistically and clinically more improve- with a slowing of disease progression even after 4.6 ment in several measures of cognition, memory, years,63 but other studies have found a clearing of and activities of daily living in the HupA group βA without any cognitive benefit.64 It may be that than in placebo controls. A recent meta-analysis of βA accumulation starts a chain of events that four Chinese studies found 300-500 mcg HupA cannot be stopped by merely clearing βA depos- produced a marked improvement in cognition.73 its.65 Three phase II studies have been reviewed A U.S. phase II clinical trial of 210 mild-to-mod- elsewhere.66 It is unlikely that immunization erate AD patients over 16 weeks found 800 mcg of therapy will be practical for some time. HupA, but not 400 mcg, resulted in cognitive The advantages and disadvantages of pharma- enhancement.74 A Cochrane review concluded that, ceutical therapies are summarized in Table 1. although HupA improves cognition, there are too few studies of sufficient quality to recommend its Antipsychotics and Sedatives Warning use.75 Similar conclusions were reached in another Antipsychotics and sedatives have accelerated the review.76 At this point, HupA appears to be progression of AD, defined as an increase of one effective and better tolerated than FDA-approved or more points in the Global Deterioration Scale,67 AChEIs, but larger studies with longer treatment and produced a 50-percent decrease in cortical periods would be desirable. plasticity in cats.68 Thus, care should be exercised in using such drugs for AD patients. Polyphenols Polyphenols are a group of plant-derived chemical substances with more than one phenol unit. They protect plants from stress induced by227 Alternative Medicine Review Volume 15, Number 3 Copyright © 2010 Alternative Medicine Review, LLC. All Rights Reserved. No Reprint Without Written Permission.
  6. 6. amr Review Article Table 1. Advantages and Disadvantages of Pharmaceuticals for AD Pharmaceutical Advantages Disadvantages Acetylcholinesterase inhibitors* Prolong ACh; some Often short-term e cacy; severe evidence for neuroprotec- side e ects; high costs; modest tion; FDA approved bene ts Memantine* Decreases glutamate Possible neurotoxicity; some excitotoxicity; possible severe adverse e ects; primarily other neuroprotective recommended for moderate- e ects; well tolerated; FDA to-severe AD; high cost approved for moderate-to- severe AD, but also helps mild-to-moderate AD Antihypertensive drugs Reduce in ammation; may Most human research on block Ca2+; may reduce βA hypertensive individuals and and increase ACh animals Anti-in ammatory drugs May reduce neural in am- Most research focused on risk of mation acquiring AD and not on treatment; human research correlational in nature, making causation impossible to deter- mine; e ects on intestinal tract, liver, and kidneys; therapeutic bene t questionable Secretase inhibitors May reduce βA and inhibit Little human research; severe AChE adverse e ects; insu cient data Insulin drugs Improve energy production Must be administered nasally to and cellular functions; may prevent insulin changes in reduce ADDLs and oxidative non-brain areas; little human stress; reduce cell death data Etanercept Produces dramatic improve- Little research; risky spinal ment within minutes injections required BDNF Stimulates neurogenesis; Molecule too large to penetrate reverses synaptic damage; blood-brain barrier; risky improves signaling; reduces administration via a cannula in oxidative stress and cell the skull; can produce serious death side e ects; little human research. Immunization Reduces βA Often ine ective; clearing of βA not always accompanied by symptom reduction; early in the development stage *Denotes therapies with the most research backing and therapeutic potential for AD Volume 15, Number 3 Alternative Medicine Review 228Copyright © 2010 Alternative Medicine Review, LLC. All Rights Reserved. No Reprint Without Written Permission.
