Twelve Weeks of Daily Lentil Consumption Improves Fasting Cholesterol and Postprandial Glucose and Inflammatory Responses-A Randomized Clinical Trial.

Lentils have potential to improve metabolic health but there are limited randomized clinical trials evaluating their comprehensive impact on metabolism. The aim of this study was to assess the impact of lentil-based vs. meat-based meals on fasting and postprandial measures of glucose and lipid metabolism and inflammation. Thirty-eight adults with an increased waist circumference (male ≥ 40 inches and female ≥ 35 inches) participated in a 12-week dietary intervention that included seven prepared midday meals totaling either 980 g (LEN) or 0 g (CON) of cooked green lentils per week. Linear models were used to assess changes in fasting and postprandial markers from pre- to post-intervention by meal group. Gastrointestinal (GI) symptoms were assessed through a survey randomly delivered once per week during the intervention. We found that regular consumption of lentils lowered fasting LDL (F = 5.53, p = 0.02) and total cholesterol levels (F = 8.64, p < 0.01) as well as postprandial glucose (ß = -0.99, p = 0.01), IL-17 (ß = -0.68, p = 0.04), and IL-1ß (ß = -0.70, p = 0.03) responses. GI symptoms were not different by meal group and all symptoms were reported as "none" or "mild" for the duration of the intervention. Our results suggest that daily lentil consumption may be helpful in lowering cholesterol and postprandial glycemic and inflammatory responses without causing GI stress. This information further informs the development of pulse-based dietary strategies to lower disease risk and to slow or reverse metabolic disease progression in at-risk populations.

Eight weeks of lentil consumption attenuates insulin resistance progression without increased gastrointestinal symptom severity: A randomized clinical trial.

Lentils lower acute glycemic responses and promote satiety, benefits that may aid in chronic disease prevention. However, perceived gastrointestinal (GI) effects may deter inclusion of dietary pulses in the diet. We hypothesized that 8 weeks of lentil-based vs meat-based meals would improve glycemic control and improve satiety in metabolically at-risk, nondiabetic adults. Because GI symptoms are rarely reported, we also explored the temporal effects of symptom severity. Adults with an increased waist circumference (male > 40 inches, female > 35 inches) participated in an 8-week dietary intervention that included 5 prepared midday meals each week that were isocaloric but varied in cooked green lentil dosage: 0 g (CON), 300 g (MOD), or 600 g (HI). Assessments included glucose and insulin integrated area under the curve measured during a 75-g carbohydrate tolerance test, hepatic Homeostatic Model of Insulin Resistance (HOMA-IR), and peripheral insulin resistance. On 1 randomized day each week, satiety was assessed at 4:00 pm and GI symptoms at 8:00 pm. A linear model assessed changes in glycemic and GI measures by meal group. Thirty adults (mean ± SD; age, 41.6 ± 11.7 years, body mass index, 35.1 ± 6.3) completed the intervention. HOMA-IR increased in CON (+1.2 units) and decreased in a dose-dependent manner in MOD (-0.9 units, P = .03) and HI (-1.5 units, P < .01) relative to CON. Most participants (87.4%) reported no to mild GI symptoms. Of these, flatulence was mild on average with bloating, abdominal discomfort, and cramping severity 0.3, 0.5, and 0.5 units lower (P < .001). We observed a dose-dependent reduction on rising hepatic insulin resistance and low GI symptom severity with long-term lentil consumption in metabolically at-risk adults.