Wine Information Council

 Index

1. Are alcoholic beverages and wine a risk factor for cancers? An ambivalent topic

2. Excessive consumption of alcoholic beverages and cancer risk

Regular heavy excessive consumption of alcoholic beverages and binge drinking patterns are risk factors for certain types of cancer, and the risk generally increases with increasing levels of consumption.  

3. Moderate consumption of alcoholic beverages and cancer risk

In this context, we should remember that the risk of developing cancer involves various risk factors and all cancers that have been associated with alcohol also occur in the absence of drinking.

The overall effect of light to moderate consumption of alcoholic beverages on cancer incidence is less clear and findings are inconsistent. The exception is breast cancer, which also depends on a number of other, more salient factors.

4. Cancer as a multifactorial disease and the importance of context

Since cancer is a multi-factorial disease, the cancer risk cannot be evaluated in isolation,  and studies suggest that lifestyle factors are important risk factors for cancer. Accordingly, the consumption of alcoholic beverages cannot be accurately evaluated in insolation from the other risk factors.

5. Wine consumption as part of the Mediterranean Diet - risk in context

The Mediterranean Diet (Med Diet), which includes moderate consumption of wine, is considered as one of the healthiest dietary pattern in the world by the WHO, noting that it is directly associated with a lower rate of mortality due to its effects on chronic disease prevention.  The Med Diet has been linked with a lower prevalence of several cancers, including breast and colorectal cancer.

6. Moderate wine consumption and cancer risk in context (“umbrella”) of a healthy lifestyle

Several studies confirm that moderate wine drinking is compatible with a healthy lifestyle (non-smoking, physical activity, normal body weight, balanced diet).

1. Are alcoholic beverages and wine a risk factor for cancers? An ambivalent topic

Cancers are a multifactorial disease and it is increasingly accepted that certain lifestyle choices can affect the risk of developing a cancer. Besides several unmodifiable risk factors (such as age, sex, ethnicity and genetic disposition) which may contribute to an increased risk for most cancers, improvement of lifestyle habits may contribute to a reduced risk of cancer.

According to World Health Organisation (WHO) and the World Cancer Research Fund (WCRF 2018), one third of the cancers could be prevented by adopting a healthy lifestyle (such as avoiding smoking, maintaining a normal body weight, being physically active, avoiding excessive consumption of alcoholic beverages and keeping a healthy dietary pattern)  (WHO 2017, WCRF 2018).

In addition, a study performed by the Harvard University further suggested that moderate consumption of alcoholic beverages is one of the five healthy lifestyle factors that reduce the risk of death from all causes, including cancer (Li et al 2018), where the number of low-risk behaviours adopted was inversely related to the risk for mortality.

Furthermore, the Mediterranean Diet (Med Diet) is considered as one of the healthiest diets in the world by the WHO, that notes that it is directly associated with a lower rate of mortality thanks to its effects on disease prevention (WHO Europe 2018).The moderate consumption of alcoholic beverages, particularly wine, is an important component of that diet.

So, recommendations for a “healthy” lifestyle which include a healthy diet and avoidance of alcohol, may be confusing, at least from the Med Diet perspective.

Both, the International Agency for Research on Cancer (IARC) and the World Cancer Research Foundation (WCRF) report that alcohol consumption is associated with an increased risk for certain cancers (WCRF 2018, IARC 2012).  Risk is elevated with heavier drinking for all alcohol-associated cancers, with the exception of breast cancer that merits a special consideration (see later). In this context, we should remember that the risk of developing cancer involves various risk factors and all cancers that have been associated with alcohol also occur in the absence of drinking.

Some population studies suggested that ANY consumption of an alcoholic beverage is harmful to health, because of increased cancer risk, regardless of the amount consumed and without assessing the pattern of consumption, the type of alcoholic beverage and other lifestyle factors (Gakidou et GBD collaborators 2018, Wood et al 2018).

These authors concluded that it would be best for our overall health to avoid drinking at all, despite the fact that a reduced risk of myocardial infarction and of all-cause mortality was found, and that cardiovascular diseases are the number one cause of death globally (WHO 2017)[1]. 

