My big brother Joe has a famously bad memory. At a relatively youthful 38, he often forgets conversations I have had with him only a few days before. Regularly, he regales me with stories and anecdotes that I find very amusing, but only the first time round. A couple of months ago, I was recounting a wee tale of my own to my brother, when he gleefully reminded me that I had already told him the same story earlier that day. I have to say, alarm bells were a’ringing. In my mind, what seemed to be starting as a spot of absentminded repetition was bound to end up as full-blown dementia down the track.
No one relishes the thought of losing their mental faculties as they age, but there is good evidence that we can do much to stop the rot. Plenty of research suggests our diet has an important influence on brain function. Other studies show that exercise and natural substances might also be of benefit here. It does appear that just a few simple lifestyle adjustments can really help us preserve our memory and brainpower well into old age.
The brain is to a degree dependent on the supply of certain nutrients for its proper function. Brain tissue is rich in healthy fats known as long-chain polyunsaturated fatty acids (PUFAs). In recent years, a lot of scientific attention has been focused on the role of PUFAs such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in brain function. More than one study has found that individuals with lower levels of EPA and DHA are at increased risk of mental impairment such as dementia and even Alzheimer’s disease. EPA and DHA are found in abundance in oily fish (e.g. salmon, trout, tuna, mackerel, herring and sardines), and research suggests that eating more of this can help to maintain brain function. In a Dutch study, men who ate a lot of fish were found to have half the rate of mental decline compared to occasional consumers. It really does seem as though fish is the original brain food.
The mental decline that can come with ageing is thought to be related to damaging, destructive molecules known as free radicals. Free radicals are quenched in the body by antioxidant substances such as beta-carotene and vitamins C and E. There is some evidence that upping our intake of antioxidant nutrients might help maintain our mental sharpness. One study found that individuals consuming 2.1 mg (3,500 IU) of beta-carotene per day were half as likely to suffer cognitive impairment, disorientation or have difficulty solving problems compared to those swallowing 0.9 mg (1,500 IU) or less per day. Another study found that higher levels of vitamin C in the body were associated with improvement in mood and intelligence and a reduction in everyday errors of memory and attention. Citrus and kiwi fruits, strawberries, broccoli and Brussels sprouts are especially rich in vitamin C, while deep green and yellow-orange vegetables (e.g. carrots, spinach and sweet potato) are good sources of beta-carotene.
Another link between nutrition and brain function concerns the amino acid homocysteine. Raised levels of homocysteine have previously been linked to chronic diseases such as heart disease and osteoporosis. However, Welsh research presented last year found a direct relationship between homocysteine levels and cognitive decline too. Folic acid, vitamin B12 and vitamin B6 have all been found to help reduce homocysteine levels in the body. While it is not known for sure whether lowering homocysteine levels will help brain function, keeping homocysteine in check does appear to make good sense. Folic acid can be found in green leafy vegetables, while liver, avocado, bananas and fish are rich in B6. Vitamin B12 containing foods include meat, fish and eggs.
Apart from diet, another major lifestyle factor which appears to impact on brain function is exercise. Research published last year in the Archives of Neurology found that regular vigorous exercise is associated with a significantly reduced risk of Alzheimer’s disease, dementia and other forms of mental impairment. An earlier study published in the Journal of Internal Medicine found that walking as little as ½ mile a day improved memory and reduced signs of dementia in the elderly.
For those inclined towards supplements, additional quantities of the specific nutrients mentioned above may offer long-term benefit. I generally recommend 5,000 – 10,000 IU of beta-carotene, 1 g of vitamin C, and a B-complex supplement each day. Anyone looking for just a little more in the way of mental edge might do well to take a supplement of the herb Ginkgo biloba. This herb enhances the circulation, and is believed to help improve delivery of oxygen and nutrients to the brain. In one study, individuals taking 120 mg of Ginkgo biloba extract each day for a year were found to have improved short-term memory, vigilance and mood. Other studies show that, at a dose of 120 – 160 mg of extract per day, Ginkgo biloba can improve impaired memory and brain function related to ageing. Ginkgo biloba supplements can be found in all good health food stores.