Vegetarians prone to strokes: Study

Vegetarians prone to strokes: Study

 

 

Strokes are the second most common cause of deaths and the commonest cause of severe disability.

Now a study has shown that deficiency of Vitamin B12, usually seen in vegetarians, can predispose a person to strokes much more than the usual risk factors — diabetes and hypertension.

"While 20% of Indians suffer from diabetes and high BP," says Dr Arun Garg, consultant neurologist, Max Hospitals, "incidence of homocysteinemia (increased levels of homocysteine, an amino acid) caused by vitamin B12 deficiency, is 70%. This is seen more among vegetarians as this vitamin is mainly found in meat and milk, if it's neither boiled nor pasteurised." In fact, deficiency of vitamins B12, B6 and folate causes two-thirds of strokes.

This risk is four times higher in vegetarians. As folate is found in vegetables and fruits, its deficiency is rare among Indians, but that of vitamin B12 is common.

Normal levels of homocysteine are 5-15 micromol per litre. Increased levels heighten the chances of blood clotting, which can lead to decrease in blood supply to the brain, causing a stroke. Studies have found high levels of homocysteine in over 80% of stroke patients. Even a rise of five micromol increases the risk of stroke by two times.

The link between strokes and vegetarianism was confirmed in a five-year study by Garg and Dr A K Jain, neurologist, Jain Neuro Centre, in two Max hospitals and this Centre. From 2003, 4,680 OPD patients were screened for vitamin B12 and homocysteine levels. Those with a history of stroke, heart disease, diabetes, chronic renal, liver problems, alcoholics and those on vitamin supplements were excluded. Most had vague complaints — tingling, numbness, chronic headaches and depressive symptoms like sleeplessness and fatigue.

It was found that 60% patients had vitamin B12 levels below 400 pg/ml and 38.9% had less than 200 pg/ml. Homocysteine levels were high (over 15 micromol/l) in 36%. And out of these, over 80% were either strict vegetarians or took non-vegetarian food less than once a week. This showed the co-relation between vegetarians and strokes.

To confirm the study, 418 ischemic stroke patients between 30-85 years admitted during the same period were analysed. It was found that homocysteine levels were high (over 15 micromol/l) in 77.5% of the patients showing vitamin deficiency can result in strokes. The effects of a stroke are serious and sometimes fatal — paralysis, loss of speech and vision, unsteadiness, double vision or even unconsciousness.

Dr Vinay Goyal, associate professor, neurology, AIIMS, says, "It's true that vegetarians have less vitamin B12 as compared to non-vegetarians. This has been proven in Indian Americans, Germans, and Chinese/Singaporeans."

Prevention would cost less than Rs 10 per day, says Garg. All one has to do is take prescribed doses of vitamin B12 and B6 and folic acid. These are shown to reduce homocysteine level by 38% and the risk of stroke by 20-30%. Goyal says, "Vitamin B12 is also there in soyabean, legumes, dairy products, cottage cheese, etc." Garg and Jain gave vegetarian patients in their study daily vitamin supplements.

Their symptoms disappeared completely after 3-6 months of therapy. Vegetarians with vitamin B12 deficiency need life-long treatment. A dose of 1-1.5 mg/day is required, says Garg. The government too should fortify food with it, much like iodized salt. Also, as India has a high proportion of vegetarians, screening should be done. So get going to quell that stroke of bad luck.