Restricting calories may not prolong your life
August 29th, 2012
01:01 PM ET

Restricting calories may not prolong your life

Calorie restriction has long been used to examine aging in rodents and monkeys. Past studies have shown that restricting calories in a nutritious diet by 10 to 40% can delay or prevent chronic diseases, slow aging and increase life spans.

But new research published this week in the journal Nature shows quite the opposite – that calorie restriction does not improve survival outcomes. Turns out, the issue may be more complicated than first thought.

The study

Researchers at the National Institute of Aging have been studying the effects of calorie restriction in rhesus monkeys for more than 20 years in hopes of eventually applying the results to humans.

Male and female monkeys of all ages are enrolled in the study. The experimental group eats approximately 25% fewer calories than the control group. Any animal that dies during the study undergoes a necropsy (an autopsy performed on an animal) to find the probable cause of death.

The results

Older monkeys who began the calorie-restricted diet weighed significantly less than monkeys in the control group. They had lower levels of triglycerides (fatty acids) and cholesterol.

Yet the calorie-restricted older monkeys did not live any longer than their counterparts. There were also no apparent differences in the causes of death between the two.

Twenty percent of the young monkeys in the calorie-restricted group have died of age-related causes, compared to 24% of the control group.

The calorie-restricted younger monkeys weigh less, but do not have significantly lower levels of fasting glucose or triglycerides. Cancer rates were improved in the calorie-restricted group, but diabetes and cardiovascular disease were detected in both.

“Even the control monkeys in our study are very healthy and demonstrate an increased survival relative to other captive populations of monkeys,” said study author Dr. Julie Mattison. “It is possible that we have maximized the survival benefits in our colony and thus a reduction in calories provides no further benefit relative to their very healthy control counterparts.”

Approximately 50% of the younger monkeys in the study are still alive. Using the data already collected, researchers estimate a less than 0.1% chance that the calorie restriction diet will have a favorable effect on their survival.

The other study

Scientists at the Wisconsin National Primate Research Center are doing a parallel study using rhesus monkeys on a 30% calorie restricted diet. They have reported improved survival rates in their primates.

Mattison says the differences in the monkeys’ diet composition in each study could contribute to the varying results. The NIA monkeys are from China and India, whereas the Wisconsin monkeys come only from India; the genetic makeup in each could be different.

The NIA authors say further comparisons of the two studies are “warranted and planned.”

The takeaway

First and foremost, Mattison stresses that a calorie-restricted diet is meant for studying aging, not as a “prescription for human health.” Anyone interested in following a similar plan should first speak to their doctor.

The second takeaway is that we still need more information.

“The effects of (calorie restriction) are multi-faceted in a longer-lived subject such as a monkey and it is necessary to dissect the interplay of number of calories and source of calories," Mattison says. "Unless we understand which pathways are being affected by this metabolic stress, we can’t control the many other variables that might contribute to the effect."

« Previous entry
soundoff (501 Responses)
  1. cialis super active vs cialis professional

    Cialis nova scotia cialis super active vs cialis professional how can i get cialis
    in australia

    June 16, 2021 at 07:49 | Report abuse | Reply
  2. cialis viagra mail order uk discrete billing

    30 day free trial of cialis cialis viagra mail order uk discrete billing cialis for sale in toront ontario

    June 16, 2021 at 10:29 | Report abuse | Reply
  3. generic cialis with dapoxetine 80mg x 10 tabs

    Does cialis delay ejaculation generic cialis with dapoxetine 80mg x 10 tabs generic cialis

    June 16, 2021 at 11:27 | Report abuse | Reply
  4. maximum daily dose of cialis

    Buy cialis 10 tab maximum daily dose of cialis
    buy cialis ireland

    June 16, 2021 at 12:18 | Report abuse | Reply
  5. bye cialis online from usa

    Cialis time bye cialis online from usa buy
    cialis at walmart

    June 16, 2021 at 13:18 | Report abuse | Reply
  6. pharmacy windsor canada

    Legal online pharmacies in the us pharmacy windsor canada canadian prescription pharmacy

    June 16, 2021 at 15:38 | Report abuse | Reply
  7. medical pharmacies

    Online pharmacy delivery medical pharmacies Mobic

    June 17, 2021 at 02:51 | Report abuse | Reply
  8. how long can you do one round of hcg for

    My partner and I stumbled over here from a different web page and thought
    I may as well check things out. I like what I see so now
    i am following you. Look forward to looking at your web page
    for a second time.

