Meta-analyses support curcumin’s weight management potential
Writing in the The American Journal of Clinical Nutrition, scientists from Thailand report that curcumin supplementation was associated with reductions in BMI, body weight, and waist circumference in adults with nonalcoholic fatty liver disease (NAFLD), polycystic ovary syndrome (PCOS), metabolic syndrome (MetS).
The researchers believe that, “Curcumin supplementation should be an option for treating and managing these patients, additional to lifestyle modification.”
Over two-third of adults and almost one-third of children and adolescents in the United States are overweight or obese, according to the NIH. Forty-five percent of Americans who are overweight and sixty-seven percent of those with obesity are trying to lose weight by adapting healthy dietary patterns, reducing caloric intake, and engaging in physical activity. These lifestyle modifications can be difficult, so people turn to dietary supplements promoted for weight loss in hopes that these products will help them more easily achieve their weight loss goals.
The study adds to the ever-growing body of evidence supporting the potential health benefits of turmeric (Curcuma longa) and the curcuminoids it contains (curcumin, demethoxycurcumin and bisdemethoxy curcumin). The botanical has been reported to have a range of health benefits, including brain, cardiovascular, joint, and muscle health.
The category has enjoyed meteoric growth over the last decade. According to the 2021 Herb Market Report published by the American Botanical Council (HerbalGram 136), turmeric is the number two selling herb in the natural channel, with $37.99 million in sales. It is number five in the mass channel (MULO) with $111.66 million in sales.
Consumer awareness and understanding of the botanical’s potential benefits are now very high, with data from the ITC Insights 2020 Consumer Survey showing that 86% of supplement consumers are familiar with curcumin/turmeric.
The new systematic umbrella review and updated meta-analysis (SRMAs) of randomized controlled trials (RCTs) evaluated the effects of three types of curcumin formulations on anthropometric indices.
The researchers identified 14 systematic reviews and meta-analyses (SRMAs) of 39 individual randomized controlled trials (RCTs) eligible for the umbrella review. In addition, a total of 82 individual RCTs were identified since the last search of SRMA in April 2021, of which 9 RCTs were eligible for the updated MA. In addition, 2 RCTs were identified and eligible from the reference lists, resulting in 50 individual RCTs.
Of the 50 studies, there were 3 types of curcumin formulations such as whole compounds (turmeric rhizome, powder, or capsules) with dosages ranging from 2000 to 3000 mg/d, curcumin extracts with the dosages ranging from 500 to 1950 mg/d, and bioavailability-enhanced formulas.
Bioavailability-enhanced formulas had various dosages, including curcumin ranging from 500 to 1000 mg and adding piperine 5 to 10 mg/d, nanocurcumin ranging from 80 to 180 mg/d, liposome as phytosomal or phospholipid ranging from 250 to 1000 mg/d, micelles at 294 mg/d, and amorphous dispersion at 500 mg/d.
The data indicated that curcumin supplementation was associated with a significantly reduced BMI, BW, and WC with mean differences (MDs) of −0.24 kg/m2, −0.59 kg, and −1.32 cm, respectively. Curcumin was found to significantly reduce BMI by approximately −0.74, −0.41, −0.28, and −0.23 kg/m2 in adults with PCOS, NAFLD, obesity, and MetS, respectively.
The researchers also found that the bioavailability-enhanced curcumin forms reduced BMI, BWs, and WC more, with MDs of −0.26 kg/m2, −0.80 kg, and −1.41 cm, respectively.
The exact mechanisms underlying the effects of curcumin supplementation on weight loss and anthropometric indices remain unclear. Possibilities include increased adipocyte apoptosis, fatty acid oxidation, reduction in inflammation via the inhibition of NF-κB in adipose tissue, increased metabolic activity in brown and white fat, increased adiponectin levels, and decreased leptin levels.
“Tthis study demonstrated that curcumin supplementation reduces BMI, BW, and WC, particularly in adults with PCOS, NAFLD, obesity, or MetS,” wrote the researchers.
“The benefit of curcumin supplementation seems to be the greatest in adults with obesity or T2DM. Bioavailability-enhanced formulas are preferred for their greater average treatment effect than either whole compounds or curcumin extracts.”
Source: The American Journal of Clinical Nutrition
Published online 2023 March 9 doi: https://doi.org/10.1016/j.ajcnut.2023.03.006
“The effect of curcumin supplementation on weight loss and anthropometric indices: an umbrella review and updated meta-analyses of randomized controlled trials.”
Authors: C. Unhapipatpong et al