Heart attack risk high with one cigarette a day: study

Smoking just one cigarette a day still poses a high risk of heart attack (Shutterstock)
Updated 25 January 2018
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Heart attack risk high with one cigarette a day: study

Paris: Just one cigarette a day carries nearly half the risk for heart attack and stroke as smoking a full pack of 20, according to a large-scale study published Thursday.
“If someone smokes one cigarette instead of 20 per day, intuitively we’d think that the risk drops to 1/20, or five percent,” said lead author Allan Hackshaw, a professor at University College London, whose paper analyzed 141 previous studies.
“This seems to be the case for lung cancer, but is not true for heart attacks and stroke, where one cigarette per day carries around 50 percent of the risk of a pack a day,” he told AFP.
Smokers should not be fooled, in other words, into thinking that a few cigarettes a day — or even just one — carries little or no long term harm, he added.
“Whilst 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 by email.
The findings were published in the medical journal BMJ.
Tobacco kills about seven million people worldwide every year, according to the World Health Organization.
About two million of those deaths are due to cardiovascular disease, mainly coronary heart attacks and stroke.
Earlier research suggested that smoking a few cigarettes a day was linked to a higher-than-expected risk of heart disease, but findings were inconclusive.


To probe deeper, a team of scientists led by Hackshaw analyzed the results of 141 studies, estimating the relative risk of one, five or 20 cigarettes a day.
They found that men who lit up once a day had 46 percent of the excess risk of heart disease associated with smoking a full pack a day, much higher than expected. For strokes, the excess risk was 41 percent.
For reasons that are not fully understood, the risk for women was somewhat smaller — 31 and 34 percent, respectively.
“It could be a mixture of biological difference and differences in lifestyle,” said Hackshaw.
Overall, long-term smoking shortens life expectancy by 12-15 years.
“This well conducted study confirms what epidemiologists have suspected but few among the public have,” commented University of Oxford professor Paul Aveyard, who was not involved in the research.
“The implication is obvious — anyone who smokes should stop.”
At the same time, he added, it would be wrong to conclude that cutting down is useless.
“There is more reason to believe that lower cigarette consumption will reduce the risk of chronic lung disease and lung cancer, the other two big causes of early death from smoking,” he said via Britain’s Science Media Center.


Low-carb diet linked to elevated mortality risk: study

Updated 17 August 2018
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Low-carb diet linked to elevated mortality risk: study

  • Rapid shift 10,000 years ago to grains, dairy and legumes has not allowed the human body enough time to adapt to these high-carb foods, say researchers
  • Replacing meat with plant-based fats (such as avocados and nuts) and proteins (such as soy products and lentils) reduces the risk of mortality

PARIS: Middle-aged people who get roughly half their daily calories from carbohydrates live several years longer on average than those with low-carb diets, researchers reported Friday.
The findings, published in The Lancet, challenge a trend in Europe and North America toward so-called Paleo diets that shun carbohydrates in favor of animal protein and fat.
Proponents of these “Stone Age” diets argue that the rapid shift 10,000 years ago — with the advent of agriculture — to grains, dairy and legumes has not allowed the human body enough time to adapt to these high-carb foods.
For the study, under 40 percent of energy intake from carbohydrates qualifies as a low-carb regimen, though many such diets reduce the share to 20 percent or less.
At the other extreme, a 70 percent or higher share of carbohydrates — such as pasta, rice, cakes, sugary drinks — can also reduce longevity, but by far less, the scientists found.
“Low-carb diets that replace carbohydrates with protein or fat are gaining widespread popularity as a health and weight loss strategy,” said lead author Sara Seidelmann, a researcher at Brigham and Women’s Hospital in Boston.
“However, our data suggests that animal-based low carbohydrate diets might be associated with shorter overall lifespan and should be discouraged.”
Replacing meat with plant-based fats (such as avocados and nuts) and proteins (such as soy products and lentils) reduces the risk of mortality, Seidelmann and her team found.
The optimal balance of food groups for longevity remains hotly debated.
Many studies have concluded that eating carbohydrates in moderation — 45 to 55 percent calories — is best, but others report improved short-term, cardio-metabolic health with high-protein, high-fat diets.
Measures of metabolic health include blood pressure, good and bad cholesterol, and blood sugar levels.
Seidelmann and colleagues poured over the medical histories of nearly 15,500 men and women who were 45-64 when they enrolled — between 1987 and 1889 — in a health survey spread across four locations in the United States.
Participants filled out detailed questionnaires about their dietary habits — what foods, how much, how often, etc.
Over a 25-year follow up period, more than 6,000 of the men and women died.
People who got 50-55 percent of their calories from carbohydrates outlived those with very low-carb diets, on average, by four years, and those with high-carb diets by one year.
A review of medical records for an additional 432,000 people from earlier studies yield confirmed the results, which are also in line with World Health Organization (WHO) recommendations.
“There is nothing to be gained from long-term adherence to low-carbohydrate diets rich in fats and proteins from animal origins,” said Ian Johnson, a nutrition researcher at Quadram Institute Bioscience in Norwich, England, commenting on the research, in which he did not take part.
But carb quality, not just quantity, is crucial he added.
“Most should come from plant foods rich in dietary fiber and intact grains, rather than from sugary beverages or manufactured foods high in added sugar.”
Fibers also help maintain a healthy gut flora, now considered to be a major player in health and disease.