Sticking to a vegetarian diet isn’t always healthy and some veggies may even increase their risk of heart disease, scientists say.
Consuming a plant-based diet is widely considered to be the most health conscious way to eat, but vegetarians who consume sweetened drinks, refined grains, potatoes and sweets remain at risk from cardio-metabolic diseases, despite cutting out meat.
Researchers from Harvard University designed separate diets which focused on plant food with a reduced animal food intake and a vegetarian diet that emphasised the intake of healthy plant foods such as whole grains, fruits and vegetables.
They also studied a third which was based on unhealthy diet of less healthy plant foods like refined grains.
Dr Ambika Satija, a postdoctoral fellow at the Harvard T.H. Chan School of Public Health said: ‘When we examined the associations of the three food categories with heart disease risk, we found that healthy plant foods were associated with lower risk, whereas less healthy plant foods and animal foods were associated with higher risk.
It’s apparent that there is a wide variation in the nutritional quality of plant foods, making it crucial to take into consideration the quality of foods in a plant-based diet.’
Lead author Dr Satija chose to exclude participants with coronary heart disease, stroke, cancer and coronary artery surgery.
But during a follow-up found that 8,631 participants had developed coronary heart disease.
Results showed that a diet of whole grains, fruits and vegetables were associated with a substantially lower risk of heart disease.
The Rush University Medical Centre in Chicago, IL, USA, backed the research and said not all plant-based foods are equally healthy.
In a follow up to the research authors will now examine dietary patterns to understand the effect of gradual adherence to a plant-based diet through reduced animal food intake and increased plant food intake on heart disease risk.
Dr Kim Allan Williams said: ‘Plant-based diets with whole grains, unsaturated fats and an abundance of fruits and vegetables deserve more emphasis in dietary recommendations.
‘Just as physical activity is a continuum, perhaps an emphasis on starting with smaller dietary tweaks rather than major changes would be more encouraging and sustainable.’
The study was published in the Journal of the American College of Cardiology.