Sulfites are said to cause adverse reactions in some wine drinkers, but a recent study by Sophie Parker-Thomson states that bottles made without added sulfites are more likely to cause symptoms such as headaches or watery eyes.
Instead of sulfites, Parker-Thomson writes, the culprit is likely a group of compounds called biogenic amines (BA).
Biogenic amines are found in all fermented foods and beverages and increase as the food spoils. They are produced from amino acids through enzymatic activity in living organisms such as microbes, usually a subset of bacteria. The best-known biogenic amine, histamine, is produced when microbes remove carbon dioxide from the amino acid histidine.
Histamine is produced by the body and is involved in immune and allergic reactions. If you suffer from hay fever, you can take an antihistamine pill to reduce your body's production of this biogenic amine.
Other biogenic amines in food and wine include tyramine, putrescine and phenylethylamine. In large quantities, they can all cause unpleasant side effects. However, it would be wrong to consider them toxins, as they all perform essential physiological functions.
Normally, biogenic amines are not a problem because enzymes called monoamine oxidases (MAO) and diamine oxidases (DAO) metabolize them. But if these enzymes are inhibited, or if the compounds are present in excessive amounts in food or drink, they can cause reactions such as headaches, breathing difficulties, hypertension or hypotension, allergic reactions and palpitations.
Sulfites are added to almost all wines because they repel bad microbes and protect against oxidation. But at higher concentrations, some asthmatics experience negative reactions. A wine with more than 10 milligrams per liter (mg/L) of sulfur dioxide must state "contains sulfites" on the label. This allows people who experience adverse effects from some wines to blame the sulfites.
Fortunately, it is easy to make wines with few biogenic amines by controlling microbial growth. A blast of sulfur dioxide upon receiving or crushing the grapes will eliminate bacteria and many wild yeasts from developing during the early stages of fermentation.
"A higher pH and minimal addition of SO2 is definitely beneficial for the production of biogenic amines, even in the early stages of receiving grapes," says Dr. Sibylle Krieger, head of wine bacteria research at Lallemand Oenoloy.
A dose of sulfur dioxide also paves the way for winemakers to add a selected strain of Saccharomyces cerevisiae for fermentation. Once fermentation is complete, winemakers may choose to inoculate malolactic fermentation with a specific strain of lactic acid bacteria with low biogenic amine production. Finally, the wine receives a generous dose of sulfur dioxide to further protect against biogenic amines.
Wine does not contain particularly high levels of BA compared to published levels in other foods. Red wine contains 19.6 mg/L of histamine, while white wine contains only 1.1 mg/L. Two-day-old fish contains 209 mg/L, while canned tuna (60 mg/L), fermented soy (46.2 mg/L) and fresh fish (23 mg/L) all contain more histamines than wine.
BA levels are difficult to establish legally because we don't know what levels are dangerous for most people. And individual reactions can vary enormously. Some antidepressants can inhibit enzymes and cause amine sensitivity. Smokers reportedly show a 30% reduction in the activity of these enzymes. Alcohol can also suppress their activity.
If authorities insist on low-BA wine protocol, it would kill the natural wine movement. Analyzing wines for biogenic amines would impose a significant cost and administrative burden on winemakers.
Not everyone is convinced that biogenic amines are a problem in wine.
"There has always been some confusion between allergic reactions to certain wines, and the first jump is usually that it's due to one of the biogenic amines," says wine scientist Roger Boulton, professor emeritus of enology at the University of California at Davis. "I've never been convinced there's a connection or a problem.
Others point out that alcohol itself is a toxin.
"Given that wine typically contains 12-14% ethanol, a known carcinogen, I personally choose not to worry about these small concentrations of biogenic amines," says Marcus Herderich of the Australian Wine Research Institute (AWRI), an industry group.
The AWRI examined average histamine concentrations in Australian red and white wines from 2003-2009 and found that they contained 1.75 and 0.59 mg/L, respectively. The study suggests that the histamine concentrations needed to cause physiological responses should be much higher.
"Adding unnecessary and unjustified health warnings doesn't help anyone in the industry," Herderich said. "The principle of labeling for every possible problem compound in wine is complete nonsense."
Wine enthusiasts who are sensitive to biogenic amines should avoid wines that have undergone malolactic fermentation. This information can be hard to find, although it applies to some Chardonnays and Viogniers and most red wines.
If you want red wines, look for those from a major brand that probably contains a hefty dose of sulfur dioxide from the start.
But it is too early, and perhaps counterproductive, to label biogenic amines in wine as a health hazard.
Source: WineEnthusiast.com
If you want to achieve low sulfite levels, Krieger says, it's best to inoculate the wine to inhibit the production of biogenic amines. This prevents the bad microbes from establishing themselves.
Many commercial wines are made using these biogenic-amine-safe methods, but in recent years premium wine producers have moved away from microbial control. And many proponents of natural wine avoid sulfites altogether or add them only at bottling, resulting in wines that may contain many biogenic amines.
And so the question for all winemakers is: How much is too much BA? There are no legal limits in food, except in fish. Will biogenic amines in wines, even those made without added sulfites, ever be a problem for the vast majority of consumers?
In her research, Parker-Thomson implies that wines without added sulfites should have a warning label.
"There is also a strong argument that wines with very high BA levels should have a warning because these toxic levels pose a risk even to healthy individuals when moderate amounts of these wines are consumed," she writes. "The results of this study show that wines made without low SO2 levels are most likely to have the highest BA levels.
"If SO2 additives are unconscionable to the natural wine movement, then perhaps wines without SO2 additives should have a mandatory high BA warning unless they can prove otherwise," she writes.
Doug Wregg, who works for Les Caves de Pyrene, a British import agency specializing in natural wine, disagrees.
"This smacks of bureaucratic interference, but it is based on a strange inversion of the truth," says Wregg. "Wine contains a large number of substances that are only harmful to health if consumed in very large quantities. If you look at the lab results, you see that many wines contain traces of mercury. Would you put 'contains mercury' on the label?"
He compares BA to sulfites, which are present in a whole range of foods. He cites a recent, possibly allergic reaction he had to sulfites in mortadella.
"Sulfite by itself is not toxic, but our diet, our lifestyle, can cause intolerances and allergic reactions triggered by high levels of sulfite," he says. "At least, according to my experience."
"Finally, there is the thin end argument," he says. "If you label a wine as having a high content of biogenic amines, which is a feature rather than an addition, you might as well add every addition and every process, just in case either of them, individually or in combination, impacts the health of a particular individual. Most histamine-intolerant people know not to drink wine, especially red wine."
