The type of diet we eat affects so much more than the way we look.
If you're old enough to remember television public service announcements from the '80s, you'll likely recall one from A Partnership for a Drug-Free America. In the brief spot, an egg frying in a pan symbolizes the effects of chronic, illicit drug use on the brain. It was a campaign that ran for a while. More recent research got me thinking about the interesting correlation between a "fried brain" and the totally-legal and readily-available foods we eat in America.
I've written extensively for the public on the benefits of exercise, sleep, and mindfulness meditation on brain health over the lifespan. I've not-as-frequently touched on the impact of diet. But what we put into our bodies by way of the foods we eat affects our brain health. Research this year out of the Royal Society for Open Science correlates study subject exposure to just one week of a "Western-Style Diet" with a decline in learning and memory. What do the study authors mean when they say "Western-Style Diet?" This is a way of eating that is heavy on sugar, rich in saturated fats, and low on whole foods like fruits, vegetables, and whole grains.
I believe many people understand our diets' effects on our physiques and our internal organs, like the heart. What folks may not realize is just how much influence what we eat has on how optimally our brains function. When you think about it, like your heart, your brain is always "on." Even when you're asleep, it's busy cleaning out the clutter from your mind, organizing and consolidating your memories, and so much more. But "fuel" is required for your brain to complete such tasks efficiently. And what you eat and drink provides that fuel – so what that fuel is made up of matters quite a bit.
Additionally, what we eat has a significant impact on our mood, which is also regulated by the brain. Many studies have been conducted on the subject of diet and mood disorders, including depression. As one can imagine, our moods fare far worse when we aren't consuming nutritious foods. One important reason this occurs is that food that is full of refined (not naturally occurring, like it is in fruits) sugar and fat-heavy tends to set off a cascade of inflammatory processes in the body – resulting in the release of free radicals and something called oxidative stress.
Simply put, the term oxidative stress refers to waste in the form of free radicals that are harmful to the cells of the human body. They have been linked to a wide range of conditions, disorders, and illnesses, including Alzheimer's Disease and certain types of cancer. Surprisingly, it has only been in more recent years that researchers and the broader medical community have recognized how significant an impact what we eat has on our brain health.
So, I've explained a bit about the bad news regarding diet and brain health. Now for some good news. What you eat is mostly something YOU can control. To an extent, I recognize that not everyone has access to or can readily afford high-quality, nutritious foods. But you might be surprised at how much power each of us does have in the food choices we make. For example, if the drive-thru window is the only option for a meal, consider forgoing the bun and asking for a burger protein-style (wrapped in lettuce) and without sauce. Of course, this still isn't the highest-quality nutrition. But if it's what's available, there are modifications you can make at most drive-throughs that help reduce the sugar, fat, and refined carbohydrate intake you might have otherwise consumed. Of course, when access and funds DO allow for healthier food choices, invest in staples like plant-based or lean proteins, colorful vegetables and fruits, and whole grains. Keep foods that are high in saturated fats and sugars as "sometimes foods." Not totally off the table so you don't "crave what you can't have," but not something that is otherwise part of your everyday meal planning.
Finally, I have a little word of caution. If your diet has been heavy in saturated fats and refined sugars for a long time, dramatically changing what you eat to healthier fare might have some temporary withdrawal side effects. The most-reported effect that a switch to healthier food options has in the short term is headaches. I know this seems counterintuitive since healthy food is supposed to make your brain better, but I assure you these effects are often temporary. The headaches are essentially your brain's way of "detoxing" from many years of a poor diet. Stick with it. When the fog clears, and it will, you will likely be amazed at how much more mental clarity, real energy, and concentration you end up with as a result.
Sources:
https://royalsocietypublishing.org/doi/10.1098/rsos.191338
https://www.health.harvard.edu/blog/nutritional-psychiatry-your-brain-on-food-201511168626