Is Your Brain Shrinking?

A female doctor showing a brain scan to a patient
Ariel Skelley/Getty Images

Could poor health actually shrink your brain?

The answer may be yes, especially if you have two or more risk factors for heart disease, according to the findings of a new study of middle-aged adults.

To find out more, read B12 Deficiency Linked to Brain Shrinkage

Researchers gave MRI brain scans and thinking skills tests to more than 2,100 women and men ages 37 to 55.

None of the participants had diabetes or neurological conditions, such as stroke or dementia, but some were considered by researchers as “metabolically unhealthy” — meaning they had two or more factors that increase the risk for heart disease, such as elevated levels of blood pressure, blood sugar or cholesterol.

Participants who were metabolically unhealthy, obese or both, showed evidence of brain decline. MRI scans showed they had lower total cerebral brain volume – literally, a smaller brain – than metabolically healthier adults.

Those who were both obese and metabolically unhealthy also showed more of the type of damage to the brain’s white matter that has been linked to Alzheimer’s disease, researchers reported.

Obesity was also linked to lower scores on tests of thinking skills, including verbal memory and abstract reasoning.

Why is a smaller brain worrisome? Because it indicates decreased blood flow, which can lead to the loss of brain neurons and supporting cells, according to lead researcher Rebecca Angoff, M.D., a clinical fellow in medicine at Harvard Medical School’s Beth Israel Deaconess Medical Center in Boston.

Nearly 4 in 10 Americans are considered obese and almost 25 percent of adults are estimated to be metabolically unhealthy, according to the American Heart Association. With heart health linked to brain health, Angoff says the message of the study’s findings is clear: “This is further ammunition for health care workers to convince patients to change their lifestyles.”

This new study supports a large body of evidence that what's good for your heart is also good for your brain. A new report from the AARP-founded Global Council on Brain Health (GCBH) — a group of scientists, health care professionals and policy experts — confirms that heart health and brain health are strongly connected.

What can you do?

  • Eat your veggies. More fruits, whole grains and fish also help both your heart and brain.
  • Get moving. Studies show regular, moderate physical activity (a brisk daily walk, for example) can improve brain function in people age 50-plus.
  • Talk to your doctor. Getting your high blood pressure, blood sugar or cholesterol under control can help improve blood flow to the brain.

Want to learn more? Check out these stories in Staying Sharp:
A Healthy Heart Can Boost Brain Health
Mediterranean Diet Helps Protect Brain as Well as Body

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