Meat-heavy, low-carb diets can 'shorten lifespan': study


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Meat-heavy, low-carb diets can 'shorten lifespan': study
Published Friday, August 17, 2018 10:12AM EDT

Middle-aged people who get roughly half their daily calories from carbohydrates live several years longer on average than those with meat-heavy 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 favour 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, receiving less than 40 percent of total energy intake from carbohydrates qualified 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 suggest 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 of total calorie intake -- 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.)

"Low carbohydrate dietary patterns favouring animal-derived protein and fat sources, from sources such as lamb, beef, pork, and chicken, were associated with higher mortality," the study said.

"Those that favoured plant-derived protein and fat intake, from sources such as vegetables, nuts, peanut butter, and whole-grain breads, were associated with lower mortality," it said, adding that this suggested "the source of food notably modifies the association between carbohydrate intake and mortality."

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 1989 -- 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 to 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 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 fibre and intact grains, rather than from sugary beverages or manufactured foods high in added sugar."


Well-Known Member
The whole high protein low carb thing is not about longevity. The concept of eating like humans supposedly ate long ago ignores the short brutal life aspect of that time.

I suspect the various meat, poultry and fish industries cooked up the paleo diet. Its also a quality of life issue as well. What I see is people on these diets long term have a huge amount of physical misery as their painful older days stretch out and doctor visits increase. Wild fish and game stocks are eating off the poison pile too so that is not such a great alternative.

People now really cannot have an accurate concept of the richness of animal life that lived upon our world just a few hundred years ago let alone thousands. We have clobbered this planet.
To eat high on the food chain now is to be ingesting the results of our poisoning the hell of the planet concentrated in an animals lifelong form.

The planet will recover but our species is probably going to be along for the ride in a vastly scaled back version. Smiles here we no longer have ignorance as an excuse if we ever truly blame ourselves its as the catastrophe catches up to us and its too late baby. :wave:


Well-Known Member
The study is horrible. It is clearly used for observational data. I suspect the study is extremely biased. One of the doctors is an advocate for low fat and plant based diet designed "food frequency questionnaire (FFQ)" for subjects. I read quite several articles about the doctor in particular with long history of fraud, but it is never proved.

The study is based on what they ate in "between 1987 and 1989". I read that part subjects "have high body-mass index, exercise less during leisure time, have high household income, smoke cigarettes, and have diabetes." Well, there ya go.

"Low carbohydrate consumption (<40%) " is not like a Keto or Paleo diet. People on Keto and Paleo eat way much LESS than 40% carb. The study failed to report how much amounts of fruits and vegetables they consume, and how much amounts of sugar they consume. What were the quality of protein, fat and carbs they consume? Are they a meat factory? Are they grass-fed/pasture meat? Too many skews to list.

I am neither anti-low carb or low carb. My belief is you are what you eat. That's all I said.


Well-Known Member
So many of these studies are sketchy. I am an advocate of being a critical observer of all that.

Other than that to each their own.