Substance guides

Alcohol and cancer risk: What the science says

Published July 20, 2025 · 7 min read · Updated April 2026

Reviewed for accuracy by licensed clinical professionals.

Alcohol is a Group 1 carcinogen (confirmed to cause cancer in humans) classified by the International Agency for Research on Cancer. This is the same category as tobacco and asbestos.

Linked cancers

Breast cancer (even moderate drinking increases risk). Liver cancer. Colorectal cancer. Esophageal cancer. Head and neck cancers (mouth, throat, larynx). Stomach cancer.

How much increases risk

There is no safe level of alcohol consumption for cancer risk. Risk increases with any amount and rises with quantity. However, the absolute risk increase from moderate drinking is small. Heavy drinking substantially increases risk.

The mechanism

Alcohol is metabolized to acetaldehyde, a toxic compound that damages DNA. It also increases estrogen levels (breast cancer link), impairs nutrient absorption, and causes inflammation.

The nuance

While any alcohol increases cancer risk, the absolute risk from moderate drinking is small for most cancers. The decision to drink should weigh this against other health effects and personal risk factors.

Authoritative sources

This article references guidelines from: NIDA · SAMHSA · CDC

Frequently asked questions

Does alcohol cause cancer?

Yes. Alcohol is a confirmed carcinogen linked to at least 7 cancer types. Risk increases with any amount.

How much alcohol increases cancer risk?

Any amount increases risk, but the absolute increase from moderate drinking is small. Heavy drinking substantially increases risk.

Does quitting reduce cancer risk?

Yes. Cancer risk begins decreasing after quitting, though it may take years to return to baseline depending on the cancer type and duration of drinking.

Disclaimer: Informational only. Not medical advice. SAMHSA: 1-800-662-4357.