Before you cut into a big T-bone steak with French fries, here is some food for thought: Research suggests that what we eat might have an impact on our ability to remember and our likelihood of developing dementia as we age.
Take that steak you’re about to slice into, for example. It’s loaded with saturated fat, which is known to raise blood levels of unhealthy low-density lipoprotein (LDL) cholesterol. Other kinds of fats, such as trans fats, do the same thing to LDL and this cholesterol can build up in, and damage, arteries. We know that LDL is bad for your heart, but now evidence shows that it can be bad for your brain, too.
Beta-amyloid plaque in the brain
Diets high in cholesterol and fat might speed up the formation of beta-amyloid plaques in the brain. These sticky protein clusters are blamed for much of the damage that occurs in the brains of people with Alzheimer’s.
The diet and memory connection
Evidence of this effect are the results of a study conducted by researchers at Brigham and Women’s Hospital. Women in the study who ate the most saturated fats from foods such as red meat and butter performed worse on tests of thinking and memory than women who ate the lowest amounts of these fats.
The exact reason for the connection between diets high in saturated and trans fats and poorer memory isn’t entirely clear, but the relationship may be mediated by a gene called apolipoprotein E, or APOE. This gene is associated with the amount of cholesterol in your blood, and people with a variation of this gene, called APOE e4 are at greater risk for Alzheimer’s disease. About 65% of individuals who wind up with dementia due to Alzheimer’s disease in their 60s and 70s have that gene.
How does the APOE e4 gene contribute to dementia?
Researchers aren’t exactly sure, but they have discovered that people with this genetic variation have a greater number of sticky protein clumps, called beta-amyloid plaques, in the brain. These plaque deposits, which are associated with the destruction of brain cells, are a hallmark of Alzheimer’s disease.
The connection is a little clearer when it comes to memory loss that’s related to blood vessel damage. The buildup of cholesterol plaques in brain blood vessels can damage brain tissue, either through small blockages that cause silent strokes, or a larger, more catastrophic stroke. Either way, brain cells are deprived of the oxygen-rich blood they need to function normally, which can compromise thinking and memory.
Other ways to protect memory as you age
- Diet isn’t the only way to preserve memory. If you want to keep your brain sharp as you get older, follow these recommendations:
- Control your cholesterol, blood sugar, and blood pressure levels with diet, exercise, and medicines such as statins or beta-blockers if you need them.
- Quit smoking. One review of studies associated smoking with a significantly higher risk for Alzheimer’s disease.
- Get outside for a brisk daily walk. Exercising three or more times a week has been linked to a lower risk for dementia.
- Work with your doctor to keep your weight in a healthy range for your height. A body mass index (BMI) between 18.5 and 24.9 is considered normal.