The UK government’s chief medical officer, Dame Sally Davies, has urged women to contemplate the risk of developing breast cancer every time they consider having glass of wine.

“Do as I do when I reach for my glass of wine,” Davies told the House of Commons science and technology committee yesterday.

“Think: ‘Do I want the glass of wine or do I want to raise my own risk of breast cancer?’

“I take a decision each time I have a glass,” she said.

Davies introduced controversial new government guidelines on alcohol consumption earlier this year.

Under the new guidelines, which had remained unchanged for twenty years, the recommended weekly limit for men was cut by a third, down from 21 units to 14 units, in line with the existing advice for women.

Drinkers were also advised to have several alcohol-free days each week and to otherwise spread their consumption evenly.

Pregnant woment were advised to eliminate alcohol entirely.

Defending her stance, Davies told MPs her guidelines was “advice not an instruction”.

She added: “I would be done if I didn’t tell people the science. I have to tell the truth and make sure that it’s out there.

“It should be 14 units [per week] spread over a few days for both men and women.”

The guidelines were widely criticised on publication for being out of step with advice given to the public elsewhere in Europe, as well as for misunderstanding the nature of risk.

Speaking to the Guardian, Sir David Spiegelhalter, Winton Professor of the public understanding of risk at University of Cambridge, said: “These guidelines define ‘low-risk’ drinking as giving you less than a 1% chance of dying from an alcohol-related condition.

“An hour of TV watching a day, or a bacon sandwich a couple of times a week, is more dangerous to your long-term health.”