Low-fat, high-fiber diet and serum estrone sulfate in premenopausal women.

The effect of diet on serum estrogen levels was investigated in 17 healthy premenopausal women consuming defined diets prepared in a metabolic unit. During an initial 4-wk control period all women consumed a typical Western diet (40% of total calories from fat, 400 mg cholesterol/d, 12 g dietary fiber/d, and a ratio of polyunsaturated to saturated fatty acids [P:S] of 0.5). After this control period they were switched to a low-fat, high-fiber diet for 8-10 wk, which consisted of 25% of calories from fat, P:S of 1.0, cholesterol of 200 mg cholesterol/d, and 40 g dietary fiber/d. Compared with the control period 16 of 17 women had lower serum estrone sulfate levels on the low-fat, high-fiber diet. There was an average decrease of 36% with mean levels decreasing from 2.11 +/- 0.25 nmol/L (means +/- SEM) on the control diet to 1.29 +/- 0.19 nmol/L on the experimental diet (p less than 0.001). We conclude that a low-fat, high-fiber diet can significantly reduce serum estrone sulfate levels.

Plasma lipoprotein cholesterol and endogenous sex hormones in healthy young women.

Relationships between plasma levels of lipoproteins and sex hormones were studied in 24 healthy premenopausal women with no risk factors for coronary heart disease. The women were carefully selected to remove the effects of other environmental factors, such as smoking, drugs, alcohol, and exercise, which are known to influence lipid metabolism. They all ate precisely the same Western-style diet for 1 to 2 weeks before blood samples were obtained in the follicular phase of their menstrual cycle. After adjusting for other hormones by multiple regression, significant positive partial correlations were seen between high density lipoprotein cholesterol (HDL-C) and protein bound estradiol (r = .57, P = .02), as well as between very low density lipoprotein cholesterol (VLDL-C) and protein bound estradiol (r = .63, p = .01). A significant negative partial correlation was seen between VLDL-C and free estradiol (r = -.65 P = .01). Conversely, low density lipoprotein cholesterol (LDL-C) levels were negatively correlated with protein bound estradiol (r = -.77, P less than .001) and positively correlated with free estradiol (r = .71, P less than .001). No associations between plasma lipoproteins and testosterone were seen; however, androstenedione was positively correlated with VLDL-C (r = .59, P = .01). These findings show a close link between plasma lipoproteins and sex hormones, and may help to explain the lower risk of coronary heart disease in women.

Changes in plasma lipoprotein concentrations and composition in response to a low-fat, high-fiber diet are associated with changes in serum estrogen concentrations in premenopausal women.

We have investigated the effects of a low-fat, high-fiber diet on plasma lipid and lipoprotein levels and serum sex hormone concentrations in 22 normal premenopausal women (mean age, 25.8 +/- 3.8 years). Participants consumed a baseline diet for 4 weeks (40% of calories as fat, 16% as saturated fatty acids, 8% as polyunsaturated fatty acids, 400 mg/d cholesterol, and 12 g/d dietary fiber) and then a low-fat, high-fiber diet for 8 to 10 weeks (16% to 18% of calories as fat, 4% as saturated fatty acids, 4% as polyunsaturated fatty acids, 150 mg/d cholesterol, and 40 g/d fiber). Blood samples for determination of plasma lipids and serum hormones were obtained during the follicular and luteal phases of the menstrual cycle during both diets. Compared with the baseline diet, the low-fat, high-fiber diet resulted in significant decreases in total cholesterol (TC), low-density lipoprotein (LDL) cholesterol, and high-density lipoprotein (HDL) cholesterol concentrations during both the follicular and luteal phases (TC, -14% and -16%; LDL cholesterol, -14% and -17%; and HDL cholesterol, -15% and -18%, respectively). During the follicular phase but not the luteal phase on the low-fat, high-fiber diet, women exhibited significant increases in plasma triglyceride ([TG] 22%) and very-low-density lipoprotein (VLDL)-TG (36%) concentrations. During the follicular phase, serum estrone sulfate concentrations decreased by 25% (P < .0001) when subjects were fed the low-fat, high-fiber diet.(ABSTRACT TRUNCATED AT 250 WORDS)

Changes in food patterns during a low-fat dietary intervention in women.

