Triglycerides are fat molecules consumed in foods. When you have your cholesterol checked, your health-care provider will likely also check your serum triglycerides, which are fat molecules circulating in your blood stream. Elevated serum triglyceride levels typically correlate with an unhealthy cholesterol profile. However, medium-chain triglycerides are receiving increasing attention as healthy fats that increase energy and lower body fat without negatively affecting your cholesterol profile.
Cholesterol
Cholesterol serves an important role in human health. Yale University's Dr. Jonathan Isaacsohn outlines the three main functions of cholesterol in the human body: Cholesterol is used by some glands to manufacture hormones, including sex hormones; it helps produce bile acids in the liver, necessary for the digestion of fats; and it is an important structural component of cell membranes. According to the American Heart Association, about 75 percent of cholesterol is made by your body, while about 25 percent comes from diet.
Your Cholesterol Profile
While cholesterol is necessary for human health, too much low-density lipoprotein, or LDL cholesterol can cause an accumulation of plaque on arterial walls. High-density lipoprotein, or HDL, helps to regulate LDL levels and prevent plaque buildup. A balanced ratio of HDL to LDL cholesterol, which is your cholesterol profile, is considered desirable for cardiovascular and arterial health. At one time, foods containing high levels of medium-chain triglycerides were thought to promote production of LDL cholesterol and inhibit the production of HDL. But a growing body of research indicates that MCTs may not affect cholesterol levels and may have a positive impact on health.
Medium-chain Triglycerides
Triglycerides are molecules made from chains of carbon atoms ranging from two to 22. Long-chain triglycerides are chains of 12 to 18 carbon atoms, and are found in saturated animal fats. Medium-chain triglycerides, found in milk fat, palm oil and coconut oil, are chains of six to 10 carbon atoms. Their relative short length gives MCTs distinctive properties, including being more quickly absorbed by the body and more readily burned as fuel than long-chain triglycerides. MCTs contain only 8.3 calories per gram versus 9 calories in long-chain triglycerides. A 2002 review of studies published in the "Journal of Nutrition" found dietary MCTs to increase energy expenditure, give a greater sense of satiety and facilitate weight control when substituted for long-chain triglycerides.
MCTs and Cholesterol
Because MCTs are saturated fats, they were at one time thought to pose a health risk for high cholesterol. But a growing body of research indicates that MCTs do not impact cholesterol in the same way as long-chain saturated fats. A 2002 Japanese study of healthy men found the effect of dietary MCTs to be similar to that of unsaturated vegetable oils in promoting a healthy cholesterol profile. A 2009 Brazilian study of women presenting abdominal obesity found that coconut oil, which is high in MCTs, did not have a negative impact on the cholesterol profile of subjects but was effective in reducing abdominal obesity.
References
- "Nutrition Review"; Medium Chain Triglycerides; Ward Dean, M.D., and Jim English
- "Journal of Nutrition"; Physiological Effects of Medium-chain Triglycerides: Potential Agents in the Prevention of Obesity; M.P. St. Onge and P. Jones; March 2002
- American Heart Association: About Cholesterol
- Yale University School of Medicine Heart Book; The Role of Cholesterol; Jonathan Isaacsohn, M.D.
- "Bioscience, Biotechnology and Biochemistry"; Effects of Dietary Medium-chain Triacylglycerols on Serum Lipoproteins and Biochemical Parameters in Healthy Men; N. Nosaka, et al.; August 2002
- "Lipids"; Effects of Dietary Coconut Oil on the Biochemical and Anthropometric Profiles of Women Presenting Abdominal Obesity; M. L. Assuncao, et al.; May 2009
