Sulfites: Friend or Foe?
Tough on spoilage, sulfites can be hard on humans, too.
For more than 2000 years, sulfites have been used to prevent food spoilage and discoloration. Perhaps for nearly as long, they've played a more sinister role - causing allergic-type reactions in some of the people who consume them. Ellen Wiest is one such individual. She often suffered from headaches, severe nasal congestion, abdominal cramps and diarrhea after eating. But she didn't connect her symptoms to sulfites, until one June evening in 1995.
That night, Wiest was enjoying dinner with her husband at a favorite restaurant. Halfway through the meal, she developed symptoms typical of a food sensitivity. Only this time, they were accompanied by an increased heart rate, profuse vomiting and difficulty breathing. The restaurant called 911, and paramedics rushed her to the local emergency room.
Wiest learned that her meal contained a splash of wine, and sulfites in the wine sparked the anaphylactic reaction. Similar reactions to hidden sulfites have landed her in the ER twice since then. "When we eat out, I make it clear to the waiter that I will have a life-threatening reaction if I eat anything that contains sulfites," she notes. "Most of the time, I need to explain what sulfites are and what foods usually contain them."
While the severity of Wiest's reaction may be uncommon, sulfite sensitivity is not. The U.S. Food and Drug Administration estimates that up to one in 100 people may be sensitive to the chemicals. Among asthmatics, the ratio shoots to one in 10 and even higher among those who depend on corticosteroids.
Surrounded by Sulfites
In addition to their role as preservatives, sulfites are used to bleach food starches, such as corn, potato and sugar beet. Sulfites are also put to work as preventives against rust and scale in boiler water used in making steam that may come into contact with food.
Because sulfites inhibit fungal and bacterial growth, they are sprayed on both fresh grapes and those used in winemaking. Sulfites are a normal by-product of winemaking. Sulfites lurk in many popular foods and beverages, under the names of sulfur dioxide, sodium sulfite, sodium bisulfite, potassium bisulfite, sodium metabisulfite and potassium metabisulfite. Wine, bottled lemon and lime juices, and sulfur-dried fruits have the highest levels of sulfites.
The Labeling Nightmare
Avoiding sulfites can be difficult. "I've learned to carefully read labels," Wiest says. "But it's surprising how poorly many foods are labeled with regard to sulfites."
Current labeling laws were enacted in 1985, after sulfites were linked to 15 deaths. The Food and Drug Administration now say manufacturers must identify the presence of sulfites on food labels, but only if concentrations exceed 10 parts per million. Test strips are available to test liquid foods. However, they detect sulfites only in levels greater than 10 parts per million - and many sulfite-sensitive individuals react to much lower levels.
Seek Expert Advice
Other foods, chemicals, additives, colors and substances can create the same symptoms caused by a sulfite sensitivity, which is why it is important to consult with a doctor who is familiar with the affliction. After reviewing a patient's records, the physician may perform oral provocative testing to confirm suspicions.
Observations as simple as "wine gives me gas" make elimination of the offending item fairly easy. However, eliminating large groups of foods may compromise the nutritional adequacy of an individual's diet. If the diagnosis is confirmed, the patient should work with a dietician experienced in allergies and sulfite sensitivities to help plan a diet that is adequate, while avoiding foods that increase symptoms. Dietary changes are the best way to treat a sulfite sensitivity. However, there is some scientific evidence that vitamins can help treat or prevent the sensitivity, as well.
Very high amounts of vitamin B-12 supplements - 1,500 to 5,000 micrograms or 1 to 5 millegrams per day - reduce the tendency of asthmatics to react to sulfites if taken before ingesting the sulfites. Vitamin B-12 is very safe, with no upper limits established. Due to the low level of risk involved, it may be worth trying prior to restaurant meals - but only with a doctor's approval. Asthma sufferers should always carry an inhaler when dining out. If a reaction to sulfites has occurred before, always carry an antihistamine and self-administering injectable epinephrine.