This post comes as a suggestion from a reader (@dswaddle) who contacted me with an idea for a peer reviewed article to present. ¬†Great find! If any of you have papers/ideas in mind, don‚Äôt hesitate to contact me with your suggestions!
We‚Äôve all read countless articles that show positive benefits of wine on various aspects of human health.¬† However, what is not as often studied are the more negative effects felt by certain individuals.¬† Specifically, many people claim to have a wine allergy or intolerance, which may range from very mild to severe in rare cases, although there are many other negative effects associated with any alcohol, such as alcohol addiction.¬†¬†
When I was working 5 days per week in the tasting room, I would hear at least once a day a story of how someone possessed symptoms of wine intolerance/allergy, or how a friend of theirs could not drink red wine without suffering some consequences.¬† All that we know about wine intolerance, however, is anecdotal or conjecture, since to date there have been no studies examining the frequency of wine intolerance in humans.¬†
The short exploratory study presented today aimed to evaluate how common wine intolerance actually is in a wine region, the results of which may serve as a baseline or launching point for many epidemiological studies on wine intolerance in the future.
4000 people were randomly selected from the residential population of Mainz, Germany.¬† A short questionnaire was sent out to all 4000 individuals in 2010, and 1114 of them (27.9%) were returned to the researchers.¬† Out of those 1114 questionnaires, only those that were completely filled out were analyzed, therefore a total of 948 individuals‚Äô questionnaires were subjected to analysis.
The short questionnaire asked questions regarding sex, age, as well as the average weekly consumption of wine, beer, and liquor.¬† In addition, questions regarding allergy-like symptoms after wine consumption were also included (for red, white, and ros√© wines), with a list of symptoms being supplied by the researchers.¬† Questions regarding frequency of symptoms were also included in the questionnaire.¬† Questions regarding allergies or intolerances to other items such as pollen, house dust, latex, medications, seafood, nuts, milk, apples, cherries, oranges, peaches, plums, kiwis, strawberries, grapes, bananas, carrots, peppers, alcohol, or beer were also included.¬† In addition to self-reporting, participants were asked to note if any of these allergies had been medically diagnosed.¬† All reported symptoms were considered as a symptom of wine intolerance except for headache, which is an extremely general symptom and could be a result of other ailments or problems.
Participants were labeled as being ‚Äúwine intolerant‚ÄĚ if their symptoms scores summed greater than 10 (see Table 1 for individual symptom scores), or if they self-reported to be wine intolerant.
|Table 1 from Wigand et al, 2012.|
- Mean age of participants was 43.7 years.
- 429 of the participants were men (45.3%), and 519 were women (54.7%).
- The distribution for age and sex of the study group was comparable to the entire Mainz, Germany population, with only the younger generation not as represented.
- 84.3% of participants said they consumed alcohol during the past year.
- 76.6% of participants said they consumed wine, with an average of 3.66 glasses per week.
- Participants reported consuming slightly more white wines than red, and almost no ros√© wines.
- 49.3% of participants reported consuming beer.
- 18.1% of participants reported consuming liquor.
- Men drank more wine then women; however, after only taking into account those that consume alcohol, there was no difference in wine consumption between men and women.
- 3.2% of participants claimed they have an intolerance to wine (9 men and 21 women).
- Only one man and one woman had a wine allergy that was verified by a doctor.
- 24% of participants reported allergy-like symptoms after consuming wine.
o¬†¬† 223 of the 225 reporting symptoms also reported headache, however, this symptom was not included in analysis due to the very non-specific nature of the symptom.
- More people reported symptoms after consuming red wine than white wine.
- Wine intolerance scores over 10 were observed for 23% of those that reported symptoms.
o¬†¬† Only 14 of these individuals (14 out of 52) actually claimed they had a wine intolerance.
- The following were the most common symptoms reported for wine intolerance in participants:
o¬†¬† Flushed skin (57.4%)
o¬†¬† Itching (35.3%)
o¬†¬† Rhinorrhea (32.4%)
o¬†¬† Diarrhea (27.9%)
o¬†¬† Tachycardia (25.0%)
o¬†¬† Stomach or Intestinal Cramps (25.0%)
- Of those reporting wine intolerance (68 people), 57.5% of them reported experiencing flushed skin.
o¬†¬† Flushed skin occurred often or always for 36.8% of those reporting experiencing the symptom.
