Alcohol consumption has a considerable impact on health. According to the World Health Organisation (WHO), 2.6 million deaths worldwide can be attributed to alcohol consumption each year. Furthermore, an estimated 400 million people suffer from alcohol use disorders. Of these, 209 million live with alcohol dependence.

In Spain, alcohol is the second leading preventable cause of death, accounting for around 4% of annual deaths and with a particularly high impact among young people.

Alcohol consumption is associated with the development of a wide range of diseases affecting the liver, pancreas and gastrointestinal system, as well as cardiovascular and neurological disorders and various types of cancer including breast, throat and mouth. Added to this is the role played by alcohol in traffic accidents, injuries and violence, and in social and employment problems. 

However, some observational studies have pointed to the potential health benefits of a low or moderate alcohol intake, noting a lower cardiovascular risk and mortality than among heavy drinkers and, at times, even compared to teetotallers, triggering a complex scientific and social debate. Furthermore, these results have been shown to be more consistent when a Mediterranean diet is followed, in which alcohol (specifically wine and preferably red) is drunk in small quantities and with meals, its consumption being spread throughout the week and with no binge drinking. 

This scenario poses a challenge for public health and healthcare professionals. How should these findings be interpreted? How should the potential benefits be weighed against the risks? Should a simple message of total abstinence be conveyed or is it better to include nuances based on age, gender or drinking habits?

These are some of the questions at the heart of the latest Biomedical and Health Research Debate (held on 3 June as part of the Health Prevention and Promotion series offered by ”la Caixa” Foundation), featuring two leading experts, Professors Raúl Andrade Bellido and Miguel Ángel Martínez-González.

• Miguel Ángel Martínez-González is Professor of Preventive Medicine and Public Health at the University of Navarra and Visiting Professor of Nutrition at the Harvard T. H. Chan School of Public Health.
• Raúl Andrade Bellido is Professor of Medicine at the University of Malaga, Head of the Gastroenterology Department at the Virgen de la Victoria University Hospital, and Principal Investigator of the Hepatogastroenterology, Pharmacology and Translational Clinical Therapeutics group at the Biomedical Research Institute of Malaga.

The following article outlines the key points raised by the two experts during the Debate, moderated by Beatriz Pérez, Health Editor at El Periódico de Catalunya.

 

The impact of alcohol consumption and its social perception

How many deaths are caused by alcohol?

“In Spain, between 17,000 and 20,000 deaths a year, around 4% of all deaths. In other words, alcohol is one of the most significant risk factors, especially when it comes to excessive consumption and binge drinking” – Miguel Ángel Martínez-González

Which diseases are caused by alcohol?

(A chart by the World Health Organisation was shown during the discussion, which is referred to below and can be seen at minute 03:15 of the video)

“According to estimates by the World Health Organisation, some disorders can be defined by their link to alcohol, such as alcoholic cardiomyopathy and alcohol use disorders. Around 42% of cirrhosis cases are attributable to alcohol and certain cancers, such as those of the pharynx, lip and oral cavity, have significant attributable fractions, ranging from 28% to 35%. Alcohol consumption is also linked to self-harm, suicide and interpersonal violence. Furthermore, it accounts for a quarter of deaths from road traffic accidents and pancreatitis. To a certain extent, oesophageal, laryngeal, colorectal, liver and breast cancers may also be causally linked to high blood alcohol levels. It’s also associated with deaths from tuberculosis, various injuries, epilepsy, burns, haemorrhagic strokes and hypertensive heart disease” – Miguel Ángel Martínez-González  

Why does alcohol affect women more than men?

“Women have a lower capacity to metabolise alcohol in the stomach, which is the primary site of alcohol absorption, and in the intestines. Furthermore, hormonal factors and body fat distribution also appear to increase women’s susceptibility to the toxic effects of alcohol” – Raúl Andrade Bellido

Is there a real understanding in Spain of the risks and toxicity of alcohol?

