Low-carb diet linked to elevated mortality risk: study

Foods high in carbohydrates. (Shutterstock photo)
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.


Vaccine could virtually eliminate cervical cancer: study

Transmitted sexually, HPV is extremely common and includes more than 100 types of virus, at least 14 of them cancer-causing. (Shutterstock)
Updated 20 February 2019
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Vaccine could virtually eliminate cervical cancer: study

  • Transmitted sexually, HPV is extremely common and includes more than 100 types of virus, at least 14 of them cancer-causing

PARIS: The rapid scale-up of the human papillomavirus (HPV) vaccine could virtually eliminate cervical cancer in a handful of rich countries within three decades, and in most other nations by century’s end, researchers said Wednesday.
Without screening and HPV vaccination, more than 44 million women will likely be diagnosed with the disease over the next 50 years, they reported in The Lancet Oncology, a medical journal.
Two thirds of these cases — and an estimated 15 million deaths — would occur in low- and medium-income countries.
By contrast, the rapid deployment starting in 2020 of screening and vaccination could prevent more than 13 million cervical cancers by mid-century worldwide, and lower the number of cases to below four-per-100,000 women, the study found.
“This is a potential threshold for considering cervical cancer to be eliminated as a major public health problem,” the authors said in a statement.
Earlier this month, the World Health Organization (WHO) reported 570,000 new cases worldwide in 2018, making it the fourth most common cancer for women after breast, colon and lung cancer.
The disease claims the lives of more than 300,000 women every year, mostly in lower income nations.
“Despite the enormity of the problem, our findings suggest that global elimination is within reach,” said lead author Karen Canfell, a professor at the Cancer Council New South Wales, in Sydney.
Achieving that goal, however, depends on “both high coverage of HPV vaccination and cervical screening,” she added.
Transmitted sexually, HPV is extremely common and includes more than 100 types of virus, at least 14 of them cancer-causing.
The viruses have also been linked to cancers of the anus, vulva, vagina and penis.
It takes 15 to 20 years for cervical cancer to develop in women with normal immune systems. If the immune system is weak or compromised — by HIV infection, for example — the cancer can develop far more quickly.
Clinical trials have shown that HPV vaccines are safe and effective against the two HPV strains — types 16 and 18 — responsible for 70 percent of cervical cancer cases.
The study’s projections presume the vaccination of 80 percent of girls 12 to 15 years old starting in 2020, and that at least 70 percent of women undergo screening twice in their lifetime.
This would push the prevalence of the disease below the bar of 4/100,000 women in countries such as the United States, Canada, Britain and France by 2059, and in mid-income countries such as Brazil and China by 2069, the authors calculate.