Conjugated linoleic acid does not affect digestion and absorption of fat and starch-a randomized, double-blinded, placebo-controlled parallel study.

OBJECTIVE: Conjugated linoleic acid (CLA) is known as a potent agent for altering body weight and composition. However, its effect on the process of digestion is still unknown. The aim of this study has been to elucidate the effect of a 3-month supplementation with CLA on starch and fat digestion and absorption in humans. APPROACH: The study included 74 obese and overweight adults who were randomized to receive 3.0 g of CLA or sunflower oil as placebo daily for 3 months. Digestion and absorption of fat and starch was assessed using non-invasive breath tests with a stable 13C isotope (cumulative percentage dose recovery, CPDR) before and after the supplementation period. To exclude the effect of oxidation, in addition total energy expenditure (TTE) was measured by a 13C bicarbonate breath test. RESULTS: The changes in CPDR values (∆CPDR median 〈interquartile range〉) were no different between subjects from the CLA group and the placebo group (fat: -0.2 〈-9.1-4.1〉 versus 0.6 〈-7.0-8.0〉, p < 0.4796; starch: -1.3 〈-9.5-2.4〉 versus -1.0 〈-5.1-1.7〉, p < 0.5520, respectively). The incidence of negative and positive values of ∆CPDR was no different between groups [for fat: 53.1% versus 46.7%, RR 1.138, (95% CI 0.689-1.882) and for starch: 67.7% versus 56.7%, RR 1.195, (95% CI 0.804-1.777)]. The changes in TTE did not differ between the CLA and the placebo group (respectively 1 〈48; 267〉 versus -8 〈-120;93〉 kcal; p < 0.2728). CONCLUSION: Supplementation with CLA for 3 months did not affect fat and starch digestion assessed by 13C mixed triglyceride breath test and 13C starch breath test.

Mulberry leaf extract decreases digestion and absorption of starch in healthy subjects-A randomized, placebo-controlled, crossover study.

PURPOSE: Mulberry (Morus alba L.) leaf tea has recently received much attention as a dietary supplement due to the wide range of putative health benefits, such as antidiabetic effects. Nevertheless, data evaluating its influence on carbohydrate metabolism in humans are scarce. The present study aims to investigate the effect of mulberry leaf extract supplementation on starch digestion and absorption in humans. MATERIALS AND METHODS: The study comprised of 25 healthy subjects, aged 19-27 years. In all subjects, a starch 13C breath test was performed twice in a crossover and single blind design. Subjects were initially randomized to ingest naturally 13C-abundant cornflakes (50g cornflakes+100ml low fat milk) either with the mulberry leaf extract (36mg of active component-1-deoxynojirimycin) or the placebo and each subject received the opposite preparation one week later. RESULTS: The cumulative percentage dose recovery was lower for the mulberry leaf extract test than for the placebo test (median [quartile distribution]: 13.9% [9.9-17.4] vs. 17.2% [13.3-20.6]; p=0.015). A significant decrease was detectable from minute 120 after the ingestion. CONCLUSIONS: A single dose of mulberry leaf extract taken with a test meal decreases starch digestion and absorption. These findings could possibly be translated into everyday practice for improvement of postprandial glycemic control.

Twelve weeks CLA supplementation decreases the hip circumference in overweight and obese women. A double-blind, randomized, placebo-controlled trial.

BACKGROUND: Conjugated linoleic acid (CLA) reduces body weight (BW), body fat mass (BFM), and increases or maintains lean body mass in animals. However, the results concerning the effect of CLA on weight reduction in humans are contradictory. The present study aimed to evaluate the effect of CLA supplementation on the BW and anthropometric parameters (waist and hip circumferences) in overweight and obese adult women. METHODS: A total of 74 subjects (BMI: 28-42 kg/m2) were included in a double blind, placebocontrolled trial. Subjects were randomized into two groups, those supplemented with either 3.0 g/d CLA or with placebo (sunflower oil) for 12 weeks. RESULTS: CLA significantly decreased the hip circumferences compared to placebo (p = 0.016209), but had no effect on body weight, BMI, or waist circumference. The number of subjects with a reduction in hip circumference in the CLA group was significantly larger compared to that in the placebo group (p = 0.0017;  NNT= 2.65; CI [6.27-1.685]). CONCLUSIONS: In conclusion, our findings do not support the hypothesis that 12 weeks CLA supplementation, as dosed in the present study, is effective for body weight reduction in overweight and obese women. However, its local action in decreasing the hip circumference seems to be encouraging and suggests that CLA may represent an attractive dietary supplement.