Q: Are organic and natural wines better for you than regular wine?
—Larry, Spring, Texas
A: That depends a lot on how you define "better." Organic wines (and most natural wines are organic as well) are made from grapes grown without the use of chemical pesticides, which means they're friendlier to the environment, and a healthier planet is better for all of us. But as far as the wines themselves being "better" for you, in terms of beneficial polyphenols and antioxidants like resveratrol, existing research does not indicate any advantage for organic grapegrowing. A study out of Italy in 2011, published in the Journal of Pineal Research, actually found higher levels of polyphenols in wine made with chemically treated grapes than in wine made organically.
When it comes to wines that are labeled as "organic," there are two tiers. If a bottle carries the USDA seal, its grapes must be farmed organically, its other agricultural ingredients (such as yeast) must also be organic, and no sulfites may be added to it. Wines labeled as "made with organic grapes" are just that: These wines are vinified from organically farmed fruit, but sulfites may be added, and there are looser requirements for its other ingredients.
It's not clear that such wine has any special health benefits that regular wine doesn't have. For one thing, sulfites are a problem for only a very small percentage of the population. Second, the presence of certain chemicals in the vineyard hardly guarantees their presence at problematic levels in the glass: A 2013 French study found that its sample wines did not have detectable levels of pesticides or other chemical residues.
The Mayo Clinic, referencing a 50-year study that found "organically and conventionally produced foodstuffs are comparable in their nutrient content," reports that organic foods are "probably not [more nutritious], but the answer isn't yet clear." The choice to support organic, however, involves more than just vitamin and polyphenol content. By buying organic, you indeed reduce your environmental exposure to pesticides as well as support more sustainable farming practices.