Have you ever heard of alcohol intolerance? This is an inherited metabolic disorder that causes the accumulation of acetaldehyde, which is a metabolite of alcohol, due to a deficiency of an enzyme called aldehyde dehydrogenase 2. Genetically, people of East Asian descent are more likely to experience symptoms of the disorder since we carry the rs671 allele on chromosome 12, which causes a lesser, or non-functional ALDH2 enzyme. Therefore, people who are homozygous (me), or heterozygous, for this allele often find that drinking alcohol can be a very unpleasant experience.
Some symptoms of alcohol intolerance are erythema (flushing and feeling warm) on the face, nausea, vomiting, tachycardia, migraines, blurred vision, and respiratory problems (shortness of breath) within minutes of consumption of alcohol. While the amount of alcohol it takes to cause discomfort varies by individual; sometimes, it only takes a small sip for the symptoms to appear. For example, since the drinking age in Vietnam was 18, I took a small sip of alcohol while I was there. Within 5 minutes, my whole face was as red as a tomato, I was extremely nauseous, and had trouble breathing. After getting to the hospital and having some blood tests done, I found out I had a more severe case of alcohol intolerance.
There are several ways to find out of you have the conditions or not. Determining the level of acetaldehyde in the bloodstream is the most accurate way to do this. It could be done through a breathalyzer or blood test. Genetic testing would give a more descriptive prediction of how severe the condition is, whether you are homozygous or heterozygous for the allele.
Since alcohol intolerance is not an allergic reaction, there is nothing that would help treat the symptoms apart from letting the body excrete all of the alcohol out. Antihistamines are discouraged since they mask the symptoms of intolerance and might cause overconsumption, which would worsen the condition. The best course of action for people with alcohol intolerance would be to avoid drinking alcohol, and stay away from smoking and secondary smoke because it can cause an increase in acetaldehyde.
https://my.clevelandclinic.org/health/diseases/17659-alcohol-intolerance#management-and-treatment
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3860439/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2659709/
I think a more accurate term for this condition is alcohol sensitivity. I did a short genetics paper on this condition and turns out that its more of a protective mechanism against alcohol dependence and intoxication. As human migrated out of Africa to Europe and Asia, the ADH1B gene that codes for alcohol dehydrogenase 1 underwent mutations that results in the face flushing, migraines, nausea and vomiting. Its thought that the mutant variant of ADH1B and ALDH2 genes occurred 10,000 to 7,000 years ago with the emergence and expansion of rice domestication and rice fermentation in East Asia. The article I attached explains alcoholism the differences in expression of the ADH1B genes across different populations. Its amazing how there are so many human adaptions like eye color, bone density, and language.
ReplyDeletePolimanti, R., & Gelernter, J. (2018). ADH1B: From alcoholism, natural selection, and cancer to the human phenome. American journal of medical genetics. Part B, Neuropsychiatric genetics : the official publication of the International Society of Psychiatric Genetics, 177(2), 113–125. https://doi.org/10.1002/ajmg.b.32523
Hi Thu,
ReplyDeleteThis is an interesting topic, it's my first time hearing about "Alcohol intolerance" (alcohol sensitivity) and the mechanisms behind it. I think that an interesting approach to take within this subject matter would be to look at how anxiety and binge drinking are negative factors that would affect college students who aren't aware they might have since the ADH1B gene. Seemingly, I think it would be information that should be brought to freshmen beginning college because it become inevitable that college students will drink, however bringing this to light could possibly reduce the rate of alcohol poisoning. A research study conducted demonstrated how anxiety played an influential role in heavy drinking amongst college students. The study demonstrated a gender difference, males had a stronger correlation than females did. I believe this is an interesting topic that has many factors that would be worth looking into in terms of gender, mental health, socio-economic status and other intersectionality's .
Lawyer, Steven R et al. “Heavy drinking among college students is influenced by anxiety sensitivity, gender, and contexts for alcohol use.” Journal of anxiety disorders vol. 16,2 (2002): 165-73. doi:10.1016/s0887-6185(02)00092-0
DeleteOne of the oral medications that is used to treat alcoholism targets acetaldehyde dehydrogenase— the second enzyme of alcohol metabolism. The name of the medication is Disulfiram. It was approved in 1948 by the FDA to treat alcoholism. Similar to what you described above, this medication works by inhibiting the conversion of acetaldehyde to acetate, which then leads toxic build-up of acetaldehyde in the body. Increased concentration of acetaldehyde is what causes that unpleasant reaction/effects to alcohol. This reaction/effect is intended to serve as a negative stimulus, and discourage drinking. This medication is often used in recovery programs along with counseling. Proper medical supervision is needed when used.
ReplyDeleteZindel, R. L. et al. (2014). Pharmacotherapy of Alcohol Use Disorders: Seventy-Five Years of Progress. Journal of Studies on Alcohol and Drugs, 75 (17), 79-88. PMCID: PMC4453501