Biomedical Fast Takes
A small study published a few months ago in the American Journal of Clinical Nutritioncautions that MCTs (medium-chain triglycerides) can raise total cholesterol as much as palm oil and nearly 50% more than high oleic sunflower oil, a less saturated oil. The press release, issued by the university at which the study was conducted, championed the findings, which contradict the long-held belief that MCTs have a neutral effect on low-density lipoprotein (LDL), or “bad” cholesterol levels.
What’s wrong with this study? First, more than 100 other studies in the scientific literature have found that supplemental use of MCTs can provide a wide range of health benefits including:
- increased HDL (the “good” cholesterol) without increasing LDL
- improved mitochondrial function
- enhanced thermogenesis
- enhanced antibacterial activity in the GI tract
- stabilized brain waves
Moreover, these studies have found that MCTs provide rapid energy, yet have no significant effect on insulin production. Thus, MCTs can help eliminate the condition known as “false fatigue” which often occurs after eating simple sugars. MCTs can also reduce the breakdown of muscle tissue when dieting, and improve the absorption of amino acids critical for muscle tissue repair.
Second, the subjects of this study — nine overweight middle-aged men with slightly elevated cholesterol levels — consumed more than 50% of their daily calorie intake from fat! They were hardly representative of the general population. And with only nine participants, it’s virtually impossible to generalize.
Nevertheless, these obvious design flaws did not stop one of the study’s three researchers from concluding, “The findings show that all saturated fats, with the exception of stearic acid — which is found in chocolate and beef — raise cholesterol levels.” At the level of consumption for the oils tested — more than 10 times that of the average American!! — the amounts weren’t physiological. They were given at pharmacological dose levels!
When MCTs are used in parenteral care, for those who have difficulty absorbing fats, or by infants as part of a formula, the amounts consumed are only about 10% of total calories/day — about one-fifth the amount taken by the participants in this study.
The researchers’ conclusion also stands in stark contrast to a review in The Lancet,which concluded that many saturated fats do not increase cholesterol levels; there are only three which do. These are lauric, myristic, and palmitic fatty acids.
- Cater NB, Heller HJ, Denke MA. Comparison of the effects of medium-chain triacylglycerols, palm oil, and high oleic acid sunflower oil on plasma triacylglycerol fatty acids and lipid and lipoprotein concentrations in humans. Amer J Clin Nutr. 1997;65:41–45.
- La Voie A. Energy-boosting oil may boost cholesterol. Medical Tribune News Service. January 14, 1997.
- Ulbricht TLV, Southgate DAT. Coronary heart disease: seven dietary factors. The Lancet. 1991;338:985–993.