The Study
Caloric restriction in humans reveals immunometabolic regulators of health span
This study watched a group of healthy people who chose to eat less for 2 years and compared them to others who didn’t. It can show that eating less was linked to better thymus function and changes in genes, but it can’t prove that eating less caused these changes — other things might be responsible.
Analysis score
Maximum 72 for a cohort study.
Where the score came from
This study looked at what happens when people eat 14% less food for 2 years. It found their immune factories (like the thymus) worked better and made more new immune cells. Their fat tissue also changed in ways that reduced inflammation and improved energy use. A gene called PLA2G7 seemed to play a big role — when it was turned off in mice, they got similar benefits even without eating less.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 537 / 100
Quality score
Groups of people are followed over time to see who develops an outcome. Strong for identifying risk factors and associations, but cannot prove causation as firmly as RCTs.
Key takeaways
Summary
Based on the study abstract and findings.
- 1These changes suggest that moderate calorie restriction may slow immune aging and improve long-term health, and that targeting the PLA2G7 gene could offer similar benefits without needing to restrict food intake.
- 2People who ate 14% fewer calories for 2 years had bigger thymus glands and more new T cells.
- 3Their fat tissue showed changes in 364 genes linked to better metabolism and less inflammation.
- 4Mice without the Pla2g7 gene had healthier thymuses and less inflammation as they aged.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Science
Year
2022
Authors
O. Spadaro, Y. Youm, I. Shchukina, S. Ryu, S. Sidorov, A. Ravussin, K. Nguyen, E. Aladyeva, A. Predeus, S. Smith, E. Ravussin, C. Galbán, M. Artyomov, V. Dixit
Related Content
Claims (6)
If healthy middle-aged people eat 14% less food for two years, a certain gene in their fat tissue becomes less active, and this change is linked to better energy use, less body-wide inflammation, and healthier metabolism — meaning this gene might help the body adapt to eating less.
Cutting calories by 14% for two years might reprogram fat tissue in middle-aged people in ways that reduce inflammation and boost energy burning, which could help them stay healthier longer.
In middle-aged mice, removing a gene called PLA2G7 seems to calm down overactive immune cells and reduce damaging molecules in their energy factories, especially when they're exposed to certain fats—hinting that this gene might speed up aging-related inflammation.
Eating 14% less food for two years might help middle-aged adults grow a stronger immune system by boosting the thymus, the organ that makes new immune cells — kind of like giving your body's defense system a tune-up as you age.
Deleting a specific gene in middle-aged mice helps keep their immune system stronger as they age, kind of like how eating less does — so blocking that gene’s protein might help slow immune aging.
Eating fewer calories might help your body handle a not-so-great diet better by boosting its ability to stay healthy metabolically.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.