Re: CR and insulin-like growth factor

[Guest guest]

Hi folks:

The following may have relevance to Al's post about CR and IGF-1:

http://www.nlm.nih.gov/medlineplus/news/fullstory_42330.html

Rodney.

>

> Hi All,

>

> Reduction of plasma IGF-1 and CR may produce a similar

> milieu that promotes survival in mammals.

>

> Shimokawa I, Higami Y, Tsuchiya T, Otani H, Komatsu T,

> Chiba T, Yamaza H.

>

> Life span extension by reduction of the growth

> hormone-insulin-like growth factor-1 axis: relation to

> caloric restriction.

>

> FASEB J. 2003 Jun;17(9):1108-9. Epub 2003 Apr 8.

>

> PMID: 12692087 http://tinyurl.com/3y5uq7

>

> Note, that the pathologies of those CR rats who died was

> different from those of the ad libitum feeding rats.

> Rats doing CR but with normal IGF-1

> died more from cancers than other diseases. Pituitary

> adenomas were less frequently seen in the

> transgenic (ie reduced IGF-1) rats.

>

> -- Al Pater, PhD; email: Alpater@...

>

[Guest guest]

Hi folks:

This looks like the Fontana paper referred to in that piece:

In particular: " CONCLUSIONS: Exercise training, decreased adiposity,

and long-term consumption of a low-protein, low-calorie diet are

associated with low plasma growth factors and hormones that are

linked to an increased risk of cancer. Low protein intake may have

additional protective effects because it is associated with a

decrease in circulating IGF-I independent of body fat mass. "

Here is the abstract:

" Long-term low-protein, low-calorie diet and endurance exercise

modulate metabolic factors associated with cancer risk.

Fontana L, Klein S, Holloszy JO.

Division of Geriatrics and Nutritional Science and the Center for

Human Nutrition, Washington University School of Medicine, St Louis,

MO 63110, USA. lfontana@...

BACKGROUND: Western diets, obesity, and sedentary lifestyles are

associated with increased cancer risk. The mechanisms responsible for

this increased risk, however, are not clear. OBJECTIVE: We

hypothesized that long-term low protein, low calorie intake and

endurance exercise are associated with low concentrations of plasma

growth factors and hormones that are linked to an increased risk of

cancer. DESIGN: Plasma growth factors and hormones were evaluated in

21 sedentary subjects, who had been eating a low-protein, low-calorie

diet for 4.4 +/- 2.8 y (x +/- SD age: 53.0 +/- 11 y); 21 endurance

runners matched by body mass index (BMI; in kg/m2); and 21 age- and

sex-matched sedentary subjects eating Western diets. RESULTS: BMI was

lower in the low-protein, low-calorie diet (21.3 +/- 3.1) and runner

(21.6 +/- 1.6) groups than in the Western diet (26.5 +/- 2.7; P <

0.005) group. Plasma concentrations of insulin, free sex hormones,

leptin, and C-reactive protein were lower and sex hormone-binding

globulin was higher in the low-protein, low-calorie diet and runner

groups than in the sedentary Western diet group (all P < 0.05).

Plasma insulin-like growth factor I (IGF-I) and the concentration

ratio of IGF-I to IGF binding protein 3 were lower in the low-

protein, low-calorie diet group (139 +/- 37 ng/mL and 0.033 +/- 0.01,

respectively) than in the runner (177 +/- 37 ng/mL and 0.044 +/-

0.01, respectively) and sedentary Western (201 +/- 42 ng/mL and 0.046

+/- 0.01, respectively) diet groups (P < 0.005). CONCLUSIONS:

Exercise training, decreased adiposity, and long-term consumption of

a low-protein, low-calorie diet are associated with low plasma growth

factors and hormones that are linked to an increased risk of cancer.

Low protein intake may have additional protective effects because it

is associated with a decrease in circulating IGF-I independent of

body fat mass. "

PMID: 17158430

Rodney.

> >

> > Hi All,

> >

> > Reduction of plasma IGF-1 and CR may produce a similar

> > milieu that promotes survival in mammals.

> >

> > Shimokawa I, Higami Y, Tsuchiya T, Otani H, Komatsu T,

> > Chiba T, Yamaza H.

> >

> > Life span extension by reduction of the growth

> > hormone-insulin-like growth factor-1 axis: relation to

> > caloric restriction.

> >

> > FASEB J. 2003 Jun;17(9):1108-9. Epub 2003 Apr 8.

> >

> > PMID: 12692087 http://tinyurl.com/3y5uq7

> >

> > Note, that the pathologies of those CR rats who died was

> > different from those of the ad libitum feeding rats.

> > Rats doing CR but with normal IGF-1

> > died more from cancers than other diseases. Pituitary

> > adenomas were less frequently seen in the

> > transgenic (ie reduced IGF-1) rats.

