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What is alcohol?

Jed Campbell-Williams
Health Adviser Team Manager at Bupa UK
31 March 2022
Next review due March 2025

You might enjoy the occasional glass of wine in the evening, or a bottle of beer at the weekend, but what exactly is alcohol? Have you ever wondered why it makes you feel the way it does? Here I’ll explain what alcohol is, and the effect that different types of alcohol can have on your health

What is alcohol made of?

Alcohol is made when yeast breaks down (ferments) the sugars in fruits, vegetables, or grains. Fermentation creates both ethanol and carbon dioxide. Ethanol is the type of alcohol found in alcoholic drinks. Different types of alcohol are made from different ingredients. Beer is made from fermenting grains such as hops or rye. Wine is made by fermenting grapes.

What effect does alcohol have on your body and mind?

Whether your alcohol is fruit or grain based, it will affect you in the same way. Alcohol changes the way your brain works, and the way your brain sends messages to your body. Alcohol is also a depressant, which means it slows down your brain activity. After a drink or two, you might feel relaxed or sleepy. Maybe you will feel warmer, or a bit uncoordinated. These feelings result from changes within your central nervous system. The more you drink, the more you will notice these effects.

Feeling sleepy or warm are the short-term effects of drinking alcohol. But we know that there are also longer-term effects of drinking too much which can damage your health. These include:

  • poor sleep – despite alcohol making you feel sleepy at first, it has been shown to disrupt your sleep quality during the night
  • an increased risk of breast, throat and mouth cancer
  • a higher chance of developing heart disease
  • weight gain, from the extra calories found in alcoholic drinks
  • finding it more difficult to recover from exercise, such as having sore muscles for longer

Why are alcoholic drinks different strengths?

Different alcoholic drinks have different strengths of alcohol. The strength of the alcohol depends on how long the fruit or grain was left to ferment for. Longer fermentation times create a higher alcohol content. And spirits are the strongest type of alcohol. This is because they go through an extra process called filtration, where some water is removed. This makes the alcohol more concentrated.

The average alcohol content of different drinks is as follows.

  • Vodka: 40%
  • Beer: 5%
  • Wine: 12%

Our handy infographic below helps you to understand how many units of alcohol are in your drink. Bupa's units of alcohol in a drink PDF opens in a new window (1.3 MB)

Bupa's units of alcohol in a drink

What is the healthiest type of alcohol?

Alcohol is not nutritious. You can get all the nutrients you need without drinking alcohol. But if you do choose to drink occasionally then certain forms of alcohol might be more suitable for you than others. Both the alcohol content and the nutrient content effects this.

The stronger the alcohol content, the less time it will take before you feel the effects. And smaller amounts will lead you to exceed your weekly recommended units. But also, you might usually mix spirits and other stronger alcohols with sugary drinks. This can lead you to consume more calories, which can add up if you drink regularly.

Is red wine healthy?

You might have heard about the health benefits of red wine. It’s often portrayed as being good for heart health. And red wine does contain a compound associated with good health. Its name is resveratrol, and it belongs to a group of antioxidants known as flavonoids. These antioxidants can help to protect the cells in your body from damage, which can happen more as you age. But you would have to drink a lot of red wine to get the benefits of the antioxidants. And then the negative effects of drinking too much would outweigh any benefits. Instead, you can get plenty of antioxidants from foods such green tea, dark chocolate and berries.

Also, many of the studies looking at the benefits of red wine are based on people following the Mediterranean diet. This means there are lots of other reasons why these people may be healthier. For example, they’re more likely to eat oily fish and vegetables, get more Vitamin D from the sun, and be more active.

What is the sugar content of different alcohols?

When it comes to the impact of alcohol on your blood sugar, different drinks have different effects. Wine does have less sugars than cider so it may be a better choice if you're trying to control your blood glucose levels. On average, liqueurs and drinks such as sherry have higher sugar contents so they’re worth avoiding if you want to keep your blood sugar stable.

Whichever drink you choose to have, you should stick within the recommended limits of 14 units per week. And be aware of the calorie and sugar content of any mixers you use. If you are worried about your drinking habits, then you should see a doctor for support.


Do you know how healthy you truly are? Bupa health assessments give you a clear overview of your health and a view of any future health risks. You'll receive a personal lifestyle action plan with health goals to reach for a happier, healthier you.

Jed Campbell-Williams
Jed Campbell-Williams
Health Adviser Team Manager at Bupa UK

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