Cooks around the world use seed oils such as canola, sunflower and grapeseed for their neutral taste and higher smoke point. Yet, a growing number of social media influencers, posters on forums, politicians and podcasters have claimed that they’re “toxic.” Robert F. Kennedy Jr., Donald Trump’s choice for leader of the United States Department of Health and Human Services, has recently resurfaced the argument, urging people to “Make Frying Oil Tallow Again,” selling T-shirts, hats, dog bandanas and car magnets with the slogan in his merch store.