Of all ethnic groups in the US, Native Americans are the highest to suffer from alcoholism. Does this indicate that this population is more genetically prone to alcohol-related disorders? Or is there another factor in play to explain this phenomenon amongst Native Americans?
Lack Of Research for Native American Population
There is an abundance of research on the genetic influences of Alcohol Use Disorder (AUD). However, these studies focus mainly on Caucasians and other European races. There are not many studies that have been conducted on Native Americans.
The research that has been conducted regarding Native American genetic influences on alcohol has been confined to only a small subset of tribes. From the limited studies, it has been found that Native Americans may be genetically susceptible to alcohol abuse.
Native American Genetics and AUD
South American Natives and California Natives display a heritability toward alcohol dependence. Genetically, tribes can vary in the way they react to and metabolize alcohol. Heritability of psychological and personality disorders can also influence the likelihood of an individual being vulnerable to AUD.
For example, if a person is genetically inclined to be impulsive or prone to anxiety/depression, they may use alcohol to deal with the symptoms of anxiety or depression. This example supports the self-medicating theory of the disease model of addiction.
Genetic Variations In Metabolism
The way alcohol is metabolized in the body is through alcohol dehydrogenases (ADH) and aldehyde dehydrogenases ALDH. ADH metabolizes the ethanol of alcohol via the liver. The product of this process is acetaldehyde, which is transformed into acetate by ALDH.
The higher the level of ADH activity allows for faster conversion of ethanol into acetate. The result of this is:
- The individual can experience flushing or reddening of the face and hands.
- There is protection against excess drinking.
South Californian Natives tend to be protected against the effect of excessive drinking due to the allele ADH1B*3 this population carries in their genes. However, extended research shows that genetic variations throughout the wider Native American population have little effect on developing the risk of AUD.
Electrophysical Measures And GABRA2
To get a deeper understanding, scientists are focusing on understanding how clusters of genes work together to influence a person’s disposition towards a disorder. These groups of genes, alongside a predisposition for psychological and metabolic issues, influence an individual’s possibility of developing AUD or some other substance abuse problem.
Currently, the main gene that can lead to the development of AUD is GABRA2. It is part of the GABBA cluster of genes, which are comprised of GABRA2, GARBG1, and GABRB1. These work to influence the GABA receptor found in an individual’s reward center. That is, when one drinks, they are likely to experience feelings of pleasure which increases the desire to drink more. Natives on the Great Plains have a vulnerability to AUD due to contributions by both GARBG1 and GABRA2.
A study has shown that South American Natives tend to experience antisocial alcoholism. The genetic factor behind this has been identified as the serotonin receptor encoder 5-HTR1B. Alcohol reacts with serotonin to decrease its activity and therefore heightens the chance of the drinker experiencing depression and other negative emotions.
Challenges Generalizing These Effects
The main issue with the research on Native American AUD and alcohol metabolism is that the studies have a small population sample. Only Natives belonging to the Great Plains tribes, South Californian Natives, and South American Natives have been studied.
There are 574 Native American tribes. Each tribe carries a variation in its genetic makeup which may make one tribe more or less susceptible to AUD than another.
Also, the speed at which the alcohol is metabolized can be a distinct feature of a tribe. For example, we mentioned how South Californian Natives are genetically protected against the effects of excessive drinking.
Genetics do play a role in whether an individual is more prone to developing AUD than another person. However, it is a mixture of genes and the environment one is surrounded by.
Historically, Native Americans have suffered the loss of land and forced assimilation by colonialism. Statistically, this same group is overrepresented in alcohol abuse statistics. That doesn’t indicate that they are more genetically prone than any other ethnic group to develop AUD.
The studies on genetic factors towards alcohol dependency issues have focused on Europeans.
An extensive study of all Native American tribes will provide a more comprehensive understanding of the genetic contributors to AUD.