Types of Dietary Fat and Soy Minimally Affect Hormones and Biomarkers Associated With Breast Cancer Risk in Premenopausal Women

Brown, Blakely; Thomas, William; Hutchins, Andrea M.; Martini, Margaret C.; Slavin, Joanne L.

doi:10.1207/s15327914nc431_2

Cited by 27 publications

(53 citation statements)

References 31 publications

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“…The results of the present study agree with some of the previous reports (2,4,9,23) that described an increase in the 2:16α-OH E 1 ratio and disagree with others (24,25) that observed no effect on the 2:16α-OH E 1 ratio after a soy intervention. The studies varied in feeding duration but were generally short-term (ranging from 1–3 menstrual cycles to 100 days) and mostly used soy protein or highly processed isoflavone-containing products.…”

Section: Discussionsupporting

confidence: 83%

Urinary Estrogen Metabolites During a Randomized Soy Trial

Morimoto

Conroy

Pagano

et al. 2012

Nutrition and Cancer

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One of the hypothesized protective mechanisms of soy against breast cancer involves changes in estrogen metabolism to 2-hydroxy (OH) and 16α-OH estrogens. The current analysis examined the effect of soy foods on the 2:16α-OH E1 ratio among premenopausal women during a randomized, crossover intervention study; women were stratified by equol producer status, a characteristic thought to enhance the protective effects of soy isoflavones. The study consisted of a high-soy diet with 2 soy food servings/day and a low-soy diet with <3 servings of soy/week for 6 months each; estrogen metabolites were measured in 3 overnight urines (baseline and at the end of the low- and high-soy diet) using gas chromatography mass spectrometry for the 82 women who completed the study. Urinary isoflavonoids were assessed by liquid chromatography mass spectrometry. When applying mixed models, the 2:16α-OH E1 ratio increased (p=0.05) due to a non-significant decrease in 16α-OH E1 (p=0.21) at the end of high-soy diet. Similar non-significant increases in the 2:16α-OH E1 ratio were observed in equol producers (p=0.13) and non-producers (p=0.23). These findings suggest a beneficial influence of soy foods on estrogen metabolism regardless of equol producer status.

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Section: Discussionsupporting

confidence: 83%

Urinary Estrogen Metabolites During a Randomized Soy Trial

Morimoto

Conroy

Pagano

et al. 2012

Nutrition and Cancer

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“…In one 2-month intervention study with 62 women a significant reduction was observed in luteal estradiol and estrone levels among wheat-bran but not oat- or corn-bran supplements groups [66]. However, two other dietary intervention studies (using a 12-month low-fat/high-fiber intervention among 213 women [67] or a 2-month replacement of saturated fat with polyunsaturated fat among 14 women [68]) found no influence of diet change on blood estrogen levels in the luteal [67, 68] or follicular [68] phases. Several cross-sectional studies found significant positive associations between total and monounsaturated fat intakes and follicular estrone levels [69] or inverse associations between the ratio of polyunsaturated to saturated fat (P/S) and estradiol and estrone during the luteal phase [70], or higher follicular plasma estrogen levels among high-fat/low-fiber group [71].…”

Section: Discussionmentioning

confidence: 99%

“…Several cross-sectional studies found significant positive associations between total and monounsaturated fat intakes and follicular estrone levels [69] or inverse associations between the ratio of polyunsaturated to saturated fat (P/S) and estradiol and estrone during the luteal phase [70], or higher follicular plasma estrogen levels among high-fat/low-fiber group [71]. In other studies, no significant associations were observed between dietary fiber intakes and estrogen levels during the follicular [69, 70] or luteal [68, 70] phases. Cumulatively, no strong consistent associations have been observed, and weak to moderate effects remain uncertain; our study, which is substantially larger than previous cross-sectional studies, suggests there is little, if any, association between these macronutrients and premenopausal estrogens.…”

Section: Discussionmentioning

confidence: 99%

Dietary Fat, Fiber, and Carbohydrate Intake and Endogenous Hormone Levels in Premenopausal Women

