Observational research has suggested that light alcohol consumption may provide heart-related health benefits, but in a large study published in JAMA Network Open, alcohol intake at all levels was linked with higher risks of cardiovascular disease. The findings, which are published by a team led by researchers at Massachusetts General Hospital (MGH) and the Broad Institute of MIT and Harvard, suggest that the supposed benefits of alcohol consumption may actually be attributed to other lifestyle factors that are common among light to moderate drinkers.

The study included 371,463 adults—with an average age of 57 years and an average alcohol consumption of 9.2 drinks per week—who were participants in the UK Biobank, a large-scale biomedical database and research resource containing in-depth genetic and health information. Consistent with earlier studies, investigators found that light to moderate drinkers had the lowest heart disease risk, followed by people who abstained from drinking. People who drank heavily had the highest risk. However, the team also found that light to moderate drinkers tended to have healthier lifestyles than abstainers—such as more physical activity and vegetable intake, and less smoking. Taking just a few lifestyle factors into account significantly lowered any benefit associated with alcohol consumption.

Role of genetics in alcohol consumption

The study also applied the latest techniques in a method called Mendelian randomization, which uses genetic variants to determine whether an observed link between an exposure and an outcome is consistent with a causal effect—in this case, whether light alcohol consumption causes a person to be protected against cardiovascular disease. “Newer and more advanced techniques in ‘non-linear Mendelian randomization’ now permit the use of human genetic data to evaluate the direction and magnitude of disease risk associated with different levels of an exposure,” says senior author Krishna G. Aragam, MD, MS, a cardiologist at MGH and an associate scientist at the Broad Institute. “We therefore leveraged these new techniques and expansive genetic and phenotypic data from biobank populations to better understand the association between habitual alcohol intake and cardiovascular disease.”

Results revealed that individuals with genetic variants that predicted higher alcohol consumption were indeed more likely to consume greater amounts of alcohol, and more likely to have hypertension and coronary artery disease. The analyses also revealed substantial differences in cardiovascular risk across the spectrum of alcohol consumption among both men and women, with minimal increases in risk when going from zero to seven drinks per week, much higher risk increases when progressing from seven to 14 drinks per week, and especially high risk when consuming 21 or more drinks per week.  Notably, the findings suggest a rise in cardiovascular risk even at levels deemed “low risk” by national guidelines from the U.S. Department of Agriculture (i.e. below two drinks per day for men and one drink per day for women).

Investigators found that light to moderate drinkers had the lowest heart disease risk, followed by people who abstained from drinking. People who drank heavily had the highest risk.

The findings affirm that alcohol intake should not be recommended to improve cardiovascular health; rather, that reducing alcohol intake will likely reduce cardiovascular risk in all individuals, albeit to different extents based on one’s current level of consumption,” says Aragam.

2 servings of avocado per week may cut heart disease risk by 16%

With alcohol consumption directly linked to increased risk of heart disease, alcohol lovers might want to drop the bottle for a few servings of avocado which, according to a new study, improves heart health if consumed long-term.

The study written by Lorena S Pacheco, a postdoctoral research fellow in the department of nutrition at Harvard T H Chan School of Public Health, looked at the relationship between avocado intake and long-term cardiovascular disease (CVD) in an effort to fill the knowledge gap on the subject.

Study authors noted that most previous studies on avocado consumption have focused on cardiovascular risk factor. To fill this knowledge gap, the researchers  investigated the link between avocado consumption and cardiovascular events. They found that higher consumption of avocados was linked to a lower risk of CVD and coronary heart disease (CHD).

The study, Avocado Consumption and Risk of Cardiovascular Disease in US Adults, involved 68,786 women from the Nurse’s Health Study (NHS) and 41,701 men from the Health Professionals Follow-up Study (1986-2013) who were established to be “free of cancer, coronary heart disease, and stroke at baseline”. The group of men and women were assessed for their individual diets “using validated food frequency questionnaires”. The assessments were undertaken every four years and over a period spanning 30 years.

The study found that after the relevant considerations were made for lifestyle and dietary factors, those men and women who consumed two or more servings of avocado each week, as opposed to non-consumers, were associated with a 16% lower risk of developing CVD and a 21% lower risk of developing coronary heart disease.

Furthermore, researchers also found that those participants who swapped out half a serving of margarine, butter, egg, yoghurt, cheese or processed meat for half a serve of avocado were also at a 16 to 22 per cent lower risk of developing CVD.

A nutrient dense fruit

When asked to explain what might account for the positive effects of avocado on CVD risk Pacheco said: “Avocados are a nutrient-rich food item with favorable food compounds including monounsaturated and polyunsaturated fats (healthy fats), vitamins, minerals, soluble fiber, vegetable proteins, phytosterols, and polyphenols. There are potential biological mechanisms by which avocados offer cardioprotective benefits.”

She further noted that Avocadoes contain plant sterols that could have favorable effects on lipid profiles. “Also, the soluble fiber intake in avocados can also lead to a better lipid profile, meaning lower ‘bad cholesterol’ levels,” she explained.

The authors noted some limitations to their findings. As their study was observational, they could not establish causation. The authors also noted that their study population was primarily non-Hispanic white nurses and health professionals, so their results may not be generalized to wider demographics.

This feature appeared in the March/April 2022 issue of Food Business Africa. You can read this and the entire magazine HERE