Relationship of dietary fat to plasma fatty acids, blood pressure, and urinary eicosanoids in adult men.
This experiment was conducted to determine the relationships between modest changes in dietary linoleate, blood pressure (BP) response, and levels of eicosanoid synthesis in humans. Products of eicosanoids which appear in blood were measured in urine: PGI2, 6-keto-PGF1 alpha (KPGI2); TXA2, (TXB2); PGF2 alpha, 13,14-dihydro-15-keto-PGF2 alpha, (MPGF2 alpha). Twenty-three adult men were fed controlled diets having 25 energy percent fat, and having P/S ratios of either 0.3 (low-PUFA) or 1.0 (high-PUFA), for a total of 12 weeks, with a switchover between P/S ratios at 6 weeks. The results showed that, under the conditions of this study, BP was significantly reduced by reducing dietary fat intake from about 37 to 25 energy percent. However, no further effects on BP were produced by increasing the P/S ratio from 0.3 to 1.0. KPGI2 excretion was significantly lowered on both controlled diets as compared to the self-selected (SS) diet. However, MPGF2 alpha was lowered only on the low-PUFA diet as compared to the self-selected diet. No significant decrease in TXB2 excretion was observed. Both MPGF2 alpha and KPGI2 excretion were positively correlated with urine volume and sodium excretion. On the SS diet, but not on the controlled diets, MPGF2 alpha excretion was negatively correlated with plasma linoleate and positively correlated with stearate. On the low-PUFA diet, MPGF2 alpha excretion increased with the intake of linoleate, while, on the high-PUFA diet, it decreased. This may have been due to the limited amounts of linoleate available in the low-PUFA diet (3.2-3.4 energy percent) as compared to that in the high-PUFA diet. Both KPGI2 and MPGF2 alpha excretion were positively correlated with systolic and diastolic BP. These results suggest that the amount of dietary linoleate is an important factor in the regulation of prostaglandin synthesis in humans.
Judd
J T
JT
Lipid Nutrition Laboratory, Beltsville Human Nutrition Research Center, USDA Maryland 20705.
Marshall
M W
MW
Dupont
J
J
D000328:Adult; D001794:Blood Pressure / Q000187:drug effects*; D004041:Dietary Fats / Q000494:pharmacology*; D015777:Eicosanoids / Q000378:metabolism / Q000652:urine*; D005227:Fatty Acids / Q000097:blood / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011453:Prostaglandins / Q000378:metabolism* / Q000652:urine
D004041:Dietary Fats; D015777:Eicosanoids; D005227:Fatty Acids; D011453:Prostaglandins