> >

> > -- Al Pater, PhD; email: Alpater@

> >

>

[Guest guest]

Hi folks:

And this looks like the Trichopoulos paper, giving further support to

the low protein hypothesis:

In particular: " Conclusion: Prolonged consumption of diets low in

carbohydrates and high in protein is associated with an increase in

total mortality. "

Here is the abstract:

" Low-carbohydrate-high-protein diet and long-term survival in a

general population cohort.

Trichopoulou A, Psaltopoulou T, Orfanos P, Hsieh CC, Trichopoulos D.

Department of Hygiene and Epidemiology, School of Medicine,

University of Athens, Athens, Greece.

Objective:We have evaluated the effects on mortality of habitual low

carbohydrate-high-protein diets that are thought to contribute to

weight control.Design:Cohort investigation.Setting:Adult Greek

population.Subjects methods:Follow-up was performed from 1993 to 2003

in the context of the Greek component of the European Prospective

Investigation into Cancer and nutrition. Participants were 22 944

healthy adults, whose diet was assessed through a validated

questionnaire. Participants were distributed by increasing deciles

according to protein intake or carbohydrate intake, as well as by an

additive score generated by increasing decile intake of protein and

decreasing decile intake of carbohydrates. Proportional hazards

regression was used to assess the relation between high protein, high

carbohydrate and the low carbohydrate-high protein score on the one

hand and mortality on the other.Results:During 113 230 persons years

of follow-up, there were 455 deaths. In models with energy

adjustment, higher intake of carbohydrates was associated with

significant reduction of total mortality, whereas higher intake of

protein was associated with nonsignificant increase of total

mortality (per decile, mortality ratios 0.94 with 95% CI 0.89 -0.99,

and 1.02 with 95% CI 0.98 -1.07 respectively). Even more predictive

of higher mortality were high values of the additive low carbohydrate-

high protein score (per 5 units, mortality ratio 1.22 with 95% CI

1.09 -to 1.36). Positive associations of this score were noted with

respect to both cardiovascular and cancer mortality. Conclusion:

Prolonged consumption of diets low in carbohydrates and high in

protein is associated with an increase in total mortality.

European Journal of Clinical Nutrition advance online publication, 29

November 2006; doi:10.1038/sj.ejcn.1602557.

PMID: 17136037

Rodney.

> >

> > Hi folks:

> >

> > The following may have relevance to Al's post about CR and IGF-1:

> >

> > http://www.nlm.nih.gov/medlineplus/news/fullstory_42330.html

> >

> > Rodney.

> >

> > --- In , Al Pater <old542000@>

wrote:

> > >

> > > Hi All,

> > >

> > > Reduction of plasma IGF-1 and CR may produce a similar

> > > milieu that promotes survival in mammals.

> > >

> > > Shimokawa I, Higami Y, Tsuchiya T, Otani H, Komatsu T,

> > > Chiba T, Yamaza H.

> > >

> > > Life span extension by reduction of the growth

> > > hormone-insulin-like growth factor-1 axis: relation to

> > > caloric restriction.

> > >

> > > FASEB J. 2003 Jun;17(9):1108-9. Epub 2003 Apr 8.

> > >

> > > PMID: 12692087 http://tinyurl.com/3y5uq7

> > >

> > > Note, that the pathologies of those CR rats who died was

> > > different from those of the ad libitum feeding rats.

> > > Rats doing CR but with normal IGF-1

> > > died more from cancers than other diseases. Pituitary

> > > adenomas were less frequently seen in the

> > > transgenic (ie reduced IGF-1) rats.

> > >

> > > -- Al Pater, PhD; email: Alpater@

> > >

> >

>

[Guest guest]

Is anyone else confused by the fact that this study appears to be

missing an important control group? Don't the researchers need both

a low-protein CR group and a moderate protein CR group in order to

differentiate between the effects of CR and protein intake in their

conclusions?

-Dave

> >

> > Hi folks:

> >

> > The following may have relevance to Al's post about CR and IGF-1:

> >

> > http://www.nlm.nih.gov/medlineplus/news/fullstory_42330.html

> >

> > Rodney.

> >

> > --- In , Al Pater <old542000@>

wrote:

> > >

> > > Hi All,

> > >

> > > Reduction of plasma IGF-1 and CR may produce a similar

> > > milieu that promotes survival in mammals.

> > >

> > > Shimokawa I, Higami Y, Tsuchiya T, Otani H, Komatsu T,

> > > Chiba T, Yamaza H.

> > >

> > > Life span extension by reduction of the growth

> > > hormone-insulin-like growth factor-1 axis: relation to

> > > caloric restriction.

> > >

> > > FASEB J. 2003 Jun;17(9):1108-9. Epub 2003 Apr 8.

> > >

> > > PMID: 12692087 http://tinyurl.com/3y5uq7

> > >

> > > Note, that the pathologies of those CR rats who died was

> > > different from those of the ad libitum feeding rats.

> > > Rats doing CR but with normal IGF-1

> > > died more from cancers than other diseases. Pituitary

> > > adenomas were less frequently seen in the

> > > transgenic (ie reduced IGF-1) rats.

> > >

> > > -- Al Pater, PhD; email: Alpater@

> > >

> >

>