Superfoods or Supermyths?

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Superfood is a widely used catch-all phrase, common on the internet and in the marketing of exotic (and normally expensive) fruits and vegetables. Superfood is an over-used and over-hyped marketing tool, rather than a useful guide for consumers in choosing what foods to eat.

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Superfoods or Supermyths?

  1. 1. Superfoods or Supermyths? Associate Professor Tim Crowe School of Exercise and Nutrition Sciences Deakin University tim.crowe@deakin.edu.au @CroweTim www.thinkingnutrition.com.au Nutrition @ DEAKIN 1
  2. 2. What is a ‘Superfood’? • Describes a food with a high phytonutrient content (antioxidants, fibre, selenium, omega-3s etc.) that may confer health benefits • Has no meaning among nutrition scientists • No legal definition of the term • More an over-used marketing tool • Most of the foods are fruits or vegetables Nutrition @ DEAKIN 2
  3. 3. Common ‘Superfoods’ • Blueberries • Pomegranates • Wheatgrass • Goji • Noni • Mangosteen • Açai • Broccolli • Garlic • Pumpkin seeds • Tea • Soy • Coconut oil • Spirulina Nutrition @ DEAKIN 3
  4. 4. Goji Berry • Lycium barbarum or wolfberry, widely grown in Asia, • • • though most marketing focusses on Tibetan cultivars Most research is in cellular and animal studies with extrapolation made to humans Claims relate to anti-cancer activity, aging, vision, insulin resistance and infertility Few clinical trials of any methodological quality in humans – most only show improvements in antioxidant markers and subjective feelings of ‘well-being’ Nutrition @ DEAKIN 4
  5. 5. Goji • Common claims they have the highest level of vitamin C of all plants (claims up to 500-times an orange!): completely false as has same vitamin C content as an orange • “18 amino acids” • “Life extension” claims • Can interfere with blood-clotting medications and increase bleeding risk Nutrition @ DEAKIN 5
  6. 6. Acai • Cherry-sized purple berry fruit of the acai palm • Lab studies suggest it may have anti-cancer and anti• • • inflammatory effects, as well as a possible use in treating heart disease No human studies on its health effects yet published “Six times the antioxidant level of blueberries“ “It is a poster child of the power of the Internet to promote products for which only limited phytochemical and pharmacological information is available” Heinrich M et al. Phytochemistry Letters 2011;4:10-21 Nutrition @ DEAKIN 6
  7. 7. Noni • Lime-green Polynesian tropical fruit • Noni fruit and juice derivatives have shown anti-tumour activity in rats and mice, but few clinical trials in humans • Cancer patients given daily capsules containing noni fruit extract (not juice)  no effect on tumour regression, but ↑ QoL Issell BF et al. J Clin Oncology 2005;23 (June 1 Supplement):8217 • Some evidence for ↓ post-operative nausea Prapaitrakool S et al. J Med Assoc Thai 2010;93:S204-9 Nutrition @ DEAKIN 7
  8. 8. Wheatgrass • • • • Claims: Blood cleanser and ‘detoxifier’ attributed to the 'natural plant enzymes‘ and the chlorophyll content of the freshly-juiced grass Common claim that 30 mL shot of wheatgrass juice is nutritionally equivalent to a kilogram of vegetables is a complete myth – has similar nutrient content to broccoli and spinach Floret of broccoli, or tablespoon of spinach, contain more folic acid and vitamin C than 30 mL of wheatgrass juice Chlorophyll is not absorbed by the body, requires sunlight for activation, and its supposed high levels are no higher than other green vegetables Nutrition @ DEAKIN 8
  9. 9. Antioxidants • Found in foods (especially fruit and • • • vegetables) that protect the body from the harmful effects of free radicals Free radical damage linked to development of cancer, heart disease, Alzheimer’s and Parkinson’s, and is linked to the aging process Vitamins C, E and beta-carotene are the main vitamins with antioxidant properties are Other compounds also demonstrate antioxidant properties e.g. selenium and lycopene Nutrition @ DEAKIN 9
  10. 10. Antioxidants Total antioxidant capacity (TAC) measured using ORAC (oxygen radical absorbance capacity) test Wu et al. J Agric Food Chem. 2004;52:4026-4037 Nutrition @ DEAKIN 10
  11. 11. An Apple a Day Nutrition @ DEAKIN 11
  12. 12. Cost-Benefit Analysis • Five 30 mL serves of Noni Juice ($7.50) = • • 1 navel orange Five 30 mL serves of Goji ($10) = 1 red delicious apple Three serves of Acai ($2) = 1 red delicious apple On a serve-by-serve basis, many common fruits such as strawberries and apples, contain more antioxidants, and are cheaper Nutrition @ DEAKIN 12
