A compound naturally present in blueberries may promote fat burning in muscle cells, potentially aiding weight loss, according to a study by Japanese researchers. The compound, pterostilbene, a polyphenol known for its cell-protective properties, was found to cause muscle cells to expend more energy.
In laboratory experiments, researchers exposed mouse muscle cells to pterostilbene. The study observed that the compound triggered a pathway within the cells responsible for breaking down ectopic fat. Ectopic fat is fat that accumulates within muscle cells, a condition known as myosteatosis, which is associated with an increased risk of developing conditions like diabetes.
"Our findings establish a scientific framework for developing functional foods and nutritional supplements that target muscle fat metabolism," said Dr. Takakazu Mitani, lead author of the study. "However, beyond the potential of pterostilbene itself, this work provides an experimental framework for identifying other natural compounds that [could also burn fat]."
Previous animal research has suggested that pterostilbene can contribute to weight loss, including in the liver. However, scientists emphasize that further testing in humans is necessary to confirm these effects. The current study did not specify the concentration of pterostilbene used to achieve the fat-breaking effect in muscle cells.
For context, a 2014 study involving rats that showed weight loss utilized a dosage equivalent to approximately 15 milligrams of pterostilbene per kilogram of body weight. This would equate to more than 20,000 blueberries for a kilogram of rat, given that a one-gram blueberry contains up to 520 nanograms of the compound.
The new research, published in the journal Food Bioscience, also examined four other compounds found in grapes, peanuts, rhubarb, red wine, and cranberries. The study specifically found that pterostilbene enhanced the activity of a receptor known as peroxisome proliferator-activated receptor delta (PPARδ), which plays a role in the breakdown of fat cells. This mechanism reduced fat accumulation within muscle cells, potentially lowering the risk of obesity, diabetes, and insulin resistance.
Additionally, the researchers noted that pterostilbene might encourage muscle cell growth, which could improve exercise performance and recovery. "We currently lack approved treatments specifically targeting myosteatosis," Mitani stated. "This critical gap led our team to screen food-derived compounds for natural, dietary interventions."
Ectopic fat accumulation, often exacerbated by high-calorie diets, aging, and sedentary lifestyles, can impair normal muscle function and contribute to chronic health issues such as type 2 diabetes and insulin resistance. While more human studies are required, the researchers believe pterostilbene could be a significant compound in reducing the risk of these conditions and enhancing metabolism over time.