Can we still enjoy a glass of wine with the meal without jeopardizing our health? What does the scientific evidence say regarding a possible cancer risk when wine is consumed moderately within the context (“umbrella”) of a healthy lifestyle and a Mediterranean-style diet?

What do we know – scientific evidence

The chemical substance ethanol/alcohol

The chemical substance ethanol, also referred to as ethyl-alcohol or alcohol per se has been classified as a Group 1 carcinogen by the International Agency for Research on Cancer (IARC 1988). This classification is given to agents or exposures where the agency considers there to be sufficient evidence of its carcinogenic effects in humans (IARC 1988).  

Alcohol metabolism

Two enzymes primarily in the liver (alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH)) are involved in breaking down alcohol to enable the body to eliminate it. In the first step, ADH metabolises alcohol into acetaldehyde, which is a highly toxic chemical substance and known carcinogen[2]. Then in a second step, acetaldehyde is further metabolised by ALDH to another, less active metabolite called acetate, which is then further broken down into water and carbon dioxide for elimination from the body. The damage that acetaldehyde can cause to the cells in the body depends on how quickly it is broken down in the first step into acetate (Stockley et al 2010). Therefore, the faster an individual consumes an alcoholic beverage, the higher the BAC will rise with the respective negative health consequences.

For more information on how alcohol is metabolised by the body and the influencing factors, please click here. 

What is cancer?

Cancer is a term used for a certain group of diseases in which abnormal cells divide without control and invade other body tissues and organs. Tumours form when unimpeded abnormal cell growth occurs over a period of time. Cancer cells can subsequently spread to other parts of the body through the blood and lymph systems forming secondary malignant tumours or metastases.

There are more than 100 different types of cancers and most cancers are named after the organ or type of cell in which they start.

Benign tumours do not spread, and eventually stop growing.

Several observational studies and meta-analyses, however, have also found a reduced incidence for certain cancers associated with light to moderate alcohol consumption. The mechanism by which this alcohol consumption may decrease the risks of some cancers is not completely understood and may be indirect and/or alcoholic beverage specific through anti-oxidant and anti-inflammatory effects.

For more information on the mechanism of alcohol in the development of cancer, click here. 

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2. Excessive consumption of alcoholic beverages and cancer risk

Alcoholic beverages do not cause or contribute to the cause of all cancers.

The association between the consumption of alcoholic beverages and the risk of certain cancers has been studied for several decades. These studies have found that the extent to which alcoholic beverages are a risk factor of a cancer depends significantly on the amount of alcohol consumed, the type of alcoholic beverage and how it is consumed, that is the pattern of consumption, and probably also the dietary pattern in which alcohol is consumed.

Consumption levels and drinking patterns vary greatly between cultures and societies, however, and large amounts of an alcoholic beverage as well as regular heavy and binge drinking patterns generally impact on an individual’s general health and welfare.

Excessive consumption of alcoholic beverages is a risk factor for certain types of cancer and the risk generally increases with increasing levels of consumption.

For example, there is evidence that regular heavy excessive consumption of alcoholic beverages and binge drinking patterns (Roerecke et al 2014) are associated with increased morbidity and mortality from certain cancers (Bagnardi et al 2015), and particularly cancers of the upper aero-digestive tract (such as the mouth, tongue, larynx, pharynx and oesophagus) (Pelucchi et al 2011).

This increased risk is especially seen among individuals who also smoke tobacco (Anantharaman et al 2011, Szymariska et al 2011). Alcohol and tobacco enhance each other’s effects (i.e. act synergistically) on the risk of cancers of the upper digestive and respiratory tract. Cancer of the liver can result from alcoholic liver cirrhosis, which  is related to long-term heavy drinking (Parry et al 2011, White et al 2017; Jin et al 2013, Xi et al 2017) in conjunction with an unhealthy diet and/or hepatitis C and B virus infection. Besides those cancers listed above, other malignancies shown to be associated with heavy drinking include colorectum cancer as well as female pre- and post-menopausal breast cancer (IARC Working Group 2018). These cancers are referred to as alcohol-attributable cancers, and there is sufficient or convincing evidence of the attributions (World Cancer Research Fund International 2018).

