Omega-3 Supplementation for the Prevention of Cognitive Decline in Older Adults: Does It Depend on Homocysteine Levels?

• Published in: The Journal of nutrition, health & aging health & aging, 2022-06, Vol.26 (6), p.615-620
• Main Authors: Maltais, Mathieu, de Souto Barreto, P., Bowman, G. L., Smith, A. D., Cantet, C., Andrieu, S., Rolland, Y.
• Format: Article
• Language: English
• Subjects: Aged; Aging; Alzheimer's disease; Blood; Cognition; Cognitive Dysfunction - drug therapy; Cognitive Dysfunction - prevention & control; Dementia; Dietary Supplements; Disease prevention; Executive function; Fatty acids; Fatty Acids, Omega-3 - pharmacology; Fatty Acids, Omega-3 - therapeutic use; Geriatrics/Gerontology; Homocysteine; Humans; Life Sciences; Medicine; Medicine & Public Health; Neurosciences; Nutrition; Older people; Original Research; Polyunsaturated fatty acids; Primary Care Medicine; Quality of Life Research
• ISSN: 1279-7707; 1760-4788
• DOI: 10.1007/s12603-022-1809-5

Background Recent evidence point towards an interaction between omega-3 (n-3) polyunsaturated fatty acids (PUFA) and plasma homocysteine (Hcy). Objectives This study tested the hypothesis that effects of red blood cell n-3 PUFA are modified according to baseline plasma Hcy in the large Mulit-domain Alzheimer Prevention Trial (MAPT) throughout the 3-years of treatment with an additional 2 years of observational follow-up. Design Experimental study. Participants From the 1680 participants that were randomized in the four groups of the MAPT study (two of which received n-3 PUFA, the other two without n-3 PUFA), 782 were selected because they had baseline data on both Hcy and n-3 PUFA. Measurements Cognitive performance was measured with a broad set of cognitive tests including free and total recall of the cued selective reminding test, digit symbol substitution test, category naming test and Trail-making tests (TMT-A and B) and Clinical dementia rating scale. Results We found a significant association between TMT-A and red blood cell n-3 PUFA levels in participants with Hcy values ≤16.8 µ Mol/L after adjustments at baseline (Estimate: −1.3, 95% CI: −2.3; −0.3, p=0.01). Additionally, participants with high Hcy values had a significant worsening after adjustments in TMT-B after a 5-year n-3 PUFA supplementation, compared to low levels of Hcy (Mean difference: 34.8, 95% CI: 7.8;61.7). Conclusion This study shows that Hcy levels could modify the association between red blood cell n-3 PUFA and executive function. People with high Hcy may benefit less from a n-3 PUFA supplementation to prevent cognitive decline.