- Two people reported circulatory collapse after drinking wine, though this reaction was rare.
- 22% of participants (209 individuals) reported having food intolerance, with more women reporting food intolerance than men.
o¬†¬† The most common food allergies reported were nuts, apples, and milk.
- Other common intolerances/allergies reported were pollen, house dust, and medication.
o¬†¬† Many of these intolerances were confirmed by a doctor, however, most wine/beer/alcohol intolerances went unconfirmed.
- Those participants with a wine intolerance more frequently reported that they had other intolerances in addition to wine.
o¬†¬† 15 of the 68 reporting wine intolerance also reported beer intolerance, and 19 reported intolerance to alcohol in general.
- Of the 68 individuals reporting wine intolerance, 18 did not drink wine, and 10 did not drink alcohol at all.
- Those in the wine intolerance group self-reported drinking on average 2.66 glasses of wine per week (when only those that consumed alcohol were considered) compared to 3.66 glasses per week reported by the self-proclaimed wine drinkers in the study.
- There was no difference between the 68 individuals with self-reported wine intolerance and the 880 who did not claim wine intolerance in respect to average wine consumption levels.
This study has several limitations that were presented by the authors, which make extrapolating the results to a larger population more difficult.
First, there was a low return rate on the questionnaires.¬† According to the authors, a low return rate such as this one could lead to selection bias and therefore either an over- or underestimation of the frequency of wine intolerance.¬† However, if one were to assume all of the wine intolerant individuals sent in their completed questionnaires, then that would result in a wine intolerance prevalence of 1.7% (or 68 out of 4000 people), which would therefore be the lower limit of wine intolerance.¬† This result suggests wine intolerance is higher and more prevalent in adult humans than first thought.
Second, adding up the individual symptoms to result in a ‚Äúthreshold 10 points‚ÄĚ may not be an accurate representation of which individuals are wine intolerant and which are not.¬† A single symptom could, in fact, be the result of wine intolerance, however, if that symptom were not worth ‚Äú10 points‚ÄĚ, it would not be counted as wine intolerance in this study.¬†
Third, the results of this study were based 100% off self-reported data, which may not be completely accurate.¬† Clinical trials would be necessary to corroborate or refute these self-reported figures.
Next, sociodemographics were also not considered for this study, which could potentially have an effect on the results if taken into consideration.
Finally, this study focused only on a group of individuals from one particular wine region in the world.¬† The results, therefore, may not be generalizable to the entire general public, and more studies incorporating many different groups of individuals may be required to get a greater sense of the wine intolerance in the general population.
According to the authors, this study is the first of its kind to present data on the frequency of wine intolerance in a general population.¬† About one quarter of those individuals claiming wine intolerance also claimed general alcohol intolerance, which could be one of the underlying causes of the wine intolerance:¬† it‚Äôs not that they are allergic to the wine, but in fact allergic to the alcohol within the wine.¬† It is unlikely the intolerance is a result of an allergic reaction to grapes themselves, since results showed that only 6 out of 68 wine-intolerant individuals claimed intolerance to grapes.
Also according to the authors, others may also have intolerance related to the presence of lipid transfer protein (LTP) in the wine, which is known to cause allergic reactions in some individuals.¬† Since LTP is located on the skins of grapes, it is possible that those individuals citing intolerance to red wine but not white wine have an intolerance to the LTP protein, which gets deposited in the wine after the maceration (skin contact) process of red wine production.
The results of this study, though rich in methodological limitations, suggest that wine intolerance is a relatively common occurrence in the general population, comparable to intolerance of other foods and allergenic sources.¬† Clinical research trials are required to further understand this phenomena, as simple questionnaires alone will not tease out the intricate mechanistic details of what is likely multiple reasons and mechanisms for wine intolerance.
I‚Äôd love to hear what you all this of this topic!¬† Please feel free to leave your comments below!
Source: Wigand, P., Blettner, M., Saloga, J., and Decker, H. 2012. Prevalence of wine intolerance: results of a survey from Mainz, Germany. Deutsches √Ąrzteblatt International 109 (25): 437-444.
I am not a health professional, nor do I pretend to be. Please consult your doctor before altering your alcohol consumption habits. Do not consume alcohol if you are under the age of 21. Do not drink and drive. Enjoy responsibly!