Alzheimer’s disease is a form of dementia, a typical finding in which is the deposition of a protein known as amyloid-ß in the brain. Loss of brain cells is a common feature too. One natural agent that has shown some promise in combating Alzheimer’s disease is fish oil. Fish oil is rich in two main fats: EPA and DHA. EPA seems to be important for the day-to-day functioning of the brain, while DHA seems to be more a ‘building block’ of the brain. There is some evidence that supplementing with these so-called ‘omega-3’ fats can improve brain function in those with ‘mild cognitive impairment’.
However, work in individuals with moderate or severe Alzheimer’s disease has not found omega-3 supplementation to be of benefit. It’s possible that such an approach will never work. But it’s also possible that negative results were achieved because, say, the dosage of omega-3 used in these studies was not high enough or supplementation did not go on long enough.
One way of overcoming this last problem, at least to some degree, is to study animals. Animals are not humans, and the results of studies in them cannot be directly extrapolated to us. But, animals do give researchers the opportunity to closely control treatments, and can generally treat for much longer periods than would be practical in humans.
In a recent review , researchers assessed the evidence in which animals (rats and mice) with animal models of Alzheimer’s disease had been treated with omega-3 fats for at least 10 per cent of their life spans. Long term treatment with omega-3 was found, overall, to:
• Reduce amyloid-ß deposition
• Improve cognitive function
• Reduce brain cell loss
In other words, in animals, omega-3 supplementation was found to combat key underlying processes in Alzheimer’s disease and improve brain functioning too. This is not enough to prove that long-term supplementation with omega-3 would help prevent or ameliorate Alzheimer’s disease in humans. It is enough for me, personally, to make me think that keeping up a good intake of omega-3 fats is likely to be a decent insurance against declining mental function as I age.
1. Hooijmans CR, et al. The Effects of Long-Term Omega-3 Fatty Acid Supplementation on Cognition and Alzheimer’s Pathology in Animal Models of Alzheimer’s Disease: A Systematic Review and Meta-Analysis. J Alzheimers Dis. 2011 Oct 14. [Epub ahead of print]