Is Alcoholism Hereditary? Studies Suggest Yes

Published on September 2nd, 2016

is-alcoholism-hereditaryWe all have a choice to drink or not. Whether you come from a long line of hard alcoholics or from a long line of perfectly sober health-nuts, the choice to consume alcohol is the same for us all. Gene Heyman, a psychologist and professor at Harvard, discovered that “less than 20% of alcohol users become alcoholics.” It’s a yes or it’s a no. However, whether or not the alcohol consumes you may not be much of a choice after all.

Alcoholism is a disease, and diseases tend to ‘run in the family’. Evidence suggests that some people may be genetically predisposed to say yes to drinking, and also that genetics help determine what happens to you if and when you say yes to drinking. Basically, if alcoholism is prevalent in your family, you still have the choice to say yes or no, but evidence suggests that you’re probably going to take that drink. Alcoholism may be hereditary.

Many factors contribute, however, to a person becoming an alcoholic. It’s only about half hereditary. It has been known for a long time that alcoholism is partially hereditary, but also that environment, mental states, peer influence, self-medication, stress, and countless other factors contribute to alcoholism. It’s relatively easy to see how certain life situations could play a role in someone’s developing an alcohol dependency. A hectic life, peer pressure, high stress… alcohol has been an unfortunate place to turn under these conditions. However, pinpointing the genetic aspect of alcoholism has been a rocky road. While it’s been common knowledge that alcoholism is approximately half hereditary, only recently have researchers found the actual genes that purportedly cause (the genetic aspect of) alcoholism.

Not an Excuse

This is NOT to say that alcohol abuse can be justified by your parents having drank. Human beings have powerful minds, and the choice is always ours. Justifying alcohol abuse with genetic predisposition is unacceptable. However, genetically speaking, exactly how much of that choice is yours becomes complicated. Alcoholism is a disease, yes, but it happens to be one of the only diseases you can fully prevent with healthy decisions. Hereditary cancer or diabetes, say, is perhaps unavoidable. Hereditary alcoholism is completely avoidable. Say no and get help if you can’t.

The Purdue/Indiana Study

A study by researchers from Purdue University and Indiana University recently concluded that there are “930 genes associated with alcoholism, indicating that it is a highly complex trait…” This puts alcoholism in the same category of sophistication as human height. The half of alcoholism that is hereditary is genetically quite complicated. The bright side of the study is that “promising targets for treatment” may have been discovered, but the dark side is that “the sheer number of genes that contribute to the trait suggests pharmaceutical treatments for alcoholism could be difficult to develop.”

Side note:  Human beings and rats don’t seem to have much in common, but in reality, we are over 95% genetically identical to rats. We live in the same area, eat the same food, are both warm-blooded mammals, and even suffer from the same diseases. This is why rats are so often used in scientific experiments, and for the experiment at hand, this is no different.

The researchers started with two lines of genetically diverse rats: “one group that displayed classic clinical signs of alcoholism and another that completely abstained from alcohol.” The Indiana Alcohol Research Center bred the two different lines of rats. William Muir is a genetics professor who was involved in the study, and he explained how over the course of decades, some of the rats compulsively drank alcohol, preferring it to water. They even exhibited withdrawal symptoms without alcohol. Still, though, the results varied.

“Under the influence of alcohol, some rats became docile and fell asleep in a corner while others became aggressive,” said Muir. What the study showed was that we all have the genetic makeup to potentially become alcoholics. It’s simply human. The ability to control alcoholism, however, seems to be hereditary. The next step in the study involved taking 10 rats from each line, (ten alcoholics and ten abstainers), and comparing their genetic makeups. The study revealed 930 genes associated with abusing alcohol.

The Results

Of the 930 genes found to be related to alcohol abuse, “the vast majority” are located in what are known as genetic regulatory regions, as opposed to coding regions. Genes within the regulatory region are inherited, and represent the ‘nature’ side of nature versus nurture. Genes within the coding region are the opposite, unique to the individual, and represent the ‘nurture’ side.

Think of the coding region as a car. That part of your brain is part of everyone’s brain. We are all ‘coded’ to some extent when we are born. The potential for alcoholism is in all of us, just like the potential for overeating or smoking cigarettes is in all of us. Think of the regulatory region as the pedals. How ‘fast or slow’ we go is controlled by this region of the brain. In dealing with alcoholism, a ‘fast’ regulatory region has high potential for alcoholism and a ‘slow’ regulatory region has low potential. This part of alcoholism is hereditary. The actual genes that control this potential have been hard to locate, until this recent Purdue/Indiana study.

Because the majority of the 930 genes were found in the genetic regulatory region, there is a substantial genetic component to alcoholism. The next step for these researchers is to determine the relevance of the findings in humans. It turns out that some of the genes have already been identified.

Is Alcoholism Hereditary?

