The Lowdown on Legumes
Beans may be a source of many flatulence-related jokes, but despite their unfortunate reputation, they offer some very real nutritional benefits—smelly emissions aside.
When we talk about “beans,” we are referring to certain seeds that grow in pods on plants that belong to the legume family. Legumes include pulses (dried beans, peas, chickpeas and lentils), soybeans, peanuts, fresh peas and fresh beans. Unfortunately, many people overlook beans, and legumes in general, as a regular part of their diet—beyond opening an occasional can of baked beans.
Most Canadians are not getting enough fibre, and hearty legumes are packed with fibre—and with gluten-free complex carbohydrates and protein. Three-quarters of a cup of red kidney beans provides 161 calories and has 10 grams of protein, 1 gram of fat and 12 grams of fibre. That’s a big share of the recommended daily fibre intake for adults, which is 21-25 g for females and 30-38 g for men.
Fibre is often divided into insoluble and soluble types. Insoluble fibre makes stool heavier and speeds its passage through the gut. Soluble fibre, which is the type found in legumes, breaks down as it passes though the digestive tract, trapping some substances related to high cholesterol. There is evidence that soluble fibre may lessen the risk of heart disease by reducing the absorption of cholesterol into the bloodstream.
Also worth noting: not all high-fibre foods are created equal. It’s important to consider the sugar, sodium and fat content in foods like high-fibre chocolate snack bars (high in sugar and saturated fat) or cans of bean chili (very salty). It’s much better to aim to get the bulk of your fibre from unprocessed foods like legumes.
The benefits of legumes don’t stop with fibre—legumes contain iron, B vitamins (folate, niacin and thiamin), potassium, zinc and magnesium. Research shows that consumption of legumes may have an impact on many diseases and conditions including cancer, heart disease, diabetes, constipation and obesity.
One study examined the link between bean consumption and cancer mortality and found that countries with the greatest consumption of beans had the lowest death rates due to prostate, breast and colon cancers.
Their low glycemic index and high fibre content help prevent spikes in blood sugar in diabetics, and improved blood sugars lead to better heart health and blood pressure control. The fibre and water content found in legumes may also be of benefit for those who are trying to lose weight; compared to eating meat, legumes make people feel full sooner and for longer. Beans, peas and lentils are lower in saturated fat and cholesterol and contain more fibre than meats. In fact, one study showed that individuals who consumed beans on a regular basis ate fewer calories and weighed less than non bean-eaters. Another study found that individuals who regularly eat legumes have a 22 per cent lower risk of obesity than those who don’t.
Legumes also rank high in antioxidant content, when compared to other antioxidant-rich foods. Antioxidants are compounds naturally found in fruits, vegetables, wholes grains and legumes. These compounds may counter the destructive damage to cells caused by free radicals, which occur naturally in our bodies; the body can also be exposed to them through pollution, smoking or exposure to the sun’s rays.
Free radicals are thought to play a role in the cell destruction that can lead to cancer, heart disease and cataracts, and although the role of antioxidants in disease prevention is inconclusive, they may have an influence on the decreased rates of disease seen in people who eat more vegetables, fruits, whole grains and legumes.
Just eat more
Four servings (3 cups) of legumes a week will give you the best bang for your health-benefit buck, but it’s not necessarily all or nothing. If eating legumes four times a week is not realistic, just aim to eat more than you do now. Over time, you may be able to slowly incorporate more legumes into your diet.
And it really shouldn’t be that difficult: legumes are not only cheap, but also convenient. Many canned varieties are available, including no-added salt options. If you choose dried, a little more preparation time is needed for soaking and boiling (see “Pulses 101,” above), but these foods are still a cinch to prepare.