Protein bioavailability?

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Protein bioavailability?

Postby boardn10 » Fri Nov 21, 2008 4:15 pm

Does anyone know the most bioavailable protein? I haven't read the most recent research but I always understood soy to be right up there with anything of an animal source!? I ask because this came up with someone else I know with Lyme disease who advised to eat lots of eggs since they are the so called 'perfect' protein.

-Rich
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Re: Protein bioavailability?

Postby JeffN » Fri Nov 21, 2008 4:23 pm

boardn10 wrote:Does anyone know the most bioavailable protein? I haven't read the most recent research but I always understood soy to be right up there with anything of an animal source!? I ask because this came up with someone else I know with Lyme disease who advised to eat lots of eggs since they are the so called 'perfect' protein.

-Rich


What would you want something to be the most "bio-available" when more of it is not good.

The current research on CR-ON is showing that the most available proteins are also the ones that rise IGF-1 the most, which in turn, may increase the growth rates of cancer.

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IGF-1

Postby JeffN » Fri Nov 21, 2008 4:46 pm

Here is the study, along with a private conversation with one of the participants, of which, due to the conversation having been private, I will just quote the main points. The study is public.

""Q. How often do you and (...) test for IGF-1, monthly?

We have tested IGF-1 about every 3 months since 2003. We test it along with the IGF binding proteins 1, 2 and 3, insulin, T3 and the VAP test.

We wanted to see how total protein fared against the above battery of tests as well as individual protein concentrates including whey, brewers yeast, soy protein isolate, nonfat yogurt, kefir. and a mixture of individual amino acids. The results were frightening -- each one of these substances sent IGF-1 significantly higher -- independent of total calorie intake.

The goal was to customize our CR diet to produce IGF-1 in the lower third of the reference range and to get IGFBP1, which is an indicator of SIRT1 activity, glucagon activity, etc., at the high end of the reference range.

This is consistent with the downregulation of energy availability and of anabolic activity that is shown in long-lived CR animals.

I have found, however, that protein absorbability makes a greater difference in IGF-I (and the binding proteins) than total protein, if the protein is from vegetables and grains, beans (this does not mean concentrates), and fruits.""


The Study...

Luigi Fontana, Edward P. Weiss, Dennis T. Villareal, Samuel Klein, John O. Holloszy. "Long-term effects of calorie or protein restriction onserum IGF-1 and IGFBP-3 concentration in humans." *Aging Cell. *(2008) Doi: 10.1111/j.1474-9726.2008.00417.x

Full Text
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2673798/


ABSTRACT
Reduced function mutations in the insulin/IGF-I signaling pathway increase maximal lifespan and health span in many species. Calorie restriction (CR) decreases serum IGF-1 concentration by ~40%, protects against cancer and slows aging in rodents. However, the long-term effects of CR with adequate nutrition on circulating IGF-1 levels in humans are unknown. Here we report data from two long-term CR studies (1 and 6 years) showing that severe CR without malnutrition did not change IGF-1 and IGF-1 : IGFBP-3 ratio levels in humans. In contrast, total and free IGF-1 concentrations were significantly lower in moderately protein-restricted individuals. Reducing protein intake from an average of 1.67 g kg−1 of body weight per day to 0.95 g kg−1 of body weight per day for 3 weeks in six volunteers practicing CR resulted in a reduction in serum IGF-1 from 194 ng mL−1 to 152 ng mL−1. These findings demonstrate that, unlike in rodents, long-term severe CR does not reduce serum IGF-1 concentration and IGF-1 : IGFBP-3 ratio in humans. In addition, our data provide evidence that protein intake is a key determinant of circulating IGF-1 levels in humans, and suggest that reduced protein intake may become an important component of anticancer and anti-aging dietary interventions.

Some other interesting points from the "conversation"...

"One of the most telling comparisons in the study was between our high-protein CR group and a cohort of ad-lib vegans. The CR Society group ate an average of 1772 calorie per day while the vegans ate 1980 calories per day. However, The CR group ate an average of 23.5% of total calories in protein while the vegans ate 9.6 percent protein. The excess protein eaten by our group was enough to completely nullify CR's IGF-I lowering effect."


I am hoping to have one (or two) of these researchers at the Sept 09 McDougall Advanced Weekend.

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Postby landog » Fri Nov 21, 2008 6:19 pm

What did Jeff just say???

If anyone can interpret, I'd be grateful.

Thanks,
-dig
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Postby JeffN » Fri Nov 21, 2008 7:15 pm

landog wrote:What did Jeff just say???

If anyone can interpret, I'd be grateful.

Thanks,
-dig


HI,

Sorry! :)

Read this McDougall newsletter and especially the parts about IGF-1

http://www.drmcdougall.com/misc/2005nl/ ... 0pusoy.htm

Elevated IGF-1 levels in adults can increase the growth rate of cancer. Even isolated plant proteins (like soy) can raise IGF-1 levels. We want lower IGF-1 levels especially as we get older.

The above studies showed that higher "total" protein levels raised IGF-1, and so keeping "total" protein levels low, was important.

In addition, the vegan low protein diet, produced lower IGF-1 levels than the low protein calorie restricted diet. In other words, the vegan lower protein diet, which was lower in protein than the low protein calorie restricted diet, produced lower IGF-1 levels. So, based on that one marker, the vegan diet that was not calorie restricted did better than the calorie restricted diet.

Also, when the diet was made up of proteins of higher availability, even if the total protein of the diet was low, it raised IGF-1 levels.

