There are decades worth of animal studies centered on calorie restriction and its ability to extend life span in mice, worms, and flies.
But what about moderate calorie restriction in humans? A new study confirms similar benefits and identifies how calorie restriction plays a role in enhancing long-term health in people.
In the first controlled study of calorie restriction in healthy humans out of Yale University, researchers looked at the baseline calorie consumption of 200 participants. They then asked some participants to reduce their calorie intake by 14% and tracked both groups for two years to assess any long-term impacts that the calorie restriction had on their health. The research team looked closely at the thymus gland function of participants using an MRI. The thymus gland is responsible for producing immune-based T cells. By the age of 40, most people have a fatty thymus gland that is 70% non-functional.
- After two years, the group that restricted calories had better functioning thymus glands. The thymus glands of these participants were less fatty and produced more T cells than at the start of the study.
- Participants who did not restrict calories saw no positive change to their thymus function.
- When looking at body fat, the research team observed that the gene expression of fat tissue in the group that restricted calories changed. This change led to lower inflammation, improved immune health, and increased lifespan when mimicked in mice.
The authors of this study hope that the next stage of this research could hone in on the gene PLA2G7, identified as the main factor in the positive effects of calorie restriction. There could be the potential to manipulate this gene to achieve the benefits of calorie restriction without actually changing calorie intake. The rejuvenation of the thymus gland is also a very significant finding for longevity and immune health. While the benefits of various diets continue to be hotly debated, this well-controlled study showed that moderate calorie restriction with no specific diet was enough to have a profound, positive impact on human health.