Birth control pills not a culprit for weight gain
Women might not need to be concerned about gaining weight from birth control pills, shown in a primate study.
Researchers, seeking to clarify whether oral contraceptives lead to weight gain, found birth control pills might even help women lose weight.
Scientists at Oregon National Primate Research Center at Oregon Health & Science University conducted a year long study on a group a of rhesus macaque monkeys that found weight gain associated with taking birth control pill may be nothing but a myth.
The researchers used monkeys that could be studied under controlled conditions, unlike humans. They note the reproductive systems of the primates are nearly identical to humans. During the study the scientists gave the monkeys birth control pills adjusted to weight to mimic the dose in humans.
At the study start, half of the macaque's were obese and the the other half, normal weight. The researchers tracked food intake, body fat, level of activity and lean muscle mass during the eight months that the monkeys were given oral contraceptives.
The obese group lost weight, showing the researchers the oral contraceptives, in the presence of stable diet and activity, should not lead to weight gain, and might even be beneficial for weight loss from increased metabolic activity
Alison Edelman, M.D., a physician and researcher in the Department of Obstetrics and Gynecology at OHSU and lead author of the study says, "A simple Google search will reveal that contraceptives and the possibility that they may cause weight gain is a very highly debated topic", but the findings suggest weight gain experienced by women taking birth control pills might be due to other factors, such as age.
Judy Cameron, Ph.D., senior author of the paper and a researcher at the primate center says, "We realize that research in nonhuman primates cannot entirely dismiss the connection between contraceptives and weight gain in humans, but it strongly suggests that women should not be as worried as they previously were."
The researchers note avoiding birth control pills for fear of weight gain puts women at risk for unplanned pregnancy.
According to Dr. Edelman, studies have been insufficient to prove or disprove birth controls are the culprit for weight gain reported by women from oral contraceptive use.
The new study seems to support the notion that oral contraceptives can promote weight loss. In the study, the primates given birth control pills and obese experienced an 8.5% weight loss and dropped 12% of body fat.
The normal weight group remained stable. The researchers say for women who are overweight, birth control pills might help with weight loss if food consumption remains the same.