Previously on this site I have written about the potential benefits that so-called omega-3 fats have regarding brain function. These fats appear to have anti-depressant potential, for instance, but also seem to have the capacity to help maintain basic brain function too. There is some research, for instance, which has linked higher levels of omega-3 fats in the diet or body with reduced risk of dementia.
Such studies are ‘epidemiological’ in nature, and can only tell us about associations between omega-3 fats and dementia: they cannot, however, tell us whether or not omega-3 fats actually protect against dementia. To answer this question what is required are clinical studies in which individuals are treated with omega-3 fats and the effect of this is compared to treatment with placebo (inactive medication). I was interested to read about a recent-published study which had this precise design.
The study involved 23 individuals with Alzheimer’s disease along with 23 individuals with ‘mild cognitive impairment’. These individuals were supplemented with 1.8 g of omega-3 fats or placebo (olive oil) for 24 weeks. At the start and conclusion of the study individuals were assessed with what is known as the ‘Clinician’s Interview-Based Impression of Change Scale’ as well as the ‘Alzheimer’s Disease Assessment Scale’. Data from 76 per cent (35) of study participants was then analysed.
The results of this study showed:
Overall, those taking omega-3 fats showed more improvement on the Clinician’s Interview-Based Impression of Change Scale score than those taking placebo.
In those with mild cognitive impairment, treatment with omega-3 fats showed significant improvement in the Alzheimer’s Disease Assessment Scale score compared to those taking placebo.
In those with Alzheimer’s disease, there was no significant difference in the Alzheimer’s Disease Assessment Scale score.
Higher levels of eicosapentaenoic acid (an omega-3 fat) in the red blood cells was associated with better brain function.
This study was hampered by a number of factors, including its small size and relatively short duration. The authors of this study have suggested that further research is warranted, which of course it is. However, to get some positive results despite quite considerable limitations is encouraging to say the least. The fact that higher EPA levels in the blood was linked with improved brain function is also a positive sign, as it suggests a ‘dose-response’ relationship between these two things, further strengthening the evidence here that omega-3 fats may have the ability to enhance and maintain brain function.
Chiu CC, et al. The effects of omega-3 fatty acids monotherapy in Alzheimer’s disease and mild cognitive impairment: A preliminary randomized double-blind placebo-controlled study. Prog Neuropsychopharmacol Biol Psychiatry 2008 May 25 [Epub ahead of print].