What affects the heart also affects the brain

The recipe for heart health rattles off the tongue as easily as the Pledge of Allegiance: fill your plate with fruits and vegetables, get plenty of exercise and steer clear of artery-clogging evils such as trans fats. But while Americans are conditioned to strive for clean arteries, we rarely apply the same logic to the blood vessels in our brains. Yet, both heart and brain rely on healthy circulation.

Indeed, the brain is a voracious consumer of the body’s blood and oxygen supply. Of the blood flow from the heart, roughly 20 percent goes straight to the head. Although a tissue-paper thin barrier protects the brain from direct contact with blood (a safeguard against potentially harm-ful toxins), nutrients easily pass through the blood-brain barrier. Circulation is what connects heart disease to dementia, says Decker Weiss, ND, a naturopathic physician at the Arizona Heart Hospital in Phoenix. “The same things that help the heart to beat help the brain to work.”

Factors that impede blood flow to the heart, such as high cholesterol, also slow blood flow to the brain. “When you’re looking at heart disease and dementia, what you really have is micro and macro circulation issues,” Weiss says. In other words, what damages large arteries like those in the heart also affects the tiny ones such as those found in the brain–only sooner because of their size. As examples he points to arteriosclerosis (hardening of the arteries), hypertension and diabetes. “They are all systemic diseases,” he says. “The smallest blood vessels are affected first, including those in the brain.”

Experts know that vascular disease, such as stroke and diabetes, ups a person’s risk of Alzheimer’s disease. But the exact relationship between the two problems is murky. Vascular disease and Alzheimer’s clearly overlap, according to Kenneth Langa, MD, PhD, a dementia expert at the University of Michigan, Ann Arbor. “Tantalizing research says these two things are not just coexisting but that the vascular risks actually cause Alzheimer’s,” he says.

Recent long-term, observational studies support the idea that heart disease in middle age spells trouble for the brain. Rachel Whitmer, PhD, a research scientist at the Kaiser Permanente Division of Research in Oakland, Calif., studies the connections between midlife risk factors for heart disease and dementia. For one of her most recent studies, published last January in the journal Neurology, Whitmer and colleagues traced the medical records of nearly 9,000 seniors (all Kaiser patients) from present day back to “midlife,” when the patients were between the ages of 40 and 44. They compared who had heart disease risk factors at middle age with who’d been diagnosed with dementia. What they found supports the heart-brain connection.

Each one of the four heart-disease risk factors the researchers charted carried a significant risk of dementia. Participants with hypertension had a 24 percent increase in risk, smokers a 26 percent increase, those with high cholesterol a 42 percent increase and diabetes a 46 percent increase. “I was surprised by the strength of these findings and the fact that we found an effect for all four risk factors,” Whitmer says, “given the fact that all the patients were members of a health maintenance organization and probably received corresponding treatments.”

Likewise, Langa notes a connection between high cholesterol at midlife and an elevated risk of Alzheimer’s published in a review study last year in the Journal of the American Medical Association (JAMA). The two defining characteristics of Alzheimer’s disease are amyloid plaques, (protein fragments that clump outside the brain’s nerve cells) and neurofibrillary tangles (twisted strands of a different protein inside brain cells). Langa believes high cholesterol leads to the buildup of the protein that eventually becomes amyloid plaque.

“Early evidence shows that too much cholesterol causes changes in how brain cells process this protein,” he says. “High levels of cholesterol might make brain cells more prone to Alzheimer’s.”

Langa says his research armed him with new tools to coerce his heart-disease patients into eating right and exercising. “For some people, the idea that brain health is connected to heart health is a radical idea,” he says. During office visits, he tells his patients to do what their mothers and doctors have been telling them forever–watch their diet and stay active. “It’s not rocket science,” he says. “The key is to remember you’re getting two bangs for the buck. You’ll not only prevent a heart attack, but also keep your mind sharp as you age.” While Langa’s advice is a good starting place, consider acting on one or more of the following tips to avoid a future brain drain.

Next: Five steps to keep your wits