One of many meta-analyses relating the consumption of alcoholic beverages to all cancer mortality suggested, however, that for heavy drinkers (>50 g alcohol/d), the relative risk of dying from any cancer was increased by 32% (Jin et al 2013).

→ There is no doubt that excessive drinkers have a high risk to develop cancer.  

For more information about binge drinking, click here.

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3. Moderate consumption of alcoholic beverages and cancer risk

While existing research is largely consistent as to the harms of heavy/excessive drinking in term of both cancer risk and overall mortality, there are disparate messages regarding the safety of light to moderate consumption of alcoholic beverages. Some argue that there is ‘no safe limit of alcohol’, mainly on the basis of an increased cancer risk (Wood et al 2018), and others emphasize the potential benefits for reducing cardiovascular mortality (Xi et al 2017).

Although excessive consumption has been linked to increased risk of several types of cancer, the overall effect of light to moderate consumption of alcoholic beverages on cancer incidence is less clear and findings are inconsistent (Zhou et al 2016). Whereas some studies have found a minimally increased or no increased risk of overall cancer (Xi et al 2017), others have found that even light and moderate drinking significantly contributes to an increased overall cancer risk (Bagnardi et al 2013, Bagnardi et al 2015, Cao et al 2015).

The overall cancer risk is difficult to evaluate since cancer consists of various diseases, each having specific characteristics. Furthermore, some of the meta-analyses investigating the association between the consumption of alcoholic beverages and cancer risk have limitations that need to be considered when evaluating the cancer risk: they did not assess the different drinking patterns and types of alcoholic beverages in modifying the effect of the total amount of alcohol (Bagnardi et al 2015); in addition, underreporting of alcohol consumption may partly or largely explain the cancer risk with light drinking (Klatsky et al  2014).

A large prospective study found a J-shaped association between alcohol and mortality when examining the lifetime alcohol consumption in older adults, which remained after adjusting for the cancer risk. The lowest combined risk of death and cancer was observed for light alcohol intakes (between 1 and 5 drinks/week [3]) in both men and women (Kunzmann et al 2018).

An assessment of risk for all cancer types by pooling the results of several epidemiological studies in a meta-analysis found a J-shaped curve between light to moderate drinking and overall cancer risk. This translated into a 9% lower risk of developing cancer for light drinkers (<12.5 g alcohol /d) compared to abstainers but an increased risk for excessive drinkers. No increased risk of dying from cancer for moderate drinkers (1-3 drinks/day) compared to abstainers (Jin et al 2013) was also reported.

A large meta-analysis reached similar conclusions that the consumption of alcoholic beverages (up to 1 drink/day) was not associated with the risk of most of the common cancers, except for the relatively small increase in the incidence of breast cancer in women and colorectal cancer in men (Choi et al 2018).

For more information about the link between moderate drinking and overall cancer risk, click here. 

3.1 Breast cancer 
Even though an increased overall cancer risk for women who drink moderately, was not shown by Hendriks et al (2018), it did indicate that women appear more sensitive to the pro-cancerous effects of alcohol.

Most observational, epidemiological studies have accordingly shown a small increase in the risk of breast cancer for women who consume any alcoholic beverages compared to non-drinkers. The degree of increase is usually small for light-to-moderate drinkers of between 5% and 10% increase in the relative risk for consumers of no more than one drink/day, but the risk may be higher for women consuming greater amounts  (Bagnardi et al 2015, Fagherazzi et al 2015, Choi et al 2018).

Since breast cancer is the most common cancer among women in Western countries (Bray et al 2018), even a small increased breast cancer risk from light drinking women may be relevant.

3.2 Salient confounding factors 

It has also been shown that the risk of breast cancer among obese women is higher than among non-obese women, but there are limited data on how obesity interacts with alcohol influencing the risk of breast cancer (Seiler et al 2018, Xiao et al 2019, van den Brandt et al 2000). 

