Vegetarians are about a third less likely to suffer from heart disease, diabetes or a stroke than meat eaters, according to new medical research.
Those who shun meat and fish stand a better chance of not developing the high blood pressure and soaring levels of "bad" cholesterol that leads to heart and other problems, it said.
They have a 36 per cent lower rate of metabolic syndrome, the combination of symptoms that are a precursor to diabetes, heart attacks and strokes.
Even people who only give up red meat improve their diets enough to give them a slightly lower risk of developing these conditions, said the United States study.
To be diagnosed with metabolic syndrome, a patient needs to suffer three out of five risk factors - high blood pressure, high HDL cholesterol, high glucose levels, high triglycerides (fat levels in the body) and having too big a waistband.
Vegetarians are not immune to this; 25 per cent of those studied by researchers from Loma Linda University, California had metabolic syndrome.
But this rises to 37 per cent of "semi-vegetarians" and 39 per cent for omnivores, they told the journal Diabetes Care.
Metabolic syndrome in Scotland tends to get worse as people get older. Its levels among men and woman are similar, and the link with obesity causes greater health problems. Dr Rebecca Reynolds, a reader in endocrinology and diabetes at University of Edinburgh Centre for Cardiovascular Sciences, said: "Metabolic syndrome is very prevalent in Scotland because its linked in with obesity and Scotland has some of the highest obesity rates in Europe."
She added: "Other studies has shown that following a Mediterranean style diet is also beneficial so it may be that people who are vegetarian were eating more fruit and vegetables and olive oil, that might have been why.
"Our current advice would be that a healthy balanced diet would be recommended, with exercise, rather than a restricted diet."
The researchers examined 700 volunteers from a long-term health study of 100,000 adults across North America. Of the 700, about 35 per cent are vegetarian.
The results were adjusted to account for other factors like smoking, drinking, age and physical activity so it related purely to diet and not those lifestyle factors, but Dr Reynolds added there may be other life- style factors in the people they studied which were not accounted for.
Many medical reports do not rule out meat and, particularly fish, from a healthy diet but vegetarians automatically avoid highly processed meats and fatty burgers because of their diet.
The vegetarians in this study were slimmer and healthier in general, which the researchers put down to eating more healthy foods.Researcher Nico Rizzo said: "I was not sure if there would be a significant difference between vegetarians and non-vegetarians, and I was surprised by just how much the numbers contrast.
"It indicates that lifestyle factors such as diet can be important in the prevention of metabolic syndrome."
Fellow researcher Gary Fraser added: "This work again shows diet improves many of the main cardiovascular risk factors that are part of metabolic syndrome. Trending towards a plant-based diet is a sensible choice."