- A small trial found that some older adults showed improvements in biological ageing markers after just four weeks on certain diets.
- The clearest effect was seen in a lower-fat, higher-carbohydrate diet, while people eating closest to their usual pattern showed little change.
- The findings are interesting, but they do not prove ageing has been reversed in any meaningful long-term sense.
A new study from the University of Sydney suggests dietary changes may influence biological ageing markers surprisingly quickly.
Researchers followed 104 adults aged 65 to 75 who were randomly assigned to one of four diets for four weeks.
The diets differed in two main ways.
Some were more plant-based in their protein mix, while others contained more animal protein.
Some were higher in fat and lower in carbohydrate, while others were lower in fat and higher in carbohydrate.
The researchers then looked at 20 blood-based biomarkers linked to biological age.
These included measures such as cholesterol, insulin and C-reactive protein.
The diet that showed the clearest effect was the lower-fat, higher-carbohydrate omnivorous diet.
Three of the four groups showed reductions in biological age scores, while the group eating most similarly to their usual diet showed no significant change.
That sounds dramatic, but it needs translating into plain English.
The study does not show that ageing has literally been reversed.
It shows that short-term changes in biomarkers used to estimate biological age can shift within a month.
That is still interesting, because it suggests the body can respond quite quickly to changes in diet quality and composition.
But it is not the same thing as proving longer life, lower disease risk or lasting rejuvenation.
The trial was short, modest in size and limited to a specific age group.
It also does not tell us whether the changes would persist once people returned to normal eating.
So the sensible conclusion is cautious rather than breathless.
Food clearly matters, and later-life dietary changes may improve health-related markers faster than expected.