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4. Cancer as a multifactorial disease and the importance of context

Since cancer is a multi-factorial disease, the cancer risk cannot be evaluated in isolation, and studies suggest that lifestyle factors are important risk factors for cancer (Kerr et al 2017). Accordingly, the consumption of alcoholic beverages cannot be accurately evaluated in insolation from the other risk factors.

For example, when the risk from alcohol is assessed within the context of a balanced diet and a healthy lifestyle, the results seem to be very different (see below).

Indeed, the balance between genetic predisposition and environmental factors, including nutritional components and lifestyle behaviours, determines individual susceptibility to develop cancer (Khan 2010). For example, click here. 

Smoking (30%), obesity (20%) and infections (15%) appear to account for a large proportion, while physical inactivity, an unhealthy diet and occupational hazards contribute 5% each, where the excessive consumption of alcoholic beverages contributes 3% to the overall cancer incidence (Fig. 1) (Arteaga et al 2014).

Figure 1. Besides various other risk factors, alcohol’s contribution to overall cancer incidence is estimated at approximately 3% (Arteaga et al. 2014)

Thus, it is important to assess the cancer risk in context with its cultural, drinking and eating patterns and lifestyle influences, and also to remember that epidemiological studies cannot adequately control for all possible confounding factors such as social background, education, physical activity, eating and drinking pattern, and other unknown factors.

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5. Wine consumption as part of the Mediterranean Diet - risk in context

Long-term observational studies have also found differences between the alcoholic beverages. At low to moderate wine consumption, often no association with alcohol-related cancer types was observed. Especially when the risk was assessed in the context of other lifestyle factors, light to moderate wine consumption does not seem to be related to any increased cancer (and other disease) risk (Schwingshackl et al 2017, Li et al 2020).

The Mediterranean Diet (Med Diet), which includes moderate consumption of wine, is considered as one of the healthiest dietary pattern in the world by the WHO, noting that it is directly associated with a lower rate of mortality due to its effects on chronic disease prevention (WHO Europe 2018).

Taken together, this results in a dietary pattern with a low content of saturated fatty acids (7–8% of daily total energy consumption) and a total percentage of fat of 30–40% or greater per day (Schwingshackl et al 2019; Schwingshackl et al 2017, Sofi et al 2014, Willett et al 1995; Fidanza et al 2005).

5.1 Mediterranean drinking pattern
The Mediterranean drinking pattern is not only about the amount of alcoholic beverage consumed but also the type of alcoholic beverage predominantly consumed – wine - and how it is consumed.

Drinking patterns in terms of frequency and the amount of wine consumed as well as drinking with or without a meal are important influencing factors for the biological effects of this alcoholic beverage. Risky and harmful drinking patterns including the regular consumption of heavy amounts of wine, as well as consuming heavy and excessive amounts on a single occasion (binge drinking), should be discouraged. It is thus recommended that individuals drink wine as an accompaniment to food and alternate it with a non-alcoholic beverage such as water (Boban et al 2016).

Spanish researchers examined the drinking patterns and concluded that the traditional Mediterranean drinking habits (such as moderate intake of alcoholic beverages, alcohol intake spread over the week, low spirit consumption, a preference for wine, wine consumed during meals, and avoidance of binge drinking) were also associated with a lower risk of all-cause mortality (Gea et al 2014).

5.2 Low to moderate wine consumption as part of a balanced diet such as the Med Diet
Intake of individual foods has been extensively studied in relation to cancer risk and for the chemical substance ethanol, a convincing evidence has been established, particularly for breast cancer (IARC 2012, WCRF 2018). However, individuals do not consume isolated foods or nutrients and examining dietary patterns in relation to cancer risk is consequently more meaningful.

Thus, it should be emphasized that the effect of alcohol on the tumour development depends on the context. Diet has been identified as a modifiable lifestyle component that influences the cancer development. The Med Diet is considered one of the healthiest diets because of its abundance of plant-based foods and the lack of processed foods (Willett et al 1995). Numerous epidemio­logical studies (Pellucchi et al 2009, Eleftheriou et al 2018, Soltani et al 2019) have focused on the health effects of the Med Diet, where studies that have examined the role of wine in the Mediterranean diet have identified a decreased risk of multiple health outcomes.

