We also know that women show different symptoms in some serious illnesses. When women have heart attacks, for example, they may or may not feel the stereotype of chest pain. Instead, they are more likely than men to experience
shortness of breath, cold sweat, and lightheadedness. Although sex isn't a factor in all aspects of health, when it is, it's often serious.
"We don't know yet whether [sex] is going to matter across the board in every illness, in every condition, but we need to know when it does matter," says Phyllis Greenberger, president and CEO of the Society for Women's Health Research
. She was recently a part of a congressional briefing
to discuss the role of sex differences in medical research, co-sponsored by her organization and The Endocrine Society
Greenberger's organization was also integral to helping the 1993 NIH Revitalization Act
pass, which required all National Institutes of Health (NIH) funded clinical trials to include women and minority participants. Currently, this group is one of many working to get the same consideration for the animals and cells used in preclinical research — not just humans.
Thankfully, NIH is pushing to make a substantial permanent change in research. Beginning in September of last year
, it began to introduce a series of policies, regulations, and incentivizing grants
to encourage (and in many cases necessitate
) researchers to recognize biological sex as a significant factor in their work.
"Things just continue on the way they’ve always been," says Jeffrey Mogil
, PhD, at McGill University. "In this case, I think that inertia is spurred on by this expectation that is reasonable but wrong." He is referring to the basic assumption in biomedicine that female animal hormonal cycles, which fluctuate due to the estrous and menstrual cycle, will introduce another source of variability into any data collected from them.
From a scientist's perspective, the more highly controlled an experiment can be, the better the results. Also, with less variability in the animal model (like a lab rat), researchers can use fewer animals and spend less money, so many stick to exclusively using male animals simply to make things cheaper and easier.