A decades’ worth of data from the Nurses’ Health Study II was included in the analysis, which looked into risk factors for serious diseases in women and included data from more than 100,000 nurses across the United States.
Participants were asked about their sexual orientation in 1995 as part of that study. To determine participants’ lifespans and how that was linked to sexual orientation in the 2024 paper, researchers examined 30 years of death records.
“One of the advantages of this study is that we were able to separate out bisexual and lesbian participants, because we had enough people and we followed them for long enough that we can actually look at those risks separately, which no other US study has been able to do,” Sarah McKetta, a postdoctoral research fellow at Harvard and lead author of the JAMA study, told NBC News.
The study used information gathered on the women 20 years prior, which revealed two times the prevalence of alcohol and tobacco use, as well as higher risks for breast cancer, cardiovascular disease and depression, among lesbian and bisexual participants.
McKetta added that this “this isn’t something that just happened” and attributes it to “chronic processes”.
She references further analysis they conducted involving only the participants who had never smoked, which showed the same disparities.
Why do lesbian and bisexual women have higher mortality rates?
She found this was especially the case for bisexual women, who experience higher rates of substance abuse and sexual victimisation. They also have poorer physical and mental health than their lesbian and heterosexual counterparts.
McKetta said: “We’ve known for a really long time that there are systemic and highly reproducible health disparities for LGB people, particularly LGB women, across many outcomes.
“We’ve seen disparities in tobacco use and alcohol use, in mental health, in chronic disease. Basically, pretty much any outcome that we’ve looked at across multiple surveys, we see that lesbian, gay and bisexual women are at higher risk.
“And we also know it’s due to levels of discrimination, ranging from structural to individual.
“The thing is, we actually don’t really know to what extent these disparities manifest in premature mortality differences, because there’s some real data limitations.
“This was an opportunity for us to actually quantify the magnitude of that disparity,” she added.