“Alcohol consumption is a very ancient habit. Some studies suggest it dates back over 8,000 years, associated not only with meals but also as a drink for socialising, reaching agreements and celebrating. It’s a millennia-old tradition that can be found in texts such as the Bible, without looking any further. Culturally, it’s a deeply ingrained habit and it’s difficult for people to perceive the risks. Whilst everyone understands that smoking provides no health benefits, the same can’t be said for alcohol. Alcoholic beverages, particularly those with a lower alcohol content such as wine, are the subject of a great deal of scientific literature which, with many nuances, suggests they may have some health benefits, although it’s always important to emphasise that everything depends on the total amount consumed and that, at high doses, any beneficial effect is negated” – Raúl Andrade Bellido

 

Alcohol and the risk of cancer

Is there a link between alcohol consumption and breast cancer?

“4% of breast cancer cases can be attributed to alcohol consumption. Although this may seem a small percentage, we must bear in mind that breast cancer is the most commonly diagnosed cancer in women and is a major cause of death. That 4% is of great significance in public health terms” – Miguel Ángel Martínez-González

What other cancers is alcohol specifically associated with?

(A diagram and chart were shown during the discussion, which are referred to below and can be seen at minute 09:30 of the video)

“In addition to breast cancer, the link has been studied between alcohol consumption and cancer of the mouth, lips, throat, larynx, pharynx, oesophagus, liver, and colorectum. All these cancers are referred to as alcohol-related because alcohol is a key risk factor to varying degrees. Furthermore, in many of these cases, studies have shown that if tobacco and alcohol are consumed together, the effect is multiplied. There’s a very strong synergy because alcohol is a highly effective solvent and, as a result of this solvent, the carcinogens in tobacco enter the cell and cause more damage. Furthermore, alcohol impairs the function of certain detoxifying enzymes” – Miguel Ángel Martínez-González

Is it possible to determine which section of the female population is at greater risk of breast cancer due to alcohol consumption?

“I’m not an expert in breast cancer but I get the impression that there are currently no useful tools to identify which women are at greater risk of developing breast cancer due to alcohol, since genetic, epigenetic and environmental factors are all involved. In the area I know best, namely liver disease, this is clearly the case: it’s not possible to distinguish which individuals will develop the disease when they consume alcohol” – Raúl Andrade Bellido

“There’s a higher risk in postmenopause but there are three key moments in a woman’s life that are crucial to her risk of breast cancer: menarche, the first time she gives birth and menopause. The earlier the first period occurs and the later the first child and menopause arrive, the higher the risk of breast cancer. It all has to do with hormonal cycles and alcohol also interferes with those” – Miguel Ángel Martínez-González

 

The importance of consumption patterns and their effects

What is the cardiovascular risk associated with alcohol?

(A chart was shown during the discussion, which is referred to below and can be seen at minute 16:46 of the video)

“It depends very much on the amount consumed and there’s still a lot to investigate and many questions to be resolved. There’s a publication that has compiled the results of 28 observational epidemiological studies, in which nearly 50,000 cases of myocardial infarction or other manifestations of coronary heart disease, such as sudden cardiovascular death, were noted. This publication showed that the lowest risk of coronary heart disease corresponded to a consumption of 20 grams of alcohol per day. That’s a low level of consumption, amounting to a glass of wine of about 120 millilitres. This amount carries a lower risk of cardiovascular disease but, if we go beyond that amount, the risk rockets. Looking ahead, it’s important to go beyond observational studies and conduct intervention studies, in which people are helped to alter their drinking habits, in order to analyse how the risks decrease” – Miguel Ángel Martínez-González

What are the risks of consuming large amounts of alcohol only at the weekend, known as binge drinking?

“It has an effect on the nervous system; it’s very harmful and clearly causes neuronal damage” – Raúl Andrade Bellido

“There are very significant effects on the loss of grey matter, particularly in adolescents and young people who consume large amounts of alcohol at the weekend. Furthermore, it slows down the growth of white matter. More serious lesions have also been observed, such as the formation of empty spaces in the cerebral ventricles. A much greater toxic effect on the brain and an increased risk of premature mortality have been observed with this pattern of consumption” – Miguel Ángel Martínez-González

What’s the definition of binge drinking?

“For a man, consuming five units of alcohol in a single afternoon or evening. For a woman, four. When we say one unit of alcohol, you have to consider the equivalent based on the alcohol content of the drink consumed” – Miguel Ángel Martínez-González

Does alcohol consumption affect decision-making and emotional control?

