Infertility treatments may be less effective for people who eat more foods with higher levels of pesticide residue, according to a new study.
Certain types of fruits and vegetables, such as strawberries and spinach, tend to require more pesticides to protect the crops and ‘washing them makes absolutely no difference,’ says study author Jorge Chavarro.
The Harvard University study examined women who were undergoing fertility treatment, and found that those that ate more of these types of produce were less likely to get pregnant or deliver a live baby.
As research continues to document decreasing fertility, this study may provide a clue as to how environmental factors may be linked to falling pregnancy and birth rates.
Eating produce like strawberries and spinach that are treated with more pesticides than others, and are harder to wash, may be linked to infertility, according to a new study.
Pesticides have been linked to a broad range of negative health effects for the nervous system, skin and eyes and hormone system. Some are suspected to even cause cancer.
This new study found that women being treated for infertility who ate more highly pesticide-contaminated fruits and vegetables were 18 percent less likely to get pregnant than those who ate fewer of these kinds of foods.
The ‘dirty dozen’
Every year the Environmental Working Group (EWG) publishes a list of the most pesticide-contaminated fruits and vegetables. For 2017, its ‘dirty dozen’ included (in order):
- sweet bell peppers
If women with higher intakes of pesticides did get pregnant, they were still 26 percent less likely to give birth to a live baby.
Though the study authors advise that eating fruits and vegetables is generally important to a balanced, healthy diet, the analysis revealed no significant difference the likelihood of a successful pregnancy between women who ate high or low total amounts of fruits and vegetables.
Eating organic fruits and vegetables, on the other hand, was linked to lower infertility rates.
Dr Chavarro says that buying organic produce like strawberries, spinach and nectarines is worth the extra spending.
But, for ‘clean’ produce, that either less contaminated, like avocados and corn, he says that it doesn’t make much difference if we eat organic or not.
The Environmental Protection Agency (EPA) advises that most of us are exposed to very limited levels of pesticides, likely too small to pose a serious health risk.
However, our exposure is ubiquitous, according to the study, which says that about 90 percent of Americans have ‘detectable’ levels of pesticides in our blood or urine.
In animals, evidence of how pesticides can affect reproductive health has been quite clearly documented. The powerful pesticide DDT’s effects on the hormonal systems – particularly estrogen levels – in bald eagles and ospreys nearly led to their extinction.
The ‘clean 15’
The EWG’s list of the ‘clean 15’ fruits and vegetables either require minimal pesticide treatments, or we don’t eat the parts that are treated. This year’s clean crops were:
- sweet corn
- frozen sweet peas
- honeydew melon
In humans, studies of men who were directly exposed to high concentrations of pesticides have shown links to low counts of weaker sperm and damage to their gonads.
The less obvious – and potentially more insidious – effects of pesticide exposure at levels too low to produce immediate clinical symptoms are beginning to be studied more closely.
Dr Philip Landrigan, a professor at the Icahn School of Medicine at Mount Sinai in New York, compared the signs and symptoms of ‘subclinical toxicity’ from pesticides to those of lead poisoning in children, which is now widely recognized as having serious long-term developmental effects.
He notes in his commentary that falling fertility rates and rising reproductive cancer rates are ‘too rapid to be of genetic origin,’ in his commentary. Though this study hardly proves that pesticides are to blame, it does support the hypothesis that there may be environmental causes for these trends.
Dr Chavarro’s study does not examine how exactly pesticides effect fertility, but he says ‘what appears to be driving infertility is an increase in pregnancy loss, especially early in pregnancy,’ consistent with what researchers have seen in studies of rats.
‘What we think we’re seeing is a direct effect of pesticides on cell death in developing embryos, very, very early on in pregnancy,’ he says.
Preliminary though they are, ‘the observations made in this study send a warning that our current laissez-faire attitude toward the regulation of pesticides is failing us,’ Dr Landrigan writes.