Spring is around the corner, and the last thing I want to be thinking about is fruit salad dosed with pesticides or a lovely cut of meat on the grill, generously marinated in bug spray. Why, then, is my mind traveling so firmly in this direction? It’s almost 40 years after DDT was banned, and you would think that we’d now feel safe and comfortable in knowing that we are exposed to fewer toxic pesticides. Instead there’s evidence that we’re exposed to more.
About 70,000 different chemicals are used in the US today, making the chemical companies healthy even if we’re not. Although many of these chemicals are known carcinogens, there isn’t a lot of scientific research that has successfully proved a causal link to cancer — since, in addition to being expensive, this would take decades to prove… and, of course, no one will get rich from the results. Now new research is emerging that links pesticides to other known health problems, so I thought it was important to take a look at what we know — and what we don’t know — about the dangers of the pesticides used in growing the foods we eat.
So Many Chemicals
Fruits and vegetables receive the highest dosage of pesticides, so they’re more likely to be contaminated than other foods. For instance, conventional, non-organic growers can choose from as many as 62 different types of pesticide products to treat a crop of peaches (and each crop is typically treated with many different types)… 52 for blueberries… 42 for apples. And you may not realize that pesticides also have been found in meat and chicken, especially in the thighs.
I spoke to David Pimentel, PhD, a professor in the department of entomology, systematics and ecology at Cornell University about this trend. “About 70% of the foods that consumers buy have detectable levels of pesticide residues,” Dr. Pimentel told me.
Who Is Most at Risk?
Regarding the connection between cancer and pesticides, it is safe to say there’s good reason to worry about one. Noting that more research is needed on this important topic, Dr. Pimentel said. “There is no question that pesticides can cause cancer — the question is, how many people do they affect?” He noted that people with a genetic risk for cancer are quite likely the most vulnerable.
Meanwhile, researchers continue to uncover more ways that absorbing pesticides — by eating, touching or breathing them — is bad for our health… most especially for people who are already somewhat unhealthy due to poor lifestyle or other conditions that depress their immunity. Among the recent findings…
- Parkinson’s disease. It appears that exposure to pesticides may trigger Parkinsons’s disease in genetically predisposed people. In a large 2006 study, researchers at Harvard School of Public Health found that participants exposed to pesticides (specifically, farmers, ranchers, fishermen and people who used pesticides in their homes or gardens) had a 70% higher incidence of Parkinson’s than those who weren’t exposed. The latest research, reported in February 2011 and conducted by the National Institute of Environmental Health Sciences, shows that people exposed in their professions to the pesticides paraquat or rotenone developed Parkinson’s approximately 2.5 times more often than people who were not exposed. Both pesticides cause cellular damage. Paraquat, in particular, is an extremely toxic substance originally developed as an herbicide.
- Dementia. A study that collected data between 1997 and 2003 from French vineyard workers who spent at least two decades applying pesticides to plants or working in buildings where pesticides were housed showed that these workers scored low on a test of memory and recall. Researchers speculate that the changes demonstrated in the mental functioning of these people indicate that they may eventually develop a neurodegenerative disease, such as Alzheimer’s.
- Infertility. In a 2008 review of studies on pesticide exposure, epidemiologists showed a decline in the semen quality and quantity of farm workers, which impaired male fertility by 40%. “Infertility, especially in men, is increasing in proportion to greater exposure to pesticides,” said Dr. Pimentel.
Kids Are Vulnerable
For children, there is bad news and good news. First of all, the problem of pesticide exposure is amplified compared with adults. “Kids are growing,” noted Dr. Pimentel. “In relation to body weight, they eat more than adults.” One study found that the urine of children eating a variety of conventional foods contained markers for organophosphates, a lethal group of pesticides used to disable the nervous system of pests that is, not incidentally, used to make the deadly nerve gas saran. However, the study also found that when the children’s diets were switched to only organic foods, the chemicals disappeared from their bodies within 36 hours.
What To Do
You may take some comfort — briefly — in knowing that, by Dr. Pimentel’s reckoning, newer pesticides are used at 1/1,000 of the amount as had been the case with DDT. But don’t be fooled by this simplistic comparison — ounce for ounce or pound for pound, “These newer materials are far more toxic, not just to pests but also to humans.”
Washing and peeling helps only if a chemical is on the outside of a fruit or vegetable, Dr. Pimentel noted — but the sad fact is that some of these toxins are taken up by the plant as it grows, meaning that the pesticides end up inside the flesh of the produce and therefore cannot be removed even with careful washing and peeling.
Foods least likely to have pesticide residue after washing include onions, avocados, corn, pineapples, mangoes, asparagus, sweet peas, kiwi, cabbage, eggplant, papaya, watermelon, broccoli, tomatoes and sweet potatoes. Some of these foods have thick skins that protect the food, while others face fewer threats from pests and so are sprayed less.
Avoiding the most contaminated types of fruits and vegetables or buying their organic counterparts reduces your pesticide exposure by 80%. The following foods, when grown conventionally, contain the most pesticide residue even after washing and/or peeling: Celery, peaches, strawberries, apples, blueberries, nectarines, bell peppers, spinach, kale, cherries, potatoes, grapes, carrots.
Bottom line: Choose carefully, buy organic when possible and be sure to wash fruits and vegetables thoroughly to be certain they’ll keep you healthy, not make you sick.
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Source(s):
David Pimentel, PhD, professor, department of entomology, systematics and ecology, Cornell University, Ithaca, New York.