Washington [US]: Intermittent fasting has become a hot topic in the wellness industry as numerous laboratory studies have shown the health benefits of time-restricted eating, including increased life span. However, exactly how it affects the body on the molecular level, and how those changes interact across multiple organ systems, has not been well understood. Now, Salk scientists show in mice how time-restricted eating influences gene expression across more than 22 regions of the body and brain. Gene expression is the process through which genes are activated and responds to their environment by creating proteins.
The findings, published in Cell Metabolism on January 3, 2023, have implications for a wide range of health conditions where time-restricted eating has shown potential benefits, including diabetes, heart disease, hypertension, and cancer. "We found that there is a system-wide, molecular impact of time-restricted eating in mice," says Professor Satchidananda Panda, senior author and holder of the Rita and Richard Atkinson Chair at Salk. "Our results open the door for looking more closely at how this nutritional intervention activates genes involved in specific diseases, such as cancer."
For the study, two groups of mice were fed the same high-calorie diet. One group was given free access to food. The other group was restricted to eating within a feeding window of nine hours each day. After seven weeks, tissue samples were collected from 22 organ groups and the brain at different times of the day or night and analyzed for genetic changes.
Samples included tissues from the liver, stomach, lungs, heart, adrenal gland, hypothalamus, different parts of the kidney and intestine, and different areas of the brain. The authors found that 70 per cent of mouse genes respond to time-restricted eating. "By changing the timing of food, we were able to change the gene expression not just in the gut or in the liver, but also in thousands of genes in the brain," says Panda.