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The #1 Worst Eating Habit for Memory Loss

If you’re a typical American, you may be eating to forget.
FACT CHECKED BY Olivia Tarantino

Do you remember what you ate for breakfast and lunch yesterday? Odds are it was processed or highly refined and came tucked inside a package. That's because research published in BMJ found that ultra-processed foods make up 57.9% of Americans' daily energy intake and contribute 89.7% of the energy intake from added sugars.

That breakdown describes what's called the "Western Diet," a.k.a. "Standard American Diet." S.A.D. is an appropriate acronym for our country's typical eating style because it reflects the sorry state of Americans' health. Only 12% of Americans are considered metabolically healthy, based on National Health and Nutrition Examination Survey (NHANES) data. And what's bad for the body is also unhealthy for the brain.

The SAD truth is that a number of recent studies suggest that the number one worst eating habit for memory loss is the Standard American Diet, which is characterized by large amounts of foods high in calories and fat and low in nutritional value. And many of those studies link a poor diet and obesity that results in a person's increased risk of developing neurodegenerative conditions like Alzheimer's disease.

Read on for a review of some of the research that connects what you put in your mouth to your ability to keep your memory sharp, and to take care of your brain, don't miss Popular Foods That May Improve Brain Health.

Inflammatory oils are linked to cognitive decline.

fried foods

Omega-3 fatty acids are building blocks of the brain, but there's another fatty acid that's not so healthy for your gray matter: omega-6s. Found in cooking oils like soybean and sunflower oils that are used in a lot of processed foods, and in corn, soybeans, meats, and eggs, omega-6s are prevalent in the SAD diet. Too prevalent. Many experts believe the typical Western diet contains 10 times more omega-6s than omega-3s and that increasing the ratio of 6s to 3s doesn't bode well for our brains. One review of 14 studies in the Journal of Nutrition in Gerontology and Geriatrics suggested that an increase in the ratio of omega-6 to omega-3 fatty acids may atrophy the hippocampus and cause cognitive decline in old age.

Too much alcohol may lead to brain atrophy.

man pouring a glass of wine

Even drinking what's considered a moderate amount of alcohol can hurt your brain. One study in the journal Stroke by researchers at Johns Hopkins University's department of epidemiology found that having one drink a day can result in brain atrophy. Another study in PLOS Medicine showed that drinking more than seven drinks a week resulted in increased levels of iron in the brain, which has been linked with cognitive problems.

Diets high in processed foods can lead to memory deficits.

eating junk food and watching tv

A recent rodent experiment demonstrated what happens to the brain on a diet of highly refined carbohydrates. Scientists from Ohio State University fed a group of old rats a diet made up of the kind of carbohydrates found in processed human foods like potato chips. After four weeks, the researchers found that the aging rats showed signs of impaired memory as well as signs of increased inflammation in the hippocampus and amygdala regions of their brains, both of which play pivotal roles in memory.

"These findings indicate that consumption of a processed diet can produce significant and abrupt memory deficits—and in the aging population, rapid memory decline has a greater likelihood of progressing into neurodegenerative diseases such as Alzheimer's disease," said Ruth Barrientos, the Ohio State researcher and co-author of the study.

Eat This! Instead: Part of the experiment involved supplementing the rats' diet with fish oil, which ameliorated memory loss and inflammation in the old rats. By being aware of the dangers of processed foods and the benefits of fish oil, "maybe we can limit processed foods in our diets and increase consumption of foods that are rich in the omega-3 fatty acid DHA to either prevent or slow that progression" of memory loss, Barrientos said.

 Surprising Side Effects of Taking Fish Oil Supplements After 50

High sugar intake can lead to memory problems, lower brain volume, and dementia.

sugary junk food

Two other hallmarks of the Standard American Diet are saturated fat and added sugars. Saturated fats, like those in butter, cheeses, meats, full-fat dairy, and trans fats found in fried foods and many packaged baked goods, have been associated with memory problems, lower brain volume, and dementia, according to a review in the Neurobiology of Aging.

Even more problematic may be our country's addition to added sugars. As an reader, you are aware of the link between a diet high in sugary carbohydrates and type 2 diabetes. But did you know that chronic high blood sugar can also lead to dementia and other cognitive problems? In fact, because of that some doctors and researchers have nicknamed Alzheimer's disease "type 3" diabetes.

A study in the journal Diabetologia monitored the HbA1c scores of more than 5,000 men and women over roughly 8 years. HbA1c or hemoglobin A1C is a blood test that measures your average blood sugar levels over a 3-month period and is commonly used to diagnose and manage prediabetes and type 2 diabetes. Analyzing those blood tests, researchers found that each incremental rise in HbA1c score was significantly associated with an increased decline in scores of cognitive ability.

If you haven't had an HbA1c blood test yet, ask your doctor to prescribe one. You may learn that you are one of the approximately 96 million Americans with prediabetes, 80% of whom don't know it.

Jeff Csatari
Jeff Csatari, a contributing writer for Eat This, Not That!, is responsible for editing Galvanized Media books and magazines and for advising journalism students through the Zinczenko New Media Center at Moravian University in Bethlehem, PA. Read more about Jeff