The human brain is made of food, so what we eat and drink affects our ability to keep a healthy, alert and active mind.
We all intuitively appreciate that the foods we eat shape our thoughts, actions, emotions and behaviour. When you are feeling low, you reach for chocolate; when you are tired, you crave coffee. We all use food to soothe our moods and clear our heads without seeming to think much about it.
Yet the focus of most diets is on the way we look rather than the way we think. This is in part due to western society’s fascination with appearance, and medicine’s bias towards drugs and surgery. In fact, contemporary medicine often disregards the ways that our diet helps shape our cognitive health. Medical students are not trained in nutrition. And, for what it is worth, neither are scientists.
This has been the focus of my work as the associate director of the Alzheimer’s prevention clinic at the Weill Cornell medical college, New York City. For the last 15 years, we have been doing long-term studies to demonstrate the ways that diet prevents, delays or leads to cognitive conditions such as Alzheimer’s. The good news is that we have learned so much about what every one of us can do to optimise our brain health day to day.
Studies using next-generation imaging and genomic sequencing, both central to my work, have helped reveal that some foods such as vegetables, fruit, fish, wholegrains, nuts and seeds are neuro-protective. They not only shield the brain from harm, but also support cognitive fitness over the course of a lifetime.
It comes perhaps as no surprise that other foods such as fast food, fried food, excess fatty foods and refined sugar are downright harmful instead, slowing us down in general, making us feel sluggish and tired, while at the same time deeply increasing our risk of dementia.
These effects are particularly evident by looking at brain scans of people on different diets. For example, when we compared the scans of middle-aged people who had eaten a Mediterranean diet most of their lives with those of people of the same age who ate a western diet with processed food, processed meats, sweets and fizzy drinks, we saw the way the latter group’s brains had shrunk prematurely. Subsequent studies provided even more alarming evidence that people on the western diet had started developing Alzheimer’s plaques already in their 40s and 50s. These are all signs of accelerated ageing and increased risk of future dementia.
The bottom line is this: the more processed, packaged and refined foods that you consume on a regular basis, the higher your risk of cognitive decline further down the line.
In terms of the food that helps, there is no single miracle food or supplement that will keep us young, healthy and bright-eyed with a perfect memory (and beware anyone who tells you there is). There are, however, some important and urgent best practices that we need to get into people’s kitchens.
These foods and nutrients are valuable at all stages of life. While the dietary needs of the rest of the body vary somewhat with age (more protein is needed when we are younger; more calcium and vitamin D when we are older), this does not seem to be the case for the brain. However, like every diet, the effects and efficacy of these foods will vary massively from individual to individual. My current research is looking at the differences between the ways that male and female brains need and metabolise specific nutrients. Of note in the research thus far: women’s brains seem to need more antioxidants, especially vitamins A, C and E (which can all be found in the plant-based foods listed above), as well as the anti-inflammatory omega-3s found in fish, nuts and seeds.
In the end, a brain-healthy diet optimises your capacity for keeping a healthy, sharp and active brain over a lifetime – while reducing the risk of developing age-related cognitive impairments and dementia. As individuals and as a society, we must refocus attention on how our food choices shape our brains, as surely as they shape the rest of us.