Black beans

What's New and Beneficial about Black Beans ?

• Recent research has shown that black beans provide special support for digestive tract health, and particularly our colon. The indigestible fraction (IF) in black beans has recently been shown to be larger than the IF in either lentils or chickpeas. It has been shown to be the perfect mix of substances for allowing bacteria in the colon to produce butyric acid. Cells lining the inside of the colon can use this butyric acid to fuel their many activities and keep the lower digestive tract functioning properly. By delivering a greater amount of IF to the colon, black beans are able to help support this lower part of our digestive tract. Lowered colon cancer risk that is associated with black bean intake in some research studies may be related to the outstanding IF content of this legume.
• The soaking of black beans in water has always found fairly widespread support in food science research as a way of improving overall black bean benefits. Yet, the discarding of the bean soaking water has been a topic of considerable controversy. A recent study that may help put this controversy to rest looked at many different advantages and disadvantages of tossing out the water used to soak beans. It found that the advantages clearly outweigh the disadvantages. On the advantage side of things, getting rid of the soaking water also means getting rid of some of the phytates and tannins that can lower nutrient availability. It also means reducing flatulence-related substances like raffinose (up to 33% removed along with the soaking water) and stachyose (up to 20% removed). A final advantage was the retention of resistant starch. While some of the total carbohydrate content in the black beans was lost along with the discarding of the soaking water, the amount of resistant starch remained unchanged. (Resistant starch is a type of carb that will typically make its way all the way down to the large intestine without being digested. Once it arrives in the large intestine, it can help support the growth of desirable bacteria in that area of the digestive tract.) On the disadvantage side of things was that 15% of total phenols were lost, we actually don't think that that is an amount that is of concern. There was a slight loss of some additional phytonutrients as well as minerals. When adding up all of their findings, the researchers concluded that the many advantages of discarding bean soaking water clearly outweighed the disadvantages and then made this recommendation a firm part of their research conclusions.
• We tend to think about brightly colored fruits and vegetables as our best source of phytonutrients, but recent research has recognized black beans as a strong contender in phytonutrient benefits. The seed coat of the black bean (the outermost part that we recognize as the bean's surface) is an outstanding source of three anthocyanin flavonoids: delphinidin, petunidin, and malvidin. These three anthocyanins are primarily responsible for the rich black color that we see on the bean surface. Kaempferol and quercetin are additional flavonoids provided by this legume. Also contained in black beans are hydroxycinnamic acids including ferulic, sinapic, and chlorogenic acid, as well as numerous triterpenoids.
• In Brazilâ€"a country that, along with India, grows more black beans than any country in the worldâ€"beans have been given an exclusive place on the Brazilian Food Pyramid. In other words, beans are recommended as their own unique food group! The country's 2006 Food Guide for the Brazilian Population recommends that beans be consumed at least once every day. That recommendation is actually quite close to the Dietary Guidelines for Americans, which establish 3 cups of cooked legumes per week, or 1/2 cup serving six days per week, as the minimum desired amount. Recent research linking bean intake to lower risk of type 2 diabetes, many types of cardiovascular disease, and several types of cancer was one of the key factors used by the Brazilian government and the U.S. government in establishing their bean intake recommendations. 
• Health Benefits
  Among all groups of food commonly eaten worldwide, no group has a more health-supportive mix of protein-plus-fiber than legumes. Included here, of course, is the amazing protein-plus-fiber content of black beans. From a single, one-cup serving of black beans you get nearly 15 grams of fiber (well over half of the Daily Value and the same amount consumed by the average U.S. adult in one entire day of eating) and 15 grams of protein (nearly one third of the Daily Value and equivalent to the amount in 2 ounces of a meat like chicken or a fish like salmon). You won't find this outstanding protein-fiber combination in fruit, vegetables, grains, meats, dairy products, nuts and seeds, or seafood. The almost magical protein-fiber combination in legumes--including black beans--explains important aspects of their health benefits for the digestive tract, the blood sugar regulatory system, and the cardiovascular system. Each area of systems benefit has a strong research basis.
  
  
  Digestive Tract Benefits
  Unlike dietary sugar, which can move very quickly through the digestive tract and out of the digestive tract into the bloodstream, or dietary fat, which can move very slowly through the digestive tract and out of the digestive tract into the lymphatic system or bloodstream, both protein and fiber can move through the digestive tract at a moderate pace. In terms of digestion, both protein and fiber help to "steady" digestive processes. Movement of food from the stomach to the small intestine (called "gastric emptying") and movement of food through the small intestine and the large intestine can occur at a more desirable pace when foods are rich in protein and fiber. This steadying of the digestive process helps lessen the burden on any one part of the digestive tract. This allows food to move along in a way that supports optimal chemical balances and populations of micro-organisms.
  The idea of digestive tract support from black beans may sound surprising. Many people think about black beans (and beans in general) as problem-causing foods in the digestive tract, perhaps largely because of gas production. But recent research has shown that black beans actually provide special support in the lower large intestine (colon) where gas if often produced. The indigestible fraction (IF) in black beans has recently been shown to be larger than the IF in either lentils or chickpeas. It is the perfect mix of substances for allowing bacteria in the colon to produce butyric acid. Cells lining the inside of the colon can use this butyric acid to fuel their many activities and keep the lower digestive tract functioning properly. By delivering a greater amount of IF to the colon, black beans are able to help support this lower part of our digestive tract. Lowered colon cancer risk that is associated with black bean intake in some research studies may be related to the outstanding IF content of this legume.
  
