When you sip a glass of wine or eat a dried apricot, you might be getting more than you bargained for: More than likely, you’re consuming a mouthful of sulfites, sulfur-based compounds used to preserve certain foods, drinks, and even some medications and cosmetics.
Historically, sulfites have been used since ancient Roman times to sanitize wine vessels and were introduced as a food preservative in the 1600s. Sulfites are often added to wines to protect them against oxidation and microbial growth. “Without them, [long-term] preservation of wine would be impossible,” says Jeremy Fisher, sommelier at The Frog and the Peach in New Brunswick, NJ. “A 1961 Bordeaux would taste like vinegar.” The fermentation process produces small amounts of sulfites—not enough to preserve wine indefinitely. “Transporting wines around the world without sulfites would be impossible, according to most winemakers,” says Fisher.
In addition to wine and dried fruit, you’ll find sulfites added to many foods, such as some canned seafood and white potatoes meant for frying. You might also see them in dried vegetables, pickled onions, fruit juice, vinegar, lemon and lime juice, fruit bars, gravy, pizza dough, deli meat, shrimp, lobster, and gelatin. In cosmetics and pharmaceuticals, they may turn up in hair dye, tanning lotion, anti-aging cream, bath gel, perfume, blush, and certain medication such as anti-fungal and corticosteroid creams and some antibiotics. Some people say that sulfites impart a bitter taste to food and drink, but that’s up for debate.
Sulfites occur naturally at low concentrations in some foods, such as grapes. If the sulfites occur or are added in excess of 10 or more parts per million (ppm) in a finished product, you’ll see a “contains sulfites” label on the package—a mandate by the U.S. Food and Drug Administration (FDA) because sulfites are a known allergen.
How Do Sulfites Affect Your Health?
You may have heard that the sulfites in red wine can make your head pound. But there’s no verdict on whether red-wine-related headaches are due to sulfites or other compounds. What we do know: Sulfites can cause itchy skin, low blood pressure, abdominal pain, and diarrhea—as well as life-threatening anaphylactic shock and asthma attacks.
However, you have to be sensitive to sulfites to see these reactions. About 1 percent of people have a sulfite sensitivity. “This sounds like a little—but in the U.S. alone, this would amount to more than 3 million people,” says Vincent Pedre, M.D., author of Happy Gut and an internist at Concierge Choice Physicians in Rockville Centre, New York. When you’re considering asthma suffers, between three and 10 percent are sensitive. “Sulfites are only bad for people that have a known sensitivity, because of the uncomfortable feelings they will develop,” says Pedre.
Related: What Does It Mean to Have Food Sensitivities?
Aren’t sure if you’re sensitive to sulfites? You can visit an allergist for a skin prick test or blood test. The Mediator Release Test is one recommended blood test that can determine food sensitivities. If you’re not an asthmatic, you can try the DIY test. Pedre suggests avoiding wine for a month, then having wine with a significant amount of sulfites. If you notice any unusual symptoms after drinking the wine, you might have a sulfite sensitivity.
Measuring Your Exposure to Sulfites
Sulfite-free wine doesn’t actually exist, since all wines contain at least some sulfites. If you see a “contains no detectable sulfites” on the label, that means it has less than 10 ppm sulfites. In this case, “there are still some sulfites present, although in minimal amounts that are deemed incapable of causing an allergic reaction of any kind,” notes Fisher.
How many sulfites does your glass of wine contain? U.S. wine isn’t allowed to contain more than 350 ppm, and most wines end up with less than 150 ppm. Italian and French varieties tend to contain fewer sulfites and typically max out at 250 parts per million.
Red wines generally contain fewer sulfites than whites and roses. While sulfites help preserve light colors, the natural tannins in red wines also do this. Sweet dessert wines have a much higher sulfite level, up to 500 ppm, to stop the sugars from continuing to ferment in the bottle.
Organic wines contain fewer sulfites than conventional, but the distinction in labeling is important: U.S. labeled organic wine must contain less than 10 ppm added sulfites—and wine labeled “made with organic grapes” needs to have 100 ppm or less sulfites. Estate-bottled wines and biodynamic ones are likely to have lower sulfite levels, too.
Even though wine gets a bad rap when it comes to sulfites, many foods have much higher levels. “Sulfite levels are much higher in food than wine, up to ten times higher,” says Fisher. Foods that have more than 100 ppm sulfites include bottled lemon juice, dried fruit other than raisins and prunes, sauerkraut, and molasses. If you’re sensitive to sulfites, you might be better off dehydrating your own fruit and squeezing fresh lemon juice.
While fresh green and fruit salads are no longer allowed to contain added sulfites, all grapes contain some naturally occurring sulfites. The organic version should contain less, as conventional ones are treated with sulfites to prevent fungus growth.
You can also reduce sulfites by filtering them out. Products like Ullo act as a wine purifier to remove sulfites from drinks (but aren’t recommended for champagne, since they remove some carbonation, too). They’re expensive, running around $80 for a purifier and four single-use filters. “That seems like a lot of money to spend,” says Fisher. When it comes to removing sulfites from produce, you can attempt this yourself: Soak vegetables or fruit that might contain sulfites in electrolyzed water that has a pH between 9 and 11, such as AQUAhydrate. “Alkaline water is very effective in removing pesticides and additives,” says Pedre.