“Alcohol is an addictive substance. If the patient is an alcoholic, i.e. they need alcohol to maintain their vitality, then this substance will indeed have a significant influence on their decision-making ability, as they’ll be entirely conditioned by that addiction, affecting their emotions. Alcohol consumption influences the development of violent behaviour. However, in non-addicted individuals, moderate consumption shouldn’t lead to significant changes in mood, behaviour, temperament or decision-making ability” – Raúl Andrade Bellido

 

The possible benefits of moderate alcohol consumption and the mediterranean diet

Can low or moderate alcohol consumption reduce cardiovascular risk?

(A chart was shown during the discussion, which is referred to below and can be seen at minute 26:37 of the video)

“We must be very cautious with these claims. One of the professors from our department, Alfredo Gea, conducted a study as part of the SUN project (Seguimiento Universidad de Navarra), which involved more than 18,000 volunteers over 12 years . One of the observations made was that, for the same total amount of alcohol consumed, in cases where there was a drinking pattern associated with the Mediterranean diet (known as MADP, Mediterranean Alcohol Drinking Pattern, characterised by red wine consumption, a moderate intake with meals and spread throughout the week), cardiovascular risks and long-term mortality were reduced. This study has been replicated in other countries and the effect of ethanol appears to be modified by the pattern of consumption” – Miguel Ángel Martínez-González

What is moderate consumption?

“Not exceeding one glass of wine a day for women and two for men. And we’re talking about small glasses, of just over 100 cubic centimetres. Furthermore, wine seems to be better than other drinks and, within wine, red is preferable. That’s because red wine contains a range of phenolic compounds, antioxidants and anti-inflammatory agents that have beneficial biochemical effects. Such effects have scarcely been observed in beer. On the other hand, high-alcohol drinks are the most irritating to the digestive tract and are most likely to increase the risk of cancer” – Miguel Ángel Martínez-González

How does alcohol consumption fit into the Mediterranean diet?

“The Mediterranean diet is currently the global benchmark for a healthy diet. No other diet has accumulated such a wealth of scientific evidence regarding disease prevention and lower premature mortality. All definitions of this diet have always included a glass of wine a day with a meal. However, more extensive studies are needed to determine whether this is a healthy habit or if there are better alternatives” – Miguel Ángel Martínez-González

What is the UNATI trial and how does it aim to study these potential benefits?

(A diagram of the UNATI experiment design was shown during the discussion, as well as a chart, which are referred to below and can be seen at minute 26:11 and minute 33:34 of the video)

“UNATI, funded entirely by the European Research Council (ERC), is a randomised clinical trial that will follow around 10,000 people (men aged 50 to 70 and women aged 55 to 75) who drink between 3 and 40 glasses a week, over a four-year period. It’s a scientific endeavour involving more than 500 doctors and researchers across Spain. We’re leading it from the Department of Preventive Medicine at the University of Navarra and it will be the largest study ever conducted worldwide on the effects of the moderate consumption of alcohol” – Miguel Ángel Martínez-González

“Participants are invited who are already drinkers and they’re assigned psychologists, dieticians, doctors and nurses to give them advice on how to make their drinking habits healthier. The aim is to measure the consequences of these changes” – Miguel Ángel Martínez-González

“To date, we’ve recruited just over 9,200 volunteer participants who’ve already been registered by their doctors, and more than 7,800 of these have already been assessed by our team of professionals. We’re continuing to seek volunteers until 30 June to reach our target of 10,000 participants. You can find all the information on the UNATI website and register using the participation form” – Miguel Ángel Martínez-González

 

The risks of heavy alcohol consumption

What is acute alcoholic hepatitis?

“Mortality attributed to alcohol due to liver disease occurs at a relatively young age, between 45 and 55 years. Alcoholic hepatitis is rare but very serious, with a high mortality rate. I’ve seen patients recover, remain alcohol-free for a time, relapse, be readmitted and die. This demonstrates the devastating effects of uncontrolled alcohol consumption” – Raúl Andrade Bellido

What’s the link between alcohol consumption and chronic pancreatitis? 

“It’s less common but is caused almost exclusively by alcohol abuse. It leads to exocrine pancreatic insufficiency, which significantly impairs digestion and is also a predisposing factor for pancreatic cancer. Alcohol consumption has a large number of toxic effects and, really, when you encounter such situations in clinical practice, you’re left emotionally shaken” – Raúl Andrade Bellido

 

A message that should resonate with the public

Could the message that moderate consumption may have some benefits be counterproductive?

