IGF-1 and grass fed and finished beef

[nmonaco]

Is any one aware of any studies where totally grass fed  beef is accounted for in the measurement of IGF-1?

From what I have read the nutritional value of pastured and grass fed and finished beef is significantly different from factory farmed corn (and antibiotic laden) fed cows.

 

Anyone know something about this?

Thanks

 

[drewab]

Is any one aware of any studies where totally grass fed  beef is accounted for in the measurement of IGF-1?

From what I have read the nutritional value of pastured and grass fed and finished beef is significantly different from factory farmed corn (and antibiotic laden) fed cows.

 

Anyone know something about this?

Thanks

 

I'm not aware of any such data. You could conduct the study yourself. 3 months of regular beef followed by 3 months of grass fed beef, measuring IGF at the intervals and keeping everything else relatively constant.

 

I personally haven't had red meat in over 6 years and probably wouldn't go back. 

[Gordo]

You may really be wondering, why do animal proteins (meat, dairy, & eggs) raise IGF-1 levels? The reason is that most animal proteins have a high amount of the sulfur-containing amino acid methionine, and that amino acid spikes IGF-1. Researchers have found in animal studies that they can extend maximum life span simply by restricting methionine which is why some consider excess amounts a promoter of aging or perhaps just fuel for cancer which most will eventually get if they don't have heart disease. When it comes to IGF-1 grass fed vs. factory meat makes no difference. That said, factory meat could perhaps promote cancer in other ways which could conceivably make it a "double whammy" so to speak.

[mccoy]

Probably the most significant effect is on fat and milk composition. Methionine content of lean beef in cronometer is 0.8 gr per 100 gr cooked portion, whereas it is not indicated in the grass fed beef varieties I found ( I did not look'em all though).

 

What Dr. Cordain contends is that milk and whey protein is a greater promoter of mTOR activity (which can cause cancer if overly excited) than meat. But those 100 gr of lean beef contain about 3 gr of Leucine, which is a necessary signal to trigger mTOR.

 

An isoproteic quantity of whole milk, that is 4 cups, contains the same Leucine amount and exactly the same methionine. so 1 liter of milk is supposed to have the same effect on mTOR as 100 grams of cooked lean beef.

 

Bottom line is that animal protein like beef and milk both are promoters of IGF-1 and mTOR stimulation. Most probably, amminoacids content between traditionally farmed and grass-fed has no greater variation than the inherent statistical variability of meats. Hence, moderation is crucial. 

 

But organic, grass-fed beef carry have no growth hormones or antibiotics, so it's sure healthier than the industrial variety, providing it's eaten in small amounts and boiled or steamed to avoid heterociclic ammines.

[nmonaco]

I have done some additional reading on methionine and the IGF-1 issue and according to some of the Paleo proponents, while this does exist, consumption of bone broth mitigates this effect.

See https://chriskresser.com/do-high-protein-diets-cause-kidney-disease-and-cancer/

 

The part that makes me a little crazy is that it is so hard to know whose research to believe.

[mccoy]

nmonaco,

 

welcome to the asylum of modern nutrition science!!

 

I read the linked blog from Chris Kesser and the other blog from Denise Minger.

 

Only a single paper on the alleged benefits of glycine is cited. The paper has been released in 2011, the blog's date was 2014. Denise Minger's blog also carries the date of 2014. CK confirms that it is the only paper to his knowledge.

 

I don't know about any other studies on the alleged benefits of glycine. That's a very weak argument in favour of eating bone broth, organs and offal. A single article on mice amounts really to nothing.

 

I also share the doubts about the reliability of Longo's study based upon the NANHES III database. My main doubt is not that too many proteins may be harmful, rather than after 66  lots of proteins are favourable to health and lifespan.

 

Also, in the same paleo circle, there is a group which supports Dr Ron Rosedale's contention that protein restriction must be absolutely practiced if we are keen on longevity. This based not upon the mere IGF-1 pathway, rather upon the mTORC1 pathway, of which IGF-1 is only a single part. mTOR upregulation according to Dr Rosedale is an ancestral mechanism shifting the metabolism to growth and reproduction. Such an amplified pathway can lead to growth of cancer cells. Those who eat too many protein, in particular animal proteins, rich in BCAAs and in particular Leucine, whose signal is sensed by the mTOR complex, may keep mTOR upregulated hence paving teh way to degenerative disease.

 

In a few words, the argument on IGF-1 is superseded by the argument on mTOR. We can have an high IGF-1 signal but not an amplified mTOR, theoretically by eating a lot of methionine but very little leucine. On the other side the IGF-1 + insulin signal is needed  to activate akt, which is one half of the activation of mTOR. By restricting both methionine and Leucine we are pretty much sure we cannot have an upregulated mTOR pathway.

