Wednesday, February 10, 2010

More on calorie restriction & aging

A commenter from the previous post sent a link to this interview that I think deserves its own posting.

If anyone else gets a chance to listen to the interview (~40 minutes), I recommend it. It’s with Greg Critser, author of the book Eternity Soup: Inside the Quest to End Aging.

Aging/Anti-Aging is a topic of much interest to people, for obvious reasons. It is also a hot topic in science among researchers. Why?

1) We now know that aging can be slowed.

2) We know that “aging” is not universal across all living beings. One of the main reasons humans die is because our immune system stops functioning.

A number of species do not really age, but rather, ultimately die because of predation or infectious disease. For example, we know the pacific rockfish lives at least 200 years and their immune system remains intact.

(photo credit here)

Critser talks about the Caloric Restriction Society -- people who eat 30-40% fewer calories than would normally be consumed at a meal. The theory for why caloric restriction works is that it lowers growth hormone over time, thus re-channeling energy from growth and development into body maintenance (this is in contradiction to the anti-aging industry selling growth hormone to prevent aging).

Critser was skeptical of this caloric restriction idea, saying the only evidence for this is based on animal studies. The data for humans just doesn’t exist yet.

I agree it would be nice to have evidence in humans. But I am also wondering how long it will take to get that evidence? We may not have it until these human experimenters’ lifetimes are over. And by then, non-members of the “Caloric Restriction Society” may already be dead! Maybe animal studies are the best we can rely on for now to make our own life-decisions. At least future generations will benefit from human evidence that comes along.

There was a caller from the Caloric Restriction Society (who seemed a bit miffed at Critser) who said that actually, there is already evidence for benefits of caloric restriction in humans – improvements in carotid plaque, cholesterol, heart elasticity, and endocrinological changes.

When asked, the caller stated that he eats ~1800 calories/day.

Wait, 1800 calories/day doesn’t seem too restrictive??


  1. This post is fascinating...I am going to check out this interview.

    Also, I want to be a pacific rockfish in my next life.

  2. hey christina. i was reading a back issue of the new york times magazine (food issue) and came across an article that i thought you would enjoy. i found a version of it online:


  3. Amanda, thank you! I just took a quick look and cannot wait to read it in detail!!

  4. Thanks for mentioning my book and the show. It is kind of you to do so.
    FYI: The 1800 calories that that caller was on means that he normally for his size ate 2200 calories. CR only works when you cut 30-40 percent from your normal caloric intake.You have to kind of create a low-level of metabolic stress.
    So, if you are slight already, and eat, say, 1800 calories a day. you would have to eat 1440 a day to get the CR effect.
    anyway this is a nice siteand i am glad you liked the book

  5. Of interest as well to your audience is the fact that Lisa Walford, perhaps the leading yoga trainer in Los Angeles, is the daughter of Roy Walford, the first scientist to advocate humans doing CR.