Dr. Perricone's No. 4 Superfood: Beans and Lentils
July 15, 2005
There are good reasons that beans occupy two places on the U.S. Department of Agriculture's Food Guide Pyramid: the first is with high-protein foods such as meat, eggs, poultry and fish, and the second is with vitamin-rich vegetables. The beneficial phytochemicals found in beans offer other preventive health attributes not reflected in the USDA's Pyramid. The multi-faceted nutrition and prevention powers of beans—a category that encompasses common beans (e.g., kidney, black, navy, pinto), chickpeas (garbanzo beans), soybeans, dried peas and lentils—make them an anti-aging dietary necessity.
Beans are low in fat (except for soybeans), calories and sodium but high in complex carbohydrates and dietary fiber, and they offer modest amounts of essential fatty acids—mostly omega-6s (only soybeans have significant amounts of omega-3 fatty acids). They are also an excellent source of protein, needing only to be combined with grains such as barley or oats to provide all the amino acids necessary to make a complete protein for vegetarians who do not have other sources of protein for their meals.
Beans are extremely beneficial in an anti-diabetes diet because they rank low on the glycemic scale, which means that they do not cause the inflammatory, hunger-inducing spike in blood sugar levels associated with refined grains and baked goods. Beans offer ample fiber (one cup of cooked beans can provide as much as 15 grams of dietary fiber, more than half the recommended "daily value" of 25 grams and are released into the bloodstream slowly, providing energy and satiation for a sustained period. However, I recommend no more than 1/4 to 1/2 cup cooked beans per meal.
Dried beans and lentils are a staple of many cuisines worldwide. For thousands of years, beans and lentils have been and continue to be one of the most nutritious foods available. In addition, beans and lentils are extremely versatile. They can be combined with fragrant herbs and vegetables and made into delicious soups. They can be used in salads or puréed and served as a dip or spread. Chickpeas and lentils can also be ground into a high-protein, low-glycemic flour.
Beans are heart-healthy for a number of reasons in addition to their fiber content:
They are a good source of potassium, which may help reduce your risk of high blood pressure and stroke. More than 80 percent of American adults do not consume the daily value for potassium (3,500mg), and just 1/2 cup of cooked dry beans contains as much as 480mg, with no more than 5mg of sodium.
Dry beans are a good source of folic acid, which protects against heart disease by breaking down an amino acid called homocysteine. (One cup of cooked dry beans providing about 264 mcg of folate, or more than half the recommended daily intake of 400mcg.) High levels of homocysteine in the blood, or inadequate amounts of dietary folate, can triple the risk of heart attack and stroke. Folate is also key in preventing birth defects, and may help reduce the risk of several types of cancer because it plays an important role in healthy cell division and is crucial to the repair of damaged cells.
In a large study of almost 10,000 men and women, those who ate beans four or more times a week cut their risk of coronary heart disease by about 20 percent, compared with those who ate beans less than once a week. It appears that this health benefit was independent of other health habits, since adjustments to account for other important cardiovascular disease risk factors produced minimal change in the risk estimates.
Other studies show that within two to three weeks, diets high in either canned or dry beans (3 to 4 ounces per day) reduce blood cholesterol levels by 10 percent or more: an effect that can result in a 20 percent decrease in the risk of coronary heart disease.
Beans and lentils have the same potent anti-inflammatory antioxidants—flavonoids and flavonals—found in tea, fruits, grapes, red wine and cocoa beans. In particular, the reddish flavonal pigments in bean and lentil seed coats exert antioxidant activity 50 times greater than vitamin E, protect against oxidative damage to cell membrane lipids, promote healthy collagen and cartilage and restore the antioxidant powers of vitamins C and E after they've battled free radicals.
Beans are among the richest food sources of saponins, chemicals that help prevent undesirable genetic mutations.
Preparation Tips Beans Generally speaking, the larger the bean, the longer they need to soak: and the longer you soak beans, the faster they cook. Dried chickpeas, beans and whole dried peas need about eight hours of soaking.
If you forget to soak them the night before, just do it before you leave in the morning and they'll be ready to cook when you get home. Or, add three times the amount of water as beans, bring them to a boil for a few minutes, remove from the heat, and let sit for an hour. Throw out the soaking water, and cook as normal. You can also use a pressure cooker, which will reduce the cooking time by more than half, and reduce nutrient loss. (Of course, you can just drain and rinse canned beans, and add them directly to salads, soups or curries.) You can also prepare large batches to freeze in meal-sized portions, as cooked beans freeze well.
Well-soaked beans take 45 minutes to an hour to cook, depending on the variety. Cook beans until soft and then rinse them thoroughly because the residual starch on the surface feeds the harmless bacteria in your gut, which then release gas. Some of the gas-producing starch stays in the soaking water so don’t cook with it.
You can prevent gas by adding beans to your diet gradually, eating just a bite or two per day to start until your body adjusts period. Drinking ample fluids also helps. You can also try an enzyme supplement such as Beano, sold in most supermarkets, which will digest the gas-producing sugars. Just put a few drops on the first bite of food.
Like other legumes, lentils are low in fat and high in protein and fiber, but they have the added advantage of cooking quickly. Lentils do not need pre-soaking. Simply remove any debris, then rinse and boil them. Red lentils take only twenty minutes, green lentils take 30 to 45 minutes, and brown lentils cook in 45 to 60 minutes. Do not add salt to cooking lentils, as this may toughen them. Like beans, lentils will keep almost indefinitely in a cool, dry place. Their colors may fade slightly after long storage, but their flavor and nutrition won’t. Lentils are the perfect way to add protein, fiber and all the antioxidant benefits of this food group to any meal. And they taste wonderful, adapting themselves to a wide range of aromatic spices and herbs—particularly turmeric and ginger.