  7. 7. Review Article amr ultraviolet radiation, disease, pests, and physical systems that protect cells.77,89 Animal models damage. Polyphenols also protect animals by suggest that resveratrol mimics the effects of activating a number of intracellular processes that caloric restriction on longevity and negates the preserve neurons. harmful effects of a high-fat diet,90 doubles resistance to muscle fatigue,91 reduces neurotoxic- Curcumin ity, decreases cell death, reduces degeneration of Curcumin is extracted from the plant Curcuma the hippocampus, and prevents learning impair- longa (turmeric). Reviewers suggest curcumin may ment.92 Several studies have shown that moderate be a promising therapy for AD because it has at consumption of red wine reduces the risk of least 10 neuroprotective properties, including developing AD.93 anti-inflammatory, antioxidant, inhibition of βA Resveratrol is similar to curcumin in that oral formation, clearance of existing βA, and copper bioavailability is low because it is quickly metabo- and iron chelation. 42,77,78 lized and excreted. Attempts have been made to Curcumin readily penetrates the blood-brain increase bioavailability by the use of quercetin, barrier, but oral administration may produce barely catechin, apigenin, fisetin, myricetin, and kaemp- detectable blood levels at doses of 2 g and low ferol.94 Whether resveratrol will slow the progres- levels at 8 g.79 The reasons for bioavailability sion of AD awaits the outcome of trials currently problems appear to be low absorption, rapid underway.95 metabolism, quick elimination, and the inherent instability and hydrophobic nature of curcumin. Herbal Supplements Efforts to increase bioavailability have been Ginkgo biloba covered in an extensive review.80 One approach is Ginkgo biloba contains compounds that have to use adjuvants, such as piperine, that increase antioxidant and anti-inflammatory properties that bioavailability by blocking metabolic pathways. protect neuron membranes, regulate neurotrans- Adding 20 mg of piperine to 2 g of curcumin mitters, and retard cell degeneration. It is sold as a increased bioavailability by a factor of 20 in supplement in the United States, dispensed as a humans.81 Quercetin may also enhance bioavail- pharmaceutical in Europe, and has been used for ability.82 Bioavailability has been significantly centuries in traditional Chinese medicine. In vitro enhanced by combining curcumin with phosphati- data show that Ginkgo biloba extract EGb 761 dylcholine or other lipophilic formulations.83 Other reduces βA and neuron death.96,97 Elderly mice fed approaches combine curcumin with turmeric oil or EGb 761 exhibit hippocampal neurogenesis.98 use nanoparticles.84 Numerous other animal and in vitro studies Turmeric is a widely used spice in India, which support Ginkgo’s neuroprotective benefits. may explain why India has a much lower incidence Many early human studies found that Ginkgo of AD than the United States.85,86 Bioavailability improved cognition in AD patients. However, these may not be a problem for Indians because it is studies often used few subjects and had method- combined with oil in cooking. A randomized, ological problems. More recently, a number of double-blind, placebo-controlled clinical trial tested randomized, double-blind, placebo-controlled trials nine subjects from old-age homes and 24 from have produced positive results. Ginkgo produced dementia clinics over six months. A daily dose of 1 more cognitive benefits than placebo for 156 AD g or 4 g curcumin without bioavailability enhancers patients receiving 240 mg daily for 24 weeks,99 for produced no cognitive benefit relative to a pla- 202 AD patients receiving 120 mg daily over 52 cebo.87 No significant effects were found on several weeks,100 in a 2003 re-analysis of Kanowski et al cognitive tests in another randomized, double- 1999 data using previously unpublished data,101 for blind, placebo-controlled trial that used 2 g or 4 g 214 patients with probable AD given 240 mg curcumin enhanced by piperine and green tea Ginkgo daily for 22 weeks,102 and for a post hoc extract (Curcumin C3 Complex®) in 36 mild-to- analysis of LeBars et al showing that Ginkgo moderate AD patients.88 improved cognition for mild to very mild impair- ment and reduced deterioration in subjects with Resveratrol more severe dementia.103 Resveratrol, a polyphenol found in red wine, In contrast, recent randomized, double-blind, peanuts, and other plants, reduces oxidative stress, controlled studies, using subjects without demen- decreases inflammation, reduces βA, protects DNA, tia, concluded that Ginkgo did not slow dementia decreases cell death, and modulates various other onset. One study gave 120 mg Ginkgo twice daily229 Alternative Medicine Review Volume 15, Number 3 Copyright © 2010 Alternative Medicine Review, LLC. All Rights Reserved. No Reprint Without Written Permission.
