Protein Restriction to Extend Life
		
		
				
					
					
To disable ads, please log-in.
 
			
				
					Posted in Dr. Gabe Mirkin's weekly health/fitness e-zine today.  Curious as what you folks think about it.  I know a lot here are on high-protein diets.
-----------------------------------------------------------------------
Dr. Gabe Mirkin's Fitness and Health E-Zine
February 20, 2011
Restrict Protein, Not Just Calories, to Prolong Life
         Recent research show that protein restriction may be far 
more effective  than calorie restriction in prolonging the lives of 
humans.  Many studies show that restricting calories prolongs the 
lives of yeast, worms, spiders, flies, insects, rats and probably 
monkeys.  Humans who severely restrict calories have long-life 
characteristics, such as low cholesterol and blood pressure and 
hearts that are more than 15 years younger than those of other 
North Americans their age (Experimental Gerontology, August 2007). 
         However, most of the test group of humans who restrict 
calories do not have a drop in a hormone called Insulin-Like 
Growth Factor-1 (IGF-1) that appears necessary for living a long 
time.  High blood levels of IGF-1 are associated with premature 
aging and diseases of aging such as diabetes and cancer.  
IGF-1 levels are lower than normal in worms, flies and mice on 
restricted-calorie diets, but not in humans.  This week a report 
shows that IGF-1 shortens life by increasing cell DNA genetic 
damage, and causes cancer by blocking apoptosis that causes cancer 
cells to kill themselves before they destroy their host (Science 
Translational Medicine, February 16, 2011).
         Luigi Fontana, a professor of medicine at Washington 
University in St Louis, noticed that most calorie-restricting 
humans eat high levels of protein, about 1.7 grams per kilogram of 
body weight/day. This is more than the US government-recommended 
intake of 0.8 g/kg/day, and even higher than the 1.2 g/kg/day that 
the average American eats.  Dr. Fontana asked humans on calorie 
restricted diets to reduce their intake of protein to 0.95 g/kg/day. 
After just three weeks of reduced protein intake, their IGF-1 levels 
dropped markedly (Aging Cell, September, 2008). 
	Among the calorie-restricting humans, vegans have lower 
levels of IGF-1 than meat-eaters (Rejuvenation Research, February 
2007).  Strict vegans also have significantly lower IGF-1 levels 
than people who restrict just calories, even if they are heavier 
and have more body fat. Strict vegans take in about 10 percent of 
their calories from protein, whereas those on calorie restriction 
tended to get 24 percent of calories from protein.  Other data 
show that diets lower in protein might protect against some 
cancers.  So restricting protein may be more important than 
restricting calories. 
         If fruit flies and rodents are fed special diets that 
restrict protein, they can eat as many calories as they want and 
still live longer (Nature, December 2009).  This suggests that as 
long as you are not overweight, you may not need to restrict 
calories. Instead, restrict only protein which is far easier to do. 
	Furthermore, you can probably eat all the fruits and 
vegetables you want and not restrict calories as long as you 
restrict protein.   That's very good news because it is far easier 
to restrict protein than it is to restrict all foods. The only way 
that you can restrict calories and still remain healthy is to eat 
a diet based on vegetables.  It now appears that you extend your 
life far more by reducing protein that you would by restricting 
just calories.
				
			 
			
		 
			
				
			
				
			
			
				Emily
2011 Jamis Dakar XC "Toto" - Selle Italia Ldy Gel Flow
2007 Trek Pilot 5.0 WSD "Gloria" - Selle Italia Diva Gel Flow
2004 Bike Friday Petite Pocket Crusoe - Selle Italia Diva Gel Flow