What you eat can help keep your
heart and arteries healthy—or lead to excessive weight, high blood
pressure, and high blood cholesterol—three key factors that increase
the risk of developing cardiovascular disease, according to the
National Heart, Lung and Blood Institute. Based on the best available
scientific evidence, the American Heart Association (AHA) recommends a
diet that includes a variety of fruits, vegetables, and grains, while
limiting consumption of saturated fat and sodium. Fruits and vegetables have lots of antioxidants such as vitamin C
and vitamin A that neutralize free radicals and may prevent oxidation
in the arteries, dietary experts say. Fruits and vegetables also
contain plenty of soluble fiber, a substance that has been shown to
reduce blood cholesterol levels, which is healthy for the endothelium.
Breads, cereals, and other grain foods, which provide complex
carbohydrates, vitamins, minerals, and fiber, are associated with a
decreased risk of cardiovascular disease, according to the AHA Dietary
Guidelines. However, some studies suggest eating less sugar, breads, and
other simple and complex carbohydrates can lower blood insulin levels
and decrease body fat and weight—three factors that are linked to an
increased risk of heart disease and stroke. In recent years, a number
of dietary recommendations based on these findings have become popular
and are currently catching the public’s awareness. While contentious,
these are important issues and long-term studies are required to
determine the risks and benefits of such diets, Dr. Lakatta says.
Saturated
fats are usually solid at room temperature. These fats are primarily
found in animal foods like meat, poultry, and dairy products like
butter. Saturated fats tend to raise levels of “bad” low-density
lipoprotein (LDL) and increase the risk of atherosclerosis. In fact,
within 2 hours of eating a high saturated fat meal, endothelial cells
don’t work as well. Such meals can cause a temporary 50 percent dip in
endothelial function, even in healthy young people who have no risk
factors for atherosclerosis, Dr. Lakatta says. In addition to saturated fats, some scientists are concerned about
trans-fatty acids—unsaturated fats that have been artificially
solidified by food manufacturers in a process called hydrogenation to
make products like margarine and vegetable shortenings. These
scientists suspect that trans-fatty acids, which are often described as
hydrogenated or partially hydrogenated fats on many food labels, are
more damaging to the heart and arteries than saturated fats.
They’ve concluded that one type of polyunsaturated fat—omega-3 fatty acid—found in fish may
promote several things that improve endothelial function, including
increasing nitric oxide production, slashing the production of free
radicals and other substances that cause inflammation, and boosting HDL
cholesterol levels. Fish such as salmon, herring, and mackerel are good
sources of omega-3s. Control over the condition of our arteries may also lie in how
much salt we consume. In cultures where little sodium (in the form of
salt) is consumed, blood pressures do not rise with age. Cultural
differences have also been found in arterial stiffness. One study
compared rural and urban populations in China. The urban population
consumed much higher levels of sodium than the rural groups. And they
had stiffer arteries. Other researchers found that sodium appears to
accelerate age-associated stiffening of arteries. In particular, sodium
promotes thickening of aging arterial walls, reduces the amount of
nitric oxide available to endothelial cells, and promotes the formation
of oxygen free radicals. But shifting to a low sodium diet, research
suggests, can begin to diminish arterial stiffness in as little as 2
weeks.
Most of the sodium in your diet comes from processed foods. The
remaining is added at the table and while cooking. Scientists who study
this issue suggest limiting the amount of sodium that you consume from
all these sources to no more than 1,500 milligrams (mg) each day (an
average American adult consumes about 3,300 milligrams daily). They
recommend reading food labels carefully and buying foods that say
“reduced sodium,” “low in sodium,” “sodium free,” or “no salt added.”
Some dietitians suggest seasoning foods with herbs and spices like
oregano, onion powder, or garlic instead of sodium.
Scientists suspect the more lifestyle changes, including diet and
exercise, you can incorporate into your life, the better off your
arteries will be, because these interventions work independently as
well as in unison to promote the vitality of endothelial cells and
contribute to reducing the risk of cardiovascular disease.
Excerpted from "Aging Hearts and Arteries" by the National Institute on Aging of the National Institutes of Health.