Five Foods That Negatively Impact Your Brain Health

Artificial sweeteners and fried and low-fiber foods aren't doing your thinker any good.

Your brain is one of the most miraculous organs in your body—it controls everything from your memories and emotions to your ability to breathe and even see. That's why it's so important to make sure you're doing everything you can to take care of it. One of the best ways to do so is to eat a healthy diet, as certain deleterious foods can negatively impact your thinker's health. In fact, our brain uses roughly 20 percent of our caloric needs, and eating well has a direct link to our mood, memory, and focus, notes Carissa Galloway, R.D.N. "Eating poorly can cause short-term issues like brain fog and long-term issues like chronic inflammation of brain cells," she says.

Unfortunately, the standard American diet (SAD), which is high in red and processed meats, refined sugars, processed oils, excess sodium, chemical additives, and preservatives, is not conducive to brain health. "Processed foods, in particular, are often low in fiber, digested quickly, and can cause large swings in our blood sugar levels that can increase inflammation and oxidative stress and have many other deleterious effects upon our brain health," warns Scott Kaiser, M.D., a board certified geriatrician and Director of Geriatric Cognitive Health for the Pacific Neuroscience Institute at Providence Saint John's Health Center in Santa Monica, California.

If you're looking to boost your brain health, here are the foods you should avoid, according to our experts.

assorted take out junk food on wood table
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High Fructose Corn Syrup (HFCS)

An artificial sugar derived from corn syrup, HFCS causes major issues when it enters the bloodstream in excess, warns Galloway. "Excess sugar in the bloodstream can interact with proteins to form harmful compounds known as AGEs (advanced glycation end products) that contribute to inflammation of blood vessels and other body tissues," she says. "Over time, chronic inflammation leads to cardiovascular disease, stroke, and degenerative brain diseases."


This artificial sweetener is found in thousands of products, including diet soft drinks, chewing gum, yogurt, salad dressings, medications, cough drops, and even multivitamins. Consuming aspartame can be dangerous, especially for the brain, notes naturopathic doctor and clinical nutritionist David Friedman, N.D., D.C., as it can elevate the levels of phenylalanine and aspartic acid—compounds that can inhibit the neurotransmitters, dopamine, norepinephrine, and serotonin, which are known regulators of neurophysiological activity. "Not only is aspartame a chemical stressor that may increase oxidative stress in the brain, but it is able to cross the blood-brain barrier and disrupt the production of neurotransmitters," he says.

Fried Foods

You probably know that fried foods are considered a guilty pleasure. In other words, they may taste good, but they provide little-to-no nutrients to your body. "Not only do fried foods lead to weight gain and increased blood cholesterol levels, but they also can form AGEs," says Galloway. "As we have learned more about brain health, we've better understood the connection between vascular health and the health of our brain." Avoiding fried foods will help your heart and your brain.

Low-Fiber Foods

Although low-fiber foods might not be as detrimental for brain health as others, they are not the best choice, according to Galloway. "High-fiber foods slow the absorption of the foods you eat, leading to a lower insulin response by your body, which over time lowers your risk of diabetes and inflammation," she says. "Second and similarly, consuming fiber helps you feel fuller longer, which leads to less risk of overeating—which leads to less risk of being overweight. This supports your overall health and reduces your chances of developing diabetes and heart disease." She recommends incorporating high-fiber foods like beans, broccoli, avocados, and whole grains into your diet as much as possible and limiting your intake of low-fiber options, like white bread, canned vegetables, and peeled potatoes.

White Flour

"Milling techniques involved in creating white flour remove the healthful nutrient-rich bran and germ, which contains dietary fiber, B vitamins, iron, magnesium, and vitamin E. All that is left is the starchy endosperm, which extends the grains' shelf life," says Dr. Friedman. "White processed flour also has a high glycemic load, meaning it raises your blood sugar levels quickly, and can impair brain function and put you at a greater risk of dementia and Alzheimer's disease." Instead of consuming products made from white processed flour, he suggests opting for flours milled from whole grains, quinoa, almond, buckwheat, or coconut.

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