One cigarette a day is half as harmful as smoking a pack

Just one cigarette a day carries nearly half the risk of heart attack and stroke as smoking a full pack of 20, according to a study published on Thursday.

Just one cigarette a day carries nearly half the risk of heart attack and stroke as smoking a full pack of 20, according to a study published on Thursday.

"If someone smokes one cigarette instead of 20 a day, intuitively we'd think that the risk drops to 1/20, or 5 per cent," said lead author Allan Hackshaw, a professor at University College London, whose paper analysed 141 previous studies.

"This seems to be the case for lung cancer, but it is not true for heart attack and stroke, where one cigarette a day carries around 50 per cent of the risk of a pack a day," he said.

Smokers should not be fooled into thinking that a few cigarettes a day - or just one - carries little or no long-term harm, he added.

"While it is great that smokers try to cut down - and they should be positively encouraged to do so - in order to get the big benefits on cardiovascular disease, they need to quit completely," he said.

Tobacco kills about seven million people worldwide every year, according to the World Health Organisation.

About two million of those deaths are due to cardiovascular disease, mainly coronary heart attack and stroke. - AFP

Higher chance of heart attack after influenza episode

People who get the flu may face a six-fold higher risk of heart attack in the week following the infection, said a study on Wednesday, bolstering the need for widespread vaccination against the flu.

The risk of heart attack - or myocardial infarction - is particularly acute in older adults, said the report in the New England of Medicine.

"Our findings are important because an association between influenza and acute myocardial infarction reinforces the importance of vaccination," said lead author Jeff Kwong, a scientist at the Institute for Clinical Evaluative Sciences and Public Health, Ontario. The study was based on nearly 20,000 adult cases of influenza infection in Ontario, Canada, from 2009 to 2014.

Of those, 332 patients were hospitalised for a heart attack within one year of their flu infection.

The risk was highest in the first week for older people, those with influenza B infection, and patients who never had a heart attack before. - AFP

Cancer risk for inflammation-linked diet?

People who consume lots of foods linked to chronic inflammation, such as red meat, sugar, trans fats and refined grains, may be more likely to develop colorectal cancer than individuals who tend to avoid these foods, a US study suggests.

Researchers examined more than two decades of US survey data on eating habits and cancer diagnoses for 74,246 female nurses and 46,804 male health professionals.

They sorted participants into five groups based on how likely it was that their daily diets could contribute to inflammation.

Compared to people with diets that had the least potential to cause inflammation, individuals with diets that were most likely to cause inflammation were 32 per cent more likely to develop colorectal cancer during the study, researchers report in Jama Oncology.

"A dietary pattern that is associated with higher levels of inflammation will chronically stimulate the bowels, leading to the production of a constantly higher level of circulating inflammation mediators that may contribute to the development of cancer," said lead study author Fred Tabung, a researcher at the Harvard T.H. Chan School of Public Health and Brigham and Women's Hospital in Boston. - REUTERS