February 9, 2023

expert reaction to study looking at long-term caloric restriction on DNA methylation measures of biological aging in healthy adults

A study published in Nature Aging looks at calorie restriction and a DNA measure of biological aging in healthy adults.

Prof Neil Mabbott, Personal Chair in Immunopathology, The Roslin Institute, University of Edinburgh, said:

“Data in this study of 200 healthy, non-obese adults showed that a reduction in dietary calorie intake of approximately 25% over a two year time period coincided with changes to the DNA in their blood cells that the authors estimate translates to a modest reduction in the rate at which their bodies were aging.  Although a reduction in calorie intake appeared to have reduced the pace of aging, it is important to note that this did not translate to an increase in estimated lifespan.

“When designing interventions that may improve aging it is important that rather than simply extending longevity, they increase the healthspan or the duration of healthy living free of chronic and aging related disease.  Further studies are now necessary to determine whether calorie restriction can similarly increase the healthspan and improve the duration of healthy aging.”

Dr Duane Mellor, Registered Dietitian and Senior Lecturer, Aston Medical School, Aston University, said:

“This is an interesting study which looked at 220 people aged between 21-50 years old, who were randomised to a 25% energy (calorie) restriction for 2 years or to eat to their appetite.  It is difficult to interpret the data in this study, to tell how the data reported in this study matched to the diets people actually stuck to, only that those told to eat less were reported to have DNA that aged slightly, but significantly more slowly.

“This study enrolled people considered to be in the healthy weight range and those who were overweight, not people living with obesity.  It suggests that measures of ageing from DNA may slow, but does not report on any physical or functional changes in ageing.

“Although interesting, it is important to be cautious and not encourage especially older adults just to reduce their food intake to slow ageing.  As, in ageing adults, maintaining a healthy weight, being physically active and eating a varied and healthy diet with enough protein is known to reduce the risk of falls.”

Prof Naveed Sattar, Professor of Metabolic Medicine, University of Glasgow, said:

“This seems well done research on complex markers in the context of a small scale calorie reduction trial, but do we really need to prove that eating less calories slows aging processes?  This should be evident from national data sets that show people from Japan who remain leaner than most are amongst the longest living of any nation.  There is also evidence from trials that drugs that remove excess sugar calories and appear to help attenuate “cellular over nutrition” also lower many outcomes linked to ageing such as heart failure or chronic kidney disease.   This new work therefore fits with an emerging body of evidence all pointing in the same direction.”

‘Effect of long-term caloric restriction on DNA methylation measures of biological aging in healthy adults from the CALERIE trial’ by R. Waziry et al. was published in Nature Aging at 16:00 UK time on Thursday 9 February 2023.

DOI: 10.1038/s43587-022-00357-y

Declared interests

Prof Neil Mabbott: “None.”

Prof Naveed Sattar has consulted for companies that make weight loss drugs and SGLT2i, and has been involved in lifestyle induced weight loss trials.

Dr Duane Mellor: “No conflicts of interest.”