Is Alcohol the Most Harmful Drug? What the Evidence Shows

Is Alcohol the Most Dangerous Legal Drug? Five Claims Examined

By one of the most influential measures ever published, yes: alcohol is the most harmful drug overall. In 2010 a team led by the British psychopharmacologist David Nutt scored twenty legal and illegal drugs for the damage they do, and alcohol came top with 72 points out of 100, ahead of heroin (55) and crack cocaine (54). It ranked first mainly because of the harm it causes to people other than the drinker, from road crashes to violence and broken families.

That does not mean a single drink is more dangerous than a dose of heroin. For the individual user, heroin, crack and methamphetamine were rated worse. Alcohol tops the table because it is legal, cheap and used by billions of people, so its harms add up on a vast scale. Below we look at what the research actually found, which popular claims about alcohol stand up, and which do not.

What the 2010 Lancet study measured

The study, published in The Lancet in November 2010, came from the Independent Scientific Committee on Drugs, a group of UK experts. Using a technique called multicriteria decision analysis, they rated twenty substances on sixteen criteria. Nine described harm to the user, such as death, dependence, physical and mental damage and loss of relationships. Seven described harm to others, such as crime, injury, family conflict, economic cost and damage to communities.

The chart above shows the result. Each bar combines the two kinds of harm, with harm to others in red and harm to users in orange. Alcohol's long red section is what pushes it to the top. At the other end of the scale, LSD, buprenorphine and magic mushrooms scored lowest, and they also carried the lowest risk of dependence.

The authors were open about the limits. The scores reflect expert judgement, the weight given to each criterion changes the totals, and the ranking describes the situation in the UK, not in every country. Still, the main finding has held up in later reviews and was repeated in a similar European analysis.

The scale of alcohol harm worldwide

The World Health Organization estimates that alcohol caused about 2.6 million deaths in 2019, around 6.7 percent of all deaths among men and 2.4 percent among women. Roughly 400 million people, about 7 percent of the world's adults, live with an alcohol use disorder, and about 209 million are dependent on alcohol.

A large share of the damage lands on bystanders. Of an estimated 298,000 deaths in alcohol-related road crashes, the WHO attributes 156,000 to someone else's drinking. Alcohol is also tied to falls, drowning, burns, suicide, sexual assault and intimate-partner violence. This is the "harm to others" that dominates the Lancet chart.

Five common claims, checked

"Alcohol costs health systems more than cannabis"

This is broadly true. A Canadian estimate often quoted online put health costs at about 165 dollars per alcohol user per year, compared with about 20 dollars per cannabis user; we could not confirm the original figures, but the direction matches larger studies, which consistently find alcohol among the most expensive substances for health care because of liver disease, injuries, cancers and heart problems.

"A fatal dose is close to a normal dose"

Partly true. In a 2006 article in American Scientist, the researcher Robert Gable compared the usual effective dose of different drugs with a potentially lethal one. For alcohol the gap was about tenfold, which is narrow compared with many other substances. Alcohol poisoning kills people every year, often after binge drinking, and the risk rises sharply when alcohol is mixed with opioids or sedatives.

"Alcohol causes many types of cancer"

True, with some corrections. The International Agency for Research on Cancer classes alcoholic drinks as a Group 1 carcinogen, the highest category of evidence. The cancers firmly linked to drinking are those of the mouth, throat, larynx, oesophagus, liver, colon and rectum, and the female breast. Lists shared online often add lung and prostate cancer, but the evidence there is not established, and for the pancreas it is mixed. The main culprit is acetaldehyde, a substance the body produces when it breaks down alcohol and which damages DNA.

"It is highly addictive and withdrawal can kill"

True. Long-term heavy drinking changes the brain's reward system, and stopping suddenly can trigger seizures or delirium tremens, a medical emergency. Anyone who drinks heavily every day and wants to stop should talk to a doctor first rather than quitting alone. A 2011 study in Alcoholism: Clinical & Experimental Research estimated that a large share of hospital-treated assaults and injuries were linked to the injured person's own drinking.

"It fuels violence"

Alcohol does not cause violence on its own, but it makes it more likely in people already prone to it. A 2003 study of men in treatment for partner violence found the odds of physical aggression were about eight times higher on days the men had been drinking, and about eleven times higher for severe violence. The US anti-sexual-violence group RAINN describes alcohol as the "most commonly used chemical in crimes of sexual assault."

So why is alcohol legal?

A popular argument online says alcohol stays legal because hospitals, cancer clinics and prisons profit from it. That is opinion, not evidence, and none of the studies usually cited for it show any such motive. The real reasons are mostly historical and practical.

Alcohol has been part of meals, religion and celebration in many cultures for thousands of years, long before modern drug laws existed. When the United States tried national prohibition between 1920 and 1933, drinking fell but organised crime, unsafe bootleg liquor and lost tax revenue made the policy deeply unpopular, and it was repealed. Most governments now choose to regulate alcohol through taxes, age limits, licensing and drink-driving laws rather than ban it. Many public-health experts argue those controls are still too weak, given the scale of harm described above.

Cannabis, mixing drugs and other myths

A popular claim is that cannabis is not addictive. That is wrong. The US Centers for Disease Control and Prevention estimates that about three in ten people who use cannabis have cannabis use disorder, and the risk is higher for those who start young, use often or choose high-THC products. Cannabis scored well below alcohol in the Lancet ranking, but lower harm is not zero harm.

Two other points from drug research are worth remembering. First, risks grow with repeated and heavy use: dependence develops over time, and the potential varies between substances and between people, influenced by genes, mental health, friends and circumstances. Second, combining substances raises the danger beyond the sum of the parts. Alcohol with sedatives or opioids can stop breathing; stimulants such as cocaine combined with alcohol strain the heart.

What this means for everyday drinking

Less is better. The WHO said in 2023 that no level of drinking is safe for health, so any reduction lowers risk.
Never drink and drive, and do not let friends do so. Road crashes are among alcohol's biggest harms to others.
Avoid mixing alcohol with sleeping pills, painkillers, opioids or other drugs.
Watch for warning signs such as needing more to feel the effect, drinking in the morning or failing to cut down. If you recognise them, talk to a doctor or a local support service.

Alcohol's legal status makes it feel ordinary, and for many people moderate drinking is part of social life. The evidence simply asks us to see it clearly: a powerful drug whose risks are real, well documented and shared by everyone around the drinker.

Sources: Based on an earlier article by Marco Torres for Prevent Disease. Imperial College London (2010): Alcohol most harmful drug based on multicriteria analysis; Nutt, King and Phillips, The Lancet (2010); WHO: Alcohol fact sheet; WHO (2023): No level of alcohol consumption is safe; Wikipedia: Alcohol and cancer; CDC: Cannabis use disorder; RAINN: Drug-facilitated sexual assault; chart data: The Lancet.

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