Resource article for July: Alcohol and CVD Part II

The adverse effects of heavy drinking: too much of a good thing can be bad

As promised, I present here the second part of the series of resource posts on alcohol consumption and its effect on cardiovascular health. In the first part, I’ve tackled the health benefits associated with light to moderate alcohol drinking. In this post, I present a review of the adverse effects of alcohol drinking.

In a review paper [1], Swiss researchers found that the health consequences of drinking can be acute (e.g. traffic accidents) or chronic (e.g. diseases).

We all know that drinking and driving don’t mix and we hope that all of us will keep this in mind. This resource post, however, will dwell more on the chronic adverse health effects, especially on the heart and the vascular system, of alcohol consumption.

Alcohol and chronic diseases

Many chronic diseases have been linked to alcohol consumption, namely [1]:

• Cardiovascular disorders which include hypertensions, coronary heart disease, stroke, and cerebrovascular disease.
• Different types of cancer, including cancers of the mouth, throat, esophagus, liver, and breast.
• Neuropsychiatric disorders such as unipolar major depression, epilepsy, and other alcohol use disorders.
• Digestive disorders such as cirrhosis of the liver
• Diabetes mellitus
• Fetal alcohol spectrum (FAS) disorder (for infants born to chronic and heavy drinking mothers)

Alcohol and cardiovascular disorders

While light to moderate drinking may have some cardiovascular benefits, heavy and binge drinking can easily reverse the protective mechanism of alcohol.

“Heavy drinking appears to lower the threshold at which the ventricular heart muscle begins a rapid contraction pattern; without prompt intervention, this pattern prevents normal heart function and results in death.” [1].

In an Irish study [2], heavy drinking was observed to lead to hypertension and atherosclerosis in men and ventricular enlargement in women.

In another study [3] on 2609 white Americans aged 35 to 80, drinking alcohol outside mealtimes was shown to adversely affect blood pressure and lead to hypertension, regardless of the amount of alcohol or the type of drink consumed.

So what does heavy drinking to our heart and vascular system? A few observations are listed below [1]:

• Occasions of heavy drinking can lead to increased low density lipoproteins (LDL) levels in the blood;
• Irregular occasions of heavy alcohol consumption have been linked to thromobosis or blood clot formation;
• Irregular but heavy drinking episodes increase the risk for structural changes in the myocardium (heart muscle) which can interfere with the electrical impulses and lead to fibrillation.

In sum, a pattern of irregular heavy drinking occasions is mainly associated with physiological mechanisms that increase the risk of sudden cardiac death and other cardiovascular outcomes [1].

Alcohol and cancer

Alcohol consumption has been linked to cancers of the upper digestive tract (e.g. mouth, throat, and esophagus) but there is limited data on this. An earlier study reported increased risk for breast cancer with every glass of alcoholic drink. Women who drink one or two glasses of alcohol a day have a 10% higher risk for breast cancer. With 3 glasses, the risk increases by 30%. The type of alcohol drink consumed doesn’t matter [4].

Alcohol and pregnancy

Alcohol consumption during pregnancy is strongly discouraged. A Danish study [5] – and many other studies before it – show that binge drinking, 3 times or more during pregnancy highly increases the risk of stillbirth. Alcohol consumption also causes the so-called fetal alcohol spectrum (FAS) disorder. According to the Canadian Paediatric Society, the exact prevalence of FAS is unknown but has been estimated to be as high as 43 out of 1000 (4.3%) births among babies born to heavy drinkers.

In another study on Swedish women [6], an estimated 30% of women continue to drink alcohol during pregnancy. However, only about 6% admits to doing so.

Know your limit

Although many of the research studies presented tried to define the difference between light to moderate drinking which is beneficial and heavy drinking which is harmful, the demarcation line is pretty fuzzy. The American Heart Association defines “drinking in moderation” as follows:

If you drink alcohol, do so in moderation. This means an average of one to two drinks per day for men and one drink per day for women. (A drink is one 12 oz. beer, 4 oz. of wine, 1.5 oz. of 80-proof spirits, or 1 oz. of 100-proof spirits.)

However, individuals vary in terms of their tolerance to alcohol. It’s still up to us to find out what is best for us.

Here are some tips to make sure that we don´t overimbibe:

• Do not drink alcohol when you are thirsty. This will only lead to you to overconsumption. There is nothing better to quench thirst than water.
• Do not drink on an empty stomach. The alcohol is rapidly absorbed into your system. A glass of wine is enjoyed best with a meal.
• Know your limit and know when you’ve had enough. Listen to your body. Although most research studies try to define the difference between moderate and heavy drinking, alcohol consumption and its effects can actually depend on so many other factors including body weight, genetics, food consumption, and interaction with drugs and medications. I have low tolerance to alcohol and I know it. This is probably due to my size and my Asian genes. What is light drinking to some people is just too much for me. I know my limit – it’s half a glass of wine.
• If you feel that you are drinking too much, do not hesitate to seek professional help. It’s your health and your life that is at stake.

Remember – too much of a good thing can actually be bad.

Next in this series: Women benefit less from alcohol than men.

Sources:

1. Alcohol Res Health. 2003;27(1):39-51. Review.
2. Heartwire, 15 May 2008.
3. Hypertension. 2004 Dec;44(6):813-9. Epub 2004 Oct 11
4. CBCNews Canada, 27 Sept 2007
5. Obstet Gynecol. 2008;111:602-609.
6. American Journal of Obstetrics & Gynecology, April 2008

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