Vegetarians healthier than meat eaters, study suggests

Blood and urine tests on over 170,000 UK adults provide further evidence of the benefits of vegetarianism, writes Peter Stubley

Vegetable-munchers have lower levels of biomarkers linked to diabetes, cancer and heart disease, researchers found (Getty)

Vegetarians appear to be healthier than meat-eaters even after accounting for age, obesity, smoking and alcohol consumption, according to a new study.

Researchers found that those who renounced red meat, poultry and fish had fewer "biomarkers" linked to conditions such as diabetes, heart disease, cancer, and kidney function problems.

However vegetarians also had lower levels of "good" biomarkers such as vitamin D and calcium, which are linked to bone and joint health.

"Our findings offer real food for thought", said research leader Dr Carlos Celis-Morales from the University of Glasgow.

"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."

The cross-sectional study looked at data from 177,723 healthy people aged between 37 and 73 who reported no major changes in diet over the last five years. Of those, 4,111 were categorised as vegetarian and 166,516 were classed as meat eaters.

Blood and urine tests from each participant were analysed for 19 biomarkers which can have both bad and good effects.

Researchers also attempted to account for potentially influential factors including age, sex, education, ethnicity, obesity, smoking, and alcohol intake.

The analysis revealed that vegetarians had significantly lower levels of 13 biomarkers including total cholesterol, so-called 'bad cholesterol' (low-density lipoprotein cholesterol), apolipoprotein A and apolipoprotein B (both linked to cardiovascular disease), gamma-glutamyl transferase and alanine aminotransferase (liver function markers indicating inflammation or damage to cells), IGF-1 (a hormone that encourages the growth and proliferation of cancer cells), uric acid, total protein, and creatinine (a marker of worsening kidney function).

Vegetarians had significantly higher level of blood fats (triglycerides) and cystatin-C, suggesting a poorer kidney condition.

They also also had lower levels of "good" biomarkers including high-density lipoprotein, vitamin D and calcium.

No link was found for blood sugar levels, systolic blood pressure, aspartate aminotransferase (a marker of damage to liver cells) or C-reactive protein (a marker indicating inflammation).

While the study involved a large number of participants, the authors caution that no conclusions can be drawn about direct cause and effect and raise the possibiltiy that biomarkers might fluctuate for reasons unrelated to diet. Their analysis also relied on participants accurately reporting their dietary intake.

The study is being presented at the European Congress of Obesity, which is being held online from Monday 11 May to Wednesday 13 May.