How is heart health related to cognitive health?

We have long known that the diseases and conditions that clog the arteries of the heart also clog the arteries of the rest of the body, including the brain. It all boils down to damage of the arteries, the blood vessels that are critical for blood flow and oxygen delivery to the organs. Arterial damage leads to arterial blockages, which lead to heart disease and heart attacks, strokes, peripheral vascular disease, and vascular dementia.

Meanwhile, Alzheimer’s disease used to be thought of as a different process, because the brains of people with Alzheimer’s seemed to be full of tangled tube-shaped proteins (neurofibrillary tangles). However, more and more research is linking Alzheimer’s dementia to the same risk factors that cause heart disease, strokes, peripheral vascular disease, and vascular dementias: obesity, high blood pressure, high cholesterol, and diabetes.

The evidence is substantial: studies show that people with these risk factors are significantly more likely to develop Alzheimer’s disease. Meanwhile, studies also show that people with Alzheimer’s disease have significantly reduced brain blood flow, and autopsy studies show that brains affected by Alzheimer’s can also have significant vascular damage.

Researchers are now focusing on why this is — what is the connection? It appears that good brain blood flow is key for clearing those tubular proteins that can accumulate and become tangled in the brains of Alzheimer’s patients, and so one solid hypothesis is that anything that reduces brain blood flow can increase the risk for Alzheimer’s, and conversely, anything that increases blood flow can reduce the risk for Alzheimer’s.

What’s the take-home message?

Even if someone has a family history of dementia, particularly Alzheimer’s dementia, and even if they already have mild cognitive impairment (forgetfulness, confusion), they can still reduce their risk of developing dementia by simply living a heart-healthy lifestyle. That means a minimum of 150 minutes per week of activity, a plant-based diet aiming for at least five servings of fruits and vegetables daily, avoiding toxic foods like processed grains, added sugars, sodium, and saturated fats, avoiding or quitting smoking, and curbing alcohol use as much as possible.