A Harvard professor has called coconut oil ‘pure poison’ at a lecture held at the Harvard T.H. Chan School of Public Health.

Karin Michaels delivered the speech, saying coconut oil is one of the worst foods you can eat because it is made mostly of saturated fatty acid, which poses a greater risk than straight lard.

Michaels, like many experts, are skeptical of its rising popularity as a purported health food. Dr. Alice H. Lichtenstein, a Tufts university professor of nutrition science and policy, says despite the hype there is virtually no data to support it.