The effect of a medium chain triglyceride (MCT) preparation on blood ketones was determined in fourteen normal subjects and six patients with diabetes mellitus of the maturity-onset type. Ingestion of 100 gm. of the MCT (containing 86 per cent C8 and 14 per cent C10 fatty acids) was followed by a small but statistically significant rise in blood ketones in each of the groups. The rise in ketones was slightly but significantly higher in the diabetic patients than in the normal subjects. In all subjects, ketone rises were negligible after ingestion of 100 gm. of corn oil.
The ketogenic effect of MCT may result in part from its rapid absorption from the gut, with a high proportion of the component fatty acids traveling in the portal vein directly to the liver in the free acid form. In the liver, these fatty acids appear to be rapidly degraded and converted in part to ketones. The predictable mild hyperketonemia induced by MCT makes this glyceride a useful tool in the study of ketogenesis.