Limitations to Data supporting Caloric Restriction for Anti-Ageing

[Youㅤ]

Caloric restriction (CR) has been shown to extend lifespan of various model organisms, most notably mice, but interestingly also in mouse lemurs (

Spoiler: My thread on that

Caloric Restriction Delays Visual Signs Of Aging In Lemurs

The control lemur clearly looks unhealthy, and the CR lemur looks young and healthful. The CR group has 30% less calories than the control. The median lifespan for the control group was 6.4 years, compared to 9.6 years for the CR group. When the last control lemur died at 11.3 years, one third...

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) and rhesus monkeys (In the University of Wisconsin study but not the NIA study).

There are issues, however, with the translatiability of these findings to humans.

• In at least most of the studies, the researchers augment the caloric intake without altering micronutrient (mineral and vitamins) intake. Therefore, the concentrations of micronutrients are increased in CR groups. Additionally, this reduces the translatiability of the findings to humans, for if a human were to reduce caloric intake, then micronutrients would be reduced as well.
• When researchers implement CR in rodent models, while the ad libitum freely eats throughout the 24 hour day, the CR rodents, hungry for food, will ravenously consume all of their food for the day within a few hour period. This means that, in addition to CR, these groups are basically also doing OMAD or intermittent fasting. Considering the faster metabolism of mice compared to humans, these 20-22 hour fasting periods are comparative to a human fasting for much longer. Additionally, it has been suggested that in the ad libitum groups, the incessant feeding throughout the day could result in circadian clock disturbances.
• Another factor that makes the studies less comparable to humans is that the diets used for CR are usually highly purified. They are eating chow (soy protein, fish meal, constarch, sucrose, soybean oil, micronutrients). It is possible that if one was to eat a whole foods diet, restricting food intake would confer a lesser extension of lifespan than if one were on a purified diet.
• Lastly, not all researchers have prevented obesity in control groups. Some researchers restrict the ad libitum group to 90 or 95% of true as libitum to prevent the obvious detrimental effects of obesity on lifespan and ageing, but many studies fail to prevent obesity in the an libitum control groups. In the longevity community, CR is usually considered an anti ageing strategy regardless of your body fat percentage. However, much of the benefits seem in some experiments could be a result of removeing the harm of obesity in the lab animals.

 

[Youㅤ]

Also, CR is more potent on short lived animals like c. Elegans (roundworm) vs the longer lived murine (true mice and rat) models. This trend would suggest that CR would have even less of a percent extension in humans. If CR activated a genetic program to slow ageing, it could be less effective in humans, because evolutionarily, a famine period would be a smaller percentage of the lifespan in a human compared to a shorter lived animal like a mouse.

I still think CR slows ageing in humans. The question is the degree. I think CR mimetics are a superior strategy because restricting calories takes a lot of willpower and would reduce micronutrient intake. Protein restriction is a dietary restriction (DR) intervention that may have much of the benefits of CR.

 

[Youㅤ]

Protein restriction is a dietary restriction (DR) intervention that may have much of the benefits of CR.

Intriguingly, core body temperature reduction has been shown to mediate the lifespan extension effect of CR. In humans, protein restriction and not CR per se has been shown to mediate IGF-1 reduction in humans, which has been shown to mediate a reduction in core body temperature.

 

[Youㅤ]

@ReinerGeist1 @ph4ntom @arabcelxxx @PotassiumMaxxer @KING REIDYZ @spirili @lookmaxascend @BrahminBoss @7zyzz7

 

[Youㅤ]

@enchanted_elixir @finn899 @DR. NICKGA

 

[IAMNOTANINCEL]

Humans as test subjects

 

[synock21]

good thread, cleared some misconceptions. Wonder if increasing vitamin intake and lowering food intake could negate the negative effects, I read that increasing the intervals between consuming food has the same effects as fasting.

 

[Youㅤ]

good thread, cleared some misconceptions. Wonder if increasing vitamin intake and lowering food intake could negate the negative effects, I read that increasing the intervals between consuming food has the same effects as fasting.

i think its vital to supplement on a CR diet, problem is that natural sources are gonna be better than pills. in an article i read, the tessted multivitamins havent extended mouse lifespan, in fact some shortened it. theres only so much eating nutrient dense can do though. our soils are depleted of minerals so its impossible to get optimal minerals even not on CR.

well, some of the benefit of CR may be due to fasting. its even been suggested that the benefit is due to circadian alignment. that is why i do early time restricted feeding (not eating dinner) I also eat a low protein diet. low protein will reduce IGF-1 and mTOR even if i dont restrict calories, so probably the main benefit of CR assumeing youre already lean. I also take aspirin as a modest CR mimetic