Wine is made entirely of grapes, with alcohol being the main by-product of fermentation and some other influences like oak and ageing playing a lesser role. So what could be in wine to cause an allergic reaction? Are there other noxious substances lurking in the bottle? American Doctor, Harvey Finkle shares his thoughts on the subject...
Let’s begin with the conclusion: Wine contains only one potential toxin, alcohol, but that toxin is harmful only in wretched excess. When consumed in moderation and in combination with the polyphenolic compounds found in wine, alcohol enhances health, well-being and may even contribute to extending one’s life span.
Frequently wine consumers raise the question of allergic reactions to wine. When considering this possibilility it’s important to keep in mind that allergies may be idiosyncratic and since wine contains many mysterious trace compounds so we cannot dismiss rare complaints just because they are unexplained. But we can address what’s known, that is, what’s been scientifically investigated. Sulfite allergy generally receives the most attention. This group of compounds did not first appear into wine when the words “contains sulfites” were mandated to be printed on wine labels. To the contrary, sulfites are natural by-products of fermentation thus have always been a part of wine. In the vineyard and winery, judicious addition of sulfites protects vines from pests and wine from oxidation and spoilage. Modern techniques and careful winemaking go a long way towards minimizing the need to add sulfites, as they minimize all other manipulation, though even wines certified as organic will ultimately contain some level of sulfites.
It is therefore impossible to make wine containing zero sulfites, and even at a minimum it is exceedingly difficult to make wine without the addition of some. Many foods, even medicines used by allergic and asthmatic individuals, are burdened by more sulfites than most wines, but, oddly, are not required to have a warning label, and seem not to cause trouble. Serious allergic reaction to sulfites is virtually limited to a very small subgroup of corticosteroid-dependent severe asthmatics.
Headache, a frequent complaint amidst the noise and frenzy of modern living, is often blamed on drinking and some type of allergic reaction. Many white wine drinkers are certain that red wine causes headaches. The Bordelais, who are devoted to red wines, believe that white wine causes headaches. If you ask the Champenois they trust bubbles to prevent headaches. My friend’s sister-in-law complains that dessert wines like Sauternes cause her headaches, but then again she only drinks the sweet nectar as the sixth wine of a lavish dinner.
Given that the science of headache study is muddled I find that much reflection upon the subject gives me a headache too. However studies indicate that sulfites, histamines, tyramine, prostaglandin, and polyphenols, may all be accused suspects yet they are all exculpated as direct causes. As a Doctor I am convinced that almost all headaches related to wine drinking are the quantitative result of alcohol, if not of the wine bills in restaurants themselves!
Fears of contamination of wine by lead, urethane, and pesticides have proved to be tempests in a wineglass. With use of unleaded fuel, lead contamination of vines has ceased to be of concern. Lead capsules are no longer used (to solve a disposal problem). For older bottles, simply wipe the lip of the bottle before pouring. Do not mistreat wine by leaving it for days in a lead-crystal decanter to pick up lead, and never store any potable in a ceramic container that might be lead-glazed. Urethane, another natural product of fermentation, has been reduced to a vanishingly small trace. The need for and means of testing wine for pesticides and fungicides have not been and seem unlikely to be established.
Finally, to get back to alcohol, human bodies are not all the same. Women neutralize alcohol only half as efficiently as do men, so they should take that into account when drinking. Inexperienced drinkers may be rendered comatose by a quantity a steady drinker handles with aplomb. Some people’s detoxifying enzyme systems are genetically sub-optimal leading to distress after drinking even small amounts. This is particularly common among some Asian populations.
I saw a film many years ago about a man who got into legal trouble from alcoholic intoxication without drinking. He got out of trouble when it was found that his body manufactured its own alcohol. An amusing fancy, I thought, until a recent study revealed that obesity in mice slows intestinal motility enough to allow bacterial overgrowth to produce excessive alcohol, which ultimately causes liver injury. Is this a warning to the corpulent among us?
And remember, alcohol is best used in regular portions, especially with meals. Binge drinking is particularly damaging.
Harvey Finkle is a Clinical Professor of Medicine (retired) at Boston University Medical Center; International writer and lecturer on the influences of wine on health who has won many awards and is the author of scores of articles and one book on the subject.
