6 New Scientific Findings About Supplements

Enhance Fat Metabolism With Leucine

Leucine is an essential amino acid that provides calories, builds proteins and chemically signals key metabolic pathways. Higher dietary intake of leucine is linked to a reduced risk of obesity. Researchers from Suzhou University in China, in a study on mice fed a high-fat diet, found that long-term leucine supplementation enhanced fat metabolism, prevented fat and weight gain, reduced fat accumulation in the liver and increased brown fat activity. Leucine activates the mTOR pathway, which is important for muscle protein synthesis. It stimulates brown fat, which helps regulate bodyweight by converting food energy to heat instead of storing it as fat. Leucine is an important supplement for bodybuilders. Whey protein is high in leucine, but athletes benefit from additional leucine supplements (about three grams per protein shake). (Food & Nutrition Research, published online September 9, 2016)

Caffeine Boosts Mental and Physical Performance

Caffeine— found in coffee, cola, tea, energy drinks, plants and chocolate— is a favorite stimulant of physically active people. It stimulates the central nervous system by blocking adenosine receptors and enhances the effect of adrenaline (epinephrine). Caffeine may improve endurance, muscle strength and endurance, and sprint speed. A literature review led by Tom McLellan from TM McLellan Research in Canada concluded that moderate levels of caffeine (less than 400 milligrams) increase alertness, reaction time, attention and focus. Caffeine protects nerve cells, so it has long-term benefits on memory. The diuretic and cardiac stimulating properties of caffeine increase the risk of abnormal heart rhythms. Higher doses can cause anxiety and insomnia. (Neuroscience & Biobehavioral Reviews, published online September 6, 2016)

The FDA Removes Vinpocetine from the Market

Vinpocetine— a plant extract first isolated in 1975— increases brain blood flow and is a popular memory-boosting supplement sold by many mainstream supplement companies. The Food and Drug Administration (FDA) has ruled that vinpocetine should be removed from the market because it does not meet the definition of a dietary supplement as defined by the Dietary Supplement Health and Education Act. Under the act, supplement makers do not need FDA approval to sell supplements that were marketed before 1994. The FDA claims that vinpocetine should be classified as a pharmaceutical because it is chemically synthesized and analysis of marketed products found that few contained the vinpocetine listed on the label. The Natural Products Association argued that the product has no serious side effects and has been included in supplements for decades. They view the FDA action as an attempt to increase its ability to regulate supplements. (nutraingredients-usa.com, September 8, 2016)

High Doses of Antioxidant Supplements Block Fitness Gains

Antioxidant supplements such as vitamins C and E suppress highly reactive chemicals called free radicals. During normal metabolism, the body produces free radicals implicated in aging, degenerative diseases and immune system breakdown. Think of free radicals as biological rust that attacks vital cell membranes and genes. Vitamins C and E act as antioxidants that help combat free radicals and protect the body from their destructive effects. Free radicals do good things, too. A study led by John Hourihan from Harvard Medical School found that antioxidants suppress an enzyme called IRE-1 that is important for triggering cell repair and protein synthesis. Antioxidant supplements can interfere with tissue repair and fitness gains, so athletes should consume foods high in antioxidants (fruits and vegetables) instead of supplements and drugs that suppress them.

Protein Plus Carb Supplement During Intense Training Increases Muscle Mass

Supplementing proteins and carbohydrates immediately after intense cycling increased muscle cross sectional area (measured by muscle biopsy) but had no effect on performance during a 30-kilometer cycling time trial. A sophisticated study by Andrew D’Lugos, Michael Saunders and colleagues from James Madison University in Virginia examined the effects of supplemental protein plus carbohydrates versus carbohydrates during normal, intense and reduced intensity cycle training on skeletal muscle and performance in a cycling time trial. They used only seven subjects and the training blocks lasted only 10 days. They found measureable changes in muscle structure during a short training cycle, so supplementing protein during intense training might enhance performance during longer cycles. (Nutrients, 8: 550, 2016)

Vitamin D Supplements Promote Blood Sugar Regulation

Supplementing 420 IUs of vitamin D for one year in Japanese adults resulted in small decreases in blood sugar and insulin resistance— according to a study led by Xiaomin Sun from Waseda University in Japan. Individual differences in exercise habits and body composition did not influence the results. While the study was interesting, they didn’t use a control group and the changes in blood sugar were small, so it’s difficult to establish whether the supplement made any difference. Also, the supplement dose was much lower than recommended by some nutrition experts (at least 1,000 IU per day). Many studies support the role of vitamin D in preventing some cancers, heart disease, fractures, type 2 diabetes, autoimmune diseases, flu and depression. (Nutrition Research, published online July 27, 2016)