Lately, I’ve started to identify more with the feminist movement. Perhaps my proclivities toward women-power were spurred when I stumbled upon Facebook COO Sheryl Sandberg’s Ted Talk encouraging women to “lean in”—a video that sent me into a late-night tizzy of investigating glass-ceiling pay rates, body objectifications, confidence gaps, and notably, infuriating women’s health discrepancies.  

So recent suggestions from the National Institutes of Health encouraging scientists to include more female lab animals into research made me momentarily balk: I didn’t even know there was a gender bias in preclinical studies.

Thanks to the Revitalization Act of 1993, human health trials are up to par. Over half of NIH-funded research participants are women. But animal studies are largely conducted on male rodents—a grave issue considering that preclinical testing lays groundwork for potentially lifesaving health therapies. “Bias in mammalian test subjects was evident in eight of 10 scientific disciplines in an analysis of published research conducted by Irving Zucker, a professor of psychology and integrative biology at the University of California, Berkeley,” reports the New York Times.

Vexingly, many scientific journals don’t even require disclosure of an animal's gender—even when examining diseases that are common in women, such as anxiety and thyroid disease. “Every single cell has a sex, and the sex of the cell affects the biological and biochemical properties of the cell. And that’s important in research,” says Janine Clayton, director of the US NIH Office of Research on Women's Health.

The damage done?

Let’s commend the NIH for finally announcing that diseases and drugs affect males and females differently. Gender bias is antiquated, and it harkens back to the days when women's bodies were inadequately researched and "mysterious." (Remember reports of female hysteria—a lazy umbrella term diagnosing everything from anxiety to fainting to emotional outbursts?) Certainly, NIH's guidelines are an important move toward health care equality.

But I lament the thousands of studies that only explored how male animals react to vital drugs and supplements. Who knows the extent to which this practice has poorly impacted women’s health? Like ripples in a pond, the repercussions may be serious and far reaching. 

Let’s hope the NIH’s initiative to balance animal genders will trickle up the many phases of health research to enhance understanding of how diseases and treatments affect women.

With rapid adoption, I believe this serious oversight can be improved, if not remedied.