Natural or added sulfites are present in every bottle of wine, as well
as in many foods. What are sulfites, and do they carry health risks?
If you’ve ever looked closely at a bottle of wine, “Contains
Sulfites” is likely to appear somewhere on the label. These two
little words have been the subject of some confusion and concern in recent
years, especially as people have been paying more attention to what goes
into the foods and beverages they consume. “Contains sulfites”
has a somewhat scary ring to it, and it makes people wonder if sulfites,
as additives, are automatically something bad. Before deciding whether
to avoid products containing sulfites, it’s important to understand
what sulfites are, what they’re used for, and whether they present
any health risks.
Sulfites are naturally-occurring compounds that plants produce to protect
themselves from microbial infection. In winemaking, sulfur dioxide (SO2)
is also released during fermentation; and traditionally, winemakers add
extra sulfur to wine to preserve freshness and prevent spoiling. Both
white and
red wine contain sulfites, ranging between 20 and 200 parts per million. Even wines
with no sulfites added are usually required to have “contains sulfites”
on the label, because natural fermentation creates as much or more SO2
than what would have been added by the winemaker.
Are sulfites in wine harmful? Probably not. While 200 parts per million
sounds like a lot, it is really a tiny amount compared to some foods,
such as dried fruit, which can contain as much as 3,000 parts per million.
But what about the famous “wine headache?” Don’t sulfites
have something to do with this common complaint? The wine headache phenomenon
has been studied repeatedly, and still no scientific link has been found
between sulfites and headaches. And according to these same studies, sulfites
cannot be blamed for hangovers, either. "In high doses, sulfites
can cause an adverse reaction in asthmatics," cautions
Abhijit Adhye, MD, FACP, a board-certified internal medicine physician at
St. Joseph Health Medical Group. "Less than 1 percent of the population is estimated to have a specific
sensitivity to sulfites. These people may experience rashes, itching or
hives, or have trouble breathing. In rare cases, people can go into anaphylactic
shock."
The Food and Drug Administration (FDA) has decreed that sulfites are safe,
but recommends that they should be avoided by people with asthma, liver
or kidney problems. The World Health Organization recommends, for a man
of average weight, that sulfite consumption not exceed the equivalent
of a third of a bottle of white wine per day.
Besides wine and dried fruits, there are many commercially-prepared foods
that typically contain some sulfites. These include processed meats, fish
and shellfish, drink and soup mixes, beer and cocktail mixes, baked goods,
frozen pizza, jams, sauces and toppings, fruit and vegetable juice, processed
grain products and various condiments.
Sulfites are often confused with nitrites (and their close cousins nitrates,
both of which are used as preservatives--they're nearly identical,
so we'll just refer to nitrites). But sulfites and nitrites are not
exactly the same thing, even though both are used to preserve
cured meats, where they prevent the growth of bacteria keep meat looking red. These
salts are found in jerky, lunch meat, ham and bacon.
Are nitrites harmful? "Nitrites are considered safe, but not especially
healthy," says Dr. Adhye. "Most nitrites need to be consumed
in huge amounts to be toxic, though multiple studies have found a connection
between processed meat consumption and increased risk of colorectal cancer."
Moreover, even unprocessed meats cooked over high heat can form nitrosamines,
which have also been linked to cancer. One food that is probably best
to eat in moderation (or avoid) is bacon. Bacon is especially high in
nitrites, and produces high levels of nitrosamines when fried at high
temperatures. To reduce the risk, bacon should be cooked slowly at a low
temperature.
Given the low risk of sulfites in wine, plus its documented health benefits,
it’s probably just fine to indulge in that second glass, says Dr.
Adhye. Just go easy on the bacon and pepperoni pizza!
Have you experienced any side effects from sulfites or nitrites? Share
your story below.
This information is not intended as a substitute for professional medical
care. Always follow your healthcare professional's instructions.