Cardiovascular System

Is the “J-Curve” Real?

  

1. J-curve - Lower risk for light to moderate drinkers compared to abstainers

For many decades, epidemiological studies have consistently shown that light-to-moderate  consumers of alcoholic beverages have a lower risk of cardiovascular disease (CVD) and a lower risk of death from all causes (including total cancer) compared with non-drinkers or those who drink heavily. It is not limited to alcohol-related causes of death, but instead captures all deaths combined (Brien et al 2011, Ronksley et al 2011, di Castelnuovo et al 2006, Roerecke et al 2012, Ferrari et al 2014, Jayasekara et al 2014, Xi et al 2017, Wood et al 2018, Colpani et al 2018).

  • Such a J-shaped relationship (J-curve) has been shown in many different populations and dozens of observational studies. In different degrees, it is also seen in men and women and with other types of alcoholic beverages.
  • Observational studies cannot prove causality but the observed association is considered biologically plausible (see below). However, there is a scientific debate at which level of consumption the nadir of this curve lies.

 

  • Such a J-shaped relationship (J-curve) has been shown in many different populations and dozens of observational studies. In different degrees, it is also seen in men and women and with other types of alcoholic beverages.
  • Observational studies cannot prove causality but the observed association is considered biologically plausible (see below). However, there is a scientific debate at which level of consumption the nadir of this curve lies.

 

2. Comparison to Smoking

WHO and other institutions have repeatedly declared the risks of alcohol consumption equivalent to smoking. However, no benefit of “moderate smoking” has ever been found.

WHO and other institutions have repeatedly declared the risks of alcohol consumption equivalent to smoking. However, no benefit of “moderate smoking” has ever been found.

 

De Gaetano et al, 2017, Alcohol and health – praise of the J-curve, J Am Coll Cardiology, vol 70, no 8

 

3. J-shape also for other diseases

In addition to CVD and total mortality, a J-shaped curve exists for the risk of other diseases, for example for type-2 diabetes and dementia. 

 

4. Correlation or cause?

Observational studies can only provide statistical associations and present absolute or relative risks of developing certain diseases and cannot be interpreted as a proof of a causal relationship. However, the associations described are biologically plausible: controlled experiments have proven the beneficial physiological effects of light to moderate drinking of wine/alcoholic beverages.

 

Biologically plausible: How does it work?

Effect of alcohol:

  • Improvement of cholesterol levels: „good“ HDL increases, „bad“ LDL decreases
  • Lowering of blood viscosity (blood becomes „thinner“)

Effect of phenolic, non-alcoholic compounds of wine:

  • Improvement of endothelial function
  • Antioxidant effect/scavenger of free radicals

 

5. Wine versus other alcoholic beverages

Light to moderate wine consumption may be more beneficial than consuming other alcoholic beverages. An increasing number of both animal experiments and human trials demonstrate that non-alcoholic substances (polyphenols) in wine provide additional protective effects against risk factors and diseases.

 

6. Influencing factors

Most epidemiological studies have only used the average amount of alcohol consumed (over a week or month) as the measure of exposure, however, other factors play an important role in the health outcome. i.e. Regular moderate consumers of alcoholic beverages had considerable health advantages compared to binge drinkers, even though they consumed on average the same amount.

  • Drinking pattern (moderate, regular vs. binge drinking)
  • Drinking with the meals
  • Alternate wine with water
  • The famous advice of Serge Renaud is: “You drink water, but you sip wine”.

 

7. Underreporting

An important problem of observational studies is “under-reporting” of alcohol intake. This subsequently affects the J-curve. When “under-reporters” are removed from the study analysis, the curve shifts to the right, which means that the lowest risk of moderate drinkers is actually related to a higher amount of alcohol intake and the increased risk starts at a higher dosage.

