In India, trans fats often take the form of vanaspati, an inexpensive cooking oil that is sometimes used repeatedly by restaurants and street vendors.

Researchers say the process of reheating vanaspati, which is made from palm oil, renders it even more lethal, and likely contributes to soaring rates of heart disease among South Asians.

Until now, efforts by the Indian government to reduce the use of vanaspati have been stymied by food producers.

Trans fats are more common in eastern Europe and particularly in countries like India, where they are in vanaspati, a type of vegetable ghee.