Effect of Dietary Fat and Omega-3 Fatty Acids on Urinary Eicosanoids and Sex Hormone Concentrations in Postmenopausal Women: A Randomized Controlled Feeding Trial

Abstract

Substantial evidence relates increased sex hormone concentrations with increased breast cancer risk. Varying omega-3 (n-3) fatty acid (FA) intake may lead to alterations in eicosanoid balance and changes in circulating sex hormones that reduce risk. To clarify effects of dietary fat and n-3 FA intake on breast cancer risk markers, circulating sex hormones and urinary eicosanoids were measured in response to controlled feeding of diets designed to increase plasma concentrations of n-3 FA. A controlled cross-over feeding trial in postmenopausal women was conducted using 3 diets: high fat (HF; 40% energy from fat), low fat (LF; 20% energy from fat), and low fat plus n-3 FA (LFn3; 20% of energy from fat plus 3% of energy from n-3 FA) in 8-wk feeding periods. Plasma phospholipid fatty acid n-3 increased with the LFn3 relative to HF and LF (P < 0.0001). Plasma estradiol increased by 51% with HF (P = 0.03). Urinary prostaglandin E metabolite increased with HF relative to LF (P = 0.02) and urinary 11-dehydro-thromboxane B(2) increased with HF (P = 0.01). These results do not support a role of n-3 FA in the reduction of sex hormone levels.

Associations of long-chain ω-3 fatty acids and fish intake with endometrial cancer risk in the VITamins And Lifestyle cohort

“…In a smaller controlled, crossover feeding trial of 16 postmenopausal women, a low-fat diet and a low-fat, high v-3 diet were associated with a higher excretion of urinary estrogens (42). In the same study, no relative increase in sex hormones measured in blood was found (43). It is possible that, in overweight and obese women, increased estrogen production from adipose tissue in conjunction with that from v-3 intake may lead to a greater risk.…”

Long-chain ω-3 fatty acid intake and endometrial cancer risk in the Women’s Health Initiative

“…However, studies of nonsteroidal anti-inflammatory drugs suggested an inverse association in obese women only (47). There is limited evidence that v-3 is associated with endogenous sex hormones (48), but findings from a number of small controlled feeding trials were inconsistent (49)(50)(51)(52)(53). That the association between LCv-3PUFA and endometrial cancer was restricted further to type I cancers, which are considered estrogen-responsive (54), strongly suggested interrelations in fatty acids, sex hormones, inflammation, and cancer risk.…”

Effect of Different Cooking Methods on Minerals, Vitamins, and Nutritional Quality Indices of Rainbow Trout (Oncorhynchus mykiss)

“…EPA + DHA:EPA and DHA are long chain n-3 fatty acids that are precursors of hormones known as eicosanoids which play important roles in biological processes within the body. [26] According to American Heart Association about 1.0 g/day of EPA+DHA, or two servings of fatty fish per week reduce the risk of death from coronary heart disease. [27] Consequently, "EPA (2014) In another study have shown in cooked kutum roach (Rutilus frisii kutum) the "EPA+DHA" content reduced during cooking procedure which supports our findings about reduction of "EPA+DHA" content.…”