Many people enjoy wine with a meal, on a special occasion, or as an everyday treat. Some pay later with headaches or other unpleasant effects. We often hear that reactions to wine are caused by sulfites, but the truth is a little more complicated. Here's what you need to know about sulfites in wine.
What Are Sulfites?
Sulfites – sometimes spelled “sulphites” – occur naturally in some foods and drinks. For centuries, people have used them as food preservatives. Today they are used to keep shrimp and lobster from turning dark, bleach some starches, and lessen bacterial growth in wine.
Sulfite use surged in the 1970s and 1980s. Among other uses, restaurant owners relied on them to keep their salad bars looking fresh. A few people had severe reactions to sulfites, and in 1986 the Food and Drug Administration (FDA) banned their use on fresh fruits and vegetables.
Why Does Wine Contain Sulfites?
Wine is fermented using yeast, which produces sulfites, so almost all wine contains sulfites. Winemakers have been adding sulfur dioxide to wine since the 1800s. It has several effects on the winemaking process, including:
- Protecting against oxidation, which can affect the color and taste of wine
- Preventing the growth of unwanted microorganisms
- Preserving the desired color
- Promoting the growth of yeast for better fermentation
- Improving the release of desirable compounds from the skin and seeds of the grapes
Winemakers have been experimenting with physical methods to preserve wine – using electricity, microwaves, and ultraviolet light, as well as trying other substances. Some have used resveratrol – a healthy compound found in grape skins – with good results. Resveratrol occurs naturally in wine, but scientists haven't found an easy way to increase the amount.
Effects of Sulfites
Most people can ingest sulfites with no problem, but two groups can experience negative effects. Those with sulfite-sensitive asthma can have severe respiratory episodes after taking in too many sulfites. Those who lack the enzyme that breaks down sulfites – sulfite oxidase – can also have serious reactions.
It is unclear what percentage of the population could be sensitive to sulfites. One source estimates that about 1% of the population and about 5% of those with asthma react to sulfites. If you have a sensitivity, you will probably have a reaction within 15 minutes of ingesting too many sulfites.
Sulfite reactions normally affect breathing, but some people with sensitivity have skin reactions, such as hives, or digestive problems, such as abdominal pain or diarrhea. Some individuals experience a mixture of symptoms, including respiratory, skin, and digestive reactions.
Do Sulfites Cause Wine Headaches?
Those who suffer headaches after drinking wine often blame the sulfites in wine, but it is unclear whether they are really to blame. A hangover headache may come after drinking too much alcohol of any kind, but those who have migraine headaches can develop a headache after as little as one glass of wine.
Those who get wine headaches often say that they get them after drinking red wine. Since white wine contains more sulfites than red, it is unlikely that sulfites are to blame. Also, sulfites are also high in certain foods, such as dried fruit, soy sauce, and pickles. If the sulfites in wine cause headaches, these foods should cause a similar reaction.
Some experts suggest that drinking low-quality wine may cause headaches. Such wines often contain compounds that can interfere with the production of serotonin, an important brain chemical. Also, low-quality wines are often highly processed, unlike wines made using more natural processes, which could be better for your health.
It's likely that headache triggers are different for different people. If you suffer from wine headaches or other reactions to wine, talk to your doctor about whether you should avoid drinking it.
Wines With Minimal Sulfites
If you would like to keep your intake of sulfites low, look at wine labels before you drink. In the United States, wines that contain 10 or more parts per million (ppm) of sulfites must state on the label that they contain sulfites. This rule applies to both imported and domestic wines.
U. S. winemakers can leave out the label warning if their wines have undergone official analysis, and they have been shown to have less than 10 ppm of sulfites. If lab testing finds no sulfites, the label may say that the wine contains no detectable sulfites. It may not say "no sulfites" or "sulfite free".
In the United States, wines labeled as organic cannot have added sulfites. Some wines are labeled, "made with organic grapes." These wines may have sulfites added later during processing.
If you like to travel and are sensitive to sulfites, check the labeling laws of your destination before you drink wine. The wine you drink in other countries is likely to contain sulfites, but may not have a sulfite label.