Food for Thought (literally)

by Dr. Thor Bergersen

Glucose = Brain Fuel

First, a disclaimer: I’m a psychiatrist, not a nutritionist. I have a pretty good idea of what’s healthy to eat and what isn’t, but my purpose here is not to get specific about food. Rather, it is to give simple, practical advice for those who wish to maximize their ability to concentrate consistently throughout the day.

A story I hear frequently goes something like this: “I was in a hurry this morning and didn’t have time for breakfast, then things were so hectic at lunchtime that I forgot to eat, and at around three I was starving, but I thought I’d just wait until I got home, and by five I was exhausted and couldn’t think straight, so I had to leave.”

The above run-on sentence exemplifies the difficult relationship some of us have with eating. That is, we forget to stop and eat. My patients with ADHD already tend to hyper-focus and struggle to be present in the moment, so stepping back to observe their hunger and other bodily needs does not take priority over other immediate concerns. After all, starvation takes more than missing a meal.

The brain is powered by glucose. Derived from the Greek word glukus, which means sweet [Wikipedia], it is the only simple sugar capable of passing through the protective membranes around our central nervous system. It’s also the primary energy source for almost every organism, including bacteria.

When we eat or drink something with calories, the sugar level our blood increases. Depending on how easily our bodies can break the food or drink down into glucose, this process can occur within minutes or hours. Because the nerve cells in the brain are dependent upon an adequate, steady supply of glucose for the energy they need to send signals to each other, any interruption of this sugar pipeline can be disastrous. If even a few billion neurons start sputtering - running on molecular fumes - the whole system can backfire.

Which is why it’s important to keep glucose levels as steady as possible throughout the day. Eating sweet stuff causes a quick rise and fall in blood sugar. Eating protein and complex carbohydrates leads to a more gradual elevation and subsequent decline. When a reasonable mix of calorie sources is consumed several times a day, the result is a gently shifting, cognitively effective level of glucose that keeps brain cells running smoothly.

Forgetting to eat all day is not an effective approach to productivity and efficiency. Snacking all day keeps your brain happy. Pay attention to hunger and thirst. Burn calories through exercise. Sleep enough to recharge your brain and body. Eat, sleep, and exercise, and the rest will fall into place.