“You are what you eat” is a very well known and slightly overused phrase. The problem with overused phrases is that we say them so much that they tend to lose their meaning. When you really take a look at the information, you start to realize what a huge impact nutrition has on brain function. Our brain needs fuel, but it needs the right kinds of fuel to function well. It is estimated that 20% of our caloric intake is used by our brain.
The brain uses carbohydrates for supplying glucose. Low glucose levels affect the prefrontal cortex, which is responsible for our executive control function. When levels fall, our thinking becomes confused and foggy. In other words, you need food for thought. So when you don’t take time to eat breakfast or you skip lunch, you are starving your brain and inhibiting your cognitive performance. Complex carbohydrates are the best because they break down slowly and keep glucose levels steady over a longer period of time. Glucose also influences the release of a neurotransmitter called acetylcholine that is necessary for learning and memory.
Neurotransmitters are like chemical messengers in the brain that pass signals between neurons through neural pathways. Most neurotransmitters are made from amino acids that come from the protein we eat. In addition to learning and memory, they also affect focus, sleep and our moods. If production of certain neurotransmitters is reduced, imbalances in the brain can occur. For example, reduced dopamine levels can cause depression and low norepinephrine levels can negatively impact your metabolic rate, as well as the transfer of short term memory to long term memory.
The brain is composed mostly of fat, nearly 60%. For instance, myelin, the insulation surrounding the branches of neurons, is made up of fat. Eating essential fatty acids (EFAs), especially omega-3s, helps the brain maintain a healthy lipid balance and promotes flexibility in brain cells making it easier for information to pass between them. Omega-3s are found in cold water fish like salmon and sardines, as well as walnuts, almonds, avocados, soy beans and flax seeds. It is important to know that the body cannot manufacture EFAs, we can only get them by ingesting them. Our brain and the rest of our body must have these fats in order to regenerate and produce new cells.
As the brain ages, neurons (nerve cells in the brain) become susceptible to oxidative stress. Eating foods that are high in anti-oxidants can help protect these cells. Many fruits, vegetables and nuts are high in antioxidants. The USDA created a rating scale of Oxygen Radical Absorbance Capacity, or ORAC units. Berries, black plums, cooked artichokes, walnuts, black beans, kidney beans, unsweetened cocoa powder and ground cloves are some of the foods with the highest ORAC values.
Neuroscientist Jim Joseph headed a series of studies on antioxidants at the USDA Human Research Center on Aging. He discovered that adult to middle-aged rats that were given food with extracts of strawberry and spinach did not experience age-related cognitive decline like the rats in the study that received standard food. Later studies used mice that carried a genetic mutation leading to increased amounts of the Amyloid plaques in their brain that are linked to Alzheimer’s Disease. Some rodents were fed extracts of blueberries in their food for eight months, while the others were fed regular food. They were all tested after 12 months and the rats that were fed blueberries out-performed their counter parts. The amount of plaques did not differ between the two groups, but the blueberry-fed did not display any plaques-related decline. They also performed at the same level as a control group who did not have the genetic mutation.
This is by no means a comprehensive discussion of nutrition and the brain. Certain vitamins and minerals play an important role in brain health as well. The effectiveness of supplements is a much debated topic and the list of foods that are not beneficial to the brain is significant. Hopefully, though you have gained a better understanding of just how much what we eat impacts our brain, and the next time you hear “you are what you eat” you will have a new appreciation for the phrase.
Written by: BrianCoach Paulette Hicks