Heart Beat: March 2018
More Findings Confirm How Heart Function Impacts Brain Health
New research reveals some insight into why some people live long lives with their memory intact. The brain is highly dependent on a steady flow of oxygenated blood. When the heart is unable to meet the brain’s needs—for example, when heart failure weakens the heart’s pumping power—brain function is impaired. What about patients who don’t have heart failure? A study published online Nov. 8, 2017, in Neurology included 314 healthy participants, 39 percent of whom had mild cognitive impairment, and the remainder had normal cognitive function. When their brains were scanned with MRI, those with a lower cardiac output showed reduced blood flow to the left and right temporal lobes—areas responsible for memory processing and the location where Alzheimer’s disease starts. The researchers speculated that the network of very small blood vessels in the temporal lobes might be vulnerable to reduced blood flow from the heart. These findings reinforce that raising cardiac output with exercise and medications may help maintain brain health, as well as heart health. They also suggest that increasing cardiac output may help prevent early memory loss from progressing.
Blood Thinner Stands Out in Its Ability to Prevent Strokes from Atrial Fibrillation
Patients with atrial fibrillation are prescribed blood thinners to prevent blood from pooling in the heart and forming blood clots that could cause a catastrophic stroke if ejected into the bloodstream. Until a few years ago, warfarin (Coumadin) was the only blood thinner available to these patients. But the development of direct oral anticoagulants (DOACs) in recent years made stroke prevention easier to swallow. Unlike warfarin, which requires frequent and regular blood testing to ensure proper levels of the drug are being maintained, DOACs require no such monitoring. In a short time, they also proved to have superior stroke-prevention ability in patients with atrial fibrillation. Now a meta-analysis of 23 randomized trials involving about 95,000 patients, published online Nov. 28, 2017, in BMJ, showed that the DOAC apixaban (Eliquis) was more effective than edoxaban (Savaysa), rivaroxaban (Xarelto), dabigatran (Pradaxa) and warfarin at preventing strokes, pulmonary emboli, heart attacks and death from all causes. It was also the least likely to cause gastrointestinal bleeding.
Mediterranean Diet Associated with a Longer Life, but Only Up to a Point
A diet rich in fruits, vegetables, whole grains, legumes, olive oil and seafood and scarce in meat and dairy products—the type of diet favored in Mediterranean countries—has been associated with a healthier heart and longer life. That’s why this diet is recommended to prevent coronary artery disease or lessen its risks. But after a patient with heart failure experiences a worsening of their condition that requires medical intervention, sticking with a Mediterranean diet may no longer be beneficial. As explained in the January 2018 issue of JACC: Heart Failure, Spanish researchers polled 991 heart failure patients about their diets. Of these, 53 percent adhered to a Mediterranean diet, and 47 percent did not. After following both groups for up to 3.4 years, the researchers found the choice of diet made no difference in survival. However, the heart-failure patients who followed the Mediterranean diet had fewer hospitalizations.
Chocolate and Nuts As Heart Medicine? Yes, but There’s a Trade-Off
Researchers investigating the effects of almonds, chocolate and cocoa on overweight or obese patients with elevated blood cholesterol levels found these popular foods had some benefit. Participants followed four separate regimes for four weeks: an average American diet; one-third cup of almonds a day; 2 tablespoons of cocoa powder plus one-quarter cup of dark chocolate a day; or almonds plus the cocoa powder and chocolate. Compared with no almonds or chocolate, the almond diet reduced LDL cholesterol by 7 percent and total cholesterol by 4 percent; the almonds plus chocolate diet decreased small dense LDL by 12 percent. It must be noted that the almonds were eaten in place of butter and cheese—not in addition to them, and the dark chocolate may have replaced less-healthful sugary foods.