5.3 Med diet and all-cause mortality
More adherence to a Mediterranean dietary pattern resulted in: a reduced risk of all-cause mortality, cardiovascular diseases, coronary heart disease, stroke, overall cancer, diabetes and neuro-degenerative incidence (Dinu et al 2018, Soltani et al 2019).

An updated meta-analysis quantified the association of adherence to the Med Diet and all of its components with all-cause mortality (Eleftheriou et al 2018). When looking at the Med Diet components, a statistically significant inverse association was highlighted for a moderate consumption of alcoholic beverages compared to abstinence or excessive consumption[4].

5.4 Med Diet and cancer risk
The extent to which different drinking and dietary patterns, lifestyle habits and/or beverage specific ingredients are responsible for the observed reduced risk of certain cancers continues to be discussed, and may provide an explanation as to why no increased breast cancer risk has generally been observed within the context of a Med Diet (Trichopoulou et al 2010, Cade et al 2011, Couto et al 2011, Toledo et al 2015).

When examining moderate wine consumption in the context of the Mediterranean diet and typically with the meals, no increased cancer risk, even for breast cancer and colorectal cancer (Schwingshackl et al 2017, Toledo et al 2015) was observed. Furthermore, a better adherence to the Med Diet was also associated with a lower risk total mortality, that is dying from any cause (Soltani et al 2019).

Furthermore, a better adherence to the Med Diet was associated with a lower risk of total mortality, that is dying from any cause (Soltani et al 2019).

The above results were confirmed by large meta-analyses, where a greater adherence to the Med Diet was associated with a lower cancer risk (Schwingshackl et al 2017, Galbete et al 2018). When focusing specifically on prospective trials, this meta-analysis highlighted significant decreases in the risk of suffering colorectal and breast malignancies and in cancer mortality among subjects with high Med Diet adherence.  In line with these findings, a randomized controlled trial has studied the effect of this dietary pattern on cancer incidence. Adherence to the traditional Med Diet in the context of the PREDIMED Study demonstrated a decrease in the development of all sub-types of breast cancer and a decrease in its recurrence (Toledo et al 2015). It should be emphasized however that such findings need to be confirmed in further long-term trials. 

Regarding the alcohol, as stated by Schwingshackl et al. (2017), the attribution of anti-cancer effects to its consumption seems controversial, considering that it is categorized by the IARC as a Group 1 carcinogen for humans (IARC 2012) and by the World Cancer Research Fund as a convincing carcinogen for mouth, pharynx, larynx, esophagus, stomach, liver, colorectal, and breast malignancies (WRCF 2018). Low-to-moderate wine consumption contributes, however, to a higher Med Diet adherence (linked to the previously described benefits) and no dose-response effect of the toxicity of alcohol or wine consumption can be inferred from their conclusions.

5.5 Wine – a protective component of the Med Diet
The inclusion of alcohol in the Med Diet usually means moderate wine consumption as part of a meal (Gea et al 2014). When analysing the components of the Med Diet that contributed most to such a decreased cancer risk, researchers have specifically identified the moderate, but not excessive consumption of alcoholic beverages and predominantly wine, fruits, vegetables and whole grains as protective components (Schwingshackl et al 2017, Eleftheriou et al 2018).

There is sufficient clinical evidence to point out that moderate wine drinkers have a lower risk for cancer compared to drinkers of other alcoholic beverages. So far, the anti-cancer effects of wine-specific polyphenols have only been observed in animal and laboratory studies. In some epidemiological studies, however, the risk of cancer has been shown to be lower in wine drinkers than in those who consumed other alcoholic beverages (Xu et al 2019, Groenbaek M et al 2000).

5.6 Possible mechanisms
Wine provides large amounts of several bioactive compounds such as polyphenols that may be potentially responsible for some of the wine’s anti-cancer effects (Fernandes et al 2017) and the possible counter effects of the entire dietary composition of a Med Diet against the toxicity of alcohol on cancer has not been explored (Hernaez A et al 2019). Thus, the observed positive health effects of light to moderate wine consumption may be - at least in part - linked to the protective effects of specific bioactive ingredients in the wine (polyphenols) as well as in the foods consumed with higher abundance in the Mediterra­nean diet (Eleftheriou et al 2018).