  8. 8. amr Review Articleto 2,587 healthy subjects and 482 subjects with another study of 96 subjects with probable AD overmild cognitive impairment over a period of 6.1 22 weeks, comparing daily doses of 240 mg Ginkgo,years, with testing at six-month intervals. Ginkgo 5 mg donepezil increasing to 10 mg after fourwas no better than placebo at preventing the onset weeks, or placebo. Although the groups did notof dementia or AD.104 A second study examined differ significantly, there was a suggestion that a3,069 healthy individuals given 120 mg Ginkgo combination of the two might be better than eithertwice daily for 6.1 years. There was no effect on alone.112cognitive decline.105 Another study of 240 mg There are indications from a small placebo-Ginkgo daily to 118 subjects with no cognitive controlled, double-blind study of 28 healthy youngimpairment for 42 months found no effect on adults that 120 mg Ginkgo is more effective whencognitive decline.106 Thus, it appears that Ginkgo combined with 360 mg phosphatidylserine (PS) asaids cognition when subjects have AD but does not a phytosome (Virtiva®). Subjects were givenprevent the onset of AD. cognitive tests at intervals of from 1-6 hours after A study that is an exception to this conclusion dosing and were tested every seventh day for fivefailed to find benefit from 120 mg Ginkgo daily for sessions. Ginkgo improved performance fromsix months.107 This study recruited 176 partici- baseline when complexed with phosphatidylserine,pants with mild-to-moderate dementia by ads and but not as a standardized extract alone or com-by a clinical diagnosis of dementia from the plexed with phosphatidylcholine.113 Whether thisindividuals’ physicians rather than by uniform, outcome would apply for AD patients is unknown.objective criteria. Although individuals were Although concern has been raised aboutexcluded if they admitted taking AChEIs, the increased bleeding with Ginkgo, a review of theauthors mentioned there was some noncompliance. clinical-trial literature lends no credence to thisOther interventions were allowed, which could hypothesis.114have masked the effect of Ginkgo. A final studyfound a benefit for Ginkgo only for a subset of AD Panax ginsengpatients who also had behavioral disturbances.108 Panax ginseng (Chinese, Asian, or KoreanAs the authors concluded, this outcome can be ginseng) has been studied for its effects onquestioned because the placebo group failed to cognition. Although an early review of randomized,decline over the course of the study, as would have placebo-controlled clinical trials on ginseng foundbeen expected, thereby potentially masking any three of four studies produced cognitive benefits,effect of Ginkgo. the reviewers nevertheless concluded that its A Cochrane review of 36 trials concluded that effectiveness was in doubt because of methodologi-the effect of Ginkgo is inconsistent, except in cal deficiencies.115 In a placebo-controlled, double-subjects having dementia with neuropsychiatric blind, crossover design, a single dose of 200, 400,features, and that further clinical trials are unwar- or 600 mg Panax ginseng enhanced memory in 20ranted.109 This meta-analysis combined studies on young healthy adults, with 400 mg providing thedementia patients with studies of subjects with most benefit.116 Subjects were tested at intervalslittle cognitive impairment or just age-related from 1-6 hours following dosing.cognitive decline. A subsequent meta-analysis The active components in ginseng are thought toavoided such confounding by including only be steroid-like compounds called ginsenosides.studies with a diagnosis of mild-to-moderate AD or Ginsenoside Rg3 reduced βA1-42 by 84 percent inAD plus vascular dementia, including several more vitro and by 31 percent in vivo.117recent studies and excluding older, methodologi- Despite promising results, there have been fewcally problematic studies.110 The screening yielded studies on AD. A recent review found only twonine randomized, double-blind trials ranging from studies that met the inclusion criteria. Although12-52 weeks and totaling 2,372 subjects; all but those studies found significant cognitive benefits,one study was placebo-controlled. Ginkgo was the authors concluded that methodologicalmoderately more effective than placebo and the shortcomings rendered the evidence inconclu-difference was statistically significant. sive.118 A recent trial examined the effect of 4.5 g Ginkgo and donepezil appeared equally effective Panax ginseng powder daily for 12 weeks on 58in a 24-week, randomized, placebo-controlled, patients with probable AD, with 39 patientsdouble-blind study of 76 mild-to-moderate AD serving as controls. The ginseng group graduallysubjects given 160 mg Ginkgo, 5 mg donepezil, or a improved over the 12 weeks of treatment, whereasplacebo daily.111 Similar results were obtained in the placebo group gradually declined.119 During a Volume 15, Number 3 Alternative Medicine Review 230Copyright © 2010 Alternative Medicine Review, LLC. All Rights Reserved. No Reprint Without Written Permission.
