Flow-mediated dilatation is impaired by a high-saturated fat diet but not by a high-carbohydrate diet.
Study Goal
The researchers aimed to determine whether a low-fat, high-carbohydrate diet impaired endothelial vasodilation compared to diets high in different types of fats.
Results Summary
The high-carbohydrate diet did not impair flow-mediated dilatation (FMD) relative to monounsaturated or polyunsaturated fat diets, despite raising triglycerides and lowering HDL cholesterol. It performed similarly to these diets and better than the saturated fat diet in terms of endothelial function.
Population
40 healthy subjects
Effective Dosage
Not specified (diet contained at least 25 g of relevant fat or was low-fat, high-carbohydrate)
Duration
3 weeks per diet
Interactions
None mentioned
| Intervention | Direction | Endpoint | Population | Dosage | Impact | Claim # |
|---|---|---|---|---|---|---|
high saturated fat (SFA) diet | decrease | flow-mediated dilatation (FMD) | forty healthy subjects | 5.41+/-2.45% versus 10.80+/-3.69% | impaired | #1 |
low-fat, high-carbohydrate (CARB) diet | no change | flow-mediated dilatation (FMD) | forty healthy subjects | - | did not change | #2 |
low-fat, high-carbohydrate (CARB) diet | increase | triglyceride | forty healthy subjects | 23% to 39% | rises | #3 |
low-fat, high-carbohydrate (CARB) diet | decrease | HDL cholesterol | forty healthy subjects | 10% to 15% | falls | #4 |
high saturated fat (SFA) diet | increase | P-selectin | forty healthy subjects | 121+/-52.7 ng/mL versus 98+/-44.5 ng/mL and 96+/-36.4 ng/mL | was highest | #5 |
high saturated fat (SFA) diet | decrease | flow-mediated dilatation (FMD) | forty healthy subjects | - | caused deterioration | #6 |
high saturated fat (SFA) diet | increase | inflammatory responses | forty healthy subjects | - | may also be increased | #7 |
OBJECTIVE: It is unknown whether a low-fat diet, which may elevate triglycerides and lower high-density lipoprotein (HDL) cholesterol, harms the endothelium. Our aim was to determine whether a low-fat, high-carbohydrate (CARB) diet impaired endothelial vasodilation compared with high saturated fat (SFA), monounsaturated fat (MUFA), or polyunsaturated fat (PUFA) diets. METHODS AND RESULTS: Forty healthy subjects were randomly crossed over to 4, 3-week isocaloric diets high in PUFA, MUFA, or SFA, containing at least 25 g of the relevant fat or a low-fat, CARB, high-glycemic load diet. Flow-mediated dilatation (FMD), fasting blood lipids, high sensitivity C-reactive protein, plasma intercellular, and vascular adhesion molecules plasma E- and P-selectin were measured after each intervention. SFA impaired FMD compared with all other diets (5.41+/-2.45% versus 10.80+/-3.69%; P=0.01). FMD did not change on CARB relative to MUFA or PUFA, despite 23% to 39% rises in triglyceride and 10% to 15% falls in HDL cholesterol. P-selectin was highest after SFA (121+/-52.7 ng/mL) versus MUFA (98+/-44.5 ng/mL; P=0.001) and PUFA (96+/-36.4 ng/mL; P=0.001). CONCLUSIONS: High SFA caused deterioration in FMD compared with high PUFA, MUFA, or CARB diets. Inflammatory responses may also be increased on this diet.