For more information about wine polyphenols, click here.

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6. Moderate wine consumption and cancer risk in context (“umbrella”) of a healthy lifestyle

Several studies confirm that adopting a healthy lifestyle and a balanced diet, including a moderate consumption of wine/alcoholic beverages, has a number of positive and protective health effects. 

6.1 More years without chronic diseases

A large study from Harvard University examined comprehensively how multiple lifestyle factors relate to life expectancy without major diseases and confirmed these recommendations: following a healthy lifestyle at mid-life is associated with a longer life expectancy and a lower risk of major diseases such as cancer, cardiovascular and diabetes. The study highlights five specific lifestyle factors, one of them is the moderate consumption of alcoholic beverages (Li et al 2020):

The researchers found that women (at age 50) who ate a healthy diet, exercised 30 minutes each day, had a normal body weight and consumed alcoholic beverages in moderation lived to an average of 84.4 years old without developing diabetes, cardiovascular disease and cancer. Those women who did not practice these healthy habits were more likely to develop those diseases in their 70s. Middle-aged men practising these habits lived to an average of 81.1 years old without chronic diseases compared to 73.5 years old for men who did not.

Thus, in the context of a healthy lifestyle, moderate wine/alcohol consumption is one lifestyle factor that contributes to a longer life expectancy free of major diseases (Li et al 2020).

6.2 Longer life expectancy 

The same Harvard researchers (Li et al 2018) (Fig. 3) had already shown earlier that those five lifestyle factors could increase the life expectancy. They were surprised how immense the benefits of all these five lifestyle factors would be:

• 50 year old women who would practice ALL these healthy lifestyle factors could enjoy 14 additional years (93 instead of 79 years) and
• 50 year old men would benefit with 12 additional years (87 instead of 75 years).
• The reference group consisted of individuals with none of these lifestyle factors.
• Compared to this group, the mortality risk was 74% lower when all 5 factors would be followed, the cancer risk was 65% lower and the CVD risk was 82% lower. 

One of the five lifestyle factors - a moderate amount of alcoholic beverages - was defined for women 5-15 g of alcohol/day or the equivalent of 50 to 150 ml of wine and for men, 5-30 g of alcohol/day or the equivalent of 50 to 300 ml of wine.

Figure 3: Impact of healthy lifestyle factors on life expectancies in the US population (Li et al 2018)

A recent large European study reported similar results (Nyberg et al 2020), where the higher the number of healthy lifestyle habits, the longer the lifespan without major chronic diseases (type 2 diabetes, coronary heart disease, stroke, cancer, asthma, chronic obstructive pulmonary disease, heart failure, dementia*). The longest life span free of disease was observed among those participants with a normal weight (BMI < 25) and two of the following lifestyle factors: never smoking, physical activity and moderate consumption of alcoholic beverages (1-14 drinks per week for women and 1-21 drinks per week for men[5]). 

Even the World Cancer Research Fund recently stated five lifestyle factors that contribute to a lower cancer risk (WCRF 2018), among them a healthy diet, including moderate wine/alcoholic beverage consumption.

(*)These specific diseases were selected because they are the most common major non-communicable diseases in developed countries and targets prioritised for global disease prevention by WHO (Gakidou et al 2018)

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[1] https://www.who.int/en/news-room/fact-sheets/detail/cardiovascular-diseases-(cvds) [back to reading]

[2] A chemical that promotes carcinogenesis or the promotion and progression of cancer. [back to reading]

[3]  One glass of wine = approx. 147 ml = approx. 14 g of alcohol [back to reading]

[4] Med diet score for alcoholic beverages = value of 1 for men who consumed quantities from 10 g /day to less than 50 g/day and a value of 0 otherwise; the corresponding cut-offs for women were 5 g/ day and 25 g/ day (Trichopoulou et al 2009) [back to reading]

[5] One drink being equivalent to 10 g of alcohol [back to reading]