Beans, lentils and chickpeas: what the evidence says

The best evidence for pulses is on LDL cholesterol. A 2014 meta-analysis in the Canadian Medical Association Journal included 26 randomized trials lasting at least three weeks, each comparing a diet emphasizing beans, chickpeas, lentils or peas with a diet of the same calories without them. At a median of 130 g a day, about one serving, LDL fell by 0.17 mmol/L Ha 2014. That is a modest change, and two related measures (apolipoprotein B and non-HDL cholesterol) did not move, so the authors asked for longer and better trials. It is still a consistent result for a cheap, filling food.

Pulses are digested slowly and bring fiber and protein with their carbohydrate. A meta-analysis of 41 trials, in people with and without diabetes, found pulses eaten on their own lowered fasting blood glucose and insulin, and diets built around pulses as part of a low-glycemic-index or high-fiber pattern lowered HbA1c or fructosamine, markers of longer-term blood sugar Sievenpiper 2009. Results varied a great deal with diabetes status, the type and form of pulse, the dose and the quality of the study, which is why the grade stops at moderate. The blood sugar page compares other foods.

In 21 trials with 940 participants, adding about a serving of pulses a day led to slightly more weight loss, 0.34 kg on average over about six weeks, even in diets not designed to cut caloriesKim 2016. That is small and short-term, so count it as a side benefit rather than a reason to eat beans.

Fear of gas keeps many people away from beans. In three US feeding studies where adults ate half a cup of beans a day for 8 or 12 weeks, fewer than half reported more flatulence with pinto or baked beans in the first week, and only 19% did with black-eyed peas. Between 3% and 11% reported more gas even on the control diets Winham 2011. The authors concluded the worry is often exaggerated, and that people vary by bean type.

Starting with small portions and building up over a few weeks gives the gut time to adjust. Soaking and discarding the water is a traditional step covered on the soaking and souring page. If you want to see how much fiber your usual meals already provide, a nutrient tracker such as Cronometer totals it from its food database.

Raw kidney beans contain 20,000 to 70,000 hemagglutinating units of the toxin, fully cooked beans 200 to 400. White kidney beans have about a third as much as red ones FDA. Canned beans have already been cooked.

Any supermarket sells dried and canned pulses. For organic or less common varieties, iHerb lists dried lentils and other pulses.