Two newspapers in the United Kingdom recently reported that eating raspberries could boost fertility; scientists now call these reports “misleading.” On August 25, 2013, MailOnline published an article entitled, “How eating raspberries could increase your chances of becoming a father,” that claimed the antioxidants in this popular fruit would protect sperm from oxidative stress. The next day, the Daily Express told a similar story.
Authors based the stories on a small 2012 study of 80 men that looked at whether their self-reported intake of micronutrients including vitamin C, vitamin E, beta-carotene, zinc, and folate were associated with poor sperm quality, a common condition that can lead to male infertility. This study, led by scientists from the U.S. Department of Energy’s Lawrence Berkeley National Laboratory, found that men who had a high intake of certain micronutrients had less DNA damage to their sperm, though the researchers were unable to establish a clear cause and effect.
While the 2012 study underscores theimportance of a nutritious diet to male fertility, the results from this study do not substantiate the claims in the two newspaper articles. Most importantly, researchers in this 2012 study did not specifically investigate raspberries – the authors did not even mention the fruit in their findings. Secondly, none of the 80 men participating in the original study had fertility problems.
The authors of the 2013 online articles based their information on a cross-sectional study performed by Juliet Wilson, a fertility nutritionist. The Daily Express quoted Wilson as saying, “Raspberries provide essential nutrients that are known to enhance fertility in men and women.”
The largest problem with a cross-sectional study, which strives to make a generalized statement about the entire population rather than looking only at individuals with certain characteristics, is that they cannot make specific links between cause and effect. In other words, the cross-sectional study can tell researchers whether men with sperm with the most or least DNA damage have different micronutrient intakes, but it cannot show if or how raspberry intake is linked to low sperm counts.
Source:
- Williams, Olivia. "How Eating Raspberries Could Increase Your Chances of Becoming a Father." DailyMail Online. 25 Aug 2013. Web. 10 Sept 2013.
- "Raspberries 'Boost Fertility.'" Express. 26 Aug 2013. Web. 10 Sept 2013.
- Krotz, Dan. "Nutrition Tied to Improved DNA Sperm Quality in Older Men." Berkeley Lab News Center. Berkeley Lab for the U.S. Department of Energy’s Office of Science. 27 August 2012. Web. 10 Sept 2013.
- Wilson, Juliet. "Enjoy Eating Raspberries and Enhance Your Fertility." Juliet Wilson Essential Nutrition for Life. 30 Aug 2013. Web. 10 Sept 2013.