    June 17, 2021 at 03:04 | Report abuse | Reply
  9. hcg injections for weight loss in Janesville

    I am sure this post has touched all the internet users, its really really fastidious
    article on building up new website.

    June 17, 2021 at 03:09 | Report abuse | Reply
  10. certified canadian pharmacies

    Northwest pharmacy certified canadian pharmacies prescription drugs definitions

    June 17, 2021 at 07:41 | Report abuse | Reply
  11. exporteddrugs.com

    Awesome! Its really awesome piece of writing, I have got much clear idea on the topic of from this
    piece of writing.

    June 17, 2021 at 08:27 | Report abuse | Reply
  12. canadian overnight pharmacy review

    Most dangerous prescription drugs canadian overnight pharmacy review canadian pharmacy lantus

    June 17, 2021 at 12:35 | Report abuse | Reply
  13. cialis dick

    Canadian pharmacy cialis brand cialis dick cialis sales

    June 17, 2021 at 12:37 | Report abuse | Reply
  14. generic cialis 30 pills 20mg

    Staxyn vs cialis generic cialis 30 pills 20mg inexpensive cialis

    June 17, 2021 at 16:10 | Report abuse | Reply
  15. Kristian

    I have been browsing online greater than three hours these days, but I never found any interesting article like yours.
    It's beautiful worth sufficient for me. In my opinion, if all webmasters and bloggers made excellent content material as you did,
    the web will probably be much more helpful than ever before.

    Here is my web blog; Kristian

    June 17, 2021 at 20:55 | Report abuse | Reply
  16. cialis use instructions

    Buy cialis without presc cialis use instructions generic daily cialis

    June 17, 2021 at 23:06 | Report abuse | Reply
  17. the cost of cialis

    Overnight pharmacy cialis the cost of cialis \'generic cialis\'

    June 18, 2021 at 01:53 | Report abuse | Reply
  18. how to order cialis from canada

    Cialis levitra how to order cialis from canada generic cialis india safe

    June 18, 2021 at 04:28 | Report abuse | Reply
  19. cialis 36 hour dosage

    Cialis for daily use disount cialis 36 hour dosage
    cialis drugs

    June 18, 2021 at 07:57 | Report abuse | Reply
  20. cialisis online

    Generic cialis 5mg cialisis online cialis

    June 18, 2021 at 08:56 | Report abuse | Reply
  21. cialis 20mg

    By cialis tablets in frankfurt pharmacy cialis 20mg what does cialis

    June 18, 2021 at 12:04 | Report abuse | Reply
  22. can cialis be taken with food

    Cialis 20mg prices can cialis be taken with food alternatives to cialis

    June 18, 2021 at 12:43 | Report abuse | Reply
  23. online pharmacy oxycodone 30mg

    Weight loss drugs approved in canada online pharmacy oxycodone 30mg health canada controlled drugs and substances

    June 18, 2021 at 13:52 | Report abuse | Reply
  24. do have to have a prescription for cialis?

    Cialis doesn\'t work do have to have a prescription for cialis? What are the ingredients in cialis

    June 18, 2021 at 14:48 | Report abuse | Reply
  25. Prometrium

    Drug store Prometrium discount drugs online pharmacy

    June 18, 2021 at 17:38 | Report abuse | Reply
  26. viagra canadian pharmacy legit

    Rx good neighbor pharmacy viagra canadian pharmacy legit canadian mail order pharmacy ratings

    June 18, 2021 at 18:09 | Report abuse | Reply
  27. cialis dosage strengths

    Cialis 20 mg price costco cialis dosage strengths
    how much are cialis pills

    June 18, 2021 at 19:59 | Report abuse | Reply
  28. when does cialis lose its patent

    Is cialis when does cialis lose its patent cialis
    for pulmonary hypertension

    June 18, 2021 at 21:59 | Report abuse | Reply
  29. canadian online pharmacy cialis

    Free samples of cialis canadian online pharmacy cialis cialis free trial

    June 19, 2021 at 02:47 | Report abuse | Reply
  30. cvs pharmacy store finder

    Best rx online pharmacy cvs pharmacy store finder Sinemet

    June 19, 2021 at 03:12 | Report abuse | Reply
  31. brand cialis australia

    Cialis dapoxetine brand cialis australia buy
    cialis on line without presciption

    June 19, 2021 at 09:10 | Report abuse | Reply
  32. phentermine review

    Pretty nice post. I just stumbled upon your blog and wanted to say that I have truly enjoyed browsing
    your blog posts. After all I'll be subscribing to your feed and I hope you write again soon!

