Half of all smokers die from tobacco-related conditions - 100,000 a year in the UK, where 21 per cent of women and 22 per cent of men smoke

Female smokers are significantly more likely to suffer heart disease than men. The risk of developing coronary heart disease – Britain's biggest killer – is 25 per cent higher for women, despite the fact they generally smoke fewer cigarettes than men, according to research published in The Lancet.

Smoking was traditionally a male activity but a fifth of the world's smokers – 220 million people – are now women. The tobacco industry spends millions of pounds every year targeting women by purporting links between cigarettes and slimness through the design of cigarettes and packaging. This comprehensive research, a meta-analysis of four million people from 86 studies, will add pressure on the Government to introduce plain packaging which contains only health warnings.

Previous research has shownthat female smokers are twice aslikely to develop lung cancer as men.

Amanda Sanford, from Action on Smoking and Health, said: "This study confirms that women are more susceptible to the health risks posed by smoking, even though research has traditionally focused on men. We have to stop the tobacco industry from blatantly targeting women with misleading myths about the links between smoking and being slim."

The British Heart Foundation said the findings were "alarming" as it seemed to show that women are biologically more susceptible to the dangers of smoking and passive smoking at a time when tobacco companies are increasingly targeting women with slim brands and slick packaging.

Half of all smokers will die from tobacco-related conditions such as heart disease and lung cancer. In the UK, where 21 per cent of women and 22 per cent of men smoke, around 100,000 people die every year from tobacco-related diseases.

The risk of death from coronary heart disease to smokers decreases rapidly once they stop, but research shows that women find it much harder to quit than men. Smoking rates are also increasing more rapidly among women in developing countries where advertising and sales regulations are more lax.

Women metabolise nicotine more quickly than men and cigarette smoke appears to be more toxic for women, but the biological differences between the sexes needs further examination, according to The Lancet.

The researchers, from the University of Minnesota and Johns Hopkins University, warn that the risk to women could actually be much higher as they tend to smoke fewer cigarettes per day. In many countries the smoking habit started later in women so the full impact is not yet known.

Dr Rachel Huxley and Dr Mark Woodward conclude: "Present trends in female smoking... suggest that inclusion of a female perspective in tobacco-control policies is crucial."