One friend swears by the Mediterranean plate, another by plant-based eating, a third by cutting out something else. Each camp picks a winner.
A new analysis of nearly 7,500 adults suggests the whole contest misses the point.
Researchers at the German Center for Neurodegenerative Diseases (DZNE) compared ten well-known healthy eating patterns.
As they report in Nature Communications, every one of the ten patterns was linked to slower biological aging in the body.
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How the ten diets stacked up
The patterns include the Mediterranean diet, the DASH approach designed to lower blood pressure, the brain-focused MIND diet and the Nordic diet.
They also cover several plant-based scores and the EAT-Lancet pattern that balances health with lower environmental impact.
Blood samples from 6,470 adults in DZNE's Rhineland Study in Bonn made up the main dataset. The findings were then checked in a separate group of 1,034 people from a German nutrition study in Potsdam.
The team measured biological age through DNA methylation. These are small chemical tags on the DNA that switch genes on and off, and they shift in predictable ways over the course of life.
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Three so-called epigenetic clocks drew on roughly 850,000 DNA sites in total, about double what earlier work has looked at.
Different plates, same core pathways
Each diet left its own fingerprint in the methylation data. But more than 70 percent of the biological pathways affected by the diets overlapped across all ten patterns.
Those shared pathways involved cell structure, cell signaling and metabolism. Very different plates appeared to be nudging the same core machinery in the body.
"When it comes to slowing down the aging process, there isn't just one healthy diet, but indeed a whole repertoire," says Juliana Tavares, a doctoral researcher at DZNE and lead author on the study.
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A stronger signal in smokers
One result stood out. The link between higher diet quality and slower biological aging appeared stronger in smokers, even though their overall diet quality was lower than that of non-smokers.
The researchers describe them as a group that may stand to gain the most from improving the plate. The study is observational, so it cannot prove that eating better causes slower aging, only that the two track together in these cohorts.
What it means for your next shopping trip
The practical takeaway is less rigid than the usual "this is the best diet" advice. Any of the ten patterns the team examined carries a measurable link to slower biological aging in blood.
The pattern also fits with earlier research in this area.
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One short-term trial found that diet changes may lower biological age in just four weeks, suggesting the epigenetic clock responds relatively quickly to what people eat.
The DZNE association held up in both the Bonn group and the Potsdam group. The authors' answer to the question of which diet to pick is that any of these ten is a reasonable, evidence-backed choice.
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This article is made and published by Ida-Marie Palm Varbæk, who may have used AI in the preparation.