Low-dose Alcohol and Breast Cancer Risk

Every year, around the globe 3.3 million people die from 60 different alcohol related health issues. This raises some very important questions.

Is all alcohol harmful? Is there a safe dose? Is any particular type of alcoholic beverage beneficial to the health?

Firstly, and most importantly, there is no dispute that consuming more than four drinks per day on a regular basis and/or binge drinking (defined as five or more drinks in one sitting), is related to significant alcohol related health issues and should be discouraged.

Secondly, around 1 in 20 people carry one of the genes for alcoholism and they should avoid all alcohol. But, many people enjoy low-dose or moderate consumption of alcohol and the evidence is conflicting whether this is harmless, harmful or possibly may even confer some health benefits.

image source: http://www.sl.nsw.gov.au/

Around 1.7 million cases of breast cancer are diagnosed worldwide on a yearly basis and this accounts for around a quarter of cancer diagnoses for women. Breast cancer is the second commonest cause of death in women. There are multiple risk factors for breast cancer which include older age, early onset of periods and, of course, a family history.

A recent meta-analysis of 119 studies collected clinical information on 12 million women reporting 260,000 cases of breast cancer. The study suggested that as little as a small glass of wine or beer per day, which is the equivalent of 10 g of alcohol, increased premenopausal breast cancer by 5% and postmenopausal breast cancer by 9%. The study also found that obesity and especially the typical weight gain that occurs with menopause increases the risk of breast cancer in people over the age of 50. Conversely, regular exercise appeared to reduce the risk of both pre-and postmenopausal breast cancer. There was also strong evidence that a high intake of vegetables decreased breast cancer risk.

Another report published in the journal Alcoholism: Clinical and Experimental Research explored three areas of alcohol research and its relationship to breast cancer.

Firstly, there is a clear relationship between alcohol directly affecting hormone levels, with also alcohol metabolites shown to be cancer-causing substances. Alcohol also blocks a key metabolic pathway, known as the 1-C metabolic pathway, which has strong immuno-protective mechanisms.

Secondly, the evidence from 15 trials in a meta-analysis suggests that consuming regular low-dose alcohol-one daily for women is associated with increased breast cancer risk.

Finally, it is estimated that 144,000 breast cancer cases and 38,000 breast cancer deaths were directly due to the regular consumption of alcohol at any dose.

Well, does this seal it? Should women avoid alcohol completely, because of these well-established facts?

You may be surprised to hear that I don’t believe it is that straightforward. The clue is in the title of the journal.

Alcoholism: Clinical and Experimental Research

Although I believe it is irresponsible for any doctor to encourage any person to drink, I also believe it is important to look at the entire body of evidence before publishing a blanket statement such as “Low-dose alcohol increases breast cancer risk.”

Let’s look at the well-established data that have not been considered in this article

1. There is a clear link between obesity, Type II diabetes and a number of cancers, including breast cancer. Could it possibly be obese and/or diabetic women who consume low dose alcohol have the increased risk and not those with an acceptable BMI?
2. If you consider the data from the Mediterranean, there is, in fact, a 50 percent reduction in cardiovascular disease and cancer in consumers of low dose alcohol, especially red wine. So, it may even be the interaction between low dose alcohol and a poor western diet with or without obesity and diabetes that contributes to breast cancer risk.
3. Almost never spoken about in the medical literature or in the media is the well-established long-term data from the Nurses’ Health study that shows in those women who took a daily, high-quality multivitamin and consumed low dose alcohol, the breast cancer risk was negated.
4. Certainly not considered here are the psychosocial factors that may be associated with breast cancer and/or the reasons certain people may consume alcohol.
5. Finally, many people who consume alcohol underreport their intake; so, again it may be that higher doses are consumed despite the fact that the women may claim they are only drinking 1–2 glasses per day.

It is my opinion, with the totality of evidence just presented that if women enjoy a low level of alcohol consumption, with a particular emphasis on red wine, consume a healthy Mediterranean style diet (avoiding western processed packaged rubbish masquerading as food, and I stress the phrase low-dose alcohol), it is not the alcohol that is the issue but all the other associated factors in totality that are increasing the risk for not only breast cancer but any other alcohol related disease as well.