value (calories per serving): Moderate
High Fat: Low
Very high Sodium: Low
vitamin contribution: Vitamin B6, folate
mineral contribution: Iron, magnesium, zinc
the Nutrients in This Food
seeds, high in complex carbohydrates including starch and dietary fiber.
They have indigestible sugars (stachyose and raffinose), plus insoluble
cellulose and lignin in the seed covering and soluble gums and pectins
in the bean. The proteins in beans are limited in the essential amino
acids methionine and cystine." All beans are a good source of the B
vitamin folate, and iron.
cup canned kidney beans has 7.5 g dietary fiber, 65 mcg folate (32.5
percent of the RDA for a man, 36 percent of the RDA for a woman), and
1.6 mg iron (10.6 percent of the RDA for a woman of childbearing age).
contain antinutrient chemicals that inactivate enzymes required to
digest proteins and carbohydrates. They also contain factors that
inactivate vitamin A and also hemaglutinins, substances that make red
blood cells clump together. Cooking beans disarms the enzyme inhibitors
and the anti-vitamin A factors, but not the hemaglutinins. However, the
amount of hemaglutinins in the beans is so small that it has no
measurable effect in your body.
Most Nutritious Way to Serve This Food
grains. The proteins in grains are deficient in the essential amino
acids lysine and isoleucine but contain sufficient tryptophan,
methionine, and cystine; the proteins in beans are exactly the opposite.
Together, these foods provide "complete" proteins.
iron-rich food (meat) or with a vitamin Córich food (tomatoes). Both
enhance your body's ability to use the iron in the beans. The meat makes
your stomach more acid (acid favors iron absorption); the vitamin C may
convert the ferric iron in beans into ferrous iron, which is more easily
absorbed by the body.
That May Restrict or Exclude This Food
for: Smooth-skinned, uniformly sized, evenly colored beans that are
free of stones and debris. The good news about beans sold in plastic
bags is that the transparent material gives you a chance to see the
beans inside; the bad news is that pyridoxine and pyridoxal, the natural
forms of vitamin B6, are very sensitive to light.
Beans sold in bulk. Some B vitamins, such as vitamin B6 (pyridoxine and
pyridoxal), are very sensitive to light. In addition, open bins allow
insects into the beans, indicated by tiny holes showing where the bug
has burrowed into or through the bean. If you choose to buy in bulk, be
sure to check for smooth skinned, uniformly sized, evenly colored beans
free of holes, stones, and other debris.
beans in air and moisture proof containers in a cool, dark cabinet where
they are protected from heat, light, and insects.
Preparing This Food
beans and pick them over carefully, discarding damaged or withered beans
and any that float. (Only withered beans are light enough to float in
beans with water, bring them to a boil, and then set them aside to soak.
When you are ready to use the beans, discard the water in which beans
have been soaked. Some of the indigestible sugars in the beans that
cause intestinal gas when you eat the beans will leach out into the
water, making the beans less "gassy."
Happens When You Cook This Food
are cooked in liquid, their cells absorb water, swell, and eventually
rupture, releasing the pectins and gums and nutrients inside. In
addition, cooking destroys anti nutrients in beans, making them more
nutritious and safe to eat.
Other Kinds of Processing Affect This Food
Canning. The heat of canning destroys some of the B vitamins in the
beans. Vitamin B is water-soluble. You can recover all the lost B
vitamins simply by using the liquid in the can, but the liquid also
contains the indigestible sugars that cause intestinal gas when you eat
Preprocessing. Preprocessed dried beans have already been soaked.
They take less time to cook but are lower in B vitamins.
