The hypotensive response to oral fat is comparable but slower compared with carbohydrate in healthy elderly subjects

The objective of the present study was to determine the comparative hypotensive responses to drinks containing predominantly fat and carbohydrate (CHO) in healthy elderly subjects. Using a randomised, cross-over study, the participants, twelve elderly subjects, six of them female (72.2 (sd 5.7) years), were investigated. On three separate days, blood pressure (BP) and heart rate were measured following ingestion of 300 ml drinks containing: (1) CHO (75 g glucose and 93 g Polyjoule (CHO polymer) providing 2732 kJ (653 kcal)); (2) 88 % fat (cream blended with milk providing 2732 kJ (653 kcal)); (3) water. Systolic BP decreased following the CHO drink (P<0.001) and the high-fat drink (P<0.001) but not water; there was no difference in the magnitude of the decrease between the CHO drink and the drink containing fat (13.4 v. 15.6 mmHg). However, the onset of the fall was slower after the fat-containing drink (13.0 v. 26.5 min (P=0.01); area under the curve for 0-30 min for CHO drink -6.5 v. fat-containing drink 125.4 mmHg x min (P=0.043)). We conclude that ingestion of a high-fat drink results in a comparable fall in BP to a CHO drink although the onset is relatively slower. These observations may have implications for the management of postprandial hypotension.