Throughout the developed world, cardiovascular disease is the leading cause of death and accounts for up to 50% of all deaths. Considering this, it is of outmost relevance that epidemiological studies are showing consistently a reduced mortality from coronary heart disease (CHD) and other forms of cardiovascular diseases (CVD) by 25-30% in middle-aged and elderly individuals.
Moderate wine drinkers seem to live longer than those who abstain or drink heavily. This widely accepted association is known as the J-curve. The relative risk of dying from CVD is lowest among light to moderate drinkers and greater among abstainers. However, the risk increases steadily with each drink above moderation. Thus, while one or two glasses can be considered “good for your health”, drinking more than the guidelines will not provide more benefits, only more harm!
In a recent most comprehensive meta-analysis, an international research team examined results from 84 longitudinal cohort studies from all over the world comparing drinkers of alcoholic beverages with non-drinkers for the outcomes of overall mortality and mortality from cardiovascular disease (CVD), coronary heart disease (CHD) and stroke as well as incident coronary heart disease and incident stroke. Meta-analyses for each of these outcomes were performed. The researchers carefully accounted for possible confounding factors.
As result, the cardiovascular mortality risk for drinkers of alcoholic beverages compared to non-drinkers was significantly reduced by 25%. Dose-response analysis revealed that the lowest risk of coronary heart disease mortality occurred with 15-30 g of alcohol a day but for stroke mortality ≤ 15 g of alcohol a day. Very importantly, also with regards to all cause mortality, moderate drinkers had an advantage compared to abstinent individuals: up to 15 g/day, their total mortality risk was 13% lower. The scientists concluded that light to moderate alcohol consumption is associated with a reduced risk of multiple cardiovascular outcomes and total mortality and further, they suggested that current scientific data indicate causality.
The results of another meta-analysis concerning the biochemical and physiological mechanisms showed that moderate consumption of alcoholic beverages (up to 15 g alcohol a day for women and up to 30 g alcohol a day for men) has beneficial effects on a variety of biomarkers linked to the risk of coronary heart disease.
Approximately half of the cardio-protective effects of wine are believed to be due to alcohol itself since it has a beneficial effect on blood lipids.
Vascular disease occurs when bad cholesterol (LDL) is deposited in artery walls and builds up atherosclerotic deposits, eventually rupturing, causing a clot to form which can instantaneously block mostly or completely the flow through the coronary artery. Alcohol stimulates the production of the “good” high density lipoprotein cholesterol (HDL) which is believed to remove cholesterol deposits from arteries and veins where it can form plaques.
It also reduces the “stickiness” or the clotting together of red blood cells which could form a clot and block the blood flow in an artery (thrombosis) resulting in a heart attack or stroke. In addition, it lowers the fibrinogen level which is a pro-inflammatory, thus alcohol works as an anti-inflammatory agent that affects the blood vessels positively and is involved in delaying the development of atherosclerosis.
Wine, in addition, contains phenolic substances such as resveratrol, anthocyanins, flavonols and catechins which act as antioxidants and inhibit “bad” LDL cholesterol from being incorporated in the artery wall. These antioxidants also reduce the damage caused by the body's free radicals (toxic waste products) which contribute to causing degenerative diseases in the body such as cancer, Alzheimer's disease, Parkinson's disease and ageing. Furthermore, rather than the phenolic compounds themselves, their metabolites might be the real key players in cardiovascular and cancer protection. It should be noted that the antioxidant activity in unfermented grape juice is lower than in the finished wine - antioxidant activity increases during fermentation and maturation. Antioxidant levels will depend on the processing, filtering as well as on the variety, vintage, altitude and soil.
The phenolic compounds are also associated with reducing blood clotting and also maintaining the ability of the blood vessel wall to expand and contract.
The findings described in the above quoted meta-analyses provide the most thorough examination of the literature and strengthen the case for a causal link between alcohol intake and a reduced risk of coronary heart disease, suggesting that the lower risk of heart disease observed among moderate drinkers is caused by the alcoholic beverage itself, and not by other associated lifestyle factors. The scientific evidence is very convincing that regular moderate consumption of alcoholic beverages, in particular wine, can provide cardiovascular benefits in older adults.
High blood pressure (hypertension) occurs when vessel walls lose their flexibility causing excess pressure on arterial walls. If the elevated blood pressure is not reduced, the risk of heart disease, stroke, visual loss, and kidney failure increases. Early detection and treatment is lifesaving. The treatment often involves a modification of lifestyle. It has been a general, long-held belief that consumption of alcoholic beverages, in any form, in any quantity, raises blood pressure, and, therefore, many of those at risk have been advised not to drink at all.
Epidemiological studies suggest a lower risk of morbidity and mortality among lighter drinkers. The investigators found that the association between intake of alcoholic beverages and risk of cardiovascular disease (CVD) followed a J-shaped curve, whereas alcohol drinking is linearly associated with blood pressure, and the CVD risk also increases linearly according to blood pressure level. However, several studies indicate that moderate wine consumption does not increase or can even decrease blood pressure. This effect seems mostly due to relaxed blood vessels immediately after consuming alcoholic beverages. The non-alcoholic elements of wine, such as polyphenols may have additional antioxidant, anti-inflammatory and blood vessel relaxant properties.
International comparisons and some prospective research data suggest that wine is more protective against coronary heart disease (CHD) than liquor or beer. Possibly beneficial non-alcohol components in wine may exert the extra protection by wine, but a healthier drinking pattern or more favorable risk traits in wine drinkers (such as a healthier lifestyle) may be involved. Heavy drinking or a binge drinking pattern definitely associated with an increased risk of hypertension. Reducing the intake of alcoholic beverages to moderate levels often leads to substantial reduction of elevated blood pressure.
The above summary provides an overview of the topic, for more details and specific questions, please refer to the articles in the database.