  9. 9. Review Article amr 12-week follow-up period without treatment, the bovine PS is no longer available. ginseng group gradually declined to the level of the There is very little research on soy-based PS for control group. AD. An open study found cognitive benefit for 18 healthy elderly subjects with age-associated Withania somnifera memory impairment treated with 100 mg soy- Withania somnifera, a small evergreen shrub based PS three times daily for 12 weeks. Testing at commonly called ashwagandha or Indian ginseng, six and 12 weeks showed cognitive gains relative to has been used in India for thousands of years to baseline performance (there was no control treat many different diseases. A recent review group).129 In a second randomized study, 120 enumerated many neuroprotective properties of elderly subjects with age-associated memory ashwagandha, including anti-inflammatory, impairment received 300 mg or 600 mg soy PS or antioxidant, inhibition of βA, inhibition of calcium, placebo daily for 12 weeks. Various cognitive tests inhibition of AChE, and reduction of cell death.120 were given after six, 12, and 15 weeks. No signifi- In vitro research has demonstrated that ashwa- cant effects or interactions were found.130 The lack gandha regenerates damaged axons, dendrites, and of recent research and convincing data on soy- synapses.121,122 Oral administration of ashwa- based phosphatidylserine presents a confusing gandha to mice reversed damage to the hippocam- picture requiring more research. pus and cortex by decreasing neurite atrophy, restoring synapses, and improving memory.122 At alpha-Lipoic acid (ALA) least 18 withanolides, the active components in ALA, a fatty acid found in all cells and in some ashwagandha, have been identified. Withanolides foods, is manufactured in the body. It is a powerful have different neuroprotective properties; for antioxidant that readily penetrates the blood-brain example, withanolide-A preserves axons whereas barrier, chelates metals, reduces inflammation, and withanolides IV and VI preserve dendrites.123 increases ACh. The potential mechanisms underly- There is no published research on possible ing these and other neuroprotective effects are therapeutic effects of ashwagandha on AD. reviewed elsewhere.131-133 However, a recent double-blind, randomized, Despite potential benefits, there has been a placebo-controlled study of the effects of ashwa- paucity of human studies. In one open study, nine gandha on stress found that it reduced symptoms patients with AD and similar dementias were given of stress, including forgetfulness and inability to 600 mg ALA daily for an average of 337 days. concentrate, in a dose-dependent manner, with Before ALA supplementation, cognitive test scores 500 mg/day more effective than 250 mg/day. No had continuously declined; however, after onset adverse effects were found.124 the scores remained constant.134 This study was extended to 48 months for 43 subjects with the Nutrients same result.135 Although promising, these studies Phosphatidylserine had few subjects, no control group, were not Phosphatidylserine is important in neurotrans- double-blind, and came from only one lab. mission, mitochondria function, and cell metabo- lism. It has also been implicated in the enhance- Omega-3 Fatty Acids ment of nerve growth factor. In vitro research Omega-3 fatty acids have many beneficial effects demonstrates PS increases ACh125 and provides that make them investigative prospects for AD. A neuroprotection by inhibiting βA and recent study followed 5,395 healthy adults for an inflammation.126 average of 9.6 years to assess the relationship Supplemental PS was originally derived from between dietary omega-3 intake and risk of bovine brains, and research using bovine PS developing AD. Dietary intake of omega-3s was the typically found cognitive benefits. The largest same for the 365 subjects who developed AD as for double-blind, multi-center, placebo-controlled those who did not.136 study investigated 494 patients with moderate-to- Another study showed no effect of 2 g/day severe cognitive decline, 69 of whom dropped out. docosahexaenoic acid (DHA) on 402 subjects with They were given a placebo or 300 mg bovine PS mild-to-moderate AD, but there was a slower rate daily for six months. The PS groups showed of cognitive decline among those without the cognitive improvement relative to the placebo.127 APOE ε4 allele.137 Although 1.7 g DHA plus 0.6 g of Other early positive studies have been reviewed EPA did not slow the rate of cognitive decline in elsewhere128 and will not be covered here because 204 mild-to-moderate AD patients, a subset with231 Alternative Medicine Review Volume 15, Number 3 Copyright © 2010 Alternative Medicine Review, LLC. All Rights Reserved. No Reprint Without Written Permission.
