Clarifying krill – what’s the hype?
Nina Bailey
BSc MSc PhD ANutr
Krill are shrimp-like crustaceans of the species
Euphausia superba, found mostly in the
Antarctic and North Pacific oceans
• The DHA content of krill is similar to that of oily fish,
but the EPA content is generally higher
• Krill oil also conta...
• The message that krill may provide benefits similar to
fish oil has been growing rapidly although there are
still relati...
Krill oil – USPs
• The long-chain fatty acids in krill are absorbed
and carried to the body’s cells in phospholipid
form
•...
 All fat must be digested before uptake:
Lipase breaks bonds in triglycerides
Phospholipase breaks bonds in phospholipids...
 After absorption into enterocytes, the
metabolism of long-chain fatty acids
involves re-esterification into:
Triglycerid...
 Much of the marketing of krill oil focuses on its
superior bioavailability, with consumer targeted
messages such as ‘les...
Vitabiotics
Ultra Krill oil
MegaRed Superba
Red
Bioglan Holland &
Barrett
CardioRed Healthspan
Krill oil content (mg/capsu...
 Krill vs fish oil in ‘like for like’ dosing (Maki et al., 2009)
2g krill oil vs 2g fish oil
 Comparing krill with fish ...
Study 1
Study 1
• 4-week randomised double-blind intervention in ‘healthy’
but overweight individuals
– Krill oil (2.0 g/day)
• 21...
– Krill oil
216 mg EPA: 90 mg DHA
(omega-3 = 306 mg)
– Fish oil
212 mg EPA: 178 mg DHA
(omega-3 = 390mg)
Krill oil deliver...
Main findings
 No significant differences in changes in serum lipids, glucose
homeostasis, markers of inflammation or oxi...
Study 2
• 7-week intervention ‘healthy’ individuals
– Krill oil (3.0 g/day)
• 543 mg EPA + DHA
• n = 36
– Fish oil (1.8 g/day)
• 8...
Main findings
 No significant differences in changes in serum lipids or markers of
inflammation or oxidative stress
 Sig...
Baseline 7 weeks
40
45
50
55
60
65
70
75
Fish oil Krill oil Control
Changes in EPA blood plasma levels (mmol/L) after seve...
Changes in DHA blood plasma levels (mmol/L) after seven weeks of
supplementation with krill oil, fish oil or placebo
Basel...
Baseline 7 weeks
175
177
179
181
183
185
187
189
191
193
195
Fish oil
Krill oil
Control
Changes in AA blood plasma levels ...
Study 3
Incorporation of EPA and DHA into plasma phospholipids in
response to different omega-3 fatty acid formulations
Double-bli...
• Main findings
– The omega-3 concentrations in plasma phospholipids were at
their highest 24 hours after consumption of a...
Study 4
Double-blinded, randomised, placebo-controlled,
crossover trial
Three treatment phases:
3g krill oil providing 600mg of om...
Main findings
 Consumption of 3g/day krill oil for 4 weeks increased plasma
and RBC concentrations of total omega-3, EPA,...
However……
 Careful examination of the fatty acid profiles of the oils used
showed that the fish oil used was not a typica...
However……
 The omega-6 content of the krill oil was low (1.73g/100g oil)
compared with fish oil (21.95g/100g oil)
 Linol...

Nichols et al., 2014
 2g krill oil vs 2g fish oil
Comparable uptake of EPA and DHA
 3g krill oil vs 1.8g fish oil
Comparable uptake of EPA an...
 Although superior bioavailability of omega-3 in krill oil
over fish oil is suggested, none of the studies have
managed t...
• It is likely that EPA and DHA in phospholipid found in krill oil is
more bioavailable than EPA found in fish oil as eith...
• Krill delivers approx. 123mg EPA per gram and delivers both
EPA and DHA
• It is generally accepted that highly concentra...
Summary
• There is little evidence to support the bioavailability claims
related to krill oil
• Many of the health benefit...
References
• Maki KC, Reeves MS, Farmer M, Griinari M, Berge K, Vik H, Hubacher R, Rains TM: Krill oil
supplementation inc...
ninab@igennus.com
www.igennus.com
drninabailey.co.uk
01223 421434
07527384229
Vitabiotics
Ultra Krill oil
MegaRed Superba
Red
Bioglan Holland &
Barrett
CardioRed Healthspan
Price £ 14.95 17.99 23.95 2...
