While the temptation of French fries washed down with soda or a cold beer is real, new evidence shows those looking to enhance memory and focus might consider eliminating these foods from their diet.

Nutritional psychiatrist, Harvard Medical School faculty member, and author of This Is Your Brain on Food, Uma Naidoo, reveals that gut bacteria can trigger metabolic processes and brain inflammation that impact memory. Studies show that the likelihood of experiencing dementia may be reduced by avoiding foods that can compromise gut bacteria and weaken memory and focus, including:

Added Sugars

A high-sugar diet can lead to excess glucose in the brain, which has been linked to memory impairments and reduced plasticity of the hippocampus the part of the brain controlling memory. Processed foods, sugary drinks, and baked goods can be loaded with added sugars and flood the brain with too much glucose. The American Heart Association recommends that women consume no more than 25 grams of added sugar per day, and men stay under 36 grams added sugar per day.

Fried Foods

While tempting, guilty pleasures like French fries, fried chicken, or anything deep friend, cause inflammation which can damage the blood vessels that supply the brain. Abundant research has linked diets high in fried foods with lower scores in learning and memory, as well as depression.

High-glycemic Carbohydrates

White bread, pasta, potatoes, white rice, and other foods made from refined flour are processed the same way the body processes sugar and raise the risk for depression and cognitive issues. When it comes to carbs, choose whole grains and high-fiber foods that rank low on the glycemic index.


Instead of completely avoiding alcohol, drink in moderation. A 2018 study in the British Medical Journal reported that people who had abstained from alcohol completely, or who consumed more than 14 drinks per week, had a higher risk of dementia compared to those who drank alcohol in moderation.


The preservatives that are often used in cured meats like salami, bacon, and sausage alter gut bacteria and have been connected to depression and bipolar disorder. If you have to indulge, seek out those made with buckwheat flour, which is used as a filler and contains important antioxidants.

Authored by Zach Meeker, Research Assistant for Midwest Orthopaedics at Rush University Medical Center

References: Yamashita T, Kasahara K, Emoto T, Matsumoto T, Mizoguchi T, Kitano N, Sasaki N, Hirata K. Intestinal Immunity and Gut Microbiota as Therapeutic Targets for Preventing Atherosclerotic Cardiovascular Diseases. Circ J. 2015;79(9):1882-90. doi: 10.1253/circj.CJ-15-0526. Epub 2015 Jul 22. PMID: 26212124 Sabia S., Fayosse A., Dumurgier J., Dugravot A., Akbaraly T., Britton A, et. al. Alcohol consumption and risk of dementia: 23 year follow up of Whitehall II cohort study. BMJ 2018; 362:k2927

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