  10. 10. amr Review Articlevery mild AD did benefit.138 A randomized, double- protection against ischemia, as reviewed.151-153 Datablind, six-month study of 485 subjects with on CoQ10 have been obtained from in vitro studies,age-related cognitive decline found 900 mg algal animal models, and human research on neurode-DHA daily improved performance on learning and generative diseases other than AD. The one trial tomemory tests relative to a placebo.139 These data examine the effect of CoQ10 on AD has not yetsuggest that the benefits of omega-3 fatty acids are been published.154 CoQ10 has been found to be safelimited to those with very mild cognitive and well tolerated at doses as high as 3,600 mg/day,impairment. although maximum plasma levels are reached at a dose of 2,400 mg/day.153Acetyl L-Carnitine (ALCAR) Idebenone is a synthetic variant of CoQ10 that ALCAR, derived from the amino acid L-carnitine, protects cell membranes and mitochondria fromworks synergistically with ALA to transport acetyl oxidative stress, preserves adenosine-triphosphate,groups and fatty acids into the mitochondria for stimulates nerve growth factor,155 and protectsenergy production. ALCAR is a small molecule that from βA toxicity.156 A two-year, randomized,readily penetrates the blood-brain barrier and double-blind study with 450 mild-to-moderate ADpromotes biosynthesis of ACh while clearing subjects found that each of two idebenone groupsmitochondria of toxic fatty-acid metabolites.140 Its (90 and 120 mg three times daily) scored signifi-effect on APP helps prevent the buildup of amyloid cantly better than the placebo group in severalplaque and preserves synaptic function.141 ALCAR cognitive measures, with the 120-mg group scoringalso increases nerve growth factor.142 better than the 90-mg group.157 A six-month, ALCAR has been found to produce cognitive randomized, double-blind, placebo-controlledbenefits for AD patients. A small double-blind study of 300 mild-to-moderate AD patientsstudy of seven probable AD patients and five compared idebenone (30 or 90 mg three timesplacebo controls found that 3 g ALCAR daily daily) with placebo. At the end of six months, onlyresulted in less cognitive decline over the course of the 90-mg group performed better than theone year.143 A meta-analysis of 21 double-blind, placebo on several cognitive tests.158 However, notrandomized, placebo-controlled studies lasting all studies have been positive. A randomized,from three months to one year showed that ALCAR double-blind, one-year study of 536 subjects witheither improved cognitive deficits or delayed the probable AD compared idebenone (120, 240, orprogression of cognitive decline.144 These effects 360 mg three times daily) with placebo. There werewere both statistically and clinically significant no significant differences among the four groups,with the magnitude of the effects increasing over although one cognitive test showed a small buttime. Most studies used daily doses from 1.5-2 g, significant difference between the placebo and thewhich were well tolerated. three idebenone groups combined. The authors concluded that the difference was too small to be ofCoenzyme Q10 (CoQ10; Ubiquinone)/Idebenone practical import.159 Coenzyme Q10 is essential for mitochondrialenergy production. Mitochondrial dysfunction can Vitamins and Mineralsresult in generation of reactive oxygen species and B Vitaminsoxidative stress.145 Many mitochondrial dysfunc- Low levels of vitamin B12 and folate appear to betions occur in AD brains, including disruption of associated with an increased rate of cognitiveenergy production, apoptosis deregulation, altered decline.160,161 Also, in a study of 107 normal elderlycalcium homeostasis, and others (reviewed individuals, those with low-normal vitamin B12 hadelsewhere).146 For these reasons, mitochondria are the greatest five-year loss of brain volume.162 Sinceviewed as promising therapeutic targets.147 AD patients typically have high levels of homocys- CoQ10 reduced oxidative stress and tau pathol- teine,163 researchers have examined the possibilityogy in mice,148 and metabolized βA and inhibited that lowering homocysteine would be therapeutic.its formation in vitro.149 The reduction of βA found A combination of vitamins B12 and B6 and folatein a mouse model was attributed to the antioxidant lowered homocysteine both in normal seniors164properties of CoQ10.150 and in those with mild-to-moderate AD,165,166 but CoQ10 has other neuroprotective virtues, had no effect on cognition. Homocysteine levelsincluding protection of mitochondria, reduction of appear to correlate with aging but not withapoptosis, extension of life, reduction of brain cognition.167atrophy, promotion of energy production, and Volume 15, Number 3 Alternative Medicine Review 232Copyright © 2010 Alternative Medicine Review, LLC. All Rights Reserved. No Reprint Without Written Permission.