So, the take home message from this is keep your total protein low and choose proteins which are less bio-available, which are plant proteins. Just more support to follow the program. :)

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Re: IGF-1

Postby maorseven » Tue Aug 23, 2022 3:25 am

JeffN wrote:We wanted to see how total protein fared against the above battery of tests as well as individual protein concentrates including whey, brewers yeast, soy protein isolate, nonfat yogurt, kefir. and a mixture of individual amino acids. The results were frightening -- each one of these substances sent IGF-1 significantly higher -- independent of total calorie intake.


Hi Jeff,

I cannot seem to locate any reference in the published study to the aforementioned protein concentrates. In addition, the elaboration as part of a private conversation does not note any dosage. I find it difficult to draw any meaningful conclusions without further information.
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Re: Protein bioavailability?

Postby Lizzy_F » Sat Sep 03, 2022 10:58 am

Hi Jeff. I am very interested in further clarification (in non-scientist terms!) about the referenced study. The link you shared to the McDougall 2005 newsletter doesn't go anywhere - is that newsletter still available somewhere? If not, would you mind summarizing the key points sometime when you have a few minutes?

Thank you so much. My husband eats a lot of animal protein and he is a science and research type of guy. I already provided the research study, but I would love to share with him your & Dr. McDougall's interpretation of the research.

Thanks for all you do for us!!!!!
Beth

"Long-term sustainable change is what we are really after." ~Jeff Novick
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Re: Protein bioavailability?

Postby JeffN » Sat Sep 03, 2022 12:09 pm

Sure. Here you go. Let's do it in steps so it makes sense. It would also be something you could show your husband which he could explore for himself, without you having to explain it. This is everything from above but organized and put in order.

First, read these 2 newsletter from Dr McDougall as he discusses the issue of IGF-1, what it is, the concerns with it, etc

In this one, read the section on, "Growth Hormone Promotes Aging" till the end, https://www.drmcdougall.com/misc/2006nl ... /aging.htm

In this one, read the section on, "Calcium Loss and Cancer Growth from Protein Concentrates"
https://www.drmcdougall.com/misc/2005nl ... 0pusoy.htm

Some of the discussion may seem familiar as he went over it in his recent talk on Dairy (in the program) and also on Aging which I think was just posted.


Second, here is a study that I mention above which came out around the same time and basically supports everything Dr McDougall said in the above 2 links and his current updated talks..

Luigi Fontana, Edward P. Weiss, Dennis T. Villareal, Samuel Klein, John O. Holloszy. "Long-term effects of calorie or protein restriction onserum IGF-1 and IGFBP-3 concentration in humans." *Aging Cell. *(2008) Doi: 10.1111/j.1474-9726.2008.00417.x

Full Text
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2673798/

ABSTRACT
Reduced function mutations in the insulin/IGF-I signaling pathway increase maximal lifespan and health span in many species. Calorie restriction (CR) decreases serum IGF-1 concentration by ~40%, protects against cancer and slows aging in rodents. However, the long-term effects of CR with adequate nutrition on circulating IGF-1 levels in humans are unknown. Here we report data from two long-term CR studies (1 and 6 years) showing that severe CR without malnutrition did not change IGF-1 and IGF-1 : IGFBP-3 ratio levels in humans. In contrast, total and free IGF-1 concentrations were significantly lower in moderately protein-restricted individuals. Reducing protein intake from an average of 1.67 g kg−1 of body weight per day to 0.95 g kg−1 of body weight per day for 3 weeks in six volunteers practicing CR resulted in a reduction in serum IGF-1 from 194 ng mL−1 to 152 ng mL−1. These findings demonstrate that, unlike in rodents, long-term severe CR does not reduce serum IGF-1 concentration and IGF-1 : IGFBP-3 ratio in humans. In addition, our data provide evidence that protein intake is a key determinant of circulating IGF-1 levels in humans, and suggest that reduced protein intake may become an important component of anticancer and anti-aging dietary interventions.

As a result of the study (and his other work) we invited Dr Fontana to the next Advanced Study Weekends.


In addition, here are some additional comments that are not in the study but come from one of the subjects in the study who was in the CR Group. These comments were posted in the CR yahoo group of which I am a longterm member. They also confirm the above concerns and comments on protein and IGF-1.


"One of the most telling comparisons in the study was between our high-protein CR group and a cohort of ad-lib vegans. The CR Society group ate an average of 1772 calorie per day while the vegans ate 1980 calories per day. However, The CR group ate an average of 23.5% of total calories in protein while the vegans ate 9.6 percent protein. The excess protein eaten by our group was enough to completely nullify CR's IGF-I lowering effect."


Lastly, here is a further conversation with this person, which is not in the study but was posted on the CR group. He is discussing his own experiments with a few others in the CR Group which further reflect the same concerns about isolated/concentrated proteins. In addition, the concerns of of higher bioavailable proteins (more digestible and absorbable), plant or animal.


Question: How often do you and (...) test for IGF-1, monthly?

"We have tested IGF-1 about every 3 months since 2003. We test it along with the IGF binding proteins 1, 2 and 3, insulin, T3 and the VAP test.

We wanted to see how total protein fared against the above battery of tests as well as individual protein concentrates including whey, brewers yeast, soy protein isolate, nonfat yogurt, kefir. and a mixture of individual amino acids. The results were frightening -- each one of these substances sent IGF-1 significantly higher -- independent of total calorie intake.

The goal was to customize our CR diet to produce IGF-1 in the lower third of the reference range and to get IGFBP1, which is an indicator of SIRT1 activity, glucagon activity, etc., at the high end of the reference range.

This is consistent with the downregulation of energy availability and of anabolic activity that is shown in long-lived CR animals.

I have found, however, that protein absorbability makes a greater difference in IGF-I (and the binding proteins) than total protein, if the protein is from vegetables and grains, beans (this does not mean concentrates), and fruits."



Hopefully, that will all make sense now. If not, let me know

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