By K. Aleisha Fetters for U.S. News
If you’ve ever picked up an apple from the organic section of your supermarket, you probably thought that by doing so, you were improving your health. And if you haven’t, you may belong to the camp that believes the potential health benefits of going organic don’t outweigh the literal costs.
But what if the benefits included weight loss? Here, we explore how eating organic may affect your slim-down efforts. Whether or not you choose to go organic, however, is ultimately up to you.
More Nutrients, Better Weight?
While experts have debated for years whether organic foods really are more nutritious than their conventionally raised counterparts, last year a British Journal of Nutrition review of 343 studies concluded that on average, organic foods (both crops and packaged foods derived from those crops, like bread) contain higher concentrations of antioxidants than conventionally grown foods.
That’s because, while an organic apple and a conventionally grown apple may both contain the same number of vitamins and antioxidants, the organic apple is much smaller, meaning that it contains more of them per ounce, says study co-author Charles Benbrook, a research professor at Washington State University's Center for Sustaining Agriculture and Natural Resources.
Why the size difference? The funny thing is, the reason may be because organic, nitrogen-rich fertilizer is so expensive, meaning that organic farmers can’t typically afford to over-fertilize their crops to the same extent that conventional farmers can, Benbrook says. And nitrogen is to plants what calories are to people, so when conventional plants get too much nitrogen, they do the same thing we do: They get big. However, their nutritional properties, like our muscles, don’t balloon with them.
“When produce is over-fertilized, the ratio of calories per antioxidant activity goes way up,” Benbrook says. That means that bite per bite, you are typically getting fewer good-for-you nutrients and more calories (granted, probably not enough to wreck your diet) out of that conventionally raised, albeit bigger, apple, he says, versus the smaller organic variety.
Previous research from Newcastle University found that on average, organic fruits and vegetables contain 12 percent more healthy plant compounds – resveratrol and other polyphenols, for example – than conventionally grown produce. What’s more, research in The American Journal of Clinical Nutrition suggests that flavonols, one of these beneficial plant compounds, may stabilize blood sugar levels, helping to keep appetite in check, while another such compound, resveratrol, has been shown to promote fullness. Some pesticides used in conventional farming, however, may reduce the level of resveratrol in plants.
So if vitamins and antioxidants aren’t what’s making that non-organic apple bigger, what is? Simple sugars and starches, which explains why conventional produce is oftentimes sweeter and juicier, Benbrook says.
His research shows that some organic fruits and vegetables contain 20, 30, even 40 percent more antioxidants per calorie than conventionally raised versions. “If you choose organic foods to hit your five-a-day produce requirement, it’s like you are getting a sixth serving without consuming any additional calories,” Benbrook explains.
Still, just because an apple is organic doesn’t guarantee the farmer hasn’t piled on the nitrogen, thereby reducing its antioxidant concentrations while increasing its calories, Benbrook says. Some studies, including a 2012 review in the Annals of Internal Medicine, have found that organic and non-organic produce don't vary greatly in terms of nutrients. While, in general, organic crops may be more nutrient-dense than conventional crops, an organic seal isn’t proof they will be. It just proves the crops were grown without synthetic pesticides, growth hormones, antibiotics, genetic engineering or chemical fertilizers.
So, Can Pesticides Mess With Your Weight?
The average American is exposed to 10 to 13 pesticide residues per day, including one to three highly toxic pesticides called organophosphates. Organic production reduces average overall dietary exposure by 97 percent, according to research from The Organic Center, a nonprofit research and educational organization.
Benbrook notes that while research doesn’t show that being exposed to those pesticides as an adult will affect your metabolic health or weight, if you eat conventional produce during your pregnancy or feed conventional produce to your child during his first two years, it may affect his future weight. Research in PLOS One and Environmental Health Perspectives have linked chemical pesticide exposure to increased body mass indexes in children and increased weight, abdominal fat and insulin resistance in rodents.
“During fetal development and then through age 2, humans are sensitive to epigenetic changes,” Benbrook says. “Some pesticides during this time can up-regulate the child’s ‘thrifty’ genes so that [the child] grows up laying on fat.”
Defenders of conventional crops say, however, that any pesticide residue found on produce is too small to have real impact – whether on your overall health or your weight.
“I really don’t think that the levels we are exposed to pose a risk. We can detect pesticide residues in food supply many levels of magnitude lower than what would cause harm,” says Carl Winter, a pesticide and food toxin expert at the University of California–Davis.
Still, if you want to limit your pesticide exposure, the best place to start is with the nonprofit Environmental Working Group’s Dirty Dozen. The EWG estimates that when it comes to buying the 12 foods on the list, you can reduce your pesticide exposure by 80 percent if you reach for organic varieties.
Either Way, You Still Need More Produce
Organic or not, filling up on fruits and veggies is consistently linked to weight loss.
“Vegetables and fruit are integral for weight loss because they provide volume for very few calories,” says registered dietitian Georgie Fear, author of “Lean Habits for Lifelong Weight Loss.” The most important factor in successfully losing weight is how much of them you eat not how they were grown, she says. “I’d rather have people eat larger amounts of conventional produce than smaller amounts of organic produce,” Winter adds.
So how much produce do you need? “Each person’s recommendations are going to be individualized based on age, gender and activity level. However, in general, it will be between 4 and 6 cups of fruits and vegetables per day,” says registered dietitian Kristi King, spokeswoman for the Academy of Nutrition and Dietetics. “Aim to make half of your plate at lunch and dinner fruits and vegetables, and you should be on the right track.”
And if you consume a variety of colors while you’re at it, you’ll score a variety of antioxidants, vitamins and minerals, too.