 

Bottom line, there are mechanistic reasons to believe that too many protein is bad for health and longevity. What people do not like to discuss though is that 'too many' is an unknown, variable quantity for each individual.

And the paleo guys are pretty much divided. Ron Rosedale is a staunch supporter of few protein (really, very few) and Gary Taubes, Eric Westman and others are staunch supporters of the high protein diet.

 

Fact is that many paleo people are absolutely insane in their ideas, touting concepts and contentions which are totally unsubstantiated by facts and living in a fairy tale where the heroes are called Eskimos, paleolithic gatherer-hunters and so on and everyone in the modern world is afflicted by gluten intolerance and lactose+casein intolerance. Even if they don't know!!

[mccoy]

The cited paper on glycine si by Joel Brind et al., FASEB journal (not one of the most popular/authoritative) 2011:

 

Dietary glycine supplementation mimics lifespan extension by dietary methionine restriction in Fisher 344 rats

1. Joel Brind1,2, 
2. Virginia Malloy2, 
3. Ines Augie2, 
4. Nicholas Caliendo2, 
5. Joseph H Vogelman2, 
6. Jay A. Zimmerman2,3 and 
7. Norman Orentreich2

+Author Affiliations

1. ¹ Natural Sciences, Baruch College, City University of New York, New York, NY
2. ² Orentreich Foundation for the Advancement of Science, Inc., Cold Spring-on-Hudson, NY
3. ³ Biology, St. John’s University, Queens, NY

Abstract

Dietary methionine (Met) restriction (MR) extends lifespan in rodents by 30–40% and inhibits growth. Since glycine is the vehicle for hepatic clearance of excess Met via glycine N-methyltransferase (GNMT), we hypothesized that dietary glycine supplementation (GS) might produce biochemical and endocrine changes similar to MR and also extend lifespan. Seven-week-old male Fisher 344 rats were fed diets containing 0.43% Met/2.3% glycine (control fed; CF) or 0.43% Met/4%, 8% or 12% glycine until natural death. In 8% or 12% GS rats, median lifespan increased from 88 weeks (w) to 113 w, and maximum lifespan increased from 91 w to 119 w v CF. Body growth reduction was less dramatic, and not even significant in the 8% GS group. Dose-dependent reductions in several serum markers were also observed. Long-term (50 w) 12% GS resulted in reductions in mean (±SD) fasting glucose (158 ± 13 v 179 ± 46 mg/dL), insulin (0.7 ± 0.4 v 0.8 ± 0.3 ng/mL), IGF-1 (1082 ± 128 v 1407 ± 142 ng/mL) and triglyceride (113 ± 31 v 221 ± 56 mg/dL) levels compared to CF. Adiponectin, which increases with MR, did not change in GS after 12 w on diet. We propose that more efficient Met clearance via GNMT with GS could be reducing chronic Met toxicity due to rogue methylations from chronic excess methylation capacity or oxidative stress from generation of toxic by-products such as formaldehyde. This project received no outside funding.

 

Please note that professor Joel Brind here has a conspicuos conflict of interests, being involved in commercial glycine supplementation (under the brand name of sweetamine).

 

 

 

 

Joel Brind

From Wikipedia, the free encyclopedia

 

 

Joel L. Brind Fields Endocrinology Institutions Baruch College Alma mater

• Yale University (B.S.)
• New York University (Ph.D.)

Thesis Studies on the androgen-dependent differentiation of cells of the mouse preputial gland : metabolism of testosterone and effects of selected drugs and hormones (1981) Known for Abortion-breast cancer hypothesis Website
Brind's faculty page

Joel Lewis Brind is a professor of human biology and endocrinology at Baruch College, City University of New York since 1986, a research biochemist since 1981, and CEO of Natural Food Science, a maker of glycine supplement products founded in 2010. 

 

He wrote some interesting blogs on glycine, but they are not peer- reviewed science and here we are in the middle of a critique to such allegedly rigorous studies, so the blogs are another arena.

 

Bottom line, the stuff on glycine mimicking methionine restriction is very interesting but still very hypothetical. And, from this 2016 thread on longecity, there appear to have been no further studies on the subject.

 

http://www.longecity.org/forum/topic/84394-glycine-dosage-for-methionine-restriction/

 

Further bottom line: glycine supplementation to mimick methionine restriction, as supported by the paleo guys, still appears to constutue a huge leap of faith and so should be treated.

[Michael R]

To get back to the original question: despite the hype of advocates, there are only very modest nutritional differences between pasture-fed and feedlot-fed beef, mostly related to quantity and composition of fat pasture-fed beef is higher in both omega-3 and -6 fatty acids). None of that should affect its influence on IGF-1.