High-Sugar Diet Linked To Insulin Resistance and Muscle Loss

27 Apr 2015 --- According to the latest statistics from the US Centers for Disease Control and Prevention (CDC), more than 19 million Americans (6% of the US population) are 75 years or older, a number that has been increasing steadily as the Baby Boom generation enters its golden years. The progressive loss of muscle mass and function (collectively called sarcopenia) often accompanies aging.

Sarcopenia, which can result from a variety of factors such as declining physical activity, hormonal changes, poor nutrition, and chronic inflammation, can impact a person's quality of life. And although researchers know that sarcopenia is generally due to an imbalance of muscle breakdown and synthesis, they continue to search for ways it might be prevented and treated. In a recent study published in the May 2015 issue of The Journal of Nutrition, a research team led by Dr. Laurent Mosoni (National Institute of Agronomic Research and Clermont 1 University, France) investigated the possibility that decreasing sucrose (table sugar) intake and increasing antioxidant/anti-inflammatory dietary supplements might be useful in this regard.

The study utilized relatively old male laboratory rats fed diets differing in sucrose and a multivitamin/multimineral supplement containing rutin, a bioactive antioxidant found in certain fruits and vegetables such as apples and onions. After 5 months, the researchers investigated how the various diets influenced the rats' body composition, overall inflammation and antioxidant status, insulin sensitivity, and protein synthesis rates.
 
Regardless of whether they consumed the rutin-containing supplement, animals fed the high-sucrose diets had less muscle and more fat than those fed the low-sucrose diets. Sucrose intake also altered insulin sensitivity such that animals eating the low-sucrose diet needed less insulin to regulate their blood sugar. Those consuming the low-sucrose diet also had higher muscle protein synthesis rates after a meal - an outcome that would theoretically stave off sarcopenia. Consuming the rutin-containing supplement reduced oxidative stress and slightly reduced the increase in fat mass, but had little effects on muscle mass. The researchers concluded that high chronic sucrose intake accelerates sarcopenia in older male rats via alteration of muscle protein synthesis, and that this may be modulated by insulin resistance. Of course, whether this holds true for elderly men will require controlled clinical experimentation.