Your Questions on Alcohol Consumption Answered

Humans have been consuming alcohol for thousands of years, and our ability to metabolise it evolved millions of years ago, long before modern society. Alcohol acts directly on the brain’s reward systems, producing pleasurable and relaxing effects by altering key neurotransmitters, which helps explain why both humans and other animals are drawn to it.

You can read more about the science and history behind this in the Preface to Why We Drink Too Much.

There is no single threshold at which alcohol suddenly becomes harmful, but risk increases as consumption increases. In the UK, current guidelines suggest keeping intake below 14 units per week, spread over several days, as a way of limiting long-term health risks rather than guaranteeing safety.

If you’re interested in how these guidelines were developed, the Science Updates section explores the evidence behind alcohol and health in more detail.

Although alcohol can make people feel sleepy, it disrupts the quality of sleep by reducing restorative deep and REM sleep later in the night. This often leads to poorer concentration, lower energy, and increased fatigue the following day, even when drinking feels moderate.

Alcohol can temporarily reduce anxiety or lift mood, but these effects are short-lived and often followed by increased anxiety, low mood, or irritability. Over time, alcohol can interfere with the brain systems involved in emotional regulation, making stress and low mood harder to manage.

This relationship between alcohol, mood, and behaviour is a recurring theme throughout Why We Drink Too Much.

Alcohol has addictive properties because it acts on the brain’s reward and learning systems. While not everyone who drinks develops dependence, repeated exposure can increase tolerance and make alcohol more central to how stress, reward, or social situations are managed.

Health exists on a spectrum, and many people who drink alcohol also engage in healthy behaviours. However, alcohol offers no health benefit of its own, and its effects need to be considered alongside sleep, diet, exercise, and mental wellbeing.

The book explores how cultural norms often blur these trade-offs, particularly in social and professional settings.

Small changes can make a meaningful difference, such as having alcohol-free days, alternating drinks, or becoming more aware of situations where drinking feels automatic rather than chosen. Many people find that curiosity and experimentation are more effective than rigid rules.

You may find it helpful to explore reader reflections and research links in Other Resources.