According to a recent study of over 166,000 UK adults presented at this week’s European Congress on Obesity (ECO), vegetarians tend to have a healthier biomarker profile than meat-eaters, and this extends to adults of any age and weight and is unaffected by smoking or alcohol intake.
Biomarkers have been commonly used to measure the impact of diets on health and can have both bad and good health effects, encouraging or preventing cancer, cardiovascular and age-related diseases, and other chronic conditions. The proof for the metabolic advantages associated with being vegetarian is unclear.
Researchers from the UK-based University of Glasgow conducted a cross-sectional study analyzing data from 177,723 healthy participants (aged 37-73 years) in the UK Biobank study who reported no significant dietary changes in the previous five years to see whether the dietary choice would affect the levels of disease markers in blood and urine.
participants were classified as vegetarians (do not consume red meat, poultry, or fish) or meat-eaters, according to their self-reported diet. Researchers examined the connection between 19 blood and urine biomarkers related to diabetes, cardiovascular disease, cancer, liver, bone and joint health, and kidney function.
Even after accounting for potentially influential factors such as age, sex, education, ethnicity, obesity, smoking, and alcohol consumption, the study found that vegetarians had significantly lower levels of 13 biomarkers than meat-eaters, including;
Total cholesterol; low-density lipoprotein (LDL) cholesterol–the so-called ‘bad cholesterol; apolipoprotein A (linked to cardiovascular disease), apolipoprotein B (linked to cardiovascular disease); gamma-glutamyl transferase (GGT) and alanine aminotransferase (AST)–liver function markers indicating inflammation or damage to cells; insulin-like growth factor (IGF-1; a hormone that encourages the growth and proliferation of cancer cells); urate; total protein; and creatinine (a marker of worsening kidney function).
Vegetarians, on the other hand, had lower levels of beneficial biomarkers such as high-density lipoprotein ‘good’ (HDL) cholesterol, vitamin D, and calcium (linked to bone and joint health).
They also had slightly higher levels of fats (triglycerides) in the blood and cystatin-C (suggesting a poorer kidney condition).
Blood sugar levels (HbA1c), systolic blood pressure, aspartate aminotransferase (AST; a marker of liver cell damage), or C-reactive protein (CRP; inflammatory marker) were all found to be unrelated.
Dr. Carlos Celis-Morales from the University of Glasgow, remarked that “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, fiber, 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 their study was large the authors emphasize that it was observational, so no conclusions regarding direct cause and effect can be drawn.