In this monthly column, Dr Kailas Roberts discusses the importance of diet and some foods that can contribute to a healthy brain, especially in older adults.
There is no doubt that what you eat has a profound effect on your health, including that of your brain. The longer you can sustain good eating habits, the more benefit you are likely to get. Related to this, the earlier in life you start, the more advantages healthy eating confers.
When it comes to cognitive impairment, another factor needs to be borne in mind – the state of your brain when you start your healthful diet.
There is no doubt that prevention is more potent than cure here. In general, we have no evidence that dementia can be reversed by changing what you eat unless you are treating an underlying nutritional problem such as B vitamin deficiency. But we do have good data to support the idea that certain dietary habits can protect the brain against diseases that cause dementia.
This is a controversial area, but the weight of the evidence suggests that for most, a diverse Mediterranean-style diet is best. Rigidly adhering to a diet based on these principles – packed with antioxidants, fibre, omega 3 fatty acids and vitamins, and relatively lacking saturated fat, processed food and sugar – can give you a brain that is seven years younger compared to if you choose not to follow it at all.
But what if dementia has already set in? Is there any value in eating healthily? There may well be indirect benefits – increased energy, better sleep, better mental health and the like – but the current research is not so optimistic about the ability of foods to improve cognitive function specifically. It might well be that once dementia is present, whatever disease is causing it – Alzheimer’s most commonly – has damaged the brain so much that no amount of good nutrition is going to fix it.
Modern science allows us to detect Alzheimer’s disease early on, however – perhaps two decades or more before we start seeing its symptoms. We can use brain scans and blood tests to determine the presence of the proteins that cause the condition. This is very hopeful as it allows for early intervention, and many of the favourable effects of healthy eating may be achievable even though the disease process has begun.
Then there is a condition called mild cognitive impairment, or MCI. This is not well known but for many is the first stage of Alzheimer’s disease (or other diseases) that has clinical symptoms. Memory decline and/or other cognitive problems are measurable on tests but do not greatly interfere with your ability to function day to day. Year on year there is an up to 15% chance of this developing into full-blown dementia.
For many, MCI is a golden opportunity as we know there are things you can do to reduce the risk of this becoming dementia, and someone with MCI is often more motivated to change their lifestyle too as they are experiencing symptoms. Exercise is one of the most important things to incorporate – research suggests it reduces the chances of someone with MCI developing dementia. Eating healthily may also help – again most evidently by following a Mediterranean diet.
I am a firm believer that it is preferable to get your nutrition from foods rather than pills and supplements, but there is also interesting and hopeful research looking at certain manufactured compounds. One of the most studied, for instance, is a milky drink called Souvenaid, which contains a patented formula of nutrients specifically for brain health. Consuming this daily, over a long period of time, has been shown to reduce the risk of developing dementia in those with MCI.
Dr Roberts is a medical specialist and expert in cognitive assessment and is the founder of the Your Brain in Mind cognitive optimisation clinic, where he works alongside a team of experienced and passionate healthcare professionals to assess clients’ brain health. He is also the author of Mind Your Brain: The Essential Australian Guide to Dementia (UQP, 2020) and the creator of BrainScan, a phone app that allows users to know and address their risk factors for poor brain health and dementia.