Blood 'signature' of ultra-processed diets may explain about half of their link to heart disease and diabetes

Researchers from UCL and Imperial College London published a study in BMC Medicine looking for a biological fingerprint of ultra-processed diets in the blood.

The study

• Type: observational cohort study (Whitehall II, British civil servants recruited in the 1980s).
• Participants: just over 6,000 adults who had blood tests, filled in diet questionnaires and were followed for up to 20 years.
• Method: 233 blood metabolites were measured by NMR spectroscopy; machine learning picked out 34 linked to an ultra-processed diet and 50 linked to a minimally processed diet (8 overlapped).

Findings

• The ultra-processed pattern featured lower omega-3 fatty acids and HDL (“good”) cholesterol and higher VLDL triglycerides; the minimally processed pattern was the opposite.
• People in the highest third of ultra-processed food intake had a 17% higher risk of cardiovascular disease than the lowest third.
• The highest third of minimally processed intake had a 19% lower cardiovascular risk and a 40% lower type 2 diabetes risk.
• The metabolite signature accounted for about 51% of the diet link with cardiovascular disease and 43% with type 2 diabetes. The link remained after accounting for sugar, fat and salt content; sugar explained an estimated 27% of the diabetes link.

Lead author Eunice Wang said the results hint that processing itself may play a role, but more research is needed. The UK’s Scientific Advisory Committee on Nutrition is currently reviewing evidence on ultra-processed foods.

Limitations

Because this is an observational study, it cannot establish cause and effect, the researchers note. Diet was self-reported, and the cohort of civil servants may not represent the wider population. The unexplained part of the link might involve gut microbes, inflammation or appetite signals not measured here. For advice on your own diet, talk to your doctor.