The way the brain sends messages to the body is through neurotransmitters, which are chemicals that transfer between brain cells. They make the body do everything, from blink and breathe to decide whether or not that yellow light is safe to drive through. There are many different neurotransmitters, and one of the several that control pleasure and reward is dopamine. When released, dopamine creates pleasure, and as well as being released naturally through rewarding activities such as eating or cuddling, dopamine is released by many illicit substances. Alcohol is not excluded.

Science Daily published in 2007 an article showing the gene DRD2 to be associated with alcoholism. “The DRD2 gene, which codes for one of the five dopamine receptors, has been heavily studied for possible links to alcoholism…” Furthermore, a nearby gene called ANKK1 “may also be involved in addictive behaviors.”

In a study published by Newcastle University, it was found that “mice with a genetic mutation to the gene Gabrb1 overwhelmingly preferred drinking alcohol above water, choosing to consume almost 85% of their daily fluid as drinks containing alcohol…” Mice with the mutation literally got drunk on purpose. Because of our near-perfect genetic similarity with these creatures, Newcastle University Professor Howard Thomas said, “This is important when we come to try to modify this process first in mice and then in man.” Modifying the process translates to treating addiction, and these discoveries all add up to some optimistic stuff.

While still imperfect, science continues to identify the actual genes that account for half of the cause of alcoholism.

The Other 50%

None of this means that an alcoholic family history produces an alcoholic. Several other factors contribute to alcoholism. Common factors include:

  • Drug Accessibility – You have to able to acquire alcohol in order to consume it. If your social environment places you around alcohol, chances are better you’re going to consume it. The same scenario applies with almost anything tempting. If a neighbor brings you a plate of cookies, you’re way more likely to have a cookie than if none were ever delivered to you. Same goes for alcohol. If something is out of sight it is out of mind. Alcohol is one of the only addictive drugs never out of sight though. Ads are everywhere, and it is legal nationwide.
  • Abuse – Traumatizing events sometimes cause people to turn to alcohol. Abuse, whether physical, emotional or otherwise, can lead a person to self-medicate with alcohol. There is no genetic predisposition to abuse; it can happen to anyone. Unfortunately some of those who are abused turn to alcohol.
  • Peer Pressure – Even those who do their best to avoid alcohol become victims of peer pressure. It can occur at any age. A twelve-year-old who finds a bottle of rum in her basement may ask a friend to consume it with her, just as a forty-year-old at a wedding may try and get his straight-edge friend to drink with him. Years of resistance to alcohol can be turned around by one peer’s influence.
  • Boredom – As mentioned, alcohol is legal. Sometimes boredom sets in and people fill their spare time in with alcohol (and/or other illicit substances).

What does this mean for treatment?

There is a plus side and a negative side to the studies’ findings when it comes to alcohol abuse treatment. The negative side is that due to the complex genetic workings in the trait of alcoholism, creating a single drug to treat it is unlikely. As Muir said, “It’s not one gene, one problem…This trait is controlled by vast numbers of genes and networks. This probably dashes water on the idea of treating alcoholism with a single pill.”

However, the Purdue/Indiana study revealed that the glutamate receptor signaling pathway, which is a connection of brain cells partly responsible for reward, contains a large number of alcoholism-related genes. The researchers said this may offer a place to start for future treatment. On top of that, researcher Hugh Perry from the Newcastle study said that “… the results of this long-running project suggest that, in some individuals, there may be a genetic component [to alcoholism].” Modern science is able to treat diseases based on genetic components, so the more we understand about the hereditary aspect of alcoholism, the better the treatment will become.

The last problem in the way of a scientific cure for alcoholism is a big one. Human behavior is extremely unpredictable and relies on a multitude of factors. Alcoholism is hereditary to an extent, but is not determined by genetic makeup alone; much more factors into addiction. (Find out if you are at risk of becoming an alcoholic here).

The Mystery of Addiction

Although a significant portion of alcoholism can be attributed to hereditary factors, a significant portion cannot be. Life is full of surprises and unexpected situations, so complex that there is no equation for it. Even someone with zero hereditary history of alcoholism can become an alcoholic.

Brien Riley is the director of the molecular genetics lab at Virginia Commonwealth University. He said this to Science Daily: “Previous evidence indicates that genes play a major role in liability to addictions, including alcoholism. Yet genes are certainly not sufficient to produce disease by themselves. The individual must be exposed to alcohol, which, in common with any chemical encountered in the world, is explicitly environmental.”

In Conclusion

Anyone can become an alcoholic, whether or not he or she is genetically predisposed to becoming one. For now, genetics are only thought to make up about half of the risk for alcohol dependence. The rest is truly up to you. Even if you have the DRD2 gene and the ANKK1 mutation, you can still say no.

As William Muir of the Purdue/Indiana study said, “You can’t just blame your drinking on your parents.”

PSA brought to you by QuitAlcohol.com
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