Les régimes hyperprotéinés, aussi mauvais que la cigarette ?

[Yoda]

Des chercheurs ont constaté que les personnes ayant un régime alimentaire riche en protéines animales montraient un risque plus élevé d'avoir un cancer. Plus inquiétant, le risque serait pratiquement similaire à celui d'une personne d'âge moyen fumant 20 cigarettes par jour.

http://www.maxisciences.com/prot%e9ine/les-regimes-hyperproteines-aussi-mauvais-que-la-cigarette-pour-la-sante_art32123.html

[Yoda]

J'adore le titre , je ne fais que relayer hein.

[Gilles]

L'étude en question :

Low Protein Intake Is Associated with a Major Reduction in IGF-1, Cancer, and Overall Mortality in the 65 and Younger but Not Older Population
Morgan E. Levine et al.
Cell Metabolism, Volume 19, Issue 3, 407-417, 4 March 2014

Highlights
High protein intake is linked to increased cancer, diabetes, and overall mortality
High IGF-1 levels increased the relationship between mortality and high protein
Higher protein consumption may be protective for older adults
Plant-derived proteins are associated with lower mortality than animal-derived proteins

Summary
Mice and humans with growth hormone receptor/IGF-1 deficiencies display major reductions in age-related diseases. Because protein restriction reduces GHR-IGF-1 activity, we examined links between protein intake and mortality. Respondents aged 50–65 reporting high protein intake had a 75% increase in overall mortality and a 4-fold increase in cancer death risk during the following 18 years. These associations were either abolished or attenuated if the proteins were plant derived. Conversely, high protein intake was associated with reduced cancer and overall mortality in respondents over 65, but a 5-fold increase in diabetes mortality across all ages. Mouse studies confirmed the effect of high protein intake and GHR-IGF-1 signaling on the incidence and progression of breast and melanoma tumors, but also the detrimental effects of a low protein diet in the very old. These results suggest that low protein intake during middle age followed by moderate to high protein consumption in old adults may optimize healthspan and longevity.



L'étude complète (PDF)

[Gilles]

L'article du Guardian donne un éclairage un peu plus critique sur cette étude et en souligne l'aspect controversé :

Diets high in meat, eggs and dairy could be as harmful to health as smoking
People under 65 who eat a lot of meat, eggs and dairy are four times as likely to die from cancer or diabetes, study suggests
The Guardian, Wednesday 5 March 2014

A diet rich in meat, eggs, milk and cheese could be as harmful to health as smoking, according to a controversial study into the impact of protein consumption on longevity.

High levels of dietary animal protein in people under 65 years of age was linked to a fourfold increase in their risk of death from cancer or diabetes, and almost double the risk of dying from any cause over an 18-year period, researchers found. However, nutrition experts have cautioned that it's too early to draw firm conclusions from the research.

(...)

Teasing out the health effects of individual nutrients is notoriously difficult. The apparently harmful effects of a high-protein diet might be down to one or more other substances in meat, or driven by lifestyle factors that are more common in regular red meat eaters versus vegetarians. Other factors can skew results too: a person on the study who got ill might have gone off their food, and seen a proportional rise in the amount of calories they get from protein. In that case, it would be the illness driving the diet, not the other way round.

"I would urge general caution over observational studies, and particularly when looking at diet, given the difficulties of disentangling one nutrient or dietary component from another. You can get an association that might have some causal linkage or might not," said Peter Emery, head of nutrition and dietetics at King's College London.

Gunter Kuhnle, a food nutrition scientist at Reading University, said it was wrong "and potentially even dangerous" to compare the effects of smoking with the effect of meat and cheese as the study does.

"Sending out [press] statements such as this can damage the effectiveness of important public health messages. They can help to prevent sound health advice from getting through to the general public. The smoker thinks: 'why bother quitting smoking if my cheese and ham sandwich is just as bad for me?'"

Heather Ohly at the European Centre for Environment and Human Health in Exeter said: "Smoking has been proven to be entirely bad for us, whereas meat and cheese can be consumed in moderation as part of a healthy diet, contributing to recommended intakes of many important nutrients."

(...)

Source

[Gilles]

2 pages qui reprennent tous les points discutables de l'étude :

High-Protein Diets Linked to Cancer: Should You Be Concerned?

To even suggest that eating protein is as bad as smoking is pure sensationalism.

Do High Protein Diets Cause Early Death?

The response is not necessarily to overreact and cut all protein, but instead consider what your body needs given it’s activity levels and goals, and then consider the sourcing of your foods and all other factors that lead to health.

[Yoda]

Bien vu Gilles