  11. 11. Review Article amr Vitamin A Lithium Vitamin A has received attention because it is Lithium is a naturally occurring mineral found in essential for learning, memory, and cognition, and small amounts in many foods. Lithium got a bad because vitamin A levels in the brain decline with reputation in the 1940s when its use as a salt age and are lower still in individuals with AD.168 A substitute produced toxicity and even fatalities. metabolic product of vitamin A, retinoic acid, is The lithium salts orotate and aspartate are some- known to slow cell death and offer protection from times recommended for neurogenerative disorders. βA.169 Lithium increases the level of a neuroprotective protein called bcl-2 in the rat hippocampus and Vitamin E frontal cortex and inhibits glycogen synthase Antioxidants have been examined extensively as kinase 3β (GSK-3), which is implicated in increas- therapeutic possibilities, although questions exist ing levels of phosphorylated tau176 and is thought regarding whether oxidative stress produces AD or to be a factor leading to βA plaques and cell vice versa. Vitamin E is low in AD patients.170 death.177 There is also human evidence that lithium Although in vitro and animal data have been increases N-acetyl-aspartate (NAA) which protects encouraging, human trials have produced conflict- cells from dysfunction and death.178 An in vitro ing results.171 The reason for this may be that most study found lithium’s neuroprotection resulted studies have used only α-tocopherol. A study that from inhibiting Ca2+ influx mediated by NMDA followed 3,718 individuals over six years examined receptors.179 dietary consumption (excluding vitamin E supple- Increases in grey matter were found for 8 of 10 ment intake, which showed no effect) of all four bipolar subjects given four weeks of lithium.180 tocopherols (α, β, γ, and δ) as determined by These neuroprotective effects have led some to questionnaires. The authors concluded that suggest that lithium may have been overlooked as α-tocopherol alone may not be as protective as the a therapy for dementia.181 combined tocopherols.172 In addition, the risk of No human trials have been published, but some AD was inversely related to the intake of α, γ, and δ data are relevant. One study found only five but not β tocopherol. In general, higher levels of percent of bipolar patients treated with lithium dietary vitamin E lowered the risk of AD and had AD compared with 33 percent of untreated slowed cognitive decline over the six-year course of patients.182 Anecdotal evidence comes from the investigation. Jonathan V. Wright, MD, who claims he has used 10-20 mg lithium aspartate or orotate for over 30 Multiple Nutrients years and found it effective for AD.183 Human trials Since AD patients often have multiple deficien- are sorely needed. cies, it makes sense to use multiple supplements. A mixture of alpha-lipoic acid, acetyl-L-carnitine, Hormones DHA, phosphatidylserine, and glycerophosphocho- Melatonin line prevented cognitive decline in aged mice.173 A Melatonin is a naturally occurring hormone that recent study found long-lasting cognitive improve- is produced in decreasing amounts with age. ment in elderly beagles with the daily use of one Melatonin is a powerful antioxidant, provides capsule/5 kg body weight of a complex with 25 mg mitochondrial support, protects against tau phosphatidylserine, 50 mg Ginkgo biloba, 33.5 mg tangles, and reduces βA toxicity.184 Melatonin d-alpha tocopherol, and 20.5 mg pyridoxine.174 readily crosses the blood-brain barrier and enters A study of 14 individuals with early AD found all cell structures. A case study in which one that a multiple formulation (400 mcg folic acid, 6 identical twin was given 6 mg melatonin daily, mcg vitamin B12, 30 IU vitamin E, 400 mg whereas the other was not, revealed that the S-adenosylmethionine, 600 mg N-acetylcysteine, melatonin-treated twin had less memory loss over and 500 mg acetyl-L-carnitine per tablet, with a 36 months.185 Another small study showed 6 mg daily dose of two tablets) improved all measures of melatonin daily improved mood and memory over cognition, although the increase in memory was six days for 10 patients with mild cognitive not statistically significant. The improvement impairment.186 In another study, melatonin (9 mg/ persisted throughout the 12-month study.175 day) was given to 14 sleep-disordered AD patients over 22-35 months. In the authors’ judgment, the subjects did not show typical cognitive decline over the course of this experiment,187 or in a similar233 Alternative Medicine Review Volume 15, Number 3 Copyright © 2010 Alternative Medicine Review, LLC. All Rights Reserved. No Reprint Without Written Permission.
