Pulses Can Reduce “Bad” Cholesterol
A 2014 meta-analysis of existing
research shows that eating pulses for at
least three weeks significantly reduces LDL-cholesterol levels, which can lower
the risk of heart attack and stroke.
A large group of researchers from Canadian and US universities and
hospitals conducted the review and meta-analysis of 26 published feeding
trials in an attempt to quantify the amount of pulses needed in the diet to
impact specific heart disease related outcomes including LDL-cholesterol.
The average dose of pulses consumed in the studies was 130 grams
or one serving per day, which is equal to about ½ to ¾ cup of pulses. Pulse
consumption lowered LDL-cholesterol levels by about 5%. This reduction
translates to a 5 to 6% reduction in events like heart attack or stroke.
“Although most heart disease prevention guidelines recommend
eating pulses as part of a healthy diet, there isn’t an exact amount
recommended to achieve a specific benefit like lowering LDL-cholesterol,” says
Dr. John Sievenpiper, lead researcher for the study. “With these results, we now have a recommended
amount we can promote as having specific cardiovascular health benefits.”
Video Link: Dr. John Sievenpiper & Vanessa Ha talk about the
importance of the research findings
“There are many easy ways to add more pulses to your diet,” says
Dr. Julianne Curran, Director of Nutrition, Science and Regulatory Affairs with
Pulse Canada. “Pulses can be used for
far more than soups and chilis. Lentil
and bean purees are a great way to reduce fat and increase fiber and protein in
baked goods. Snacks like hummus and crackers pack a serious punch by combining
pulses and cereal grains to increase fiber and protein. And there are new products on supermarket
shelves every day that include pulse ingredients.”
Video Link: Easy ways to add pulses to your diet
A manuscript of the research, titled "The Effect of Dietary Pulses on Established Therapeutic Lipid
Targets of Cardiovascular Disease: A Systematic Review and Meta-Analysis of Randomized
Controlled Trials” was published in the April 7, 2014 edition of the
Canadian Medical Association Journal.
The findings of this meta-analysis are consistent with those of
another review commissioned last year by Pulse Canada on high quality studies
specific to beans and cholesterol lowering. The study, funded by the Canadian
Agricultural Adaptation Program (CAAP), critically evaluated a total of eight
studies that met Health Canada’s criteria for health claims. Of these studies,
83% saw a beneficial effect on total cholesterol and LDL-cholesterol levels.
The minimum effective dose of beans in these studies was 130 grams per day
which is equal to ¾ cup or one serving according to Canada’s Food Guide.
“The power of pulses is remarkable. They are a low fat and low
saturated fat source of protein, and contain high amounts of complex
carbohydrates like fibre and resistant starch. As an added bonus, they have
several vitamins and minerals that are important for body processes like iron,
potassium, folate and other B vitamins,” says Dr. Curran.
Fibre includes all parts of plant foods that your body can't digest or absorb. Pulses are very high in fibre, containing both soluble and insoluble fibres. While soluble fibre helps to decrease blood cholesterol levels and control blood sugar levels, insoluble fibre helps with digestion and regularity. According to the Dietitians of Canada, many Canadians are not getting the recommended amount of fibre per day. The recommend daily intake of fibre is 38 g/day of total fibre for men and 25 g/day of total fibre for women.
Eating just 125 mL (1/2 c.) of pulses per day provides 7 - 17 g of fibre. With their high fibre levels, pulses are a healthy food choice!
Besides fibre, pulses contain other complex carbohydrates like resistant and slowly digestible starch as well as oligosaccharides (a complex carbohydrate containing three to six units of simple sugars). Resistant starch and oligosaccharides behave like fibre in the body because they are not digested or absorbed. In contrast, slowly digestible starch does get digested completely in the small intestine but this happens at a slow rate which keeps the body’s blood sugar levels closer to normal.
Pulses are somewhat unique as a plant food because in addition to high amount of fibre and complex carbohydrates, pulses typically contain about twice the amount of protein found in whole grain cereals like wheat, oats, barley and rice. Pulses have higher amounts of the essential amino acid lysine whereas cereals have higher amounts of the essential amino acids methionine and cysteine so blending pulses with cereals or nuts results in a better quality protein that contains all essential amino acids in appropriate amounts. This is particularly important for people eating vegetarian or vegan diets.
Pulses provide substantial amounts of vitamins and minerals in a relatively low amount of calories. Some of the key minerals in pulses include iron, potassium, magnesium and zinc. Pulses are also particularly abundant in B vitamins including folate, thiamin and niacin.
Low Glycemic Index
For a food that is high in carbohydrates, pulses have a low glycemic index which means they do not cause a fast rise in blood sugar after eating. Studies have shown that eating pulses is a good way to manage blood sugar levels which is particularly important for people with diabetes.
Pulses are available as whole seeds, and can also be turned into ingredients like flours, fibre, proteins and starches. Their versatility gives endless options to add more pulses to the diet and to meet the recommended weekly amounts of several important nutrients.
Many health organizations recommend eating pulses to maintain good health and prevent chronic diseases like diabetes, heart disease and cancer. Eating Well with Canada’s Food Guide states “Have meat alternatives such as beans, lentils and tofu often” and suggests that regularly choosing beans and other meat alternatives such as lentils can help minimize the amount of saturated fat in the diet.
The 2010 Dietary Guidelines for Americans says that “beans and peas are unique foods. Bean and peas are the mature forms of legumes. They include kidney beans, pinto beans, black beans, garbanzo beans, lima beans, black-eyes peas, split peas, and lentils. Beans and peas are excellent sources of protein. They also provide other nutrients, such as iron and zinc, similar to seafood, meat, and poultry. They are excellent sources of dietary fiber and nutrients such as potassium and folate, which also are found in other vegetables. Because of their high nutrient content, beans and peas may be considered both as a vegetable and as a protein food.” Pulses are also listed in “foods and nutrients to increase “ - Choose a variety of protein foods, which include seafood, lean meat and poultry, eggs, beans and peas, soy products, and unsalted nuts and seeds.
The Musical Fruit?
Some carbohydrates in pulses produce gas and bloating for some people, similar to the effects produced by certain other foods (e.g. cabbage, broccoli, and other vegetables and fruits). Eating pulses often allows your gut to adapt to the higher fibre and carbohydrates,decreasing these effects over time.
For those who find that pulses lead to gas and bloating, eat small amounts of pulses, drink lots of water and gradually increase your intake. There are also a number of easy ways to significantly reduce the digestive discomfort that can occur from eating pulses:
- Change the soaking water once or twice during the long cold soak.
- Do not use the soaking liquid to cook the pulses.
- Cook pulses thoroughly as undercooked starch is harder to digest.
- Thoroughly rinse canned or pre-soaked pulses before cooking.
- Take Beano® to help eliminate gas. It is available in health food stores, pharmacies and most grocery stores.