New studies show resolving heart problems now may preserve brain function later.
The heart and brain occupy different spaces within our bodies, but they have strikingly similar needs—including a steady supply of oxygen-rich blood and a network of open, unobstructed blood vessels to deliver it.
Healthy arteries are essential for both organs—heart and brain—to function properly. The most common disease to affect the arteries is atherosclerosis. Cholesterol-filled plaques in the arteries of the heart can rupture, suddenly stopping blood flow to a part of the heart and causing a heart attack. Atherosclerosis of the heart also increases the chance of developing the irregular heart rhythm called atrial fibrillation, as well as heart failure.
When plaques in the arteries of the brain rupture, they can stop blood flow to a part of the brain and cause an ischemic stroke. A temporary blockage in the brain is called a transient ischemic attack (TIA) or “mini” stroke. TIAs can herald a real stroke ahead. Another form of stroke that affects the brain’s small blood vessels is the lacunar stroke, which is more common in people with high blood pressure.
Looking beyond strokes
While strokes are one obvious cause of diminished cognitive function, a study released this January in JAMA Neurology found that older women with heart disease (including such conditions as atrial fibrillation, coronary artery disease, and heart failure) had triple the risk for mild cognitive impairment (a decline in mental abilities that can precede dementia)—even when they hadn’t had a stroke.
Another study, this one published in March in Annals of Internal Medicine, linked cognitive decline to atrial fibrillation. Although atrial fibrillation can increase your stroke risk fivefold, this study found that cognitive impairment occurred even in people who’d never had a stroke. While it’s possible that participants may have had multiple small “silent” strokes, “there appears to be an association between atrial fibrillation and cognitive impairment that occurs even in people who have not had strokes,” says study author Dr. Jeremy Ruskin, director of the Cardiac Arrhythmia Service at Harvard-affiliated Massachusetts General Hospital.
Doctors do believe shared risk factors may be at least partly to blame for cognitive declines in people with heart disease. “Diseases that affect both the brain and the heart have been associated with similar risk factors—diabetes, high cholesterol, high blood pressure, smoking,” says Dr. Gad Marshall, assistant professor of neurology at Harvard Medical School.
Protect your heart and mind
Taking steps to avoid heart problems can also help ward off mental decline. “My recommendations for preventing dementia are the same as those for preventing cardiovascular disease and stroke,” Dr. Ruskin says.
Those recommendations include the following:
Bring down your numbers. High blood pressure is the single biggest contributor to strokes. Get your blood pressure measured at least once a year, and if it’s elevated, work with your doctor to lower it. Also have your cholesterol and blood sugar levels checked. High cholesterol levels and diabetes have been linked to both dementia and heart disease risk.
Eat healthy. The diet that seems to have the greatest impact on heart and brain health is the Mediterranean eating plan, which goes heavy on fruits, vegetables, whole grains, and fish. “Having more fish and less red meat, and more vegetables and complex grains—that’s good for your brain. Studies comparing the Mediterranean-style diet to a more traditional ‘Western’-style diet have shown benefit in preventing dementia or slowing existing cognitive decline,” Dr. Marshall says. Limiting sodium to 2,300 mg or less per day also may help bring down high blood pressure.
Exercise. The benefits of exercise on the heart and brain are very clear. Staying active improves the health of both organs in several ways—including by lowering cholesterol levels, contributing to weight loss, reducing inflammation, and improving blood vessel health. Exercise also promotes brain-derived neurotrophic factor, a protein induced by physical activity that’s linked to neuron development. The American Heart Association recommends exercising at a moderately intense pace for at least 30 minutes on most days of the week. Add 30 minutes to your daily routine if you need to take off extra weight.
Quit smoking. Compared with nonsmokers, smokers are up to four times as likely to develop heart disease and twice as likely to have a stroke. Quitting isn’t easy, but today there are more techniques and tools to help you than ever before. Ask your doctor to recommend stop-smoking aids and programs in your area.
Get checked for atrial fibrillation. Atrial fibrillation can be a silent condition, without symptoms. Your doctor can tell if you have atrial fibrillation with an examination of your heart and an electrocardiogram. If you have heart disease, high blood pressure, or a family history of atrial fibrillation, ask your doctor about your risk of getting atrial fibrillation.