FEB 27, 2020 6:35 PM PST

Caloric Restriction Changes Gene Expression, Reduces Inflammation

WRITTEN BY: Carmen Leitch

New research has added to the evidence that suggests that dietary restriction has health benefits. The work, by a lab that has been studying this phenomenon for years, used a rodent model to show that reducing caloric intake can lower inflammation levels in the body. The findings have been reported in Cell.

"We already knew that calorie restriction increases life span, but now we've shown all the changes that occur at a single-cell level to cause that," said the senior author of the report, Juan Carlos Izpisua Belmonte, a professor in Salk's Gene Expression Laboratory and Roger Guillemin Chair holder. "This gives us targets that we may eventually be able to act on with drugs to treat aging in humans."

According to the National Institutes on Aging, calorie restriction is not just a diet; it involves reducing the caloric intake below what typical for a day without causing malnutrition or nutrient deprivation. Studies in a worm model, C. elegans, as well as in fruit flies have shown that fasting and caloric restriction, respectively, lengthened lifespan. But there is not enough evidence yet from human studied to draw firm conclusions.

We do know that as humans age, they are at greater risk for a wide variety of diseases, and animal studies have suggested that caloric restriction reduces that risk. In this research, the Belmonte lab and scientists that are Belmonte lab alumni now heading their own labs in China controlled the diets of rats from the age of 18 to 27 months, which is supposed to mimic a person's age from 50 to 70. Some rats got a normal diet while others were fed 30 percent fewer calories. The scientists also harvested several tissue types from the rodents at the start and end of that period, including fat, liver, aorta, bone marrow, muscle, and brain tissue.

Image credit: Pixabay

In this work, 56 rats yielded 168,703 cells that the researchers analyzed using single-cell genetic sequencing tools. They found that the calorie-restricted rodents did not experience many of the changes that the mice fed a normal diet did; around 57 percent of cellular changes related to aging were not observed in rodents that were fed a calorie-restricted diet.

"This approach not only told us the effect of calorie restriction on these cell types but also provided the most complete and detailed study of what happens at a single-cell level during aging," said the co-corresponding study author Guang-Hui Liu, a professor at the Chinese Academy of Sciences.

Genes related to inflammation, immunity, and lipid metabolism were found to be impacted by the change in diet. Immune cell numbers increased as rodents on a normal diet aged, which was not seen in the restricted rats. Anti-inflammatory genes in the brown adipose tissue of old rats on calorie-restricted diet were expressed at levels seen in young rats.

"The primary discovery in the current study is that the increase in the inflammatory response during aging could be systematically repressed by caloric restriction," said the co-corresponding study author Jing Qu, also a professor at the Chinese Academy of Sciences.

the ways in which caloric restriction affects various aspects of cellular function, with the overall result of reducing inflammation and the activity of many aging-related genes. / Credit: Salk Institute

"People say that 'you are what you eat,' and we're finding that to be true in lots of ways," added Concepcion Rodriguez Esteban, a study author and a staff researcher at Salk. "The state of your cells as you age clearly depends on your interactions with your environment, which includes what and how much you eat."

Sources: AAAS/Eurekalert! via Salk Institute, Cell

About the Author
  • Experienced research scientist and technical expert with authorships on 28 peer-reviewed publications, traveler to over 60 countries, published photographer and internationally-exhibited painter, volunteer trained in disaster-response, CPR and DV counseling.
You May Also Like
APR 06, 2020
Cell & Molecular Biology
APR 06, 2020
A Regulator of Fatty Acid Uptake is Identified
Scientists have found a protein that helps control how much fat is absorbed by cells in the body.
APR 15, 2020
Cell & Molecular Biology
APR 15, 2020
Sugar's Appeal Lies in a Circuit That Connects the Gut & Brain
New work may help explain why sugar cravings are so hard to satisfy.
MAY 10, 2020
Cell & Molecular Biology
MAY 10, 2020
RNA Structure Informs RNA Function
Proteins carry out many of an organism's critical functions, and they are coded for by genes. To make a protein from ...
MAY 17, 2020
Cell & Molecular Biology
MAY 17, 2020
Potential Treatment for Brain and Spinal Cord Injury is IDed
Treatment options are limited for people that have suffered swelling-inducing injuries to their brain and spinal cord. N ...
JUN 21, 2020
Genetics & Genomics
JUN 21, 2020
Controlling CRISPR Rapidly With Light
Researchers have been working on ways to use light to control the gene-editing tool CRISPR for several years.
JUL 03, 2020
Cell & Molecular Biology
JUL 03, 2020
A Gut Pathogen Moves With Help From Its Environment
Campylobacter jejuni is a foodborne bacterial pathogen that causes millions of cases of food poisoning each year.
Loading Comments...