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.
But researchers have found other types of fats may be
beneficial. Monounsaturated fats, found mainly in plant foods such as peanuts
and olives, help lower LDL cholesterol. Like polyunsaturated fats,
monounsaturated fats are usually liquid at room temperature.
Polyunsaturated fats, found in fish, nuts, and dark leafy
vegetables, have been getting a lot of
attention from scientists in the past few years. 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.
(From ‘Aging Hearts and Arteries, a Scientific
Quest’, a publication of US National Institute of Health)
