Harvard Health Letter

Should you go organic?

Organic produce may have fewer pesticide residues than conventionally grown produce. But the amounts for both are within the levels for safe consumption.

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These foods are grown without fertilizers, pesticides, and other synthetic additives. But are they better for you?

Walk through any grocery store today, and you'll likely see more shelf space devoted to organics—foods that are grown without most synthetic fertilizers and pesticides, and animal products that are free of antibiotics and hormones. Demand for organic food is up, with sales reaching $35.9 billion in 2014. "I think people believe these foods are better for them, but we really don't know that they are," says registered dietitian Kathy McManus, director of the Department of Nutrition at Harvard-affiliated Brigham and Women's Hospital.

What's the buzz about?

Organic agriculture aims to preserve natural resources, support animal health and welfare, and avoid most synthetic materials. It's not just a philosophy; the USDA regulates the organic industry with strict standards. The soil where crops are grown must be inspected and shown to be free of most synthetic pesticides and fertilizers, and the crops cannot have been genetically modified. Animals raised on organic farms receive no antibiotics or growth hormones, are given feed that has been grown organically, and are able to roam around outside. Processed organic foods must not contain synthetic additives.

The USDA then certifies organic crops, animal products, and processed foods. Only foods that are 95% organic can carry a "USDA Organic" seal.

Is there a benefit?

While organic foods have fewer synthetic pesticides and fertilizers and are free of hormones and antibiotics, they don't appear to have a nutritional advantage over their conventional counterparts. "There've been a number of studies examining the macro- and micronutrient content, but whether organically or conventionally grown, the foods are really similar for vitamins, minerals, and carbohydrates," says McManus.

According to USDA data, organic foods have fewer pesticide residues than conventionally grown produce. But the amounts for both types of produce are within the level for safe consumption. And it's unclear if the pesticides used in organic farming are safer than nonsynthetic pesticides used in conventional farming. "The verdict is still out about pesticides and fertilizers as far as the long-term impact on health. There are so many other variables in the environment. It's hard to say it's the pesticide on the peach that was the primary cause of a health-related issue," says McManus.

Similarly, we don't have enough information yet to know if the lack of hormones and antibiotics in organic animal products makes them healthier than conventional animal products.

Should you buy it?

McManus says she doesn't recommend organic food to people, but will talk with them about it if they are concerned about pesticides. "At this time, after examining the data, I don't see any nutritional reasons to choose organic foods over conventional," she says.

If you do want to go organic, you'll likely notice a higher price tag on many items, as much as 10% to 50% more than conventional foods.

How do you make the decision about going organic? "It's usually people who are concerned about what's going into food production and who can afford to make the choice for organic," says McManus. Some people intuitively feel that foods with synthetic pesticides and fertilizers, and trace amounts of hormones and antibiotics, likely have adverse health effects, even if that has not been proved. And some people choose organic foods not for health reasons, but because they think they taste better.

Making the switch to organic food

Where would you start if you wanted to go organic? "Produce," says registered dietitian Kathy McManus, director of the Department of Nutrition at Harvard-affiliated Brigham and Women's Hospital. Try buying organic versions of foods on the Dirty Dozen list, published each year by the Environmental Working Group (EWG). The list shows USDA findings of conventionally grown foods most likely to contain pesticide residues. This year's list includes apples, celery, cherry tomatoes, cucumbers, grapes, nectarines, peaches, potatoes, snap peas, spinach, strawberries, and sweet bell peppers.

Produce items with thicker skins tend to have fewer pesticide residues, because the thick skin or peel protects the inner fruit or vegetable. Remove the skin or peel, and you're removing much of the residue. The EWG puts out a list of those foods, too, called the Clean 15. On the list this year: asparagus, avocados, cabbage, cantaloupe, cauliflower, eggplant, grapefruit, kiwi, mangoes, onions, papayas, pineapples, sweet corn, sweet peas, and sweet potatoes.

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