Unpleasant symptoms after drinking wine—such as headaches, flushing, and nasal congestion—often lead people to question if they have developed an allergy. While these reactions are real, the term “allergy” is frequently misused to describe a sensitivity or intolerance. A true wine allergy, which involves the immune system, is extremely rare and typically triggered by specific proteins from the grapes or fining agents. This article clarifies the difference between allergy and intolerance, details the components most likely to cause adverse effects, and explains why reactions may begin later in life.
Differentiating Allergy from Intolerance
A true allergy to wine is characterized by an immediate, immune-system response involving immunoglobulin E (IgE) antibodies. This type of reaction is a hypersensitivity where the body mistakenly identifies a component, such as a grape protein or yeast, as a threat. Symptoms of a true IgE-mediated allergy are usually severe and happen very quickly, potentially including hives, swelling of the mouth or throat, difficulty breathing, and even life-threatening anaphylaxis.
Intolerance or sensitivity, on the other hand, does not involve the immune system’s IgE response and is far more common than a true allergy. Intolerance is instead a metabolic issue, often stemming from the body’s inability to properly process a particular compound in the wine. Symptoms are generally less severe, taking longer to appear, and may include digestive upset, headaches, skin flushing, or nasal congestion.
Common Wine Components Triggering Reactions
Since true allergies are rare, most adverse reactions are driven by non-immune responses to naturally occurring or added compounds in the wine. Sulfites are a common culprit, often blamed for discomfort, though a true sensitivity to them is relatively rare, primarily affecting people with asthma. Sulfites are used as preservatives to prevent oxidation and microbial spoilage. In sensitive individuals, they can trigger asthma-like symptoms, including wheezing and shortness of breath. Sulfites are also naturally produced during fermentation, meaning all wines contain them to some degree.
More frequently, issues stem from biogenic amines like histamine and tyramine, which are organic compounds produced during fermentation and aging, particularly in red wine. Histamine naturally causes blood vessel dilation, and an inability to break it down can lead to allergy-like symptoms such as flushing, headaches, and nasal congestion. The enzyme Diamine Oxidase (DAO) is responsible for breaking down ingested histamine in the gut.
If the DAO enzyme is insufficient or inhibited, histamine can accumulate and enter the bloodstream, triggering uncomfortable symptoms. Tyramine is another biogenic amine, primarily metabolized by monoamine oxidase (MAO). Histamine concentration tends to be higher in red wine than in white wine, which often explains why some people react more strongly to red varieties. Rarely, reactions can also be linked to residual proteins from the grapes, yeast, or fining agents used to clarify the wine, such as egg whites or milk proteins.
Developing Sensitivities Over Time
The question of whether a person can suddenly become reactive to wine is best answered by looking at the mechanisms of intolerance, as true IgE allergies typically develop earlier in life. The most significant factor in developing wine sensitivity later on is a reduction in the body’s ability to process biogenic amines, particularly due to changes in the DAO enzyme. DAO enzyme activity, produced in the intestinal lining, can decrease over time due to genetic factors or intestinal inflammation.
When DAO activity is reduced, the body cannot efficiently break down the histamine consumed in wine, leading to a threshold effect where symptoms appear only after accumulation. Alcohol exacerbates this issue by temporarily inhibiting DAO activity, making the wine’s histamine more potent. This acquired enzyme deficiency explains why a person who tolerated wine for years may suddenly experience flushing or headaches after one glass.
Changes in gut health also play a role, as the balance of gut microbiota and the integrity of the intestinal wall affect the absorption of wine components. Increased intestinal permeability, sometimes called “leaky gut,” allows more biogenic amines to pass into the bloodstream, bypassing normal detoxification. Furthermore, certain medications, such as antidepressants or antacids, can inhibit the enzymes needed to metabolize alcohol or biogenic amines, causing a sudden onset of new sensitivities.