Alcohol and Health

See also: Stress, Nutrition and Diet

We know that alcohol can help us to relax, whether at a party or at home after a long day at work. We also know that it can be addictive, and that too much is bad for our livers, heart, and general health. Most of us are aware of the general guidelines about how much is ‘too much’. However, we have also heard that red wine is supposed to be good for you ‘in moderation’. Does this also apply to other forms of alcohol?

What is the truth about alcohol and our health? Is it a good idea to drink in moderation, or would it be wiser to give up altogether? This page unpicks the science to help you make up your mind.

The Effects of Alcohol

Alcohol is far from being the ‘safe’ substance that you would expect from its wide use.

Alcohol is a toxic, psychoactive, and dependence-producing substance and has been classified as a Group 1 carcinogen by the International Agency for Research on Cancer.

The World Health Organization Europe, news release, 4 January 2023

When you drink alcohol, it passes from your stomach and small intestine directly into the bloodstream. From there, it moves around your body, and particularly to your brain, kidneys, and liver.

Your liver is responsible for breaking down (oxidising) the alcohol. It takes around an hour to break down one unit. For each unit that you consume, therefore, you need an hour to metabolise it.

Alcohol causes:

  • Your blood vessels to dilate, so that you tend to become flushed, and feel warm. This is often followed by a rapid decrease in body temperature as you lose heat through your skin, and a drop in blood pressure;

  • A reduction in control over your body movements. You may start to slur your words, or have blurred vision and less coordination. Your reaction times will be slower, which is why you should never drive when you have been drinking.

  • Changes in mood. Your mood may also be affected: some people become happy, but others become aggressive.

  • Your body to produce more urine. You may therefore become thirsty or even dehydrated.

  • Disrupted sleep, which may become insomnia in the longer term.

When you drink too much alcohol for your body to manage, you may experience nausea, vomiting and a hangover. A hangover is effectively a combination of alcohol poisoning and dehydration. It usually manifests as a headache, tiredness and sickness.

Regular drinking also has other effects on health, including:

  • Increased risk of cancer. Alcohol is the second biggest risk for cancer, after smoking. It is associated with at least seven different cancers, including mouth, oesophageal, liver, breast, bowel, colon, laryngeal, and throat cancers.

  • High blood pressure, and therefore increased risk of heart disease or stroke. Binge drinking is also associated with heart arrhythmias, which are in turn linked to sudden death.

  • Brain damage, including effects on memory, behaviour and ability to learn.

  • Liver damage. Fat deposits build up in the liver when you drink regularly. These may eventually cause alcoholic hepatitis, which can result in liver failure. Drinking can also scar the liver, resulting in cirrhosis, which increases the risk of liver cancer.

  • Changes in hormone levels, especially for women. Alcohol seems to affect oestrogen levels, which in part leads to the increased risk of developing breast cancer.

  • The potential to develop alcoholism, which is where you develop a dependence on or addiction to alcohol.

  • Heavy regular drinkers are more prone to lung problems such as pneumonia.

  • Problems with your digestive system. Alcohol is associated with stomach ulcers and inflammation of both the stomach and the intestine. It can also cause inflammation of the pancreas.

  • A decreased ability to absorb calcium, and therefore an effect on your bone strength (there is more about calcium in our page on Dietary Minerals).

  • Alcohol is linked to mental health problems such as depression, anxiety and more serious conditions such as schizophrenia.

Is There a Safe Level of Alcohol Consumption?

Governments have long advised people to limit their alcohol consumption, and set out guidelines for the maximum that should be consumed in a week.

For example, in the UK, the government advises both men and women not to drink more than 14 units of alcohol per week (see box to understand the meaning of a unit). The advice is also to spread your drinking over at least three days in each week.

What is a ‘unit’ of alcohol?

Units are a measure of the alcohol content of a drink. You can calculate units from the ‘alcohol by volume’ (ABV) on the label using a simple formula:

Units = [strength (alcohol by volume) × volume (ml)]/1000

For example, if you are drinking a pint (568 ml) of beer containing 5% alcohol by volume:

Units = (5 × 568)/1000 = 2.84 units.

As a rough estimate:

  • A 750ml bottle of wine that is around 12.5% to 13% ABV will contain 10 units.
  • A small glass of wine will contain 1.5 units, a standard glass 2 units and a large glass 3 units.
  • An 275ml bottle of alcopop at 5.5% ABV will be 1.5 units.
  • A single shot of spirits is about 1 unit.

The 2020–2025 Dietary Guidelines for Americans suggest that men should drink no more than two drinks (units) per day, and women no more than one. They also note that drinking less is better for your health than drinking more.

These guidelines also define:

  • ‘Binge’ drinking as drinking four or more drinks during a single session for women, and five or more in a session for men; and

  • ‘Heavy’ drinking as drinking eight or more drinks per week for women, and 15 or more for men.

It is therefore clear that excessive drinking is bad for your health.

However, in January 2023, the World Health Organization Europe published a statement in The Lancet Public Health that was unequivocal. It stated:

When it comes to alcohol consumption, no amount is ‘safe’.

The statement noted that half of all cancers in the European Union that were attributable to drinking alcohol were associated with drinking at a ‘light’ to ‘moderate’ level: no more than the maximum amount recommended by the UK government. This level of drinking was also associated with the majority of breast cancer in women attributable to alcohol.

The issue is that to be considered ‘safe’, it would have to be possible to identify a point below which there is no risk to health from drinking alcohol. No such point can be identified, therefore consuming any alcohol must be considered potentially harmful.

Are There Any Benefits From Drinking Alcohol?

Some studies have found health benefits from drinking red wine (but no other forms of alcohol).

Red wine seems to be beneficial for your gut microbes (and for more about these, see our page on the Gut Microbiome). This is because it contains polyphenols, which are anti-inflammatory molecules that are good for the microbes. There is also some evidence that red wine has an anti-inflammatory effect on the blood vessels, especially when consumed with a meal.

Some beers and ciders may have a similar effect, but this does NOT apply to any distilled spirits (gin, whisky, vodka etc).

However, the real question is how does this balance with the increased risk of cancer in particular?

The World Health Organization is absolutely clear about this: it is safer not to drink alcohol. The organisation cautions that excessive drinking of alcohol is far higher in disadvantaged communities, who are also less likely to understand the risks. Its statement therefore suggests that the message should be that no level of drinking is safe, and that everyone should avoid drinking. It also states that the benefits seen in studies of red wine may have been a result of the selection of the comparison groups and statistical methods.

The take-home lesson is probably that there may be a level of red wine drinking where the benefits outweigh the risks, but if so, it is a very low level. It will also depend on the individual.

One glass with a meal might be beneficial to some individuals, but certainly not to everyone.

In Conclusion

Looking at the health risks of alcohol, we may be forced to the conclusion that if alcohol were not already legal and its use so widespread, it would never be approved for consumption! The message from health authorities is clear: no level of alcohol consumption can be considered safe, even if some studies have shown some minor benefits of consuming red wine.