CLA supplements may preserve, increase muscle during dieting: RCT
Twelve weeks of supplementation with BASF’s Tonalin TG 80 CLA ingredient led to significant increases in total and trunk muscle mass, compared to sunflower oil, in overweight Chinese adults on a low fat, low sugar diet with additional lifestyle coaching.
“One of the benefits of increasing MM [muscle mass] is to maintain a higher level of resting energy expenditure (REE),” wrote scientists from Xi'an Jiaotong University Health Science Center (China) and the University of Oxford in Nutrition, Metabolism and Cardiovascular Diseases. “The higher REE one has, the more calories expended in a resting state. Therefore, appropriately increasing REE is of great importance in weight management.
“Although an increase in REE was confirmed by other CLA trials, it is worth conducting more studies to evaluate whether the changes in REE driven by CLA are directly related to regional changes in MM.
“Collectively, our results may provide novel evidence that CLA supplementation may be effective in preserving trunk MM with body weight loss.”
“Benefits for core strength, spine bone mineral density and posture”
The study was welcomed by BASF, which supplies the Tonalin-branded CLA ingredient used in the study.
“Previous clinical studies have demonstrated that Tonalin CLA supplementation improves body composition by increasing lean muscle mass and promoting fat loss,” Dr Yoram Barak, Scientific Marketing Manager, North America, BASF Human Nutrition, told NutraIngredients-USA. “The findings from this new study is in line with existing literature on the observed benefits of supplementary CLA.
“This is important and especially relevant in the current COVID-19 situation where staying in is recommended. Though people are generally still active by changing their exercise routines, habits such as stress eating and increased snacking1, especially on highly processed food may lead to undesired weight gain. Light to moderate exercise together with CLA can help offset this effect of weight gain.
“In the group who consumed the CLA supplement, an increase of lean body (mostly muscle) mass was set off in part by a trend towards a body fat loss. This is a typical effect of CLA in a weight loss setting where both the Tonalin CLA group and the placebo group reduced body weight by 1 to 2kg.”
Dr Barak concluded: “Weight loss is often accompanied by a loss in muscle mass together with fat loss. Loss in muscle mass has negative health implications and therefore strategies that protect muscle mass are of value. A new finding in this study is the observation that the muscle mass was preserved, particularly in the trunk region of the body. This could have possible benefits for core strength, spine bone mineral density and posture.”
Study details
The researchers behind the new study recruited 66 Chinese adults aged between 18 and 45 to participate in their double-blind, randomized, placebo-controlled study. All participants had elevated body fat levels (greater than 20% for men or 30% for women), and were divided into two groups. Both groups received lifestyle counseling, which included adherence to a low-fat and low-sugar diet plus moderate exercise. One group received supplemental CLA (3.2 grams per day of Tonalin) and the other received placebo (3.2 grams of sunflower oil).
After 12 weeks of intervention, the results showed that participants in both groups experienced reductions in body weight, waist circumference, BMI, body fat percentage, and fat mass, and there were no statistically significant differences between the groups.
However, the CLA group experienced significant increases in trunk muscle mass, compared to placebo. And when the researchers limited their analysis to people with high adherence to the supplementation and lifestyle recommendations, they found a greater increase in both total and trunk MM in the CLA group, compared to placebo.
Additional sub-group analysis revealed that the effect on muscle mass seemed to be more evident in men and among individuals with a body mass index < 25 kg/m2. Greater benefits were also observed in participants, or those with higher self-rated physical activity.
How?
Commenting on the potential mechanism(s) of action, the researchers said this remains “insufficiently understood”.
“Rodent models showed that CLA administration may alter muscle energy metabolism via upregulating carnitine palmitoyltransferase 1 and uncoupling protein 2, thereby increasing energy expenditure and mitochondrial β-oxidation in the muscle,” they stated. “Moreover, based on limited evidence from animal models, it is postulated that CLA supplementation may influence muscle fiber type transformation accompanied by mitochondrial biogenesis with alterations in mitochondrial volume and composition, which are known pathways driven by resistance training aimed at increasing MM.
“Importantly, direct mechanistic studies are needed to uncover the precise mechanisms of muscle metabolism triggered by CLA.”
Source: Nutrition, Metabolism and Cardiovascular Diseases
Published online ahead of print, doi: 10.1016/j.numecd.2020.05.029
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