Purpose: Extensive prior research has shown that sexual minority women are more likely to have a number of cancer risk factors, thereby putting them at higher risk for cancer than heterosexual women. However, there has been little research evaluating the association between sexual orientation and diet quality.
Method: Data come from participants (aged 24-54 years) enrolled in Nurses' Health Study 3, an ongoing, U.S.-based cohort study (N = 15,941). We measured diet using recommendations from the Dietary Approach to Stop Hypertension (DASH) and American Health Association (AHA) 2020 Strategic Impact Goals.
Results: We found limited evidence of differences across diet quality by sexual orientation. When examining predicted DASH scores, mostly heterosexual [predicted mean score (95% confidence interval), 24.0 (23.8, 24.3)] and lesbian [24.3 (23.8, 24.9)] women had healthier predicted DASH scores than the reference group of completely heterosexual women with no same-sex partners [23.6 (23.5, 23.7)]. Even though certain sexual minority women had overall healthier predict DASH scores, their consumption of certain food groups-low-fat dairy and fruit-was lower than completely heterosexual women with no same-sex partners. When measuring AHA scores, most sexual minority groups (completely heterosexual women with same-sex partners, mostly heterosexual women, and lesbian women) had higher diet quality compared to the reference group of completely heterosexual women with no same-sex partners.
Conclusion: Sexual minority women, particularly mostly heterosexual women and lesbian women, had healthier diet quality than completely heterosexual women with no same-sex partners. These data suggest that cancer risk factors (e.g., smoking, drinking, and inactivity) other than diet would drive higher cancer rates among sexual minority compared to heterosexual women. Nonetheless, it is critical for all women to improve their diet quality since diet quality was poor among participants of all sexual orientations.