Cara Rosenbloom, The Washington Post | Updated: January 19, 2017 15:57 IST
These annual reports generate a lot of media coverage, and their presence seems to influence our grocery shopping habits. But research shows that the lists - which are being questioned for their scientific validity - may be doing more harm than good.
Organic . . . or nothing?
It's vital to eat your veggies. Low in calories but rich in vitamins and antioxidants, vegetables and fruits have been linked with a reduced risk of heart disease, cancer, diabetes and obesity. Yet, most Americans aren't getting enough. Could the "Dirty Dozen" list may be part of the problem?
That depends on what message we take away when we read about pesticides in vegetables and fruit. Researchers at the Illinois Institute of Technology in Chicago wanted to know how the list influences our buying habits. They surveyed more than 500 low-income shoppers about their thoughts on organic and conventional vegetables and fruit, and published results in the journal Nutrition Today. They found that specifically naming the "Dirty Dozen" resulted in shoppers being less likely to buy any vegetables and fruit. That's right - it's not just consumption of the top 12 pesticide-laden items that drops, it seems we buy and eat less of every vegetable and fruit. Misinformation about pesticides breeds fear and confusion, and many find it easier to skip fresh produce altogether.And when asked about the promotion of organic produce, 61 percent of participants said they felt the media encouraged them to buy organic foods. The problem is that they are often unaffordable.
So, does it really make sense to pay up to 47 percent more for organic vegetables and fruit? Food toxicologist Carl K. Winter doesn't think so.
Winter is the vice chair of Food Science and Technology at the University of California at Davis, and one of the researchers who did a deep dive into the Dirty Dozen list. The results, published in the Journal of Toxicology, found that the list lacks scientific credibility.
"Foods on the Dirty Dozen list pose no risks to consumers due to the extremely low levels of pesticides actually detected on those foods," says Winter.
Think of it this way. Pesticides may be present, but mere presence is not enough to cause harm. Winter explains that the first principle of toxicology is that "the dose makes the poison"; it's the amount of a chemical, and not its presence or absence that determines the potential for harm. Plus, some pesticides are more toxic than others, but they are all treated equally in the Environmental Working Group's ranking system, which makes for a weak comparison. Unfortunately, that information is not making its way to consumers, who believe that any amount and any type of pesticide is bad news. Even though the Dirty Dozen foods do have pesticides, Winter says "actual exposure levels are typically millions of times lower than those that are of health concern."
"The methodology used to rank produce items on the Dirty Dozen list was seriously flawed as it failed to consider the three most important factors used in authentic risk assessments - the amounts of pesticides found, the amounts of the foods consumed, and the toxicity of the pesticides," says Winter. "When we consider these factors, foods on the Dirty Dozen list are clearly safe to consume."
Even the Environmental Working Group doesn't recommend avoiding the items on its own Dirty Dozen list. Their website says "the health benefits of a diet rich in fruits and vegetables outweigh the risks of pesticide exposure. Eating conventionally grown produce is far better than skipping fruits and vegetables." That should be the key message that everyone hears in 2017.
Vegetables and fruit account for 43 percent of U.S. organic food sales, so it's a big industry. And organic vegetables are healthy - no doubt. Some studies show that they have more of certain vitamins and minerals compared with conventionally grown produce, and the farming methods may be better for the planet. If organic items are affordable, available and preferable to you, buy them.
But organic food isn't necessarily pesticide-free either, explains Winter. "Studies have indicated that as much as one quarter of organic fruits and vegetables may contain pesticide residues." But remember, as is the case with conventional fruits and vegetables, the pesticide levels are not high enough to be a health concern.
So, the bottom line remains: The best thing you can do is consume lots of vegetables and fruit for their health benefits, whether you choose to buy organic or not.
When you shop for groceries, do you carry a copy of the Environmental Working Group's "Dirty Dozen," list with you? It's a list of the 12 vegetables and fruits with the most pesticides, and some people only buy organic versions of the items on the list. It's the companion piece to the "Clean Fifteen," which showcases the 15 options with the least pesticides.