A Call for a Low Protein Diet

geneticsteacher

:devil:

"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."

Not for weight loss, for longevity and disease prevention in middle aged adults.

http://www.ncbi.nlm.nih.gov/pubmed/24606898

vismal

Pure correlation. Were the high protein groups also more likely to be overweight then low protein groups? One could assume a diet of burgers, steaks, and bacon could put you at risk for many of the comorbidities mentioned. As is always my belief, overall diet, not one individual macro nutrient is usually the cause of a "healthy" or "unhealthy" state of being. Interesting study but worthless IMO as only protein intake was studied. I bet if you got a population of people who ate high protein diets, but were also a healthy weight, you would not see the same results.

Liftng4Lis

Pure correlation. Were the high protein groups also more likely to be overweight then low protein groups? One could assume a diet of burgers, steaks, and bacon could put you at risk for many of the comorbidities mentioned. As is always my belief, overall diet, not one individual macro nutrient is usually the cause of a "healthy" or "unhealthy" state of being. Interesting study but worthless IMO as only protein intake was studied. I bet if you got a population of people who ate high protein diets, but were also a healthy weight, you would not see the same results.

You rock Vis!

AJ_G

Pure correlation. Were the high protein groups also more likely to be overweight then low protein groups? One could assume a diet of burgers, steaks, and bacon could put you at risk for many of the comorbidities mentioned. As is always my belief, overall diet, not one individual macro nutrient is usually the cause of a "healthy" or "unhealthy" state of being. Interesting study but worthless IMO as only protein intake was studied. I bet if you got a population of people who ate high protein diets, but were also a healthy weight, you would not see the same results.

Yep, nothing much else to say, he said it all.

geneticsteacher

The study population included 6,381 adults ages 50 and over
from NHANES III, a nationally representative, cross-sectional
study. Our analytic sample had a mean age of 65 years and is
representative of the United States population in ethnicity, edu-
cation, and health characteristics (
Table S1
).
On average, subjects consumed 1,823 calories, of which the
majority came from carbohydrates (51%), followed by fat
(33%) and protein (16%), with most of it (11%) derived from an-
imal protein. The percent of calorie intake from protein was used
to categorize subjects into a high protein group (20% or more
of calories from proteins), a moderate protein group (10%–
19% of calories from proteins), and a low protein group (less
than 10% of calories from proteins).


http://www.cell.com/cell-metabolism/pdf/S1550-4131(14)00062-X.pdf

AJ_G

People who eat high amounts of protein and red meat are less likely to consume adequate fiber and people who eat large amounts of protein and red meat also typically exercise less than other people. If you statistically correct for these variables the lifespan of those who eat high protein and above average amounts of red meat do not have shorter lifespans than those who eat low protein. As mentioned the study you provided does not show causality, only correlation...

WalkingAlong

I think that if one wanted to eat mainly for longevity, the science leans heavily in favor of very low calorie diets, doesn't it?

davert123

and correlation doesn't = cause->effect :- )

davert123

I would also say that this shows how difficult it is to interpret literature. I think the guy above has really hit the nail on the head though regarding possible factors which distort the figures. In Europe a Mediterranean diet of high protein from fish along with plenty of exercise seems to give people the longest life expectancy. When looking at research I would advise people don't assume correlation=causal relationship, see who the research fits into the overall picture and see if there is a theory about the underlying mechanisms - and see how this fits into the underlying body of research. If the results fly in the face of what is generally believed I would be extremely dubious about it. I wouldn't discount it but I wouldn't believe it without a substantial amount of evidence to back it up

vismal

Also was the data on calorie and macro nutrients self reported? I could not find that information but given the nature of the study, I assume it was. If it was, then the numbers are all but worthless. As the million "I'm eating 1200 calories and not losing weight" threads prove, people absolutely suck at tracking their intake. Any study that relies on self reported nutritional data is almost as good as just making the number up IMO.