Clarifying krill – what’s the hype? with Dr Nina Bailey
Clarifying krill – what’s the hype? with Dr Nina Bailey
Clarifying krill – what’s the hype? with Dr Nina Bailey
Clarifying krill – what’s the hype? with Dr Nina Bailey
Clarifying krill – what’s the hype? with Dr Nina Bailey
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Clarifying krill – what’s the hype? with Dr Nina Bailey

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Clarifying krill – what’s the hype? with Dr Nina Bailey

  1. 1. Clarifying krill – what’s the hype? Nina Bailey BSc MSc PhD ANutr
  2. 2. Krill are shrimp-like crustaceans of the species Euphausia superba, found mostly in the Antarctic and North Pacific oceans
  3. 3. • The DHA content of krill is similar to that of oily fish, but the EPA content is generally higher • Krill oil also contains the carotenoid astaxanthin, a naturally occurring antioxidant that gives krill oil its red/pink colour and that acts as a natural preservative • The growing interest in krill as an alternative source of omega-3 is leading to an increase in krill oil products
  4. 4. • The message that krill may provide benefits similar to fish oil has been growing rapidly although there are still relatively few human studies conducted on krill • Initial indications suggest that krill oil can reduce inflammation and cardiovascular risk factors including cholesterol and triglycerides • Studies confirming the specific benefits of fish oil currently run into the thousands, compared to only a handful on krill oil
  5. 5. Krill oil – USPs • The long-chain fatty acids in krill are absorbed and carried to the body’s cells in phospholipid form • Phospholipids form the structural basis of cell membranes and are more effectively utilised by the body
  6. 6.  All fat must be digested before uptake: Lipase breaks bonds in triglycerides Phospholipase breaks bonds in phospholipids Carboxyl ester lipase breaks bonds in ethyl esters Monoglycerides Free fatty acids Lysophosphatides
  7. 7.  After absorption into enterocytes, the metabolism of long-chain fatty acids involves re-esterification into: Triglyceride (2-monoglyceride pathway) Phospholipid (a-glycerophosphate pathway) Formation of chylomicrons for further transport
  8. 8.  Much of the marketing of krill oil focuses on its superior bioavailability, with consumer targeted messages such as ‘less is more’  MegaRed Krill oil 300mg ‘one-a-day-capsule’ delivers 36mg EPA and 16.5mg DHA  But are the omega-3 fatty acids in krill oil more bioavailable than those found in standard fish body oil?
  9. 9. Vitabiotics Ultra Krill oil MegaRed Superba Red Bioglan Holland & Barrett CardioRed Healthspan Krill oil content (mg/capsule) 1000 300 500 500 1500 500 500 EPA/capsule (mg/capsule) 120 36 70 60 120 70 70 DHA/capsule (mg/capsule) 55 16.5 32 27.5 75 32.5 32 Total omega-3/g oil 220 220 250 175 170 240 240 EPA/g oil 120 120 140 120 80 140 140 DHA/g oil 55 55 64 55 50 65 64 NB Average omega-3 = 216 mg/g; average EPA = 123 mg/g; average DHA = 58 mg/g
  10. 10.  Krill vs fish oil in ‘like for like’ dosing (Maki et al., 2009) 2g krill oil vs 2g fish oil  Comparing krill with fish oil (Ulven et al., 2011) 3.0g krill oil vs 1.8g fish oil  Comparing krill, rTAG and EE at comparative doses (Schuchardt et al., 2011) EPA and DHA 1680mg  Krill vs fish oil in ‘like for like omega-3’ dosing (Ramprasath et al., 2013) 600mg of omega-3
  11. 11. Study 1
  12. 12. Study 1 • 4-week randomised double-blind intervention in ‘healthy’ but overweight individuals – Krill oil (2.0 g/day) • 216 mg EPA: 90 mg DHA (omega-3 = 306 mg) • n = 25 – Fish oil (2.0 g/day) • 212 mg EPA: 178 mg DHA (omega-3 = 390mg) • n = 26 – Control group • Olive oil • n = 25
  13. 13. – Krill oil 216 mg EPA: 90 mg DHA (omega-3 = 306 mg) – Fish oil 212 mg EPA: 178 mg DHA (omega-3 = 390mg) Krill oil delivers 22% less omega-3 Plasma concentrations μmol/L
  14. 14. Main findings  No significant differences in changes in serum lipids, glucose homeostasis, markers of inflammation or oxidative stress  Significant increases from baseline in plasma levels of EPA and DHA were observed in both the krill and fish oil groups but not the control  At the end of the treatment period, the mean plasma EPA concentration was higher in the krill oil group compared with the fish oil group (377 vs 293 μmol/L), whereas the mean plasma DHA concentrations were comparable (476 vs 478 μmol/L)  The authors therefore suggest that the EPA and DHA from krill oil are absorbed at least as well as that from fish oil
  15. 15. Study 2
  16. 16. • 7-week intervention ‘healthy’ individuals – Krill oil (3.0 g/day) • 543 mg EPA + DHA • n = 36 – Fish oil (1.8 g/day) • 864 mg EPA + DHA • n = 40 – Control group • no supplementation
  17. 17. Main findings  No significant differences in changes in serum lipids or markers of inflammation or oxidative stress  Significant increases in plasma EPA, DPA and DHA were observed in both the krill and fish oil groups but not the control  No significant differences in plasma EPA, DPA and DHA between the krill and fish oil groups  The authors therefore suggest that krill and fish oil represent comparable dietary sources of omega-3 even if the EPA and DHA dose in the krill oil was 62.8% of that in the fish oil
  18. 18. Baseline 7 weeks 40 45 50 55 60 65 70 75 Fish oil Krill oil Control Changes in EPA blood plasma levels (mmol/L) after seven weeks of supplementation with krill oil, fish oil or placebo Ulven SM, Kirkhus B, Lamglait A, Basu S, Elind E, Haider T, Berge K, Vik H, Pedersen JI. Metabolic effects of krill oil are essentially similar to those of fish oil but at lower dose of EPA and DHA, in healthy volunteers. Lipids. 2011 46:37-46.