  12. 12. amr Review Article Table 2. Summary of Botanicals and Nutrients for AD Nutrient or Botanical Advantages Disadvantages Huperzine A Prolongs ACh; reduces oxidative damage; excitotox- Not many studies icity & apoptosis; penetrates the blood-brain barrier better than cholinesterase inhibitors; well tolerated; bene ts cognition Polyphenols Curcumin has at least 10 neuroprotective properties Curcumin has low bioavailability unless including inhibition of oxidative stress, in amma- accompanied by bioavailability enhancers; tion, and βA; bene ts cognition; resveratrol has need more human trials; little human similar bene ts; both are well tolerated research on resveratrol therapy for AD Ginkgo biloba* Has antioxidant and anti-in ammatory properties; Appears to work for AD but not mild retards cell death; well tolerated; considerable cognitive impairment; does not reduce risk research backing cognitive bene t of getting AD Panax ginseng Has neuroprotective e ects, including reduction of Human studies few in number and weak in βA, but mechanisms are largely unknown; cognitive methodology bene ts have been reported; well tolerated Withania somnifera Many neuroprotective properties, including reduc- No research on humans with AD ing in ammation, oxidation, Ca2+, βA, AChE, and cell death; restores synapses Phosphatidylserine Important in neurotransmission, mitochondria Most positive research used bovine- function, and cell metabolism; may enhance nerve derived PS now unavailable; the studies growth factor; increases ACh and inhibits βA; well using soy-derived PS equivocal tolerated alpha-Lipoic acid Increases ACh and glucose; easily penetrates the Limited AD research; none without serious blood-brain barrier; powerful antioxidant inside and shortcomings outside cells; regenerates itself; reduces in amma- tion; well tolerated omega-3 Fatty acids Many bene cial e ects, but not speci c to AD; well Limited research; little bene t except in tolerated mild impairment Acetyl L-carnitine* Readily penetrates the blood-brain barrier; promotes More research would be welcome, but ACh and clears mitochondria of toxic metabolites; reasonable current body of literature inhibits free radicals; increases NGF; preserves synaptic function; reduces βA production; consider- able evidence of bene t; well tolerated Coenzyme Q10 Protects mitochondria and promotes energy Research has been on neurodegenerative production; reduces oxidative stress, βA, apoptosis, diseases other than AD except for one and brain atrophy. The synthetic variant, idebenone, unpublished study; not all idebenone more readily penetrates the blood-brain barrier; all studies have shown cognitive bene ts forms well tolerated Vitamins & minerals AD patients typically have low levels; supplementa- Although reasonable to supplement when tion has shown bene t for E, lithium, and some de ciencies exist, insu cient research to nutrient combinations draw conclusions in most cases Melatonin Antioxidant, protects mitochondria, reduces tau Few studies on AD subjects and those are tangles and βA toxicity; readily penetrates the small and poor in quality blood-brain barrier; enters all cell structures; cognitive bene ts in several studies; well tolerated *Denotes therapies with the most research backing and therapeutic potential for AD Volume 15, Number 3 Alternative Medicine Review 234Copyright © 2010 Alternative Medicine Review, LLC. All Rights Reserved. No Reprint Without Written Permission.
  13. 13. Review Article amr study using 6 mg/day for four months to 45 AD interventions for more than two semesters showed patients with sleep disturbances.188 One study no year-to-year decline in various measures of failed to find cognitive benefits from 3 mg melato- cognitive functioning.199 In another study, 37 nin, which is a lower dose than others typically adults were divided into placebo versus treatment used.189 groups. The treatment group, given a variety of Despite numerous studies, few have examined cognitive tasks to work on at home, showed its effect on AD and the ones that did were small modest gains in recall and face name recall (tasks and of poor quality. Since melatonin improves on which they were trained), although the training sleep, it might help memory by facilitating memory did not generalize to other cognitive measures.200 consolidation. Another study with mild-to-moderate AD The advantages and disadvantages of nutritional patients demonstrated that the benefits of and botanical therapies are summarized in Table 2. memory training lasted months after the training ended.201 Even longer-term benefits have been Stimulatory Therapies observed. A total of 2,832 elderly (mean age 73.6) Physical exercise, cognitive training, and normal adults were randomly assigned to placebo socialization are generally thought to facilitate or training on memory, reasoning, or processing cognitive functioning.190,191 Physical exercise speed. Training resulted in improved cognitive increases the blood supply to the brain and scores specific to the area in which they were regulates chemicals such as insulin that are trained that lasted five years after the first treat- necessary for a healthy brain. Recent reviews of ment.202 In all such studies, it would be desirable to studies on exercise indicate that exercise may examine the amount of sleep subjects got since facilitate learning and memory, improve vascular that is when memories are consolidated. function, reduce inflammation, improve metabo- Unfortunately, sleep quality and quantity, which lism, elevate mood, delay age-related memory loss, are commonly poor in the elderly, are generally speed information processing, increase brain overlooked. volume, aid hippocampal neurogenesis, increase Brain exercises can improve function in those synaptic plasticity, increase brain-derived neuro- suffering