Are there gender differences in how males and females react to nutrients? University of Hawaiʻi at Mānoa researcher Marla Berry is working to find out. Her efforts are part of a new initiative announced by the National Institutes of Health (NIH) to begin addressing persistent gender bias in laboratory research.
Women are not adequately represented in many clinical trials of new drugs and medical devices, according to NIH. The gender bias starts at an early stage of the scientific process—traditionally many investigators have worked only with male lab animals, concerned that the hormonal cycles of female animals would add variability and skew study results.
Berry, chair of cellular and molecular biology at the John A. Burns School of Medicine at the University of Hawaiʻi at Mānoa, will focus on gender differences in animal models with metabolic syndrome, a precursor to diabetes and in neurological development and disorders. Specifically, her study will zero in on how the body handles the essential nutrient selenium, known for its antioxidant properties.
Two independent reports highlighted a potential increase in risk of developing type 2 diabetes following high intake of selenium. Importantly, analysis of the data from both studies clearly indicates that the reported increased risk is confined to males. Berry’s studies show that genetic alterations in the way the body handles selenium result in similar consequences in male mice, providing a laboratory model to investigate the underlying causes of these gender differences.
National Institutes of Health call to end research gender bias
The $100,000 grant awarded to Berry is part of $10.1 million in funding being distributed to some 80 scientists in the U.S. studying a diverse array of subjects, including drug addiction, fetal development, migraines and stroke.
The researchers will use the additional funds to include more human participants—generally women—in clinical trials and to ensure that their laboratory animals, even cell lines, are representative of both genders. The money also will be used to analyze gender differences in the resulting data, officials said.
“It’s an early first step we’re taking to encourage people to see the value of studying sex as a biological variable,” said Janine Austin Clayton, associate director for women’s health research at NIH. “What we are after is to transform how people think about science and therefore transform how science is done.”
Scientists often prefer single-sex studies because “it reduces variability, and makes it easier to detect the effect that you’re studying,” said Abraham A. Palmer, an associate professor of human genetics at the University of Chicago. “The downside is that if there is a difference between male and female, they’re not going to know about it.”
This year, in a commentary in the journal Nature, Clayton and Francis S. Collins, director of NIH, called for an end to this bias, and warned scientists they must begin testing their hypotheses in female lab animals, tissues and cell lines.
Said Hawaiʻi’s Berry, “As an institution that has one of the highest percentages of women in leadership positions in the country, we are proud to be at the forefront of investigations on gender differences and gender bias in research. Our focus on gender differences related to metabolic syndrome and diabetes makes this research particularly relevant here in Hawaiʻi, where we have a high incidence of diabetes.”