“I’m concerned about encouraging consumption. It’s a double-edged sword because such a message could be misinterpreted. It’s not the same thing for a study to show that a person who drinks one glass of wine a day under certain conditions has some benefits for their cardiovascular health, as it is to start drinking alcohol because you’re seeking those benefits. Furthermore, there’s always the risk of creating addicts; it’s a problem we’ll always have to deal with” – Raúl Andrade Bellido

“There’s also the difficulty of applying the results of such a study to an individual. Everyone has their own physical condition and alcohol doesn’t affect everyone in the same way. For example, around 40% of the adult population has non-alcoholic fatty liver disease but many are unaware they have it. It’s associated with obesity, diabetes, etc. In such cases, alcohol consumption has been shown to accelerate the progression of the disease” – Raúl Andrade Bellido

“From a public health perspective, we can’t encourage anyone, for health reasons, to start drinking alcohol or to increase their usual consumption” – Miguel Ángel Martínez-González

So is it better to advocate total abstinence?

“The message must be that those who abstain should continue to do so. Under no circumstances should we send out a message that encourages consumption. And among those who drink moderately, we’ll see the results of the UNATI study to determine whether they should continue their moderate consumption. In any case, we must be very cautious with our recommendations and ensure the public understand that, if they’ve never drunk alcohol, they should remain teetotallers” – Raúl Andrade Bellido

 

Alcohol consumption among young people

Around 30% of 18-year-olds in Spain become intoxicated with alcohol once a month, a percentage far higher than in other countries. Why is this happening in Spain?

(A table and some charts, with data from the National Drugs Plan, are shown during the discussion, which are referred to below and can be seen at minute 50:50 of the video)

“I believe the idea has taken root among young people that there’s no party without alcohol, something that’s particularly evident at the weekend and also leads to a loss of sense of time and reality, resulting in completely disrupted circadian rhythms. The percentage of drinkers in Spain among young people aged 15 to 19 is 57%, whilst globally it’s 25%. It’s striking that the prevalence of drunkenness is higher among girls than among boys. These figures come from Spain’s National Drugs Plan. We’re facing a very serious public health problem. Young people are at very little risk of heart attack or diabetes, but they’re at risk of depression, suicide and road traffic accidents” – Miguel Ángel Martínez-González

Is alcohol consumption among young people a public health concern?

“I believe it is. And I believe the authorities are beginning to realise this; regulations and campaigns are starting to appear in an attempt to reduce alcohol consumption. Street drinking parties were very common in cities years ago but today you hardly see them” – Raúl Andrade Bellido

Can sport offset the effects of alcohol consumption?

“Alcohol has a dehydrating effect. What an athlete needs to do is stay well hydrated and try to replenish the fluids they lose, but not with alcoholic drinks” – Miguel Ángel Martínez-González

“I’m not aware that sport counteracts the negative effects of alcohol in any way. I think it’s very harmful to connect sporting success with alcohol, as is the case in advertising campaigns. The Spanish football squad, which starts the World Cup in a few days, is sponsored by a beer brand” – Raúl Andrade Bellido

What message should young people take away from this?

“In Spain, it’s very cheap to drink alcohol and become an alcoholic. If you go to a supermarket, you can buy a bottle of wine for a euro and a half or less, the same price as a bottle of water, and that’s because alcohol isn’t taxed differently. I believe that, if we want to reduce alcohol consumption, we have to take steps to make alcohol more expensive” – Raúl Andrade Bellido

“The message for young people must be that they should never start drinking alcohol. If they’ve never drunk before, they shouldn’t try to imitate their friends. Drinking won’t make it easier for them to socialise, nor will it make them more popular” – Raúl Andrade Bellido

“Alcohol isn’t the great social lubricant many people believe it to be. In fact, it’s a great saboteur. A large number of parties end badly precisely because of alcohol consumption. It’s a myth that there can be no party without alcohol” – Miguel Ángel Martínez-González

 

A call to get involved in the science

“And for those who are older, I encourage them to help us with the UNATI study and sign up by 30 June. Everyone’s welcome to join and help us to shed scientific light on moderate wine consumption within the context of the Mediterranean diet” – Miguel Ángel Martínez-González