Researchers are finding that lowering the overall number of calories a person eats each day may have huge health benefits.
In several recent studies, calorie restriction diets have prevented age-related inflammation and improved risks for age-related diseases like Alzheimer’s, cancer, diabetes and Parkinson’s disease. Learn about these diets and read more about the health benefits they bring to seniors.
A recent study found that lowering caloric intake by just 15% (over a span of two years) resulted in several positive results in older adults, including:
“Restricting calories can slow your basal metabolism, and if by-products of metabolism accelerate the aging processes, calorie restriction sustained over several years may help to decrease risk for chronic disease and prolong life,” says lead study author, Leanne M. Redman, associate professor of Clinical Sciences at Pennington Biomedical Research in Baton Rouge, Louisiana.
Another study, the “Comprehensive Assessment of Long-Term Effects of Reducing Intake of Energy” (CALERIE) study was the first to identify the effects of calorie restriction in adults of average weight/body mass.
During the 2nd phase of the study, results from 53 non-obese, healthy adults were gathered. The study participants in this group reduced their caloric intake by 15% over a two-year time span. The researchers then began gathering statistics on the study participants’ metabolism and oxidative stress levels.
Study participants in the calorie-restricted group lost approximately 19 pounds during the two-year duration of the calorie-restricted diet— but, losing weight was not the goal of the study. There were not any adverse effects (such as low iron level or any other signs of nutritional deficiencies) discovered at the end of the study. Rather, the study results revealed an improvement in mood, as well as an overall improvement in quality of life.
“We found that even people who are already healthy and lean may benefit from a calorie restriction regimen,” Redman says.
One of the benefits of calorie restriction, discovered in a research study with lab animals (mice studies) was that it led to a lower resting metabolism rate. “We know from mammalian studies that the smaller the mammal, the faster their metabolism and the shorter their longevity,” Redman says. Slower metabolism rates are considered the most beneficial for healthy aging, according to Redman.
“The CALERIE trial rejuvenates support for two of the longest-standing theories of human aging: the slow metabolism ‘rate of living’ theory and the oxidative damage theory,” said Redman.
Yet another study, published in Frontiers, found that limiting calories helped to slow down aging by lowering inflammation in the brain cells of mice. The study also found that exercise was not as effective as restricting calories when it comes to preventing age-related changes in the brain. “Obesity and aging are both prevalent and increasing in societies worldwide, but the consequences for the central nervous system are not well understood,” says Bart Eggen, lead author of the study and a researcher at the University Medical Center Groningen, The Netherlands. “We determined if a high or low-fat diet, in combination with exercise and food restriction, impacted microglia during aging in mice.”
Microglia are a specific type of cells in the brain and spinal cord; they function as immune cells to defend the central nervous system. Interruption of these microglia cells – which may be a result of a disease process – has been linked to age-related conditions such as Alzheimer’s and Parkinson’s disease.
Microglia also have an impact on inflammation in a specific area of the brain, called the hypothalamus. The hypothalamus is the area where Alzheimer’s is thought to begin to initially impact memory.
“Aging-induced inflammatory activation of microglia could only be prevented when mice were fed a low-fat diet in combination with limited caloric intake,” says Eggen. “A low-fat diet per se was not sufficient to prevent these changes.”
Future studies involving a larger number of human participants are needed to back up the findings of the CALERIE study. The next step researchers will take will be to examine the effects of a calorie-restricted diet in conjunction with foods high in antioxidants (such as Resveratrol) in human studies.
In the meantime, reducing the total caloric intake by 15% for most people (particularly those who are obese) may be a good plan for Alzheimer’s prevention. But before implementing any type of calorie restriction diet, be sure to consult with your healthcare provider.
Has calorie restriction impacted you or a senior loved one? We’d like to hear more about your experience with calorie restriction diets in the comments below.