Reply to KC Hayes

University of São Paulo Medical School São Paulo 01246-903 Brazil E-mail: lipideq{at}usp.br

Dear Sir:

In our study of medium-chain triacylglycerols (MCTs) in hypertriglyceridemic individuals (1), we were disappointed to find that provision of MCTs as the major source of dietary fat did not lower plasma triacylglycerol concentrations, which was the major objective of the study, and in addition, had the inconvenience of raising plasma cholesterol. Hayes raises the possibility that a low-fat diet (carbohydrate- or MCT-rich) may correct the hypertriglyceridemia provided that an ideal proportion of 18:2 is added to the diet. This is an interesting suggestion that should be tested experimentally in humans no matter how convincing the animal data. Whatever answers one draws from future experiments on these proposed dietary modifications, the bottom line is that MCTs seem useless for the treatment of hyperlipidemia. In contrast, carbohydrate-induced hyperlipidemia, which is a well-known phenomenon that occurs in both healthy persons and in several cases of moderate hypertriglyceridemia, may benefit from Hayes's interesting proposal because it would likely be circumvented by adding the right amount of 18:2 to a fat-free diet without raising, and probably lowering, plasma cholesterol.

REFERENCE

1. Asakura L, Lottenberg AMP, Neves MQTS, et al. Dietary medium-chain triacylglycerol prevents the postprandial rise of plasma triacylglycerol but induces hypercholesterolemia in primary hypertriglyceridemic subjects. Am J Clin Nutr 2000;71:701–5.