Why The Mice Tested In Medical Research Should Matter To Women’s Health

During the past several years, I began to look more intently at the landscape of the status of women’s health, an area which has been a passion of mine and in which I have been involved for many years. I found myself focusing more and more on research data to see if, in fact, women’s health research has changed over the past ten or twenty years. And although there have been significant gains, the scientific community would tell you that there is a real gap that exists and needs to change – A commentary by Carolee Lee, Founder, AccessCircles.

So what exactly do I mean?

Lets start with some information that will, I believe, stun you and let me state that the data I am sharing with you comes from conversations and meetings I have had with those institutions focused on women’s health research. Specifically, I would like to thank the Connors Center at Brigham, the Women’s Hospital at Harvard and Yale’s Center for Women’s Wellness for sharing their data with me and for partnering with us in the future.

We need to set the stage back in the early 90’s.

Most of us are not aware that up until 1993, all of the testing done in clinical trials, as well as the diagnostic and device development, was conducted on male mice – or men.

It was inconceivable for me to believe this, when I first heard this information 20 years ago. It was the driving force in my joining the board of an organization based in DC to become a more vocal and active advocate for advancing women’s health through science, advocacy, and education.

It took a very dedicated group of government and private sector leaders to create a shift and in1993, the historic National Institutes of Health (NIH) Revitalization Act mandated that, for the first time, women and minorities be included in NIH- funded clinical trials. Before then, the science that led to prevention, diagnosis, treatment, and even medication dosages, was based almost entirely on male physiology, assuming that, apart from reproductive organs, women and men were biologically the same.

Twenty years ago, few people understood that women are affected differently than men by some of the world’s most devastating health problems.

This emerging knowledge—that differences in the cellular makeup, down to the cellular level of men and women affect their health across their lifespan—is now driving
 advances in the way that doctors prevent, diagnose, and treat certain conditions and illnesses.

Today, the growing field of Gender Based Research is shedding new light on the impact that sex and gender has on health and on illnesses such as cancer, cardiovascular disease, Alzheimer’s disease, depression and autoimmune disease. Despite considerable progress, vast inequities still remain in the biomedical research that informs our understanding and treatment of diseases. Let me give you a few examples which are difficult for me to believe.

Cardiovascular Disease:

We now know that cardiovascular disease, the number one killer of women in the United States, affects women and men differently at every level, including prevalence, underlying physiology, risk factors, presenting symptoms, and outcomes

Mice matter in heart research

Yet only one-third of cardiovascular clinical trial subjects are female and fewer than one-third (31 percent) of cardiovascular clinical trials that include women report outcomes by sex.

Lung Cancer:

More women die of lung cancer each year than from breast, ovarian, and uterine cancers combined. It is the leading cause of cancer death in women. While about one in five people who are diagnosed with lung cancer never smoked, non-smoking women are three times more likely than non-smoking men to get it.


Depression is the leading cause of disability in women. In the United States, twice as many women than men suffer from depression, with direct costs exceeding $20 billion annually. We know that major endocrine changes throughout a woman’s life, including puberty, pregnancy, and menopause, have been directly linked to increased risk for this disease. Furthermore, basic research into drug development has shown that women metabolize drugs differently than men.Basic neuroscience, pharmacology, and physiology—all related to depression—continue to have strong sex biases.


In neuroscience, despite substantial sex differences in risk for most brain disorders, animal studies that rely exclusively on males outnumber studies in females 5.5 to 1. Fewer than 45 percent of animal studies on anxiety and depression use female lab animals, despite the fact that these disorders are twice as common in women.


Alzheimer’s Disease:

A woman’s overall lifetime risk of developing Alzheimer’s disease is almost twice that of a man, and not because women live longer. The impact of hormonal changes at menopause and sex differences in gene expression have begun to emerge as potential explanations.

Even when compared to men with similar genetic risk, women have a higher overall risk for the illness.

Two-thirds of the 5.1 million people currently suffering from Alzheimer’s disease are women. And yet 66% of the animals, including mice used in Alzheimers research are male or an unreported sex.

Autoimmune Disease:

Seventy-five percent of Americans with autoimmune disease are women. It is estimated that 50 million people are afflicted by AD. Most autoimmune patients see 5 doctors over 4.6 years before a correct diagnosis. The NIH estimates the direct cost for all ADs to be about $100 billion, while the costs of cancer are estimated to be about $57 billion,

Yet, research funding equaled about $591 million for ADs, $6.1 billion for cancer and $2.1 billion for heart disease and strokes. When we fail to routinely consider the impact of sex and gender in research, we are not going to have the best health outcomes for women – or men. The evidence on sex differences in major causes of disease and disability in women is mounting, as are the gaps in research.

Role of mice and the need for equity in biomedical and health outcomes investigations

Despite progress during the past 20 years, women still have not achieved equity in biomedical and health outcomes investigations. The science that informs medicine—including the prevention, diagnosis, and treatment of disease— routinely fails to consider the crucial impact of sex and gender. This happens in the earliest stages of research, when females are excluded from animal and human studies, or the sex of the animals isn’t stated in the published results.

This impedes our ability to identify important differences that could benefit the health of all. We cannot – and should not – expect that women’s health is a priority and that testing and publishing the results of those tests are being executed for each sex. Research on sex and gender differences will need to become the norm, not the exception, for the United States to achieve health equity and, most importantly, to improve the health and well-being of all.

Two decades after the landmark NIH Revitalization Act was signed into law, we still have much work to do to make certain that its promise is realized. The passage 
of the law was a critical milestone but now is the time to recommit to its vision and ensure that research at all levels is performed with a sex- or gender- specific lens.

Of mice and women

I believe we all have a moral and ethical obligation to be the super change agents who will create a shift for this generation and for future generations to make sure women are receiving the best prevention, diagnosis, treatment and outcomes – for this generation and future ones.

Download this infographic for more information on the impact on women’s health.

About the author:

“I am passionate about equality in all aspects of my life, which is what led me to create AccessCircles. This is a by-invitation global network for women providing connectivity, knowledge and access to thought leaders, resources and experiences that transform our lives. Our primary areas of focus are Health and Wellness and Life Planning, as they are of intense interest to all women as who make the daily and eventful choices that shape their lives, the lives of their families and their future.”  Carolee Lee