Palmolein and olive oil consumed within a high protein test meal have similar effects on postprandial endothelial function in overweight and obese men: A randomized controlled trial

- Comparing saturated vs. unsaturated rich oils on postprandial endothelial function.
- Within the context of a high protein meal.
- Palmolein and olive oil had similar effects on postprandial endothelial function.
- Palmolein and olive oil had similar effects on triglycerides, insulin and glucose.

ObjectiveThis study assessed the postprandial effects of high fat, high protein meals containing either palmolein or olive oil on endothelial function in overweight/obese men.Design28 men (32-65 yr; 25-35 kg/m2) consumed, in random order 1 wk apart, isocaloric high protein, high fat meals (2791 kJ, 40 g protein (∼3 g l-arginine), 44 g fat, 21 g carbohydrate) prepared with either 40 g palmolein or 40 g olive oil after an overnight fast. The SFA:MUFA:PUFA ratio of the oils were: palmolein, 42:47:12; olive oil, 17:76:7. Brachial artery flow-mediated dilatation (FMD), circulating endothelial function markers, nitrotyrosine (oxidative stress marker), triglycerides, glucose and insulin were assessed pre-meal and hourly for 5 h. Mixed model procedures were used to analyze the data.ResultsMeal consumption increased serum triglycerides (time effect, P < 0.001); with no meal differences (meal × time interaction, P = 0.93). Serum insulin peaked 1 h post-consumption and returned to pre-meal concentrations by 5 h with both meals (time effect, P < 0.001; meal × time effect, P = 0.68). FMD, serum intercellular adhesion molecule-1 (ICAM-1) and E-selectin did not change (meal × time effect, P > 0.4). Olive oil transiently increased plasma nitrotyrosine after 1 h compared to palmolein (meal × time interaction, P = 0.002) whereas both meals increased serum vascular cell adhesion molecule-1 (VCAM-1) after 1 h (time effect, P < 0.001; meal × time interaction, P = 0.98). Both nitrotyrosine and VCAM-1 returned to pre-meal concentrations after 2 h.ConclusionIn the context of a high protein meal, palmolein similarly to olive oil did not affect postprandial endothelial function in overweight/obese men.Trial registrationAustralian New Zealand Clinical Trials Registry (ANZCTR) (http://www.anzctr.org.au/default.aspx). Trial ID: ACTRN12613000136707.