What’s the latest thinking on the healthiest types of unsaturated fat?
Unsaturated fats include vegetable and nut oils, such as olive oil, corn oil, safflower oil, and canola oil. These are liquid at room temperature. Saturated fats, in contrast, which are solid at room temperature, are known to raise blood cholesterol levels and the risk of heart disease. Unsaturated fats are divided into monounsaturated and polyunsaturated. Some studies suggest that polyunsaturated fats are the healthiest. Don't worry too much about polys versus monos. In fact, most vegetable and nut oils contain a mix of the two.
Is it important to look at levels of dietary cholesterol in food?
If you have elevated LDL cholesterol or a family risk of heart disease, you should keep an eye on how much dietary cholesterol you consume. The Therapeutic Lifestyle Changes diet, known as TLC, has been shown in studies sponsored by the National Heart Lung and Blood Institute to significantly reduce heart disease in people at risk. The TLC diet calls for no more than 200 milligrams of dietary cholesterol a day for people with high cholesterol. Reading labels is important, of course. But more important is limiting the amount of foods that contain high levels of cholesterol, many of which don’t carry labels, such as eggs and organ meats.
What about sodium?
Too much sodium increases the risk of high blood pressure, or hypertension. High blood pressure, in turn, increases the risk of developing heart disease. Some people don’t seem to be as sensitive to salt as others. If you have high blood pressure, you should definitely limit sodium intake. The most recent evidence shows that the less sodium you consume, the lower your risk of hypertension. The DASH diet, which stands for Dietary Approaches to Stop Hypertension, originally set the limit at no more than 2,300 milligrams of sodium daily. New evidence shows that lowering your intake to 1,500 milligrams further lowers your risk of high blood pressure. Since three-quarters or more of the salt we consume comes in packaged foods, labels are particularly helpful here.
Labels also show potassium levels. What should we look for?
Too much sodium and too little potassium both play a role in high blood pressure. Low potassium levels can also affect the electrical impulses that activate the heart, causing heart beat irregularities. The Institute of Medicine recommends 4,700 milligrams of potassium a day. But rather than worry about numbers on the label, I’d suggest eating more foods with potassium, which include fruits and vegetables, especially orange juice, broccoli, garlic, bananas, tomatoes, and beans -- all of which are healthy for you in many ways.
A lot of people are cutting back on carbohydrates. What help can food labels offer?
The total amount of carbohydrates is less important than the type. The healthiest forms are unrefined carbohydrates, which are found in whole grains, beans, seeds, nuts, and other whole, unprocessed foods. (Limit less healthy carbs such as sugar, white rice, and regular breads and pastas.) It’s wise to look at a label to make sure it contains whole grains and plenty of fiber. Several studies have shown that people who eat plenty of whole grains have a lower risk of heart disease.