Could the right diet help prevent heart disease?
It certainly could. Ask a doctor or a dietitian about the value of good nutrition, and you're bound to get a lesson on the heart. Indeed, nutrition experts seem to be fixated on the organ. "This is good for the heart," they'll say, usually followed with, "And this is bad for the heart." There's a reason for all of this heart-talk: Cardiovascular disease is the number one killer in the United States, and many Americans could steer clear of it by making a few simple changes in their eating habits early on.
Why does your diet matter so much to your heart? Mainly because your blood cholesterol matters. Your choices at the dinner table and the drive-through can help lower the amount of the cholesterol in your blood -- and your risks of heart disease and stroke -- or send that level soaring. (Almost all heart attacks and strokes start when cholesterol sticks to the lining of blood vessels, a process called atherosclerosis, or hardening of the arteries.) Those food choices will also determine whether you get the vitamins, minerals, and other nutrients that can keep your heart and arteries strong and protect them from damage.
What's the best diet for preventing heart disease?
No single meal plan or menu is best for safeguarding the heart. But there are guidelines you can use to create a diet that's right for you. For some sound advice backed up by science, take a look at the current guidelines from the American Heart Association:
- Switch to a diet rich in "good fats" and low in "bad fats."
Make sure that fewer than 30 percent of your daily calories come from fat and that fewer than 7 percent come from saturated fat. If you take in 2,000 calories each day, that means you should draw the line at 67 grams of total fat; within that amount, you should limit saturated fats and avoid trans fats. This is the most important guideline, because nothing in your food -- not even cholesterol -- will raise the level of cholesterol in your bloodstream faster than saturated fat will. Some tips on identifying saturated fat: It is solid at room temperature, and the main dietary sources of it are animal products including beef, pork lard, poultry fat, butter, cream, and whole-milk dairy products. Some plant foods, such as coconut and palm oils, contain saturated fat, too.
You can check food labels to see how much fat and saturated fat you're about to get, but those figures don't tell the whole story. Fat comes in different varieties, some much more dangerous than others. In addition to limiting saturated fat, you should avoid trans fatty acids, a type of fat often found in stick margarine, fast foods, and mass-produced packaged foods like crackers and cookies. Trans fatty acids can increase the level of harmful cholesterol (LDL) in your blood while lowering the good cholesterol (HDL). (Good cholesterol helps clear other cholesterols from your blood.) One way to limit your consumption of trans fats: Read the ingredients lists on food labels, and bypass items that contain partially hydrogenated oils.
In contrast, monounsaturated fats (found in nuts and in olive, canola, and peanut oils) and polyunsaturated fats (found in safflower, corn, soybean, and cottonseed oils) may actually lower the amount of harmful cholesterol in your blood.
Furthermore, omega-3 fatty acids, a type of polyunsaturated fat found in nuts, flaxseed, and many types of fish, may help prevent the types of blood clots that can cause heart attacks and strokes. A number of studies have found that eating fish or shellfish once a week can cut the risk of dying from a sudden stroke or heart attack by more than 50 percent. The AHA now recommends eating at least two servings a week of fish high in omega-3s -- such as salmon, tuna, sardines or lake trout.
- Eat at least five servings of fruits and vegetables every day. Nine servings is even better. Many types of produce are rich in vitamins C, beta-carotene, and other antioxidants that may help prevent hardening of the arteries. Green leafy vegetables, peas, beans, and some fruits also contain folic acid, a nutrient that lowers the risk of heart attack or stroke in people who already have cholesterol building up in their arteries. Finally, many fruits and vegetables contain potassium, a mineral that both protects arteries and lowers blood pressure. A recent Harvard study of 43,738 men found that getting a high level of potassium reduced the risk of stroke by almost 40 percent.
- Eat at least six servings of grains a day, so that you get 25 to 30 grams of fiber daily. By selecting fiber-rich fruits and vegetables as well as whole grain breads and cereals, nuts, peas, and beans, you'll easily meet this important guideline. Soluble fiber -- the kind found in oat bran, oatmeal, beans, peas, citrus fruits, and strawberries -- can lower cholesterol. As a bonus, fiber may even cut down on how many calories you absorb from your meals.
Many studies have shown that this adds up to powerful protection for the heart. The Nurses' Health Study at Harvard, a dietary investigation of more than 68,000 women, found that those who ate the most fiber each day were 23 percent less likely to develop heart disease than were those who ate the least. In addition, a study recently published in the Journal of the American Medical Association found that young adults who ate large amounts of fiber were less likely to develop obesity and diabetes, two conditions strongly linked to heart disease.
- Get no more than 300 milligrams of cholesterol each day. Cholesterol, found only in animal products, is most abundant in meat, organ meats, full-fat dairy products, and eggs. The American Heart Association notes that you will probably need to limit your consumption of whole eggs, since a single egg yolk contains about 200 mg of cholesterol. Egg whites, on the other hand, are an excellent source of protein and have no cholesterol or fat.
- Limit your sodium consumption to 1,500 milligrams each day. In January 2010 the AHA reduced its recommended sodium intake levels from 2,300 mg to 1,500 mg per day. This advice may not apply to everyone, though. According to the Centers for Disease Control, roughly 70 percent of the US population is sensitive to salt. For them, cutting back could lead to a significant drop in blood pressure. For the rest, a low-sodium diet won't do much to protect the heart. To find out if you're salt sensitive, try a low-sodium diet (less than 1,500 mg per day) for two weeks and see if your pressure dips. Cutting back on sodium, of course, requires more than shunning the saltshaker; read labels on canned and other processed foods, which can be loaded with sodium.
- Drink sensibly. A small amount of alcohol each day may lower your blood pressure and boost your good cholesterol, but too much can actually destroy portions of heart muscle, increase bloodstream levels of triglycerides (a damaging kind of fat), and raise blood pressure. Many doctors say that a healthy limit is two drinks a day for men and one drink a day for women. If you're not a regular drinker, consult your doctor before adding alcohol to your diet.
Should I take any supplements to prevent heart disease?
The American Heart Association doesn't recommend it. While certain vitamins and minerals may promote heart health, there's no proof that supplements can ward off heart disease. In fact, a November 2004 report from the American Heart Association announced that vitamin E, previously thought to protect the heart, might actually be harmful in high doses.
You can get all the nutrients you need from a balanced diet. However, if there are days when you don't manage to eat enough fruits and vegetables, or if you have other reasons to be concerned about your diet, it's wise to take a daily multivitamin.
Can diet help treat existing heart trouble?
If your heart has already shown signs of stress, a healthy diet is more important than ever before. Consider the remarkable results of a French study recently published in Circulation: Journal of the American Heart Association. The study found that heart attack survivors on a so-called Mediterranean diet (rich in fruits, vegetables, cereals, and beans) were 50 percent to 70 percent less likely than patients on a typical Western diet to suffer another heart attack. The Mediterranean diet provided more fiber, vitamins, and monounsaturated fatty acids than did the Western diet and was also significantly lower in total fat.
What's the link between obesity and heart disease?
Extra weight can lead to high blood pressure, high cholesterol, and diabetes, all of which make heart disease much more likely. On average, overweight people develop heart disease about three years earlier than people of normal weight; extremely obese people tend to be about seven years ahead of schedule. Moreover, normal-weight adults with heart disease can expect to live to age 78, four years longer than obese patients. In endeavoring to control your weight, remember to combine your low-fat eating plan with regular exercise, which is another important measure for preventing heart disease.
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