et al. 2010

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The authors conducted a cross-sectional study to investigate the associations of fat, fiber and carbohydrate intake with endogenous estrogen, androgen, and insulin-like growth factor (IGF) levels among 595 premenopausal women. Overall, no significant associations were found between dietary intake of these macronutrients and plasma sex steroid hormone levels. Dietary fat intake was inversely associated with IGF-I and IGF-binding protein 3 (IGFBP-3) levels. When substituting 5% of energy from total fat for the equivalent amount of energy from carbohydrate or protein intake, the plasma levels of IGF-I and IGFBP-3 were 2.8% (95% confidence interval [CI] 0.3, 5.3) and 1.6% (95% CI 0.4, 2.8) lower, respectively. Animal fat, saturated fat and monounsaturated fat intakes also were inversely associated with IGFBP-3 levels (P < 0.05). Carbohydrates were positively associated with plasma IGF-I level. When substituting 5% of energy from carbohydrates for the equivalent amount of energy from fat or protein intake, the plasma IGF-I level was 2.0% (95% CI 0.1, 3.9%) higher. No independent associations between fiber intake and hormone levels were observed. The results suggest that a low-fat/high-fiber or carbohydrate diet is not associated with endogenous levels of sex steroid hormones, but it may modestly increase IGF-I and IGFBP-3 levels among premenopausal women. KeywordsGonadal Steroid Hormones; Insulin-Like Growth Factor I; Insulin-Like Growth Factor Binding Protein 3; Dietary Fats; Dietary Fiber; Dietary Carbohydrates Endogenous sex hormone levels play an important role in the etiology of endometrial [1][2][3][4], breast [5][6][7][8][9][10][11][12], and ovarian [13,14] cancers. Insulin-like growth factors (IGFs) are important in regulating cell proliferation, differentiation, apoptosis, and transformation, and IGF binding proteins (IGFBPs) can enhance or inhibit the effect of IGFs [15][16][17][18]. Circulating levels of IGF-I and IGFBP-3 have been associated with risk of prostate [19][20][21][22][23], breast [24][25][26][27][28], colorectal [29,30], and lung cancer [22, 25, 31 -33] in some but not all studies.Corresponding author: Xiaohui Cui, Channing Laboratory, 181 Longwood Avenue, Boston, MA, 02115, Phone: 617-407-7728, Fax: 617-525-2008, nhxxc@channing.harvard Although some epidemiological studies have suggested that dietary fat or fiber may be related to the risk of endometrial [34][35][36][37], ovarian [38][39][40][41], and colon [42][43][44] cancers, the evidence has not been consistent. A primary mechanism by which these factors might influence risk is through the modulation of hormone levels. A low-fat/high-fiber diet is thought to reduce plasma estrogen levels by increasing the fecal excretion of estrogens [45,46]. Energy and protein intakes appear to increase IGF levels [47], but little is known about the effect of dietary fat, fiber, or carbohydrates on the IGF axis, and results from previous studies are inconsistent [48][49][50][51].Data from dietary fat and fiber in relation to sex hormone and I...

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“…A total of 18 RCTs assessed circulating estrogens levels (E1, E2, and/ or E3) Fifteen of 18 studies found no significant impact from soy compared to the control group (p>0.05) [129,132,133,138,140,143,145,147,149,150,155,156,158,160,163]. Three studies found a significant reduction in circulating estrogens compared to the control group (p<0.05) [151,153,155].…”

Section: Resultsmentioning

confidence: 99%

Soy, Red Clover, and Isoflavones and Breast Cancer: A Systematic Review

et al. 2013

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BackgroundSoy and red clover isoflavones are controversial due to purported estrogenic activity and possible effects on breast cancer. We conducted a systematic review of soy and red clover for efficacy in improving menopausal symptoms in women with breast cancer, and for potential impact on risk of breast cancer incidence or recurrence.MethodsWe searched MEDLINE, Embase, the Cochrane Library, and AMED from inception to March 2013 for human interventional or observational data pertaining to the safety and efficacy of soy and red clover isoflavones in patients with or at risk of breast cancer. ResultsOf 4179 records, we included a total of 131 articles: 40 RCTs, 11 uncontrolled trials, and 80 observational studies. Five RCTs reported on the efficacy of soy for hot flashes, showing no significant reductions in hot flashes compared to placebo. There is lack of evidence showing harm from use of soy with respect to risk of breast cancer or recurrence, based on long term observational data. Soy intake consistent with that of a traditional Japanese diet (2-3 servings daily, containing 25-50mg isoflavones) may be protective against breast cancer and recurrence. Human trials show that soy does not increase circulating estradiol or affect estrogen-responsive target tissues. Prospective data of soy use in women taking tamoxifen does not indicate increased risk of recurrence. Evidence on red clover is limited, however existing studies suggest that it may not possess breast cancer-promoting effects. ConclusionSoy consumption may be associated with reduced risk of breast cancer incidence, recurrence, and mortality. Soy does not have estrogenic effects in humans. Soy intake consistent with a traditional Japanese diet appears safe for breast cancer survivors. While there is no clear evidence of harm, better evidence confirming safety is required before use of high dose (≥100mg) isoflavones can be recommended for breast cancer patients.

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Types of Dietary Fat and Soy Minimally Affect Hormones and Biomarkers Associated With Breast Cancer Risk in Premenopausal Women

Cited by 27 publications

References 31 publications

Urinary Estrogen Metabolites During a Randomized Soy Trial

Urinary Estrogen Metabolites During a Randomized Soy Trial

Dietary Fat, Fiber, and Carbohydrate Intake and Endogenous Hormone Levels in Premenopausal Women

Soy, Red Clover, and Isoflavones and Breast Cancer: A Systematic Review

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