Three new studies suggest that both diet and supplements have the potential to lower your risk of developing Alzheimer’s dementia.
The first evidence came from the dietary analysis of 923 people, aged 58-98, who were followed for an average of 4.5 years. Those whose eating fitted a pattern known as the MIND diet were 53% less likely to develop Alzheimer’s disease if they followed it rigidly, and 35% less likely to develop Alzheimer’s if they stuck to it moderately well compared with those who followed it poorly. And this was after accounting for other known Alzheimer’s risk factors such as age, education, physical activity, doing brain-stimulating activities and inheriting a gene variant known as APOE ε4.
Based on a hybrid of the Mediterranean diet and the DASH diet, which was originally designed to lower blood pressure, the MIND diet includes 10 different brain-healthy foods groups, and involves eating two servings of vegetables per day (especially green leaves for folate), two weekly servings of berries (especially strawberries, for antioxidants), fish at least once per week (for omega-3s), beans, wholegrains, nuts, beans, poultry, olive oil and – best of all – a daily glass of wine. So far, so good. I can do all those.
Fish oils and brain health
The second study looked for any association between taking fish oil supplements, brain size and ability to think straight in older adults. Given that long-chain omega-3s (DHA and EPA) play an important structural and signalling role in the brain, and that we become less able to produce these from short-chain omega-3s as we get older, it was likely that those with a good dietary intake of pre-formed DHA and EPA would benefit.
The researchers compared 229 US adults (aged 55 to 90) with normal mental function, 397 with mild cognitive impairment, and 193 with a diagnosis of Alzheimer’s disease. Mental function tests and brain MRI scans showed that those taking fish oil supplements performed better, and had less brain shrinkage of areas involved in memory and cognition than those who did not – but only in those with normal mental function at the start, and only in those who were APOE ε4–negative. Genes always win out in the end. Or do they?
Fish oil plus B vitamins
The third, and most exciting study, from Oxford University, suggests that combining omega-3 fish oils with high dose B vitamins might even arrest shrinkage of the brain in people with Alzheimer’s, and slow the progression of the disease.
The researchers randomised 168 people over the age of 70 years with mild cognitive impairment to either take high-dose B vitamins (folic acid 0.8 mg, vitamin B6 20 mg, vitamin B12, 0.5 mg) or placebo for two years.
In those taking the B vitamins, the rate of brain shrinkage slowed by 40% compared with those on placebo but only in those who also had high blood levels of omega-3 fatty acids. In those who had a raised homocysteine level (an amino acid that damages arteries and is linked with dementia) the rate of brain shrinkage reduced by 70%. The most likely explanation is that this protective effect was due to reduce hardening and furring up of the arteries, as folic acid, vitamins B6 and vitamin B12 are needed by enzymes that lower levels of a harmful amino acid (homocysteine) linked with atherosclerosis. No significant effect on the rate of atrophy was seen in those with low omega-3 levels, however, suggesting that optimum levels of B vitamins and omega-3s (whether from foods or from taking supplements) are both needed for protection.
This is the first evidence to suggest that the brain shrinkage seen in Alzheimer’s disease can be slowed through dietary intervention, and has been hailed as a major breakthrough in dementia prevention.
If you fancy taking a free Cognitive Function Test online, visit the Alzheimer’s charity, foodforthebrain.
Does Alzheimer’s occur in your family? If so are you taking any steps to reduce your risk?
Image credits: william_ismael/flickr;