Research suggests vegetarians have healthier levels of disease markers than meat eaters

The results of a large-scale study conducted by researchers from the University of Glasgow found that adult vegetarians appear to have a healthier biomarker profile than meat-eaters, regardless of factors such as age, weight, smoking or alcohol consumption.

The researchers analysed data from 177,723 healthy participants (aged 37 – 73 years) who had reported no major dietary changes over the past five years. The study examined the association with 19 blood and urine biomarkers related to diabetes, cardiovascular diseases, cancer, liver, bone and joint health and kidney function. It was found that compared with meat eaters, vegetarians had significantly lower levels of 13 biomarkers, including total cholesterol, low-density lipoprotein cholesterol, apolipoprotein A, apolipoprotein B, gamma-glutamyl transferase and alanine aminotransferase, insulin-like growth factor, urate, total protein and creatinine.

However, vegetarians were found to  have lower levels of high-density lipoprotein cholesterol, vitamin D and calcium, plus significantly higher levels of triglycerides and cystatin-C.

No link was found for glycated haemoglobin, systolic blood pressure, aspartate aminotransferase or C-reactive protein.

The lead researcher, Dr Carlos Celis-Morales, states “Our findings offer real food for thought. As well as not eating red and processed meat which have been linked to heart diseases and some cancers, people who follow a vegetarian diet tend to consume more vegetables, fruits, and nuts which contain more nutrients, fibre, and other potentially beneficial compounds. These nutritional differences may help explain why vegetarians appear to have lower levels of disease biomarkers that can lead to cell damage and chronic disease.”

Although it was a large-scale study, it was observational, so no conclusions can be drawn about direct cause and effect. The researchers note several limitations including only testing biomarker samples once for each participant, and it is possible that biomarkers might fluctuate depending on factors unrelated to diet, such as existing diseases and unmeasured lifestyle factors. They also note that the study was reliant on self-reported dietary intake using food frequency questionnaires, which is not always reliable.


Boonpor J, Petermann Rocha F, Parra Soto S, Ho FK, Gray SR, Celis Morales C. Differences in health-related biomarkers profile of vegetarians and meat-eaters: A cross-sectional analysis of the UK Biobank study. Abstract EP3-33. 28th European Congress on Obesity. 10-13 May 2021.


Research reviewed by Jackie Day ND