All Things Not Being Equal

July 9, 2010

Gretchen Reynolds, writing for the Well blog at The New York Times, reports that gender still matters a great deal in health research. It’s just difficult for some scientists to remember that.

Reynolds focuses on a pair of studies by David Rowlands, MD, a senior lecturer with the Institute of Food, Nutrition and Human Health at Massey University in New Zealand, in which he attempted to determine the importance of protein in the recovery from hard exercise. The first study, completed in 2008, involved only male cyclists and found that ingesting protein had a significant long-term effect on overall athletic performance.

After Rowlands published those results, which were in line with conventional wisdom, female cyclists asked him to include them in any further studies. To his credit, he decided to repeat the entire experiment again with the female cyclists.

The results completely contradicted the original study. Not only did women fail to see benefits from ingesting protein — their legs actually felt more tired and sore.

The reason for the discrepancy — and what role estrogen plays in all this — still puzzles Rowland. In any case, the bigger lesson was obvious: excluding women from research is scientifically unsound.

The danger of using male bodies to represent all bodies became very clear once again last week when Northwestern Medicine in Chicago announced a new formula for figuring out a women’s maximum heart rate, considered a critical number in constructing an optimum workout.

The traditional formula (subtract a person’s age from 220) has led some women to experience frustration and exhaustion from workouts that should have been exhilarating, writes Tara Parker-Pope. The new formula for women, based on new research, is 206 minus 88 percent of age.

The new formula will also more accurately predict the risk of heart-related death during a stress test.

“Now we know for the first time what is normal for women, and it’s a lower peak heart rate than for men,” said Martha Gulati, MD, assistant professor of medicine and preventive medicine and a cardiologist at Northwestern Medicine and lead author of a study published June 28 in the journal Circulation. “Using the standard formula, we were more likely to tell women they had a worse prognosis than they actually did.”

“Women are not small men,” Gulati added. “There is a gender difference in exercise capacity a woman can achieve. Different physiologic responses can occur.”

Next up for Gulati: an iPhone app that will make quick calculations using the new formula.

Plus: For some historical context, the Society for Women’s Health Research provides a brief outline of efforts waged in the late 1980s and early 1990s to require that women be included in federally funded clinical research. It ended in the NIH Revitilization Act, which was signed into law in 1993.

Comments are closed.