  19. 19. Changes in DHA blood plasma levels (mmol/L) after seven weeks of supplementation with krill oil, fish oil or placebo Baseline 7 weeks 20 30 40 50 60 70 80 Fish oil Krill oil Control Ulven SM, Kirkhus B, Lamglait A, Basu S, Elind E, Haider T, Berge K, Vik H, Pedersen JI. Metabolic effects of krill oil are essentially similar to those of fish oil but at lower dose of EPA and DHA, in healthy volunteers. Lipids. 2011 46:37-46.
  20. 20. Baseline 7 weeks 175 177 179 181 183 185 187 189 191 193 195 Fish oil Krill oil Control Changes in AA blood plasma levels (mmol/L) after seven weeks of supplementation with krill oil, fish oil or placebo Ulven SM, Kirkhus B, Lamglait A, Basu S, Elind E, Haider T, Berge K, Vik H, Pedersen JI. Metabolic effects of krill oil are essentially similar to those of fish oil but at lower dose of EPA and DHA, in healthy volunteers. Lipids. 2011 46:37-46.
  21. 21. Study 3
  22. 22. Incorporation of EPA and DHA into plasma phospholipids in response to different omega-3 fatty acid formulations Double-blinded cross over n = 12 (males) Single dose of: • 7.0g krill oil (1050 mg EPA: 630mg DHA) • 3.4g fish oil ethyl-ester (1008mg EPA: 672mg) • 3.4g fish oil triglyceride (1008mg EPA: 672mg)
  23. 23. • Main findings – The omega-3 concentrations in plasma phospholipids were at their highest 24 hours after consumption of all three EPA and DHA containing oils – EPA and DHA were absorbed in the following order Krill oil > triglyceride > ethyl ester – Krill oil contained high amounts of EPA and DHA as free fatty acids rather than as total phospholipid (22% EPA and 21% DHA) – However, due to high standard deviation values, there were no statistically significant difference in uptake between the three treatments
  24. 24. Study 4
  25. 25. Double-blinded, randomised, placebo-controlled, crossover trial Three treatment phases: 3g krill oil providing 600mg of omega-3 3g fish oil providing 600mg of omega-3 3g placebo control (corn oil) Each treatment lasted 4 weeks with each separated by an 8-week washout phase
  26. 26. Main findings  Consumption of 3g/day krill oil for 4 weeks increased plasma and RBC concentrations of total omega-3, EPA, and the sum of EPA and DHA compared with fish and corn oil  Consumption of 3g/day krill oil for 4 weeks decreased plasma omega-6 fatty acids with a subsequent decrease in the omega-6 to omega-3 ratio  Authors conclude that krill is superior to fish oil in increasing omega-3, decreasing the omega-6 to omega-3 ratio and improving the omega-3 index
  27. 27. However……  Careful examination of the fatty acid profiles of the oils used showed that the fish oil used was not a typical fish oil  To match the concentrations of omega-3 and volumes between krill and fish oil, the fish oil was diluted with corn oil at a ratio of 1.3:1.0  Of the 3g ‘fish oil’ total, only 1.7g was true fish oil, with 1.3g corn oil added to ‘make up the volume’
  28. 28. However……  The omega-6 content of the krill oil was low (1.73g/100g oil) compared with fish oil (21.95g/100g oil)  Linoleic acid was the dominant fatty acid (32%) in the fish oil giving it an omega-6 to omega-3 of >1  The omega-3 content of the krill oil delivered 17% more omega- 3 than the fish oil (778mg vs 664mg)  Due to the fatty acid profile being non-representative of typical commercially marketed fish oil, the conclusions presented were subsequently deemed not justified and misleading (Nichols et al., 2014)
  29. 29.  Nichols et al., 2014
  30. 30.  2g krill oil vs 2g fish oil Comparable uptake of EPA and DHA  3g krill oil vs 1.8g fish oil Comparable uptake of EPA and DHA but no significant difference in omega-3 levels with higher intake of krill – doesn’t support the ‘less is more’ claim  Krill vs rTG vs EE Supplementing with 7g krill delivers comparable EPA and DHA to rTAG and EE without significantly increased bioavailability  3g krill oil vs 3g fish oil Uptake of EPA and DHA as krill oil superior to fish oil ?? Issue with study bias
