Can consuming small amounts of alcohol daily will help keep the heart in good shape is a common question faced by many doctors across the country. The presumed benefit of moderate alcohol use was first published in 1926 as a book by American biologist Raymond Pearl based on multiple patient case histories.
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He describes the effect of alcohol consumption — from none to heavy drinking — on human survival as a J-shaped curve. The J-curve suggested that when people drank no or very less alcohol (represented by the portion to the left of tipping point of J) they experienced lower survival rate, as did those who drank heavy alcohol (represented by the portion of the right J-point), while those who consumed ‘modest’ amounts of alcohol lived longer. The study and its conclusions gave birth to the myth that moderate alcohol consumption was beneficial. Multiple studies on further larger cohorts of patients, the J-shaped curve and its persistent conclusion that moderate alcohol consumption improved survival stood the test of time.
But an important question remained: why was alcohol, which kills millions globally each year, improving survival in those who drank modestly? Scientists got on top of it and found an answer — a particular type of heart condition called ischemic heart disease (IHD) in which the arteries that supply the heart become narrowed leading to muscle damage and poor pumping capacity reduced with moderate alcohol use. If IHD was reduced with modest alcohol use, there had to be another reason behind it. A group of doctors from the Maastricht University, Netherlands who began studying it found the answer. In a study published in March 2023 in Cardiovascular Diabetology, they concluded that modest alcohol consumption led to a reduction in damage to tiny vessels that regulate blood flow into heart muscles, called microvascular dysfunction or MVD that was responsible for IHD. And to complement that study, another group of researchers from the Massachusetts General Hospital found (Journal of the American College of Cardiology) that improved heart health was due to reduction in the stress-related brain network activity with modest alcohol use.
But a group of scientists relooked at all the J-curve studies and found something everyone overlooked. In a study published in JAMA Network in March 2023, they found the favourable health benefit of moderate alcohol use was because people also had healthier lifestyles. When these individuals were excluded, moderate alcohol use was found associated with greater risk for heart disease. The risk increased exponentially with increasing dose and duration. This was again confirmed by multiple studies which found that the association of low-to-moderate alcohol consumption with the reduction in heart disease risk was a result of lifestyle changes (Journal of Cardiovascular Development and Disease) and that “any reduction in alcohol consumption is in fact beneficial in terms of general health”.
The MGH study that demonstrated reduction in brain-stress and thus improved heart health also showed that any amount of alcohol increased the risk of various cancers and cancer-related death. This was again proven recently in a study published this year in JAMA Network which concluded that “low-volume alcohol drinking was not associated with protection against death from all causes”, and that it increased risk more in women than men.
Another study in Scientific Reports showed that people with modest alcohol use gained one whole year in their lifetime but the gain of one year by modest drinking was erased by a two-fourfold increase in head and neck cancer and a large loss of life expectancy and loss of nearly seven years if drinking was “more than modest.”
Any amount of alcohol damages the brain cells and reduces brain volume. Alcohol consumption prevents new learning within brain pathways and impairs memory and reasoning. Alcohol downgrades the immune system rendering it defenceless against a host of infections, especially a lethal bacteria called Klebsiella pneumonia that eats away the lung tissue. A Chinese study in Nature showed that alcohol consumption increased the risks of over 200 diseases in men. Any amount of alcohol exposure was found to be associated with various cancers, the reason why WHO recently cautioned that no level of alcohol consumption was safe for health.
Incidentally, individuals who were engaged in 15-20 minutes (BMC Medicine) of simple physical activity per day experienced a similar level of reduced mortality as seen with modest alcohol use. And the more one increases physical activity, the more the chances of living longer.
It is time to stop the narrative that moderate alcohol consumption is beneficial for the heart and overall health and instead start exercising daily. Say no to alcohol.
(Cyriac Abby Philips is a senior consultant & physician-scientist at The Liver Institute, Rajagiri Hospital, Kochi, Kerala)