 

8. Moderate wine consumption within a healthy lifestyle

Light to moderate consumption of wine/alcoholic beverages should be considered only one component of lifestyle factors related to health. The most important aspects are:

  • Don’t smoke
  • Maintain a normal body weight (avoid becoming obese)
  • Exercise regularly
  • Eat a healthy diet (e.g., a Mediterranean-type diet)
  • Consume alcoholic beverages moderately and regularly with food, unless contraindicated

These lifestyle factors contribute not only to a longer life expectancy but also a longer life free of chronic diseases.

 

9. Sick-quitters

Earlier studies included ex-drinkers in the non-drinking reference/control group that may have artificially increased the risk of disease for “current abstainers”, thus, confounding the J-shaped curve and negating a protective relationship with moderate drinking. However, more recent studies have corrected this flaw and when including only lifetime abstainers in the non-drinking category, a similar J-shaped curve was found and disproved the so called “sick-quitters” hypothesis.

The results of studies on the role of appropriate wine consumption in the prevention of cardiovascular disease are inconsistent, suggesting that the general approach to the issue needs to be revisited before further research is conducted. A number of points for consideration are raised: (1) the necessity to characterize wine analytically, as the content in important components of wine, such as resveratrol, is influenced considerably by regional factors, such as climate and local oenological procedures; (2) the bioavailability of the components of wine, which appears to be adequate as a broad range of biological effects have been documented at low concentrations that can be achieved by moderate chronic wine consumption; (3) the lack of importance of wine color, as also…
Cardiovascular diseases are among the worldwide leading causes of shorter life expectancy and loss of quality of life. Thus, any influence of diet or life habits on the cardiovascular system may have important implications for public health. Most world populations consume alcoholic beverages. Since alcohol may have both protective and harmful effects on cardiovascular health, the identification of biochemical mechanisms that could explain such paradoxical effects is warranted. The vascular endothelium is the target of important mediating pathways of differential ethanol concentrations, such as oxidative stress, lipoproteins, and insulin resistance. Alcohol-induced endothelial damage or protection may be related to the synthesis or action of several markers, such as nitric oxide, cortisol, endothelin-1, adhesion molecules, tumor necrosis factor alpha, interleukin-6, C-reactive…
OBJECTIVE: To evaluate the strength of the evidence provided by epidemiological literature investigating drinking pattern as effect modifier of alcohol intake on the risk of coronary heart disease (CHD). DESIGN: Meta-analysis of observational studies. DATA SOURCES: Medline, citation tracking, from 1966 to 2006. Review methods: Original studies investigating the amount of alcohol intake, combined with the frequency of alcohol consumption and/or pattern of alcohol drinking affecting the risk of CHD were extracted. Among them, cohort and case-control studies reporting sufficient data to perform statistical analyses and using people who abstained from alcohol as the reference were included. RESULTS: Six (4 cohort and 2 case-control) out of 118 studies reviewed met the inclusion criteria. Compared with those who abstained from alcohol,…
BACKGROUND: The association between alcohol consumption and Coronary Heart Disease (CHD) has been broadly studied. Most studies conclude that moderate alcohol intake reduces the risk of CHD. There are many discussions on whether the association is causal or biased. The objective is to analyse the association between alcohol intake and risk of CHD in the Spanish cohort of the European Prospective Investigation into Cancer (EPIC). METHODS: Participants from the EPIC Spanish cohort were included (15,630 men and 25,808 women). The median follow up period was 10 years. Ethanol intake was calculated using a validated dietary history questionnaire. Participants with a definite CHD event were considered cases. A Cox regression model was performed adjusted for relevant covariables and stratified by age.…
Since ancient times, people have attributed a variety of health benefits to moderate consumption of fermented beverages such as wine and beer, often without any scientific basis. There is evidence that excessive or binge alcohol consumption is associated with increased morbidity and mortality, as well as with work related and traffic accidents. On the contrary, at the moment, several epidemiological studies have suggested that moderate consumption of alcohol reduces overall mortality, mainly from coronary diseases. However, there are discrepancies regarding the specific effects of different types of beverages (wine, beer and spirits) on the cardiovascular system and cancer, and also whether the possible protective effects of alcoholic beverages are due to their alcoholic content (ethanol) or to their non-alcoholic components…
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