The Women's Health Trial was initiated by the National Cancer Institute to study the effects of a low-fat diet on the incidence of breast cancer in women at elevated risk for the disease. The purpose of this article is to examine the specific dietary changes that 173 women made while participating in a feasibility intervention program to reduce their fat intake to approximately 20% of total calories over a 12-month period. The intervention program used group sessions to teach nutrition information and behavioral skills necessary to make a life-style dietary change. Four-day food records were collected from participants at the beginning of the study and again at 12 months. Women in the intervention group reduced their total fat intake from a mean of 76 gm (39% of total energy) to 31 gm (22% of total energy), mainly by decreasing their fat intake from milk products, red meats, and fats/oils. These women used cheddar cheese, American cheese, whole milk, butter, mayonnaise, salad dressing, bacon, and hamburgers less frequently, and used diet American cheese, low-fat cottage cheese, and skim milk more frequently. They consumed less fat in their vegetable dishes, and their total caloric intake from fruit increased slightly. In addition, the overall quality of the diets improved, since there was a 20% to 50% increase in the energy-adjusted intake of vitamins and minerals from food sources.

Oral (n-3) fatty acid supplementation suppresses cytokine production and lymphocyte proliferation: comparison between young and older women.

The effect of (n-3) fatty acid supplementation on cytokine production and lymphocyte proliferation was investigated in young (23-33 y) and older (51-68 y) women. Subjects supplemented their diets with 2.4 g of (n-3) fatty acid/d for 3 mo. Blood was collected before and after 1, 2 and 3 mo of supplementation. The (n-3) fatty acid supplementation reduced total interleukin (IL)-1 beta synthesis by 48% in young women but by 90% in older women; tumor necrosis factor was reduced by 58% in young and 70% in older women. Interleukin-6 was reduced in young women by 30% but by 60% in older women. Older women produced less IL-2 and had lower mitogenic responses to phytohemagglutinin (PHA) than young women prior to (n-3) fatty acid supplementation. The (n-3) fatty acid supplementation reduced IL-2 production in both groups; however, this reduction was significant only in older women. The PHA-stimulated mitogenic response was significantly reduced by (n-3) fatty acid in older women (36%). Thus, long-term (n-3) fatty acid supplementation reduced cytokine production in young women and cytokine production and T cell mitogenesis in older women. The reduction was more dramatic in older women than in young women. Although (n-3) fatty acid-induced reduction in cytokine production may have beneficial anti-inflammatory effects, its suppression of IL-2 production and lymphocyte proliferation in older women may not be desirable.

The effect of dietary fat and fiber on serum estrogen concentrations in premenopausal women under controlled dietary conditions.

The effect of dietary fiber and fat on serum sex hormones was studied in premenopausal women. After an initial control period during which the diet was high in fat (40% of calories as fat) and low in fiber (12 g/day), the amounts of fat and fiber were varied in the setting of a metabolic kitchen and carefully monitored meals. Forty-eight women completed 58 protocols. When the diet was changed to low-fat (20-25% calories as fat) and high fiber (40 g/day), there were significant decreases in serum concentrations of estrone, estrone sulfate, testosterone, androstenedione, and sex hormone binding globulin (SHBG) and near significant decreases in estradiol and free estradiol. When independent effects were examined, high fiber alone caused a decrease in estradiol and SHBG, whereas fat and fiber caused the observed decrease in estrone sulfate. Dietary fat independently influenced the serum concentration of androstenedione. Increased dietary fiber caused a lengthening of the menstrual cycle by 0.72 day and a lengthening of the follicular phase by 0.85 day.