FOOD ST★RS! THE BENEFICIAL BEAN

Chances are you haven’t given beans much thought. Surprisingly the rather unassuming little bean is a powerhouse in disguise. Just what is a bean? All beans are part of the legume family – a simple fruit that opens along a seam on both sides. Examples of legumes are green beans, fresh peas, soybeans and peanuts. Pulses are a subset of the legume family, referring to the dried seed only. Examples of pulses are lentils, chickpeas and dried peas and beans. Beans are excellent sources of both fiber and protein and they are high in iron, Vitamin B1, magnesium, phosphorus, potassium, zinc and copper and naturally low in sodium.

Beans have an exceptionally low glycemic index because of their “second meal effect”

Beans are very efficient at moderating blood sugar levels after a meal, cutting them in half compared to eating the same meal without beans. At first glance this is not so surprising because beans are very high in fiber which slow the absorption of blood sugar. However the second meal effect is more than just an effect of fiber and the astounding thing is that this effect continues for hours, beyond the next meal and even into the next day. The reason for this is that beans are rich in prebiotics. They provide exactly the food that the friendly bacteria in your microbiome desire. In turn, those little bugs produce propionate, a product of fermentation that has the effect of relaxing the stomach, slowing down stomach emptying and consequently slowing the rate at which sugars are absorbed. By the time the next meal comes around, the beans have travelled as far as the large intestine and are still promoting the production of propionate and preventing blood sugar spikes. (1,2,3)

Beans lower the risk of heart disease

Studies show that people who don’t eat beans daily are four times as likely to suffer from high blood pressure (4). People who add two servings a day of beans, chickpeas, lentils or split peas to their diet significantly decrease their blood cholesterol level (5).

Beans Decrease the Risk of Diabetes

Regular bean consumption promotes a slimmer waistline and improved glucose control. One study showed that people who ate five cups of pulses weekly showed greater reduction in risk factors of metabolic syndrome than people who cut 500 calories from their daily diet (6). Also, substituting one serving of beans for one serving of white rice lowers the risk of metabolic syndrome by as much as 35% (7).

Beans Increase Longevity

Many studies point to a link between beans and a long life. A study conducted in Japan, Sweden, Greece and Australia showed that legume intake is the only food factor around the globe associated with a longer lifespan. Every 20 gram increase in daily legume intake results in an 8% reduction in risk of early death (8). On the other hand, a diet devoid of beans is linked to decreased lifespan (9).

Beans May Prevent Cancer

Researchers have looked at overall change in fruit and vegetable consumption and formation of polyps in the intestine. Polyps are the first step towards colon cancer. No association was found between polyp formation and overall fruit and vegetable consumption, however, participants who ate the most beans cut their risk of polyps by 60% (11). This may be because the phytates in beans block the ability of cancer cells to spread and grow (12,13), perhaps through their powerful inhibition of a type of free radical called hydroxyl radicals.

Beans are satiating

Beans are high in fiber which helps you feel full longer.

Beans are an excellent source of protein

One-half cup of beans contains 7 grams of protein.

What about flatulence?

The amount of extra intestinal gas produced by beans and legumes may be greatly exaggerated. Gas is a natural by-product of healthy fermentation in the intestines. When you increase your bean intake, your gut flora can adjust to the diet change but you might need to be patient for a few weeks until this happens. In one study 70% of participants who experienced flatulence after adding more beans to their diet reported that the extra gas lessened considerably after two to three weeks of bean consumption (10). One helpful trick to help reduce flatulence is to thoroughly soak your raw beans before cooking and to change the cooking water once or twice during the cooking process (16).

What about the phytates in beans?

Phytates are found in beans, grain, nuts and seeds. They have been much maligned as an anti-nutrient with concerns that they prevent absorption of some minerals. It is now known that problems only occur when very large quantities of phytates are consumed within a nutrient poor diet. While nutritionists once worried that phytate consumption might lead to calcium deficiency, the opposite is actually true. Phytates actually protect against osteoporosis (14,15). They are also protective against cancer, kidney stones, diabetes and heart disease.

What about lectins in beans?

The subject of lectins in foods comes to the forefront every few decades. There are lectins in many common foods. Most, such as the lectins found in tomatoes and lentils are non-toxic. However the lectins in some RAW beans, especially kidney beans, have the potential to cause nausea, vomiting and diarrhea. In reality, this potential is almost impossible to come to pass. There is no chance of eating raw dried beans – they are as hard as rocks. Lectins are completely destroyed by cooking and canning processes. Soaking kidney beans for a few hours and then cooking them for only three minutes will destroy all lectins. At this point they are still inedible and will probably need a full hour to render them soft enough to mash with a fork. This whole discussion is a moot point really considering the strong scientific evidence we have that legumes are associated with a longer lifespan, a significantly lower risk of colorectal cancer and are considered a natural solution for preventing and treating type-2 diabetes (7,8,9,16,17,18). Recent studies have actually shown promise that low levels of lectins might actually prevent some types of cancer….but that is a topic for another blog (19).

Canned or boiled?

