A new Cleveland Clinic study finds people who eat a diet containing the common nutrient choline, which is found in animal products like eggs, liver or fatty fish, are not pre-disposed to heart disease by genetics alone. It’s also how your body breaks down choline that increases your risk.
Stanley Hazen, MD, PhD, of Cleveland Clinic’s departments of Cardiovascular Medicine and Cell Biology, led the study that appeared in the journal Nature.
“What we find is the level of choline in our diet is actually directly related to someone’s heart risk,” says Dr. Hazen, who heads the Section of Preventive Cardiology & Rehabilitation. Choline comes from the compound lecithin—found in many commercially baked goods, dietary supplements and even children’s vitamins.
The study examined clinical data from 1,875 patients who were referred for cardiac evaluation, as well as plasma samples from mice. When fed to mice, lecithin and choline were converted to a heart-disease forming product by the microscopic organisms that reside in our intestines, or “gut flora.” This promoted fatty plaque deposits to form within arteries (called atherosclerosis). In humans, higher blood levels of choline and the heart disease-forming microorganism products are strongly associated with increased cardiovascular disease risk.
“When two people both eat a similar diet but one gets heart disease and the other doesn’t, we currently think the cardiac disease develops because of their genetic differences; but our studies show that is only part of the equation,” Dr. Hazen explains. “Actually differences in gut flora metabolism of the diet from one person to another appear to have a big effect on whether one develops heart disease. Gut flora is a filter for our largest environmental exposure—what we eat.”
The study also found that while choline is considered a natural semi-essential vitamin, getting too much of this B-complex vitamin promoted atherosclerosis.
“Over the past few years, we have seen a huge increase in the addition of choline into multivitamins—even in those marketed to our children—yet it is the same substance that our study shows the gut flora can convert into something that has a direct, negative impact on heart disease risk by forming an atherosclerosis-causing by-product,” Dr. Hazen says.
He recommends checking your vitamin supplements (especially those marketed to increase brain health, weight loss and/or muscle growth) for choline, as well as watching what you eat.
“Follow a diet that’s low in fat,” he recommends. “And so animal products such as meat, eggs, cheese, liver, certain fatty fish – these are all high sources of this pre-cursor that can lead to heart disease.”
Dr. Hazen says this new knowledge may lead to advances in both prevention and treatment of heart disease.
“These studies suggest we can we can intelligently design a heart healthy yogurt or other form of probiotic for preventing heart disease in the future. It also appears there is a need for considering the risks vs. benefits of some commonly used supplements.”
Dr. Hazen’s research is funded by a $3.8 million grant from the National Institutes of Health.