    Also visit my blog ... phentermine review

    June 19, 2021 at 11:12 | Report abuse | Reply
  33. cialis bathtub commercial

    Cheap cialis australia cialis bathtub commercial cialis 200 mg
    no prescription

    June 19, 2021 at 15:25 | Report abuse | Reply
  34. cialis and viagra together forum

    Generic drug name for cialis cialis and viagra together forum free sample of cialis

    June 19, 2021 at 21:30 | Report abuse | Reply
  35. pharmacy rx one reviews

    Motilium pharmacy rx one reviews canadian pharmacy

    June 20, 2021 at 01:02 | Report abuse | Reply
  36. canada pharmacy generic cialis

    Ez pharmacy canada pharmacy generic cialis ed drugs canada

    June 20, 2021 at 02:37 | Report abuse | Reply
  37. pharmacepticacom

    hydroxychoriquin https://pharmaceptica.com/

    June 20, 2021 at 03:14 | Report abuse | Reply
  38. online cialis reviews

    Tadalafil (cialis) online cialis reviews what to do if cialis doesnt work

    June 20, 2021 at 03:59 | Report abuse | Reply
  39. cavalier store hours

    Keep this going please, great job!

    June 20, 2021 at 04:50 | Report abuse | Reply
  40. cialis daily review

    Buy cialis with dapoxetine cialis daily review cialis maximum daily dose

    June 20, 2021 at 04:56 | Report abuse | Reply
  41. cialis and alcohol reddit

    Prescription free cialis cialis and alcohol reddit brand cialis for

    June 20, 2021 at 05:14 | Report abuse | Reply
  42. what happens when a woman takes cialis

    Canadian pharmacy cialis no prescription what happens when a woman takes cialis canadian cialis reviews

    June 20, 2021 at 05:55 | Report abuse | Reply
  43. buy cialis online india

    Where to buy cialis online for cheap buy cialis online india
    viagra cialis meds

    June 20, 2021 at 09:45 | Report abuse | Reply
  44. how long does cialis stay in your system

    Buy cialis 365 pills how long does cialis stay in your system cialis risks

    June 20, 2021 at 11:22 | Report abuse | Reply
  45. canada pharmacy online legit

    Script pharmacy canada pharmacy online legit Nootropil

    June 20, 2021 at 12:08 | Report abuse | Reply
  46. walgreens store locator 24 hour pharmacy

    Online pharmacy florida walgreens store locator 24 hour pharmacy legitimate canadian pharmacy list

    June 20, 2021 at 15:39 | Report abuse | Reply
  47. www.pharmaceptica.com

    what is hydroxychloroquine prescribed for https://pharmaceptica.com/

    June 20, 2021 at 18:04 | Report abuse | Reply
  48. okay google canadian pharmacies on the web

    Canadian government approved online pharmacies okay google canadian pharmacies on the web pharmacy online prescription

    June 20, 2021 at 20:04 | Report abuse | Reply
  49. canadian pharmacy adderall

    Capoten canadian pharmacy adderall international drug mart canadian pharmacy online store

    June 20, 2021 at 20:12 | Report abuse | Reply
  50. buy cialis online free shipping

    Cialis tablets buy cialis online free shipping voucher
    cialis index

    June 20, 2021 at 22:34 | Report abuse | Reply
1 2 3 4 5 6 7 8 9 10 11

Post a comment


CNN welcomes a lively and courteous discussion as long as you follow the Rules of Conduct set forth in our Terms of Service. Comments are not pre-screened before they post. You agree that anything you post may be used, along with your name and profile picture, in accordance with our Privacy Policy and the license you have granted pursuant to our Terms of Service.

« Previous entry
About this blog

Get a behind-the-scenes look at the latest stories from CNN Chief Medical Correspondent, Dr. Sanjay Gupta, Senior Medical Correspondent Elizabeth Cohen and the CNN Medical Unit producers. They'll share news and views on health and medical trends - info that will help you take better care of yourself and the people you love.