Endotoxemia is modulated by quantity and quality of dietary fat in older adults.

Aging is an important determinant of the rate of atherosclerosis development, mainly through low-grade inflammation. Diet, and particularly its fat content, modulates the inflammatory response in fasting and postprandial states. We aimed to study the effects of dietary fat on endotoxemia in healthy older adults. Twenty healthy older adults were randomized to three diets, lasting three-weeks each, using a crossover design: 1. A Mediterranean diet enriched in MUFA with virgin olive oil. 2. An SFA-rich diet. 3. A low-fat high-carbohydrate diet enriched in n-3 PUFA (α-linolenic acid of plant origin) (CHO-PUFA diet). At the end of each period, after a 12-h fast, the subjects received a meal with a composition similar to the dietary period just completed. We determined the fasting and the postprandial plasma levels of lipopolysaccharide (LPS) and LPS-binding protein (LBP). In the fasting state, we observed lower LPS plasma levels after the consumption of the CHO-PUFA diet (P=0.046) in comparison with the consumption of the Med and SFA-rich diets. In the postprandial measurements, we observed a statistically significant increase in plasma levels of LPS (P=0.044) and a decrease in LBP (P=0.003) after the intake of the CHO-PUFA meal, whereas no postprandial changes were observed after the ingestion of the Med and SFA-rich meals. Our results, together with those obtained in a previous study, support the concept that the consumption of the Med Diet, in contrast to a low-fat PUFA diet, constitutes a more suitable dietary lifestyle for preventing the development of atherosclerosis in a population at risk, such as older adults.