  31. 31.  Although superior bioavailability of omega-3 in krill oil over fish oil is suggested, none of the studies have managed to show significant improvement in absorption of omega-3 fatty acids from krill oil over fish oil  At the most, data from a bioavailability study in humans showed a tendency for higher bioavailability for EPA after krill oil consumption compared with fish oil (Schuchardt et al., 2013); however, this study tested an acute single dose of omega-3 PUFA over 48h  The study by Ramprasath et al, 2013 must be interpreted with caution because of study bias
  32. 32. • It is likely that EPA and DHA in phospholipid found in krill oil is more bioavailable than EPA found in fish oil as either triglyceride or ethyl-ester form • EPA and DHA are absorbed in the following order: Krill oil > triglyceride > ethyl ester, which would be expected given that krill oil is in phospholipid • Ethyl-ester bioavailability can be significantly improved if taken with other fat to provide the glycerol backbone required for re-esterification (Nordov et al., 1991) Summary
  33. 33. • Krill delivers approx. 123mg EPA per gram and delivers both EPA and DHA • It is generally accepted that highly concentrated omega-3 oils are required to deliver therapeutic outcomes – 1g EPA required for depression – 2g EPA required for schizophrenia – 2-4g EPA required for hypercholesterolaemia • Whilst krill oil raises EPA and DHA levels comparative to that of fish oil, high volumes of krill oil would required to achieve the therapeutic levels of omega-3 that can be delivered by oils containing 70-90% omega-3
  34. 34. Summary • There is little evidence to support the bioavailability claims related to krill oil • Many of the health benefits attributed to krill oil may arise from its high astaxanthin content • Given the cost of krill oil compared to standard fish oils, krill oil may not currently offer a cost-effective substitute for highly concentrated omega-3 products • More human intervention studies are required to investigate the effects of krill oil
  35. 35. References • Maki KC, Reeves MS, Farmer M, Griinari M, Berge K, Vik H, Hubacher R, Rains TM: Krill oil supplementation increases plasma concentrations of eicosapentaenoic and docosahexaenoic acids in overweight and obese men and women. Nutrition research 2009, 29:609-615. • Nichols PD, Kitessa SM, Abeywardena M: Commentary on a trial comparing krill oil versus fish oil. Lipids in health and disease 2014, 13:2 • Ramprasath VR, Eyal I, Zchut S, Jones PJ: Enhanced increase of omega-3 index in healthy individuals with response to 4-week n-3 fatty acid supplementation from krill oil versus fish oil. Lipids in health and disease 2013, 12:178. • Schuchardt JP, Schneider I, Meyer H, Neubronner J, von Schacky C, Hahn A: Incorporation of EPA and DHA into plasma phospholipids in response to different omega-3 fatty acid formulations--a comparative bioavailability study of fish oil vs. krill oil. Lipids in health and disease 2011, 10:145. • Ulven SM, Kirkhus B, Lamglait A, Basu S, Elind E, Haider T, Berge K, Vik H, Pedersen JI: Metabolic effects of krill oil are essentially similar to those of fish oil but at lower dose of EPA and DHA, in healthy volunteers. Lipids 2011, 46:37-46.
  36. 36. ninab@igennus.com www.igennus.com drninabailey.co.uk 01223 421434 07527384229
  37. 37. Vitabiotics Ultra Krill oil MegaRed Superba Red Bioglan Holland & Barrett CardioRed Healthspan Price £ 14.95 17.99 23.95 21.99 26.99 24.95 15.95 Capsules 30 30 60 30 60 60 60 Recommended dose (daily) 1-2g 300mg 1-1.5g 500mg 3 g 1g 0.5 - 1g Krill oil content (mg/capsule) 1000 300 500 500 1500 500 500 EPA/capsule (mg/capsule) 120 36 70 60 120 70 70 DHA/capsule (mg/capsule) 55 16.5 32 27.5 75 32.5 32 Total omega-3/g oil 220 220 250 175 170 240 240 EPA/g oil 120 120 140 120 80 140 140 DHA/g oil 55 55 64 55 50 65 64 NB Average omega-3 = 216 mg/g; average EPA = 123 mg/g; average DHA = 58 mg/g

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