  13. 13. Why buy them? • Superfruit juices contain a range of nutrients, but • • marketing spin vastly exaggerates their health benefits Typically sold at high cost through multi-level marketing Until better scientific evidence arises, cheaper and wiser to get antioxidants from ‘traditional’ fruit and veg sources Since 1 July 2007, marketing of products as "superfoods" is prohibited in the European Union unless accompanied by a specific medical claim supported by credible scientific research Nutrition @ DEAKIN 13
  14. 14. Eat your Fruit and Veggies • Hundreds of epidemiological studies linking F&V consumption to ↓ risk of almost all major cancers • Effect not from one particular food, but a wide variety • ↑ F&V may decrease intake of more high-calorie foods Mechanism? • Antioxidants • Fibre • Polyphenols – antioxidant activity, inhibit cell proliferation, phytoestrogenic activity • Isothiocyanates (cruciferous vegetables) – increase solubilising and inactivating enzymes • Allium compounds (onions and garlic) – suppress DNA synthesis, increase excretion Nutrition @ DEAKIN 14
  15. 15. Proposed Mechanism of Action of Cruciferous Vegetables Nutrition @ DEAKIN 15
  16. 16. Top Foods to Consume Literally thousands of natural chemicals in foods that can affect our health There is no one ‘superfood’ Think ‘super diets’ instead Should not focus on the effect of a single nutrient, but the total effect of food to health Nutrition @ DEAKIN 16
  17. 17. 10. Yoghurt • Great source of calcium • Low in fat and high quality protein • Source of ‘good’ bacteria • ‘Reduced-fat’ yoghurt may have more calories than regular yoghurt – check the labels! Nutrition @ DEAKIN 17
  18. 18. 9. Lean Meat • High-quality protein • Great source of zinc, iron and vitamin B12 • Choose lean cuts and grill or fry in a minimum of oil and avoid charring • Eat less than 500 grams (cooked weight per week) Nutrition @ DEAKIN 18
  19. 19. 8. Dark Chocolate • Dark chocolate has typically 2-3 times • • more cocoa as milk chocolate Rich source of flavanols which are potent antioxidants Clinical trials show it can – ↓ blood pressure, – ↓oxidation of LDL-cholesterol – ↑blood flow (by causing relaxation of the muscles lining blood vessel walls) – Improve the action of insulin • Some evidence that regular eaters of cocoacontaining foods have lower rates of CVD Nutrition @ DEAKIN 19
  20. 20. 7. Tomatoes • Contain a powerful antioxidant – lycopene • Found in red/orange coloured fruit and veggies • May offer protection against prostate cancer • Cooking makes the lycopene more available to the body (especially with a small amount of oil) Nutrition @ DEAKIN 20
  21. 21. 6. Soy • High-quality protein • Contains ‘isoflavones’ that have weak estrogen • • • activity Lower breast cancer risk and good for postmenopausal symptoms??? Soy found to lower LDL-cholesterol Better evidence for soy than isoflavone supplements Nutrition @ DEAKIN 21
  22. 22. 5. Tea • Rich in flavonoids (a class of polyphenols that have • • • • antioxidant activity) May slow cancer growth and lower heart disease Black and green tea both good, though greater evidence for green tea for CVD Some evidence of anti-depressant effects Good source of ‘water’ Nutrition @ DEAKIN 22
  23. 23. 4. Nuts and Seeds • High in ‘good’ mono- and poly• • unsaturated fat High in vitamin E Good source of fibre and protein • Associated with favourable body weight outcomes • Linked with CVD and diabetes protection Nutrition @ DEAKIN 23
  24. 24. 3. Oats • Good source of protein and B-group vitamins and low in fat • Great source of fibre (important for keeping blood sugar and cholesterol levels under control) • Help with feelings of ‘fullness’ after a meal Nutrition @ DEAKIN 24
  25. 25. 2. Fish • High in ‘omega-3’ fatty acids • Good sources: salmon, herring, sardines and • • capsules Edible bones for calcium Offers protection against: – Heart disease (stops blood from clotting, improves heart beat rhythm, lower blood fats) – Rheumatoid arthritis (anti-inflammatory) – Mental health: depression, ADHD – Dementia , Alzheimer’s Nutrition @ DEAKIN 25
  26. 26. 1. Cruciferous Vegetables • Broccoli, cauliflower, turnips, Brussels sprouts, bok choy, cabbage, and radishes • Broccoli: vitamins A, C, B group, and fibre • Potent cancer protection: inactivate cancer-causing molecules and act as antioxidants Nutrition @ DEAKIN 26
  27. 27. Nutrition @ DEAKIN 27
  28. 28. Nutrition @ DEAKIN 28

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