Pesticides and Fertility

Here is another health and fitness story that has been making the rounds:  “Study ties pesticides in food to reduced fertility in women.”  This one deserves close scrutiny.

It was published in the journal JAMA Internal Medicine, a reputable source, but a close look at the study itself shows that it’s also a case of reporters looking for another scary headline.  Most of the articles covering it start off carefully with phrasing like “The findings suggest that dietary pesticide exposure … may be associated with adverse reproductive consequences.”  The use of all those weasel words indicates vague and weak findings, but the typical media delivery can make it sound dire.

The study looked at 325 women undergoing treatment for infertility at a single hospital in Boston.  Researchers asked them to keep a food diary – self-reporting is always suspect – and then compared fruits and vegetables they ate to a list of those known to contain high levels of pesticide residue as listed in a government database.  They did not test the food the women were actually eating.  There was no evidence that the researchers asked whether or not the women had washed it before eating or even had picked it from their own backyard garden.

Other qualifications listed in the study included:  finding only an association rather than a "cause and effect" relationship; basing results on the estimated level of exposure; testing only women seeking treatment for infertility, not women from the general population or even those having problems but not seeking treatment; and being one of the first research studies done on humans for this relationship with no time for replication.  But it made the news anyway, as if every woman should be seriously concerned, especially those planning to start a family.

Additional information on the study came from another source.  According to the lead researcher, "A reasonable choice based on these findings is to consume low-pesticide-residue fruits and vegetables instead of high-pesticide-residue ones. Another option is to go organic for the fruits and vegetables known to contain high pesticide residues.”

As reference, produce that typically has high levels of pesticide residue includes especially those with rough or irregular surfaces:  peaches, strawberries, spinach, kale, apples, nectarines, peppers and celery.  Some products with lower levels are avocados, onions, orange juice, sweet corn, pineapples, cabbage peas, asparagus, eggplant, grapefruit and cantaloupe.  Many of these are the ones where we don’t eat the outer part.

But be careful.  A good rule of thumb is to wash all fruits and vegetables carefully before eating them.  This is a recommendation of American Congress of Obstetricians and Gynecologists for pregnant women or those trying to conceive, but it applies to everyone.  A watermelon may seem harmless because the residue and any other bacteria are on the outside, but a knife cutting through the rind will carry those contaminates directly to the part you eat.

And we shouldn’t get complacent if the food is marked as organic.  The publication PPP-109 from the Purdue Extension tells us not to assume natural and organic products are safe.  Organic pesticides “may offer advantage (such as pest specificity), but they are not necessarily safer than pesticides developed in the laboratory…All [pesticide] products have the potential to be toxic.”

Is this really a worry for people concerned about infertility and for Americans in general?  What is the level of pesticides?  “During its 2015 survey, DPR [California Department of Pesticide Regulation] found 97.3 percent of tested California-grown produce had little or no pesticide residues"   (organic or not).  What of the rest of the country?

Bottom line: If everyone washed their produce carefully, it would put these researchers out of business, which is a good thing both for our health and for our sanity as the media continue to exaggerate the importance of every new food safety study.