May 11, 2021: Vegetarians have better cholesterol levels and other measures of heart health than meat eaters, according to the largest study of its kind to date.
The researchers compared 19 health measures related to diabetes, blood pressure, heart disease, cancer, liver and kidney function in 178,000 study participants who said they had followed a vegetarian or meat-eating diet for at least the past 5 years . They presented their results at this year’s European Congress on Obesity online.
The health benefits the researchers found for vegetarians were consistent despite different levels of obesity, sociodemographic factors, and related lifestyle factors, said lead author Carlos Celis-Morales, PhD, of the University of Glasgow in Scotland.
Total cholesterol and LDL cholesterol concentrations for vegetarians in the study were 21% and 16.4% lower than those for carnivores. But some biomarkers considered beneficial, including vitamin D, were lower in the vegetarians, while some considered unhealthy, including triglycerides and the kidney function indicator cystatin-C, were higher.
The study findings clearly confirm the importance of not considering any health measure in isolation, said John C. Mathers, PhD, of the Newcastle University Human Nutrition Research Center in the United Kingdom. “Health is complex, and individual markers tell only part of the story.”
Mathers says a vegetarian diet can be nutritious, but cautions that “just because someone excludes meat from their diet doesn’t necessarily mean they’ll have a healthy diet.”
The results support previous evidence from large studies, said José Lara Gallegos, PhD, senior professor of human nutrition at Northumbria University in the United Kingdom, which showed that a vegetarian diet is associated with a lower risk of heart disease.
Strictly restricted diets could also lead to certain nutritional deficiencies, Gallegos said. “Other less restrictive dietary patterns, such as the Mediterranean diet, are also associated with … health benefits.”
Many people, whether they are vegetarians or meat eaters, follow short-term diets, for example, the Atkins or the 5:2 diet, often switching between them or going off the diet altogether.
Metabolic markers tend to show a clear improvement within 3 months of adopting a particular diet, Celis-Morales said, but improvements in disease outcomes take much longer to become apparent. In a separate study published last December, he and his colleagues found that vegetarians had a lower risk than meat eaters of heart attacks and other heart diseases over nearly a decade of follow-up.
Celis-Morales and her team are also analyzing the data to understand if the vegetarian diet also carries a lower risk of cancer, depression and dementia compared to meat eaters.