Is there a link between alcohol and cancer?
By: Madison Frye
Tags: Health, Cancer, Cancer Treatments, Alcohol, Breast Cancer

This article was written in collaboration with Dr. Robert Lum, MD, a board-certified radiation oncologist.

We are all aware of the dangers of alcohol, but its link to cancer is an area that is less understood. A new study from LiveScience uncovered more information confirming the link between alcohol consumption and cancer risk. While this new study is not the first to link alcohol to cancer, it provides a new understanding of just how that link works. Which makes it all the more important to understanding alcohol and risk factors for cancer.

New Findings

Firstly, this LiveScience study was different from previous articles because It looked into how alcohol caused this risk for cancer (LiveScience). Thanks to new research published in the journal Nature and part-funded by Cancer Research UK, we know more about one way cancer is caused (Cancer Research UK).

Earlier studies found that there is strong evidence that alcohol exposure causes cancer at seven specific sites in the body. There are likely other parts of the body that are affected by alcohol exposure, but these seven had the highest risk of cancer:

7 Cancer Risk Sites from Alcohol Exposure:

A part of the throat called the oropharynx

The larynx

The esophagus

The liver

The colon

The rectum

The female breast

There is also continually growing evidence that this strong link between increased cancer risk as effects of alcohol usage can occur in other parts of the body, including the prostate, pancreas, and skin. (LiveScience)

The Importance of Stem Cells

In the previously mentioned study, the experiment focused on the effects of alcohol usage on stem cells, which are the body’s ‘raw materials’, supplying the many different specialized cells that our bodies are made of. These cells are crucial for replenishing cells lost throughout your lifespan, and once they are damaged, they can spread that damage further (LifeScience).

While this post talks about the effects of alcohol increasing the risk of cancer, there’s a little more to it than that. As the research from this experiment highlights, it isn’t alcohol that causes damage to DNA in stem cells, but one of the chemicals that alcohol gets broken down into (Cancer Research UK).

“When the body processes alcohol, it converts it into a highly reactive toxin called acetaldehyde, which damages DNA,” explained lead study author Dr. KJ Patel, a tenured principal investigator at MRC Laboratory of Molecular Biology in Cambridge, England (LifeScience).

When that toxin isn’t broken down further, it builds up in the cells. That build-up can then cause damage to DNA and, especially in stem cells, cause cancer (Cancer Research UK).

There are two ways that a cell can cope with exposure to excessive amounts of acetaldehyde:

The enzyme ALDH2 can clear away the acetaldehyde. But if more alcohol is consumed than the ALDH2 can deal with, then the excess acetaldehyde can damage the DNA, so… An enzyme called FANCD2 must then come in to repair some of the DNA damage (BioNews).

The Experiment

In this study, researchers looked specifically at blood stem cells. The team simulated heavy drinking by giving mice doses of alcohol that would be equivalent to an adult human drinking one bottle of whiskey in a short period of time. Some of the mice were genetically engineered to lack the two enzymes described above. There were three groups of mice: a group that had all the enzymes still in place, a group that had the enzyme ALDH2 removed, and a group that didn’t have either enzyme.

Patel explained that after removing just the first level of protection (the ALDH2), which is just the enzyme that detoxifies the acetaldehyde, one big dose of alcohol is enough to initiate four times more DNA damage than in normal mice.

“That level of damage is not very dissimilar to having spent a short period of time in front of Fukushima,” Patel said (LiveScience).

The Real World Effects

While the mice in the experiment were genetically engineered to lack one or both of these levels of protection, it’s not uncommon for people to be born without either one or both of these enzymes.

The lack of the first level (ALDH2) is a condition that is especially common in Asia, and effects about 5 million people.

Problems with the second layer of protection (the DNA repair mechanism) are also quite common. DNA repair mechanisms are deficient in women who carry either the BRCA 1 or BRCA 2 mutation, which is known to increase women’s risk of breast cancer. Problems with DNA repair also occur in children with the disease Fanconi’s anemia (LiveScience).

As mentioned before, the scientists in this study focused specifically on DNA damage in blood stem cells. Previous research has shown that alcohol affects blood cells. In fact, many people with alcoholism become anemic, meaning that they don’t have enough red blood cells.

One professor who wasn’t involved in the study, Malcolm Alison (a professor of stem-cell biology at Queen Mary University in London) said that it is believed that most cancers do in fact arise from stem cells.

“Most of our organs and tissues have stem cells, immortal cells that replenish cells lost through the likes of old age throughout our lives, and the hematopoietic system (or, the system for blood cell generation in the body) is no exception,” Alison said in a statement (LiveScience).

So, having established alcohol’s link to cancer, are there any exceptions to this?

Red wine?

Alternative studies have suggested that red wine may reduce your chances of getting heart disease and reduce your risk for cancer. Other research, including this study, has shown that drinking even small amounts of alcohol can increase your risk of cancer.

Where did this idea come from? The ancient Egyptians and Greeks considered wine to be “good for health” and often used it as a form of medicine. Still, research today shows that doesn’t actually hold true.

Instead, they’ve found that only the skin and seeds of grapes may have healthy properties (mainly the antioxidant resveratrol). This natural chemical found in grapes protects your cells from damage that could lead to cancer.

Because it’s made from grapes, red wine is full of resveratrol. Still, it’s hard to determine if the benefits of this antioxidant outweigh the risks of alcohol exposure and the increased risk of cancer.

Even though some studies do suggest that a glass of wine may lower your risk of heart disease, it’s not confirmed that a glass of red wine will lower your risk for cancer. Your safest bet is to just not pour that glass (MD Anderson Cancer Center).

How You Can Use This New Information

We should all be trying our best to limit our alcohol consumption this year, as alcohol has been proven to be bad for your health in other ways (for example, causing liver damage and pancreatitis).

The American Cancer Society advises that drinking occasionally isn’t likely to increase your risk of cancer. It’s only routinely having more than one or two drinks a day that could raise your cancer risk. Still, if you have a family history of one of the cancers listed above, you should be extra careful about your alcohol consumption. Overall, limiting alcohol intake is the healthiest approach (The American Cancer Society).

Sources:

2. https://www.cancer.org/latest-news/the-link-between-drinking-and-cancer.html

3. https://www.livescience.com/55497-does-alcohol-cause-cancer.html

4. https://www.livescience.com/61348-alcohol-damages-dna.html

5. https://www.mdanderson.org/publications/focused-on-health/February-2017/red-wine-health-benefits-facts-and-myths.html