Vegetarian (and vegan) diet linked to higher stroke risk

Vegetarian and vegan diets have become increasingly popular in recent decades, promising to reduce the risk of conditions like obesity, ischaemic heart disease, high blood pressure and certain types of cancer. Still, scientists still don’t fully understand how abstaining from animal products affects the body. Now, new research sheds light on one potential risk of vegetarian and vegan diets: increased likelihood of stroke.

The study, published last week in the British Medical Journal, examined the risk factors associated with ischaemic heart disease and stroke, and it tracked the health of 48,188 men and women living in Oxford over 18 years. Each participant was grouped in one of three groups: vegetarian (including vegans), meat eater or fish eater. None of the participants had a history of ischaemic heart disease, stroke, or angina (or cardiovascular disease), and the researchers accounted for other risk factors including physical activity, education level, smoking habits and alcohol consumption.

The results showed that vegetarians were about 20 percent more likely to have had a stroke than meat eaters. However, vegetarians also had a 22 percent lower risk of heart disease, an effect the researchers suggested could be because vegetarians tend to have lower blood pressure, body mass index (BMI), cholesterol levels and incidence of diabetes.

What explains the higher risk of stroke among vegetarians? The study couldn’t provide an exact biological explanation, but the researchers did reference several studies that show:

“…that individuals with a very low intake of animal products had an increased incidence and mortality from haemorrhagic and total stroke, and also a possibly higher risk of ischaemic stroke mortality, suggest that some factors associated with animal food consumption might be protective for stroke.”

The researchers noted that vegetarians might suffer from a lack of several key nutrients.

“Vegetarians and vegans in the EPIC-Oxford cohort have lower circulating levels of several nutrients (eg, vitamin B12, vitamin D, essential amino acids, and long chain n-3 polyunsaturated fatty acids), and differences in some of these nutritional factors could contribute to the observed associations.”

The results don’t necessarily suggest you should change your diet. What’s probably more important is to make sure that you’re eating high-quality foods. For meat eaters, one easy way to improve your diet is to avoid processed foods, which a growing body of research shows can shorten lifespan and cause multiple diseases. Also, for both vegetarians and meat eaters, eating organic foods seems to be worth the slight increase in cost.

A 2018 study, for example, found that people who ate organic foods were 25 percent less likely to develop certain kinds of cancer than people who ate “conventional” diets. The New York Timesreported:

“Those who ate the most organic fruits, vegetables, dairy products, meat and other foods had a particularly steep drop in the incidence of lymphomas, and a significant reduction in postmenopausal breast cancers.”