A new study published in Metabolism of Life reports that a single postprandial blood biomarker, the 1-hour postprandial SPARC (SPARC-1H), can predict who will benefit most from adopting a Mediterranean diet. The discovery provides one of the clearest examples to date of how precision nutrition can identify personalized dietary responses using a simple blood test rather than complex multi-ohmic models.
Researchers led by Drs. Jiqiu Wang and Guang Ning at Shanghai Jiao Tong University Ruijin Hospital conducted a six-month randomized controlled feeding trial involving 235 overweight or obese Chinese adults with prediabetes. Participants were assigned to one of three calorie-restricted dietary patterns: a Mediterranean diet, a traditional Jiangnan diet, or a control diet reflecting modern Shanghai dietary habits. All participants consumed controlled meals five days a week in a 25% caloric deficit.
Throughout the trial, the researchers measured circulating SPARC, a secreted protein linked to adipose tissue inflammation, in the fasting state, 1 hour and 2 hours after glucose ingestion. They found that only the 1-hour post-glucose SPARC level at baseline, not fasting or 2-hour SPARC, predicted the magnitude of metabolic improvement in the Mediterranean diet group. Individuals with lower baseline SPARC-1H showed greater improvements in insulin resistance, fasting insulin, and fasting glucose after six months of adherence to the calorie-restricted diet. This prediction pattern was not seen in the Jiangnan diet or control groups, suggesting a diet-specific metabolic interaction.
Additional analyzes showed that SPARC-1H was strongly associated with changes in specific lipid profiles, particularly reductions in various types of plasmalogens associated with red meat intake and metabolic inflammation. These lipid shifts were characteristic of the Mediterranean diet and may underlie why SPARC-1H functions as a selective predictor for this dietary pattern.
The study also revealed that different dietary patterns may require different prognostic indicators. While SPARC-1H predicted metabolic improvements only in the Mediterranean diet group, fasting SPARC, but not postprandial SPARC, was associated with improvements among participants following the traditional Jiangnan diet. This indicates that biomarkers should be interpreted within specific dietary contexts rather than applied universally.
The findings suggest that a single postprandial biomarker could help identify individuals who are more likely to achieve significant cardiometabolic benefit from a Mediterranean diet. The work highlights a practical route to personalized dietary recommendations for people at risk of metabolic diseases and highlights the importance of considering diet-specific physiology when developing precision nutritional tools.
