Food labels tell you a great deal about the contents of foods, and they are a big help in making reasonable choices to limit the fat, sodium, and cholesterol in the foods you eat. Both the ingredients list and the nutri- tion facts panel are useful. By law, the ingredients list is in descending order of weight to give you an idea of the proportions of the ingredients in the package. The nutrition facts label tells you the number of serv- ings in the package, as well as the amount and percentage of recom- mended daily values, such as total fat, saturated fat, cholesterol, sodium, ?ber, and carbohydrates (including sugar). As the label tells you, these percentages are based on a diet of 2,000 calories a day. The label also tells you the ?ber and sugar content of the food. At the bottom of the panel, the percentages for vitamins A and C, calcium, and iron are listed (see the following section, “Nutrients”).
If you are concerned about heart disease, you will probably be pay- ing closest attention to the percentages of fat, saturated fat, and sodium. As a general rule, choose foods that are low in saturated fat; avoid foods containing trans fats and sodium. A daily value of 5 percent or less sat- urated fat is low; 20 percent or more is high. If you consume a food high in fat at one meal, it is wise to try to balance that with low-fat items at the next meal.
Another item to look for is trans fat, which is formed when vegetable oil is hardened (hydrogenated) in the manufacturing process (see page 30). Like saturated fat and cholesterol, trans fat raises harmful LDL cholesterol levels in the blood. Check the ingredients list for trans fat, shortening, or hydrogenated or partially hydrogenated veg- etable oil and limit your use of products containing them. Recently, the FDA began requiring that the amount of trans fat be listed on the nutrition panel under total fat and saturated fat. However, the labeling regulations allow as much as 0.5 g of trans fat per serving to be listed as “0 g,” so make sure the label does not mention hydrogenated oil or par- tially hydrogenated oil, both trans fats.
Nutrients
Whether you are at risk of cardiovascular disease or not, a healthy, bal- anced diet is one of the best ways to take care of your body. Eating a variety of fresh foods is bene?cial in part because these are the best sources of nutrients that your body needs. A great deal of research has focused on speci?c vitamins and minerals in an effort to isolate those that are of particular bene?t to your heart and blood vessels. At this time, many of these ?ndings are inconclusive. Some physicians recom- mend taking a multivitamin and mineral supplements each day, but there is no evidence this is bene?cial. (See page 89 for recommenda- tions about omega-3 oil supplements.)
Antioxidants
Antioxidants are believed to slow oxidation of harmful LDL choles- terol, a process that may cause the development of fatty buildups in the arteries (see page 152). Antioxidant vitamins (E, C, and beta carotene, a form of vitamin A) are found in fruits, vegetables, whole grains, and nuts. These foods are all part of a heart-protecting diet. Experts recom- mend a diet rich in the food sources of antioxidants, but studies show no bene?t to taking antioxidant supplements to prevent atherosclerosis or any other cardiovascular disease. In fact, one study showed negative effects from taking large doses of supplement vitamin E. This is prob- ably because supplement forms of vitamin E are processed substances that differ from the natural vitamin E that occurs in the foods men- tioned above.
Calcium
Doctors recommend getting plenty of calcium in your diet by eating low-fat dairy products and vegetable greens such as kale, broccoli, and soybean products. Daily calcium requirements vary by age and gender. The DASH diet, which is rich in calcium because it recommends eight servings or more a day of fruits and vegetables, as well as low-fat dairy, is proven to lower blood pressure (page 47). Use of calcium supple- ments to prevent high blood pressure has not been proven.
Iron
Some research has indicated that a high level of iron stored in the body may be linked to a greater incidence of heart attacks. But many other studies have failed to demonstrate this effect, and research continues. There is no evidence today to support reducing your iron intake or to justify screening of patients with cardiovascular disease to check their iron levels.
Minerals
Magnesium, a mineral found in leafy vegetables, dried peas and beans, nuts, and seeds, may have a positive effect on blood pressure. But the link is not clear enough to recommend the use of magnesium supple- ments. Magnesium-rich foods are good for you in any case.
The effects of other minerals on heart health are the subject of research, but there are no clear-cut conclusions. Fluoridation of public water supplies is not harmful to your cardiovascular system. A relation- ship between water hardness and heart health has not been demon- strated. Some sources of water are high in sodium, and a person with a tendency toward high blood pressure should avoid such drinking water. A number of trace elements including zinc, copper, cadmium, and lead have been studied without any demonstrable impact on cardiovascular disease.
Potassium
Potassium is an essential element that plays a role in balancing the ?uid content between body cells and body ?uids. Eating foods rich in potas- sium may protect some people from developing high blood pressure. Some people who take diuretics to control high blood pressure may be potassium-de?cient because potassium is lost in increased urination. Doctors may recommend that these people take potassium supplements or eat foods rich in potassium. Bananas, cantaloupe and honeydew mel- ons, oranges and grapefruit, prunes, raisins, tomatoes, and low-fat dairy products are all rich in potassium and are part of a healthy diet. On the other hand, some blood pressure medications such as ACE inhibitors cause the body to retain potassium, so your doctor may advise you to limit intake of potassium-rich foods (including salt substitutes contain- ing potassium).