Dr. Anne-Marie Kaulfers, assistant professor of pediatrics at the University of South Alabama College of Medicine and a pediatric endocrinologist with USA Physicians Group, said what we eat influences how we think and learn.
A protein called the brain-derived neurotrophic factor (BDNF) plays an important role in the survival, maintenance and growth of our brain cells. Diets high in saturated fats (such as butter, ghee, lard, coconut oil, cottonseed oil, dairy, and fatty meats) and simple sugars (such as juice, candy, soda, sports drinks) have been shown to reduce BDNF levels. Interference with this protein reduces synaptic plasticity in the brain, which is important for learning and memory.
In addition, poor diets suggest poorer academic performance when you are a child and more decay of the brain structure as an adult.
There also may be a connection between what you eat and Alzheimer’s disease, a severe, age-related decline in memory and cognitive functioning.
In 2005, researchers looked at the brains of people with Alzheimer’s disease. They found that their brains had very low levels of insulin, a hormone that helps the body use and store the blood sugar it gets from food.
Obesity and high-fat diets decrease the ability of insulin to get to the brain. Several parts of the brain use insulin, including the cerebral cortex, which affects how we think; the hippocampus, which controls our memory; the hypothalamus, which controls our appetite, energy level, weight gain or loss; and the amygdala, which controls stress.
“Without enough insulin in the brain, all of these systems suffer,” Dr. Kaulfers said. “Brain insulin deficiency and resistance could account for the structural, molecular, and biochemical lesions that correlate with the cognitive decline and dementia in Alzheimer’s disease.”
Insulin, although a necessity, can also confuse our body’s appetite hormones. “If you eat high fat, high sugar foods, the excessive sugar goes right to the pleasure center of the brain and causes dopamine to be released,” Dr. Kaulfers said. “This causes an exaggerated emotional response and reduced ability to stay away from that food, ultimately leading to compulsive eating.”
Dr. Kaulfers also warns of “diet” drinks and “low fat” foods because they often lead to weight gain. That’s because diet drinks, which are made with artificial sweeteners, also cause an excessive release of dopamine. “This causes us to crave real sugar, and eating the real sugar causes the weight gain,” she said. “Low fat foods add in extra sugar or artificial sweeteners, leading to the same process.”
Dr. Kaulfers said there are some foods that are beneficial in protecting the brain. These include:
• Antioxidant-rich foods: fruits, veggies, nuts, seeds, grains, olive oil, and fresh spices
• Alcohol/wine: Light and moderate drinking has proven to have a protective effect against cognitive impairment and dementia. Wine is better than beer or hard liquor, since wine has natural antioxidants.
• Fiber: improves alertness and decreases perceived stress
• Omega-3 fatty acids: fish, salmon, flax seeds, krill, chia, kiwi, butternuts, walnuts
• Flavanoids: cocoa, green tea, ginkgo tree, citrus fruits, red wine, dark chocolate (70+ percent cocoa)
Dr. Kaulfers recently gave an overview of this topic at the May Med School Café lecture. To view the lecture in its entirety, click here.