Canned beans can be as nutritious as boiled beans. The major difference is the higher sodium level in many canned beans. Check the sodium level before you buy and try to purchase low sodium or “no salt added” products. Draining and rinsing canned beans removes half of the sodium but also washes some nutrients down the drain.
What do you think of beans now?
And so you can see that beans really do “hide their light under a bushel”. Beans can be easily incorporated into your daily meal plan. They can be added to soups, rice dishes, pasta and many other dishes. Beans can be found in many delicious traditional recipes from places such as India, Mexico and Italy. When you include beans in your daily diet you will discover a delicious comfort food that packs a formidable nutritional punch.

What do you think of beans now?

And so you can see that beans really do “hide their light under a bushel”. Beans can be easily incorporated into your daily meal plan. They can be added to soups, rice dishes, pasta and many other dishes. Beans can be found in many delicious traditional recipes from places such as India, Mexico and Italy. When you include beans in your daily diet you will discover a delicious comfort food that packs a formidable nutritional punch.

SOURCES:

1 Mattei, J., Hu, F.B., Campos, H. A higher ratio of beans to white rice is associated with lower cardiometabolic risk factors in Costa Rican adults. Am. J. Clin. Nutr. 2011 94(3):869 – 876

2 Brighenti, F., Benini, L., Del Rio, D., Casiraghi, C., Pellegrini, N.,Scazzina, F., Jenkins, D.J.A., Vantini, I. Colonic fermentation of indigestible carbohydrates contributes to the second-meal effect. Am. J. Clin. Nutr. 2006 83(4):817 – 822

3 Jenkins, D.J., Wolever, T.M., Taylor, R.H., Barker, H.M., Fielden, H. Exceptionally low blood glucose response to dried beans: Comparison with other carbohydrate foods. Br Med J 1980 281(6240):578 – 580

4 Miller, W.L., Crabtree, B.F., Evans, D.K. Exploratory study of the relationship between hypertension and diet diversity among Saba Islanders. Public Health Rep. 1992 Jul-Aug; 107(4):426-32.

5 Abeysekara, S., Chilibeck, P.D., Vatanparast, H., Zello, G.A. A pulse-based diet is effective for reducing total and LDL-cholesterol in older adults. Br J Nutr. 2012 Aug; 108 Suppl 1:S103-10.

6 Mollard, R.C., Luhovvy, B.L., Panahi, S. et al. Regular consumption of pulses for 8 weeks reduces metabolic syndrome risk factors in overweight and obese adults. Br J Nutr. 2012 Aug; 108 Suppl 1:S111-22.

7 Sievenpiper, J.L., Kendall, C.W., Esfahani, A. et al. Effect of non-oil-seed pulses on glycaemic control: a systematic review and meta-analysis of randomised controlled experimental trials in people with and without diabetes. Diabetologia. 2009 Aug; 52(8):1479-95

8 Darmadi-Blackberry, I., Wahlqvist, M.L., Kouris,-Blazos, A., Steen, B. et al. Legumes: the most important dietary predictor of survival in older people of different ethnicities. Asia Pac J Clin Nutr. 2004; 13(2):217-20.

9 Chang, W.C., Wahlqvist, M.L., Chang, H.Y. et al. A bean-free diet increases the risk of all-cause mortality among Taiwanese women: the role of the metabolic syndrome. Public Health Nutr. 2012 Apr; 15(4):663-672.

10 Winham, D.M., Hutchins, A.M. Perceptions of flatulence from bean consumption among adults in 3 feeding studies. Nutr J. 2011 Nov 21;10:128.

11 Lanza, E., Hartman, T.J., Albert, P.S. et al. High dry bean intake and reduced risk of advanced colorectal adenoma recurrence among participants in the polyp prevention trial. J Nutr. 2006 Jul; 136(7):1896-903.

12 Kapral, M., Wawszczyk, J., Jurzak, M., Hollek, A., Weglarz, L. The effect of inositol hexaphosphate on the expression of selected metalloproteinases and their tissue inhibitors in IL-1β-stimulated colon cancer cells. Int J Colorectal Dis. 2012 Nov; 27(11):1419-28.

13 Vucenik, I., Shamsuddin, A.M. Protection against cancer by dietary IP6 and inositol. Nutr Cancer. 2006; 55(2):109-25.

14 López-González, A.A., Grases, F., Monroy, N. et al. Protective effect of myo-inositol hexaphosphate (phytate) on bone mass loss in postmenopausal women. Eur J Nutr. 2013 Mar; 52(2):717-26.

15 Lopez-Gonzalez, A.A., Grases, F., Perello, J. et al. Phytate levels and bone parameters: a retrospective pilot clinical trial. Front Biosci (Elite Ed). 2010 Jun 1; 2:1093-8.

16 Messina, V. Nutritional and health benefits of dried beans. Am J Clin Nutr July 2014; 100 (Supp.1): 437S-442S.

17 Singhal, P., Kaushik, G., Mathur, P. Antidiabetic potential of commonly consumed legumes: a review. Crit Rev Food Sci Nutr. 2014; 54(5):655-72.

18 Zhu, B., Sun, R., Qi, L., Zhong, R. and Miao X. Dietary legume consumption reduces risk of colorectal cancer: evidence from a meta-analysis of cohort studies. Sci Rep. 2015 Mar 5; 5:8797.

19 Chan, Y.S., Xia, L., Ng, T.B. White kidney bean lectin exerts anti-proliferative and apoptotic effects on cancer cells. Int J Biol Macromol. 2016 Apr; 85:335-45.