Combination of Higher Omega-3 Fatty Acid Status with B Vitamin Supplementation in Retarding Brain Deterioration in Elderly
Jernerin , F. et al., American Journal of Clinical Nutrition, in press, 2015
Dept. of Pharmacology, University of Oxford, Oxford, United Kingdom
Brain atrophy describes the loss of neurons (focal or overall brain ‘shrinkage’). Such ‘shrinkage’ naturally occurs to a limited extent with aging (particularly after the age of 75) and is associated with short-term memory loss and the deterioration of normal judgement and appropriate social behaviour. The present study evaluated the potential interaction between long-chain omega-3 fatty acid status (as EPA and DHA) and supplementation with selected B vitamins in reducing brain atrophy in elderly subjects with mild cognitive impairment (at an intermediary stage between normal deterioration due to aging and clinical dementia and Alzheimer disease). Previous research has indicated that taking a B vitamin mixture that reduces circulating plasma homocysteine levels can reduce brain atrophy rates while inconsistent benefits of omega-3 supplementation have been reported in other trials.
In the present study, 168 elderly subjects (average age of 77 years) with mild cognitive impairment completed the study with 85 receiving a daily B vitamin complex (providing 0.8 mg folic acid plus 0.5 mg B-12 plus 20 mg vitamin B-6) and 83 receiving a daily ‘placebo’ (no supplementary B vitamins) for a follow-up period of two years. The concentrations of EPA/DHA omega-3 fatty acids in the blood plasma of the subjects were determined at the beginning of the study and at the end. Whole - brain atrophy rates were determined from MRI (magnetic resonance imaging) at the beginning and at follow-up.
The results indicated a significant relationship between the effectiveness of the supplemental B vitamin complex to reduce the rate of brain atrophy and the EPA/DHA omega-3 status of the subjects. For those subjects with the lowest EPA plus DHA levels (bottom third of all subjects) in their circulation, the B vitamin supplement was without effect on the yearly brain atrophy rates. However, a highly significant and marked slowing of the yearly brain atrophy rates (by 40 %) was found with the B vitamin supplementation (relative to the placebo/controls) in those subjects with the higher circulating levels of EPA plus DHA. Those with the highest blood levels of EPA (top third of the subjects) exhibited a 46 % reduction in brain atrophy rates while those with the highest blood levels of DHA showed a 43 % reduction with B vitamin supplementation. The authors suggest that the benefits of B vitamin supplementation in retarding brain atrophy may require a high EPA/DHA omega-3 status in the body and that the beneficial effects of EPA/DHA on brain atrophy may require a healthy vitamin B status.
Dr. Holub's Comments:
This most interesting study indicates that maximizing the health benefits of one class of nutrients is often dependent on optimal intakes of another class and vice-versa. Regrettably, research costs and other factors have limited the vast majority of nutrient trials using supplementation to having the test subjects receive treatment with or without a single nutrient. Since the present study used measurement of omega-3 levels in the blood to determine the omega-3 status of the subjects, the intakes of EPA/DHA that would be needed to attain the higher blood levels of these fatty acids was not addressed. Furthermore, the researchers did not determine the EPA/DHA intakes of the subjects associated with the different levels of circulating EPA/DHA. However, from the published literature, it is most likely that almost all subjects who were to consume at least 400-500 mgs of EPA plus 500-600 mgs of DHA per day (via fish/seafood, enriched foods, supplementation) for at least 3-4 weeks would be in the highest group as for this study based on blood levels of EPA/DHA.