By Sue Nelson
Writer and Broadcaster
The way to boost your health?
Alcohol is bad for you. Red wine is good for the heart. It's all about moderation
Confused? You're not alone.
Government guidelines state that men and women should not consume more than 21 or 14 alcoholic drinks each week.
Yet the Million Women study reported that just one drink a week increases your risk of breast, pharynx and liver cancer.
No wonder a recent UK survey for the World Cancer Research Fund found that people are deeply sceptical about claims for what causes or prevents cancer.
In exploring the alcohol-cancer connection, Radio 4's Frontiers reveals a frightening lack of knowledge about how alcohol interacts with the body.
Scientists do not know definitively why we get hangovers or how alcohol may be causing cancer.
Alcohol is metabolised in the body into toxic compounds - but how these compounds cause damage is unknown.
Since genetics, gender and age play an important role in how we interact with alcohol, a safe amount for one is not safe for another.
The negative effects of alcohol on health and the economy are reported regularly in the media and highlighted by the government.
But despite the link between alcohol and cancer being known for over 100 years, it is an area of research that is little understood and, according to many scientists, underfunded.
This means that drinkers, no matter how moderate their consumption, are not fully aware of the risks or damage, as the science is not there.
In fact, many drinkers believe they are improving their health.
"It's an absolute myth that red wine is good for you," says Professor Valerie Beral from the University of Oxford and lead author of the Million Women study.
"The evidence is not there."
Professor Roger Corder, author of The Red Wine Diet, would disagree.
"Our research identified a group of chemicals called procyanadins which are polyphenols, and the key component in terms of protecting from heart disease."
Polyphenols, such as the antioxidant resveratrol, are found in the skins of red wine grapes.
"In high doses it does seem to enhance the lifespan of mice. But," he adds crucially, "you need huge doses."
In humans, it equates to thousands of litres of wine.
Professor Corder dismisses wines that effectively promote themselves as a health drink, with 'rich in polyphenols' or 'rich in antioxidants' on the label.
But, he says, two small glasses of a very tannic, procyanadin rich wine would confer a benefit.
"The problem is that most supermarket wines are low procyanadin and high alcohol," he said.
"We're promoting bad wine for bad habits."
Frontiers is broadcast on BBC Radio 4 on Monday 8 June at 2100 BST.