Lauren A. Wise

Intake of fruit, vegetables, and carotenoids in relation to risk of uterine leiomyomata

BACKGROUNDnUS black women have higher rates of uterine leiomyomata (UL) and lower intakes of fruit and vegetables than do white women. Whether fruit and vegetable intake is associated with UL in black women has not been studied.nnnOBJECTIVEnWe assessed the association of dietary intake of fruit, vegetables, carotenoids, folate, fiber, and vitamins A, C, and E with UL in the Black Womens Health Study.nnnDESIGNnIn this prospective cohort study, we followed 22,583 premenopausal women for incident UL (1997-2009). Diet was estimated by using food-frequency questionnaires in 1995 and 2001. Cox regression was used to derive incidence rate ratios (IRRs) and 95% CIs for the association between each dietary variable (in quintiles) and UL.nnnRESULTSnThere were 6627 incident cases of UL diagnosed by ultrasonography (n = 4346) or surgery (n = 2281). Fruit and vegetable intake was inversely associated with UL (≥4 compared with <1 serving/d; IRR: 0.90; 95% CI: 0.82, 0.98; P-trend = 0.03). The association was stronger for fruit (≥2 servings/d compared with <2 servings/wk; IRR: 0.89; 95% CI: 0.81, 0.98; P-trend = 0.07) than for vegetables (≥2 servings/d compared with <4 servings/wk: IRR: 0.97; 95% CI: 0.89, 1.05; P-trend = 0.51). Citrus fruit intake was inversely associated with UL (≥3 servings/wk compared with <1 serving/mo: IRR: 0.92; 95% CI: 0.86, 1.00; P-trend = 0.01). The inverse association for dietary vitamin A (upper compared with lower quintiles: IRR: 0.89; 95% CI: 0.83, 0.97; P-trend = 0.01) appeared to be driven by preformed vitamin A (animal sources), not provitamin A (fruit and vegetable sources). UL was not materially associated with dietary intake of vitamins C and E, folate, fiber, or any of the carotenoids, including lycopene.nnnCONCLUSIONnThese data suggest a reduced risk of UL among women with a greater dietary intake of fruit and preformed vitamin A.

Dietary glycemic index and load in relation to risk of uterine leiomyomata in the Black Women's Health Study

BACKGROUNDnHigh dietary glycemic index (GI) and glycemic load (GL) may promote tumorigenesis by increasing endogenous concentrations of insulin-like growth factor I (IGF-I) or the bioavailability of estradiol. In vitro studies have shown that uterine leiomyoma (UL) cells proliferate in response to IGF-I and display increased IGF-I gene expression and protein synthesis. Previous epidemiologic studies suggest that a high GL is a risk factor for endometrial and ovarian cancers, which, like UL, are hormone-responsive tumors.nnnOBJECTIVEnWe investigated the relation of dietary GI and GL with UL risk in the Black Womens Health Study.nnnDESIGNnIn this prospective cohort study, we followed 21,861 premenopausal women for incident UL from 1997 to 2007. Diet was assessed in 1995 and 2001 with food-frequency questionnaires. We used Cox regression to estimate incidence rate ratios (IRRs) and 95% CIs, controlled for potential confounders.nnnRESULTSnDuring 162,604 person-years of follow-up, there were 5800 cases of UL diagnosed by ultrasound or surgery. Dietary GI was weakly associated with UL risk overall (IRR for highest compared with lowest quintile: 1.09; 95% CI: 0.99, 1.19; P for trend = 0.04). Positive associations were observed between GL and UL in women aged <35 y (IRR for highest compared with lowest quintile: 1.18; 95% CI: 1.02, 1.37; P for trend = 0.15) and between GI and UL in college-educated women (IRR for highest compared with lowest quintile: 1.17; 95% CI: 1.03, 1.34; P for trend = 0.004).nnnCONCLUSIONSnOur results suggest that high dietary GI and GL may be associated with an increased UL risk in some women. The observed associations warrant investigation in future studies.

Prospective study of dietary fat and risk of uterine leiomyomata

BACKGROUNDnUterine leiomyomata (UL) are the primary indication for hysterectomy and are 2-3 times more common in black than white women. High dietary fat intake has been associated with increased endogenous concentrations of estradiol, a sex steroid hormone that is known to influence UL risk.nnnOBJECTIVEnWe assessed the relation of dietary fat intake (total, subtypes, and selected food sources) with UL incidence.nnnDESIGNnData were from the Black Womens Health Study, a prospective cohort study. Over an 8-y period (2001-2009), 12,044 premenopausal women were followed for a first diagnosis of UL. Diet was assessed via a food-frequency questionnaire in 2001. Cox regression models were used to compute incidence rate ratios (IRRs) and 95% CIs with adjustment for potential confounders.nnnRESULTSnDuring 75,687 person-years of follow-up, there were 2695 incident UL cases diagnosed by ultrasound (n = 2191) or surgery (n = 504). Intakes of total fat and fat subtypes were not appreciably associated with UL risk overall, although statistically significant associations were observed for specific saturated (inverse) and monounsaturated and polyunsaturated (positive) fatty acids. With respect to polyunsaturated fats, the IRR for the highest compared with lowest quintiles of marine fatty acid intake [the sum of omega-3 (n-3) polyunsaturated fatty acids eicosapentanoic acid, docosapentaenoic acid, and docosahexaenoic acid] was 1.18 (95% CI: 1.05, 1.34; P-trend = 0.005). The IRR for the highest compared with lowest categories of dark-meat fish consumption was 1.13 (95% CI: 1.00, 1.28).nnnCONCLUSIONSnIn US black women, the most consistent associations of fat intake with UL were small increases in risk associated with intakes of long-chain omega-3 fatty acids. Future studies are warranted to confirm these findings and elucidate which components of fatty foods, if any, are related to UL risk.

Abuse victimization and risk of breast cancer in the Black Women's Health Study [corrected].

Few studies have examined the relation between abuse victimization and breast cancer, and results have been inconclusive. Using data from 35,728 participants in the Black Women’s Health Study, we conducted multivariable Cox regression to estimate incidence rate ratios (IRRs) and 95% confidence intervals (CI) for the association of abuse across the life span (childhood, adolescence, and adulthood) with breast cancer. Incident breast cancer diagnoses were reported during 1995–2009, and abuse histories were reported in 2005. No associations were found between abuse victimization in either childhood or adolescence and breast cancer. We found a weak positive association between abuse in adulthood and breast cancer (IRRxa0=xa01.18, 95% CIxa0=xa01.03–1.34). IRRs for physical abuse only, sexual abuse only, and both physical and sexual abuse in adulthood, relative to no abuse, were 1.28 (95% CIxa0=xa01.09–1.49), 0.96 (95% CIxa0=xa00.76–1.20), and 1.22 (95% CIxa0=xa01.00–1.49), respectively. IRRs for low, intermediate, and high frequencies of physical abuse in adulthood, relative to no abuse, were 1.28 (95% CIxa0=xa01.07–1.52), 1.37 (95% CIxa0=xa01.04–1.79), and 1.24 (95% CIxa0=xa00.95–1.62), respectively. Our data suggest an increased risk of breast cancer among African-American women who reported physical abuse in adulthood, but there was little evidence of a dose–response relation. These results require confirmation in other studies.