Although there was an overall reduction in cancer risk for those eating a mostly organic diet, the reduced risk was even greater for two specific forms of the disease: lymphoma (76 percent reduced risk) and postmenopausal breast cancer (34 percent reduced risk).
“The most surprising finding was the extent of the reduction, which is far from the usual risk observed for nutritional factors,” says Julia Baudry of the Center of Research in Epidemiology and Statistics at the Sorbonne in Paris. She is the lead author of the study.
“There are lots of benefits to eating organic foods, and limiting exposure to pesticides is one of the biggest,” says Charlotte Vallaeys, a senior policy analyst and sustainability expert in the food safety and testing department at Consumer Reports. “This study adds to the current body of evidence supporting the health benefits of eating more organic foods.”
Examining the connections
One of the requirements for a food to be labeled organic in Europe and the United States is that it must be produced without the use of most synthetic pesticides. About 40 pesticides approved by the Environmental Protection Agency for use in conventional (nonorganic) food production are classified as possible or probable carcinogens by the International Agency for Research on Cancer. According to the Centers for Disease Control and Prevention, about 90 percent of us have detectable levels of pesticides in our blood and urine.
Previous research has found a link between eating more organic food and a reduced risk of non-Hodgkin’s lymphoma, but not breast cancer. “One hypothesis explaining the inverse association between organic food intake and breast cancer [in the current study] may be the endocrine [hormone] disrupting effects of some pesticides,” Baudry says.
There are several limitations to this study, which the researchers fully acknowledge. The number of people involved in the study was quite large, but the group consists of volunteers who are mostly female, well-educated and health-conscious. In addition, study subjects were 44 years old on average at the start of the research, and they were followed for only 4½ years.
“This is a very difficult area to study, and it’s very hard to accurately assess habitual consumption of organic food,” says Frank B. Hu, chair of the department of nutrition at Harvard T.H. Chan School of Public Health and author of an independent commentary that accompanies the study.
“Overall, these are interesting results, but they are very preliminary,” Hu says. “And it would be premature to make organic food consumption recommendations based just on this study.”
Should you eat only organic?
The No. 1 thing to focus on is following an overall healthy diet, Baudry says.
“These findings should not prevent people from eating fruit and vegetables, whatever the farming system [organic or not], as they are important protective factors against cancer risk,” she says.
Other lifestyle factors that play an important role in cancer prevention include maintaining a healthy weight, exercising regularly and eating a diet that’s rich in whole grains, while avoiding or limiting alcohol, added sugars, refined grains, and red and processed meat.
Still, if organic options are available and fit into your budget, “Consumer Reports recommends opting for organic foods whenever possible, in part because they are produced without most synthetic pesticides,” Vallaeys says.
In a 2015 analysis of government data on pesticide residues, experts at Consumer Reports found that some conventional fruits and vegetables pose a higher risk from pesticides than others. These include carrots, cranberries, green beans, hot peppers, nectarines and peaches.
Consumer Reports is an independent, nonprofit organization that works side by side with consumers to create a fairer, safer, and healthier world. CR does not endorse products or services, and does not accept advertising. Read more at ConsumerReports.org.