Uses and/or Benefits
risk of some birth defects. As many as two of every 1,000 babies
born in the United States each year may have cleft palate or a neural
tube (spinal cord) defect due to their mothers' not having gotten
adequate amounts of folate during pregnancy. The current RDA for folate
is 180 mcg for a woman and 200 mcg for a man, but the FDA now recommends
400 mcg for a woman who is or may become pregnant. Taking a folate
supplement before becoming pregnant and continuing through the first two
months of pregnancy reduces the risk of cleft palate; taking folate
through the entire pregnancy reduces the risk of neural tube defects.
risk of heart attack. In the spring of 1998, an analysis of data
from the records for more than 80,000 women enrolled in the long-running
Nurses Health Study at Harvard School of Public Health/Brigham and
Woman's Hospital in Boston demonstrated that a diet providing more than
400 mcg folate and 3 mg vitamin B6 a day from either food or
supplements, more than twice the current RDA for each, may reduce a
woman's risk of heart attack by almost 50 percent. Although men were not
included in the analysis, the results are assumed to apply to them as
well. NOTE: Beans are high in B6 as well as folate. Fruit, green leafy
vegetables, whole grains, meat, fish, poultry, and shellfish are good
sources of vitamin B6.
reduce the levels of serum cholesterol. The gums and pectins in
dried beans and peas appear to lower blood levels of cholesterol.
Currently there are two theories to explain how this may happen. The
first theory is that the pectins in the beans form a gel in your stomach
that sops up fats and keeps them from being absorbed by your body. The
second is that bacteria in the gut feed on the bean fiber, producing
short-chain fatty acids that inhibit the production of cholesterol in
source of carbohydrates for people with diabetes. Beans are digested
very slowly, producing only a gradual rise in blood-sugar levels. As a
result, the body needs less insulin to control blood sugar after eating
beans than after eating some other high-carbohydrate foods (such as
bread or potato). In studies at the University of Kentucky, a bean,
whole-grain, vegetable, and fruit-rich diet developed at the University
of Toronto enabled patients with Type I diabetes (who do not produce any
insulin themselves) to cut their daily insulin intake by 38 percent.
Patients with Type II diabetes (who can produce some insulin) were able
to reduce their insulin injections by 98 percent. This diet is in line
with the nutritional guidelines of the American Diabetes Association,
but people with diabetes should always consult with their doctors and/or
dietitians before altering their diet.
diet aid. Although beans are high in calories, they are also high in
bulk (fiber); even a small serving can make you feel full. And, because
they are insulin-sparing, they delay the rise in insulin levels that
makes us feel hungry again soon after eating. Research at the University
of Toronto suggests the insulin-sparing effect may last for several
hours after you eat the beans, perhaps until after the next meal.
Effects Associated with This Food
Intestinal gas. All legumes (beans and peas) contain raffinose and
stachyose, complex sugars that human beings cannot digest. The sugars
sit in the gut and are fermented by intestinal bacteria which then
produce gas that distends the intestines and makes us uncomfortable. You
can lessen this effect by covering the beans with water, bringing them
to a boil for three to five minutes, and then setting them aside to soak
for four to six hours so that the indigestible sugars leach out in the
soaking water, which can be discarded. Alternatively, you may soak the
beans for four hours in 9 cups of water for every cup of beans, discard
the soaking water, and add new water as your recipe directs. Then cook
the beans; drain them before serving.
Production of uric acid. Purines are the natural metabolic
by-products of protein metabolism in the body. They eventually break
down into uric acid, sharp crystals that may concentrate in joints, a
condition known as gout. If uric acid crystals collect in the urine, the
result may be kidney stones. Eating dried beans, which are rich in
proteins, may raise the concentration of purines in your body. Although
controlling the amount of purines in the diet does not significantly
affect the course of gout (which is treated with allopurinol, a drug
that prevents the formation of uric acid crystals), limiting these foods
is still part of many gout regimens.
oxidase (MAO) inhibitors. Monoamine oxidase (MAO) inhibitors are drugs
used to treat depression. They inactivate naturally occurring enzymes in
your body that metabolize tyramine, a substance found in many fermented
or aged foods. Tyramine constricts blood vessels and increases blood
pressure. If you eat a food containing tyramine while you are taking an
MAO inhibitor, you cannot effectively eliminate the tyramine from your
body. The result may be a hypertensive crisis. Some nutrition guides
list dried beans as a food to avoid while using MAO inhibitors.