  Benefits for Blood Sugar Regulation
  The landmark "protein-plus-fiber" combination in black beans and other legumes is also a key to their outstanding support for blood sugar balance and blood sugar regulation. As described earlier, protein and fiber can move through our digestive tract at a moderate pace. Unlike dietary sugar (which can move too quickly), or fat (which can move too slowly), both protein and fiber can move at a moderate pace. By steadying rate of movement through the digestive tract, protein and fiber help to steady the breakdown of food into component parts, including simple sugars. This better-regulated breakdown of food helps to prevent extremes with respect to simple sugar uptake from the digestive tract. Too much simple sugar uptake all at once can result in an unwanted blood sugar spike. Too little simple sugar uptake can result in an unwanted blood sugar drop. Either extreme can work to destabilize blood sugar balance. The 15 fiber grams and 15 protein grams in one cup of black beans help prevent both extremes - excessive simple sugar release from the digestive tract, and also insufficient simple sugar release.
  With respect to prevention of type 2 diabetes, researchers have become especially interested in some of the alpha-amylase inhibitory effects of black beans. Naturally occurring compounds in this legume slow down the activity of alpha-amylase enzymes. Since these enzymes are important for breaking down starch into sugar, their slowing down can result in less sugar release from food starches. We suspect that the alpha-amylase inhibitors in black beans work together with proteins and fibers to help steady blood sugar levels and make this legume especially valuable for blood sugar regulation. Although we've seen numerous studies showing decreased risk of type 2 diabetes following increased intake of fiber from plant foods (and especially legumes), we have yet to see a large-scale human study showing particular benefits for type 2 diabetes prevention from increased intake of black beans (versus increased intake of plant fibers, including all legume fibers). But we would not be surprised to see a black bean study that showed this legume to be a standout in the area of type 2 diabetes prevention.
  
  Cardiovascular Benefits
  Much of the original research on bean intake and decreased risk of cardiovascular disease focused on the outstanding soluble fiber content of beans. One cup of black beans provides over 4 grams of soluble fiber, and this is precisely the type of fiber that researchers have found especially helpful in lower blood cholesterol levels. Decreased risk of coronary heart disease (CHD) and myocardial infarct (MI, or heart attack) have both been associated with increased intake of soluble fiber from food. In particular, they have been associated with increased intake of soluble fiber from legumes. So it is anything but surprising to see black beans included in the list of legumes that provide us with cardiovascular benefits.
  More recent research, however, has gone beyond this soluble fiber story and added new aspects of black bean nourishment to its list of cardiovascular benefits. Included here is the impressive variety of phytonutrients (both antioxidant and anti-inflammatory) contained within black beans. While we tend to think about brightly colored fruits and vegetables as our best source of phytonutrients, black beans are actually a standout food in this phytonutrient area. The seed coat of black beans (the outermost layer that we recognize as the bean's surface) is an outstanding source of three anthocyanin flavonoids: delphinidin, petunidin, and malvidin. These three anthocyanins are primarily responsible for the rich black color that we see on the bean surface. Kaempferol and quercetin are additional flavonoids provided by this legume. All of these flavonoids have well-demonstrated antioxidant and anti-inflammatory properties. Also contained in black beans are hydroxycinnamic acids including ferulic, sinapic, and chlorogenic acid, as well as numerous triterpenoids. These phytonutrients also function as antioxidants and, in some cases, as anti-inflammatory compounds as well. Antioxidant and anti-inflammatory protection is especially important for our cardiovascular system. When our blood vessels are exposed to chronic and excessive risk of oxidative stress (damage by overly reactive oxygen-containing molecules) or inflammation, they are at heightened risk for disease development. The prevention of chronic, excessive oxidative stress and inflammation is a key to decreased risk of most cardiovascular diseases. We expect to see increased attention to the phytonutrient content of black beans in future research on cardiovascular support from this special legume.
  When addressing the issue of cardiovascular support, it would be wrong to ignore the rich supply of conventional nutrients in black beans. One cup of black beans provides nearly two-thirds of the Daily Value (DV) for folate--arguably one of the most important B vitamins for decreasing risk of cardiovascular disease. Black beans also provide about 120 milligrams of magnesium per cup. That's nearly one-third of the DV for a mineral that is more commonly associated with cardiovascular protection than any other single mineral. Antioxidant minerals like zinc and manganese are also plentiful in black beans. Finally, black beans provide about 180 milligrams of omega-3 fatty acids per cup in the form of alpha-linolenic acid (ALA).
  
  Other Health Benefits
  Given the impressive array of antioxidant and anti-inflammatory phytonutrients in black beans, we have not been surprised to see numerous studies connecting black bean intake with reduced risk of certain cancers, especially colon cancer. Chronic excessive oxidative stress and chronic excessive inflammatory are both risk factors for the development of many cancer types. By increasing the body's supply of antioxidant and anti-inflammatory nutrients, black beans may be able to help lower cancer risk. Most of the studies we've seen have been studies on laboratory animals, or laboratory studies on different cancer cell types. (In other words, we have yet to see large-scale human studies showing decreased risk of cancer following increased intake of black beans.) But these preliminary animal and laboratory studies have been relatively consistent in their findings and have shown black beans to inhibit the development of certain cancers and especially colon cancer. Breast cancer and liver cancer are two additional cancer types that have been studied in animals with respect to black bean intake, although the evidence here is not as strong as evidence in the area of colon cancer. As our knowledge of black bean phytonutrients increases, we expect to see increasing interest in this important area of health research.