[dnalex]

A case for low protein intake (in middle-aged people)

by dnalex on Wed Mar 05, 2014 6:47 pm

We have had a lot of discussions recently on diet and its impact on health, specifically on cancer risk. A new study, published in the journal Cell Metabolism, a very high impact Cell Press journal, has established a link between high protein intake in middle aged persons (50-65) and increased rates of mortality in general, increased rates of cancer-related deaths, and increased rates of diabetes-related deaths. Interestingly, persons 65 and over appear to receive a protective effect from cancer deaths when on a high protein diet. Animal protein sources appear to be worse than non-animal sources.

A high protein diet is defined here as deriving 20% or more of your daily caloric intake from proteins.

The mechanism of action appears through regulation of the growth hormone/IGF-1 (insulin-like growth factor 1) signaling pathway.

Here's the full text of the article
http://download.cell.com/cell-metabolism/pdf/PIIS155041311400062X.pdf?intermediate=true

It's quite an interesting read, and is definitely food for thought.

Alex

[Guitarnut]

Re: A case for low protein intake (in middle-aged people)

by Guitarnut on Wed Mar 05, 2014 9:25 pm

I saw that on the news today. Very interesting indeed. Especially about the age group where the risk is the highest yet drops after leaving that age group. The more we learn the less we seem to know.

[Multibilly]

Re: A case for low protein intake (in middle-aged people)

by Multibilly on Wed Mar 05, 2014 9:36 pm

Thanks dnalex,

This is indeed a good read. IGF-1 has already been pretty well documented as being an agent that is key for the survival of multiple myeloma cells in particular.

[dnalex]

Re: A case for low protein intake (in middle-aged people)

by dnalex on Thu Mar 06, 2014 12:33 am

Hi Multibilly,

The IGF-1 link is very interesting. I will probably write the authors and ask them about the myeloma link. I'll be curious to see what they say.

[Multibilly]

Re: A case for low protein intake (in middle-aged people)

by Multibilly on Sat Mar 08, 2014 9:06 am

The article that dnalex posted was great, but it is a difficult read for a non-scientist. Here's a couple of mainstream media summaries.

http://thechart.blogs.cnn.com/2014/03/05/middle-aged-put-down-the-meat/?hpt=he_t2

http://www.foxnews.com/health/2014/03/04/eating-large-amounts-meat-cheese-may-be-as-deadly-as-smoking-study-shows/

And here is just one of many articles that you can find on the role of IGF-1 and myeloma (just google " IGF-1 myeloma").

https://myelomabeacon.org/news/2009/05/23/igf-1-an-important-myeloma-growth-factor/

[Wayne K]

Re: A case for low protein intake (in middle-aged people)

by Wayne K on Sat Mar 08, 2014 1:50 pm

Maybe people of my age who have survived have become more immune to the chemicals in the more popular forms of protein?

[dnalex]

Re: A case for low protein intake (in middle-aged people)

by dnalex on Sat Mar 08, 2014 2:37 pm

Maybe people of my age who have survived have become more immune to the chemicals in the more popular forms of protein?

LOL

The idea is that the IGF-1, which plays a role in cancer, is elevated in a high protein diet in people 65 and under. Hence, a low protein diet reduces IGF-1 levels and confers protection.

Conversely, in older populations, IGF-1 levels have dropped, and high protein intake raises IGF1- levels to where you see a protective effect.