Although research shows that moderate consumption of alcohol may lead to a decreased risk of dying from heart disease and related cardiovascular pathologies, further research also reveals that excessive alcohol consumption can lead to increased risks of negative cardiovascular outcomes.
Cardiovascular health is dependent on several factors including blood pressure and health of heart muscle. When our cardiovascular health is compromised, we see increased incidence of adverse outcomes such as stroke, hypertension and pathological heart function.
There are several aspects of cardiovascular health that are impacted by excess alcohol consumption and consequently several adverse outcomes with increased risks.
“any positive aspects of drinking must be weighed against serious physiological effects, including mitochondrial dysfunction and changes in circulation, inflammatory response, oxidative stress, and programmed cell death, as well as anatomical damage to the CV system, especially the heart itself. “
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5513687/
Cardiomyopathy
This is a disease that occurs when the heart muscle becomes damaged over time and eventually becomes less able to effectively pump blood to the rest of the body. This disease can be caused by the direct toxic effects of ethanol on the heart muscle as well as the toxic effects of the metabolite acetaldehyde.
An analysis of several studies has shown that drinking 80g of pure ethanol a day or higher for an extended period of time, which is considered heavy drinking, leads to an increased prevalence of cardiomyopathy. There has also been evidence showing a positive correlation between the amount of alcohol regularly consumed and the size of a person’s heart. Contrary to what may seem intuitive, a bigger heart is not a good thing in this case.
Further research has revealed that consumption of over 90g of ethanol a day for a period of 5 years can lead to the development of cardiomyopathy which can be asymptomatic. If patterns of heavy consumption persist for an additional 15 years, the risk of heart failure and death related to cardiomyopathy is significantly increased.
Suggested threshold to avoid development of cardiomyopathy in men, as they are the subject of most study, is 80g of ethanol a day. There is research that reveals this threshold is likely quite lower in women.
Hypertension
Although low to moderate consumption of alcohol does not appear to impact blood pressure in a negative way and may even decrease blood pressure, heavy alcohol consumption is repeatedly linked to increased blood pressure.
Studies have shown that individuals that consume 6 or more alcoholic beverages a day have increased rates of high blood pressure and hypertension prevalence. There is also evidence that shows these negative impacts can be seen with as few as 3 alcoholic beverages consumed in one day for a prolonged period of time.
Conservative estimates report that upwards of 11% of all reported hypertension cases could be a result of excessive alcohol consumption. Therefore, just by cutting out all prolonged heavy drinking, the burden on the healthcare system as a result of high blood pressure could be reduced to 89% of the current burden.
There are many ways that alcohol could lead to a decrease in blood pressure when consumed in large, chronic doses. Some probable mechanisms of action are increased free radicals, decreased endothelial function which causes plaque build up in the arteries and changes in hormone levels which control the body’s ability to retain and excrete fluid.
Increased blood pressure, or hypertension, has several negative health outcomes associated with it. Some of the outcomes we see in hypertensive patients include:
- Heart attack
- Stroke
- Kidney failure
- Vision impairment
Heartbeat Irregularities
Irregular heartbeat, or atrial fibrillation, is what is occurring when we feel our heart flutter or race. This is one of the cardiovascular dysfunctions that occurs even with a low dose of alcohol and does not see any protective effects with low doses.
The effects of alcohol on the heart that lead to these irregular heartbeats are on the electrical control of heart function. Drinking even moderate amounts of alcohol can lead to damage of heart cells and cause small amounts of fibrous tissue to build up. This change in structure is one of the ways that we see heartbeats occurring increasingly irregularly. In addition, the electrical signals that cause the heart muscles to contract simultaneously may see changes as a result of alcohol drinking further leading to irregular beating. One final way that this outcome may result is due to altered autonomic nervous system function in response to alcohol.
Research shows that continual moderate consumption of alcohol will lead to an increased frequency of atrial fibrillation and therefore increased risk of developing a heart attack or stroke as an outcome.