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 (16 Responses)
  1. KetoBoy

    What about carbohydrate restriction diets?

    It's time to really test that hypothesis.

    August 30, 2012 at 01:07 | Report abuse | Reply
  2. hez316

    I am surprised. I had read articles for many years stating this approach extended life. Makes you wonder what you can believe.

    August 30, 2012 at 21:41 | Report abuse | Reply
  3. Lav

    If this is true I feel bad for all those people who starved themselves for years believing this was true.

    September 4, 2012 at 13:45 | Report abuse | Reply
  4. jxhonYitT

    after again griffey shoes this could be supported 2012 ken griffey jr sneakers on with all the youthful crew it looks getting a lot more just like a forge assertion whereas with every one of the elder group it undoubtedly comes economical in direction of Comfortableness and merging it utilizing a layout and elegance affirmation is mostly a bonus. Then make a listing through the objects that they really need to ken Griffey shoes really have to appear for. Lot of expenditure and financial commitment is indicated through this 12 months. When he was whining/complaining/commiserating in excess of yet another topped shot, this just one his 2nd into a very long par five, I asked him what he did to accurate the problem/swing fault/issue the last time.

    Hand and Eye Coordination. Avid followers often hold massive collections of items associated which has a specified celebrity and make investments a particular number of emotion into their ken Griffey jr shoes selection. Frequently, anyone who will get a tattoo for self-expression happens up with an genuine tattoo style and design.

    The Nikon Coolpix L120 retains the relatively significant and comfortable hand-grip of its predecessor, which nevertheless homes the 4 AA batteries required to electrical power the video clip digicam, but this time all-around it extra gains from a a little additional considerable textured rubberised place to help working with. A single other challenge of internet shopping may be the consumers getting a completely wrong griffey shoes product by misinterpretation or misunderstanding. After inquiring regarding the higher than information and facts, then it's time to check with about value. Anywhere and anytime will be the major one of a kind selling popularity of your online keep.

    Accidents are more possible to take place. Without the ideal cloth, your toes will start out to sweat without release. I used to be equipped to determine that these shoes nike griffey rapidly turned a very hot merchandise considering that they had been released to the market place.

    You definitely want incredibly comfy chairs that will continue to keep the customers around for a longer time. Just one typically will not imagine wind chimes as getting very particular. Rainfall patterns adjust could be ken Griffey shoes predicted with out triggering flooding in one put, although the drought in other places.

    In addition they look ahead to browsing for these spouse or girlfriend simply because they know them nicely and certain possess a variety of terrific present suggestions for what to invest in. Les bottes ont t un best-seller depuis 2010 avec Kate Moss, Nadine Coyle et Jennifer Aniston tous repr les porter au cours des dernires years.Massively apprcie des surfeurs australiens instant trois dcennies, UGG Bottes a enregistr une hausse impressionnante de 130pc anne de ventes en anne depuis lors . There are actually differing types of work out routines to pick from as well as plan should be to select the sort that satisfies your requirements. His / her Airness may be virtually situations away from selecting from your commitment he in addition to Nike and likewise placing your signature on on using an extra sneaker big, Adidas.

    Every Facebook consumer incorporates a information feed that may be stuffed with data pertaining to their group of close friends. The Sony Ericsson Spiro is really a Walkman phone combining a 100 % tunes library with the capabilities of your fantastic mobile. All it truly is a necessity to complete is to shop spherical and examine charges.

    there are actually naturally griffey shoes shops exactly where you will be equipped to acquire toddler cleats, on the other hand they may be normally really hard tofind.

    September 4, 2012 at 23:58 | Report abuse | Reply
  5. adidas newterrex agravic xt gtx

    nike tiempo legacy blue and orangenike air max 90 womens grey fluorescent green shoes nike air max 90 nikemens air max 2018 green blue blacknike air max 97 mens running shoe black
    adidas newterrex agravic xt gtx http://www.dellaise.com/en-mens-sale/adidas-newterrex-agravic-xt-gtx

    March 19, 2019 at 23:31 | Report abuse | Reply
  6. Zohandtiemn

    which is better viagra or viagra
    viagra 10mg or 20mg you cannot reply to topics in this forum
    online viagra
    – effects of viagra
    [url=https://viagranfl.com/#]sildenafil 100mg for sale
    [/url] viagra lily

    November 26, 2020 at 01:41 | Report abuse | Reply
  7. Zohandtiemn

    viagra 20 mg 4 tablet users browsing this forum
    viagra discount price
    generic viagra pills for sale
    – viagra injury lawyer ohio
    [/url] online farmacy, viafra, viagra

    November 29, 2020 at 01:48 | Report abuse | Reply
  8. Janis

    cialis and alcohol safe announcements cialis genu...8093 – cialis dosage 40 mg forums [url=https://pharmwalmart.com][/url] cheap cialis u.k.

    December 4, 2020 at 02:21 | Report abuse | Reply
  9. Violette

    how long does cialis work illiterate cialis hotmail spam – canadian pharmacy cialis 20mg
    you cannot reply to topics in this forum [url=https://pharmwalmart.com][/url]
    does cialis work with alcohol bbs.cgi?page=

    December 5, 2020 at 06:15 | Report abuse | Reply
  10. ZillieReact

    cialis condanna penale
    herbs for ed
    20mg cialis generic usa
    – generic cialis right now
    [url=https://cialisbin.com]looking to buy viagra, cialis,
    [/url] cialis from canada no prescription search

    December 18, 2020 at 12:37 | Report abuse | Reply
  11. Roxana

    cialis information tadalafil no registered users and cialis information patients password buying cialis online reviews – cialis
    5mg canada board index [url=https://cialisbin.com/#]blood thinner and cialis[/url] does cialis work for
    everyone guestbook.htm

    December 19, 2020 at 17:49 | Report abuse | Reply
  12. DocSnunk

    viagra uk online
    viagra 5mg in total there are
    viagra without doctor
    – viagra dose mg no registered users and
    https://viagwithoutdct.com/# – generic viagra no prescription
    do you get a better result with 20mg of viagra then 10mg

    December 30, 2020 at 03:58 | Report abuse | Reply
  13. aigovojiyie

    http://mewkid.net/when-is-xuxlya2/ – Amoxicillin 500mg Amoxicillin 500 Mg zvv.jflo.thechart.blogs.cnn.com.dvm.pt http://mewkid.net/when-is-xuxlya2/

    January 10, 2021 at 00:20 | Report abuse | Reply
  14. oqoayca

    http://mewkid.net/when-is-xuxlya2/ – Buy Amoxicillin Online Without Prescription Amoxicillin Online upm.gfjm.thechart.blogs.cnn.com.kpu.pl http://mewkid.net/when-is-xuxlya2/

    January 10, 2021 at 00:39 | Report abuse | Reply
  15. Rosa

    cialis 10mg how long does it last memberlist cialis from canada online search cialis 5 mg –
    long term effects of cialis [url=https://cialisboss.com/#]cialis generic
    20mg[/url] cialis vs viagra which is better light.cgi?page=

    January 11, 2021 at 02:44 | Report abuse | Reply
  16. Jahesbut

    canadian pharmacy cialis professional no registered users and
    cialis information side effects usergroups
    5mg cialis
    – cialis daily dosage bph
    https://cialisboss.com/# – cialis prices
    viagra cialis

    January 12, 2021 at 21:05 | Report abuse | Reply

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.