from mild cognitive impairment. A trophic factor, increase dendritic spines, enhance randomized, controlled, double-blind study on 487 the glutamatergic system, and reduce cell elderly subjects without significant cognitive death.192,193 impairment was conducted using Posit Science’s A meta-analysis of 18 studies examined the Brain Fitness Program, a series of computer-based effect of exercise on healthy but sedentary older exercises that target different areas of the brain adults. Exercise had the largest effect on executive (visual, auditory, speech, motor, etc.).203 Cognitive function (planning, coordination, working memory, training was conducted for one hour daily, five days abstract thinking, initiating appropriate actions, per week, for eight weeks. The control group and inhibiting inappropriate ones), with lesser viewed educational videos, after which they were effects on skill acquisition and visuospatial tasks.194 tested for memory of the content. For all measures, Executive functioning requires the greatest level of cognitive training produced higher scores than cognitive function and suffers significantly in AD. educational videos; the training generalized to Patients with early AD who exercised showed non-trained tasks. Other companies are pursuing less brain atrophy than those who did not.195 similar approaches but have less research backing. Another study of people with mild cognitive Most studies of music stimulation have exam- impairment found exercise (mostly walking) led to ined it as a way to moderate problematic behavior significantly better performance than control in cases of moderate-to-severe AD,204 and to reduce subjects on some, but not all, cognitive mea- levels of stress, anxiety, and depression in mild-to- sures.196 Actual changes in the brain have also been moderate AD.205 However, a few studies have found. Aerobically fit individuals had larger focused on cognitive changes. One study compared hippocampi and better spatial memory than those the effects of music with controls shown a movie. who were less fit.197 On the other hand, sedentary Once a week for eight weeks, 17 dementia subjects elderly adults showed more memory decline over were randomly assigned to music or movie groups. the course of a day than those more active.198 Cognitive testing immediately after the interven- Brain stimulation and socialization are impor- tion and the next morning showed superiority for tant in brain plasticity. Mild-to-moderate AD the subjects given music; however, the effect did patients who engaged in socialization not last until the next week’s session.206235 Alternative Medicine Review Volume 15, Number 3 Copyright © 2010 Alternative Medicine Review, LLC. All Rights Reserved. No Reprint Without Written Permission.
  14. 14. amr Review Article Mechanisms that might underlie such benefits positive attitudes by the way they interact withinclude increased natural killer cells that destroy patients, instilling confidence and a positivedysfunctional cells207 and increased serum melato- attitude.nin levels.208 A recent paper hypothesized that The advantages and disadvantages of stimulatorymusic increases steroid production that facilitates therapies are summarized in Table 3.neurogenesis, repairs cells, and increases neuralplasticity.209 Notwithstanding these studies, Therapeutic Strategiesmusic’s potential for AD therapy remains largely One therapeutic strategy is to use only FDA-uninvestigated. approved pharmaceuticals for AD. However, it has Psychological factors that might either amelio- been estimated that less than 20 percent of ADrate or exacerbate AD have generally been over- patients have even a moderate response tolooked because the emphasis has been on medica- approved drugs.210 Also, approved drugs offer littletions to treat the problem. The patient’s attitude or no neuroprotection, are effective for only a shortcould play a key role in retarding or accelerating duration, often produce serious side effects, andprogression of the disease. A patient who views all are expensive. Another option is to use FDA-as lost will likely unknowingly contribute to approved drugs off label, such as rosiglitazone andmaking that view a self-fulfilling prophecy. On the ACE inhibitors. This approach also has risks ofother hand, patients who have a positive attitude adverse effects and no conclusive evidence ofand engage in activities they enjoy may experience benefit.a slowing of AD progression. Such people are likely Some nutritional and botanical therapies,to eat better, exercise more, be more positive about although not FDA approved, have been approvedlife, and engage in other activities that could for AD in Europe and other countries.enhance brain function. Therapists can encourage Table 3. Stimulatory Therapies for AD Activity Advantages Disadvantages Physical exercise Increases blood to brain; improves None if done within ones vascular function; aids sleep; reduces physical capabilities; little in ammation; elevates mood; increases research speci cally on AD brain volume; increases synaptic patients plasticity; aids neurogenesis; reduces cell death; bene ts some cognitive processes Cognitive training Improves many cognitive functions More research indicated Socialization Preserves cognitive functioning; may Little research improve mood Music Reduces stress and depression; Little research improves cognition, perhaps by aiding the destruction of dysfunctional cells, increasing melatonin levels, facilitating neurogenesis, and increasing plasticity Psychological A positive attitude may stimulate No research speci c factors patients to exercise and engage in to AD activities that are bene cial Volume 15, Number 3 Alternative Medicine Review 236Copyright © 2010 Alternative Medicine Review, LLC. All Rights Reserved. No Reprint Without Written Permission.