Trans Fats May Increase Infertility
Trans fats are strongly linked to heart disease. New research suggests they may also increase a woman's risk of infertility.
Nutritionist Isn't Convinced
Chavarro's research team is among the first to examine the impact of specific foods and nutrients on infertility.
Last fall, they reported that iron supplements appear to help protect women from ovulation-related infertility.
Both that research and the newly published findings were based on data from the Nurses Health Study II, an ongoing health study involving female nurses.
More than 18,500 married, premenopausal nurses who either became or attempted to become pregnant between 1991 and 1999 were included in the latest assessment. A total of 438 were diagnosed with ovulation-related infertility during that eight-year period.
Neither total fat intake nor total cholesterol intake was found to be associated with ovulatory infertility.
Trans fats were the only fats found to negatively affect ovulation-related fertility.
But nutritionist Marion Nestle, PhD, MPH, tells WebMD the findings are unconvincing. Nestle is a professor in the department of nutrition, food studies and public health at New York University in Manhattan.
She points out that the researchers were only able to show an increased infertility risk when they adjusted for many other possible infertility risk factors.
"If you look at their raw data, it just didn't show an increase in risk," she says. "And even when the adjustments were made, the numbers were still very small."
Nestle says the only dietary factors proven to play a role in infertility are eating way too little and eating way too much. Infertility is common among women who starve themselves for long periods or who are very obese.
There is little to suggest that the individual foods women eat play a significant role in fertility, Nestle says.
"I am always skeptical when I hear the claim that a particular food or food component has a very large impact on health," she says.