Vegetarian diet lowers risk for cancer, heart disease: Study

Compared with meat-eaters, vegetarians have healthier levels of substances in their bodies that can be signs of risk for cancer, heart disease and chronic health conditions, a study presented Saturday during the European Congress on Obesity found.

Specifically, they had significantly lower levels of 13 measurable substances called biomarkers that may be signs of disease.

In the analysis of more than 177,000 adults in Britain, vegetarians had healthier biomarker profiles than those who eat meat, the data showed.

These biomarkers include total cholesterol and low-density lipoprotein, or LDL, cholesterol, known as "bad" cholesterol, the researchers said.

In addition, vegetarians had healthier levels of two proteins linked to heart disease and two enzymes found at high levels in people with liver damage.

Vegetarians also had lower levels of insulin-like growth factor, a hormone that encourages the growth and spread of cancer cells, and creatinine, elevated levels of which are a sign of worsening kidney function, they said.

"Our findings offer real food for thought," study co-author Carlos Celis-Morales said in a press release.

"Nutritional differences may help explain why vegetarians appear to have lower levels of disease biomarkers that can lead to cell damage and chronic disease," said Celis-Morales, a research fellow at the University of Glasgow's Institute of Cardiovascular and Medical Sciences in Scotland.

Biomarkers can have both bad and good health effects, as these substances can be involved in promoting or preventing cancer, heart and age-related diseases and other chronic conditions, according to Celis-Morales.

To understand how dietary choice affects biomarker levels in blood and urine, he and his colleagues analyzed data from 177,723 healthy adults age 37 to 73 who participated in the U.K. Biobank study, an ongoing assessment of health among British adults.

Participants, none of whom reported major dietary changes over the past five year, were categorized as either vegetarian -- meaning they do not eat red meat, poultry or fish -- or meat-eaters based on their self-reported diet.

The 4,111 vegetarians and 166,516 meat-eaters were then assessed for levels of 19 blood and urine biomarkers related to diabetes, heart diseases and cancer, as well as liver, bone and joint health and kidney function.

Although vegetarians had better biomarker profiles than meat-eaters, they did have lower levels of some "beneficial" biomarkers, including high-density lipoprotein, or "good" or HDL cholesterol, as well as vitamin D and calcium, which are linked to bone and joint health.

In addition, vegetarians had significantly higher blood levels of triglycerides, or fats, and cystatin-C, a sign of worsening kidney health.

There were no differences between the two groups in terms of blood pressure, as well as blood sugar and C-reactive protein levels, the latter of which is a sign of inflammation.

"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," Celis-Morales said.