Mouse study: When it comes to living longer, it's better to go hungry than go running

May 14, 2008

BETHESDA, Md. (May 14, 2008)-- A study investigating aging in mice has found that hormonal changes that occur when mice eat significantly less may help explain an already established phenomenon: a low calorie diet can extend the lifespan of rodents, a benefit that even regular exercise does not achieve.

"We know that being lean rather than obese is protective from many diseases, but key rodent studies tell us that being lean from eating less, as opposed to exercising more, has greater benefit for living longer. This study was designed to understand better why that is," said Derek M. Huffman, the study's lead author.

The study applies only to rodents, which are different in some key ways from humans, cautions Huffman. However, at least two studies which examined people who engage in high-volume exercise versus people who restricted their calorie intake, had a similar outcome: caloric restriction has physiological benefits that exercise alone does not. Researchers expect that clues to the physiology of longevity in mice will eventually be applied to people, Huffman said.

The study, "Effect of exercise and calorie restriction on biomarkers of aging in mice," appears in the May issue of the American Journal of Physiology published by The American Physiological Society (APS; www.The-APS.org). The study was carried out by Huffman, Douglas R. Moellering, William E. Grizzle, Cecil R. Stockard, Maria S. Johnson and Tim R. Nagy, all of the University of Alabama-Birmingham (UAB) and funded by the UAB Center for Aging. Dr. Huffman is now at the Albert Einstein College of Medicine in New York.

The study built upon previous studies that showed:Two theories

Taken together, these findings indicate that caloric restriction protects against disease better than exercise does, and has the added benefit of extending the life span of some rats. Physiologists have been trying to unravel the reasons for this, and two major theories have emerged.

One theory is that exercise places stress on the body, which can result in damage to the tissues and DNA. Another theory is that caloric restriction leads to physiological changes which benefit the body.

Huffman and his colleagues designed a study to examine the roles of exercise and caloric restriction, singly and combined. They controlled for factors such as weight and the amount of energy expended versus the calories consumed.

They found: Overall, these findings indicate that the physiological stress of exercise did not produce enough damage to tissues or DNA to explain why exercise does not lengthen life span. Instead the study suggests that caloric restriction creates beneficial changes in the body's hormone levels which exercise does not. The researchers concluded that these metabolic changes play a role in extending life.

A handful of studies comparing calorie restricted people to people who are avid exercisers, found similar hormonal benefits among those eating less. However, calorie restriction studies are difficult to carry out in people because participants often complain of feeling hungry, lethargic, and cold.

Huffman also emphasized that the benefits of exercise may be greater for humans than for mice because people are more prone to develop cardiovascular diseases, and exercise is particularly good at warding off those diseases. Mice tend to die of kidney disease and cancer, Huffman said.

"I wouldn't say this study has direct implications for people right now," Huffman said. "But it shows what physiological changes caloric restriction and exercise produce. We can continue to build upon these findings until we can get a better understanding of how this works in people."
-end-
NOTE TO EDITORS: To interview Dr. Huffman, please contact Christine Guilfoy at (301) 634-7253 or at cguilfoy@the-aps.org.

Physiology is the study of how molecules, cells, tissues and organs function to create health or disease. The American Physiological Society (www.The-APS.org/press) has been an integral part of this discovery process since it was established in 1887.

American Physiological Society

Related Aging Articles from Brightsurf:

Surprises in 'active' aging
Aging is a process that affects not only living beings.

Aging-US: 'From Causes of Aging to Death from COVID-19' by Mikhail V. Blagosklonny
Aging-US recently published ''From Causes of Aging to Death from COVID-19'' by Blagosklonny et al. which reported that COVID-19 is not deadly early in life, but mortality increases exponentially with age - which is the strongest predictor of mortality.

Understanding the effect of aging on the genome
EPFL scientists have measured the molecular footprint that aging leaves on various mouse and human tissues.

Muscle aging: Stronger for longer
With life expectancy increasing, age-related diseases are also on the rise, including sarcopenia, the loss of muscle mass due to aging.

Aging memories may not be 'worse, 'just 'different'
A study from the Department of Psychological & Brain Sciences in Arts & Sciences adds nuance to the idea that an aging memory is a poor one and finds a potential correlation between the way people process the boundaries of events and episodic memory.

A new biomarker for the aging brain
Researchers at the RIKEN Center for Biosystems Dynamics Research (BDR) in Japan have identified changes in the aging brain related to blood circulation.

Scientists invented an aging vaccine
A new way to prevent autoimmune diseases associated with aging like atherosclerosis, Alzheimer's disease, and Parkinson's disease was described in the article.

The first roadmap for ovarian aging
Infertility likely stems from age-related decline of the ovaries, but the molecular mechanisms that lead to this decline have been unclear.

Researchers discover new cause of cell aging
New research from the USC Viterbi School of Engineering could be key to our understanding of how the aging process works.

Deep Aging Clocks: The emergence of AI-based biomarkers of aging and longevity
The advent of deep biomarkers of aging, longevity and mortality presents a range of non-obvious applications.

Read More: Aging News and Aging Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.