Janelle Monáe revealed in an interview in The Cut this week that she recently changed up her diet and became a pescatarian, which led to an unexpected health scare.

Though the details are thin, the singer — who announced Thursday (Feb. 6) that she has joined the performance lineup for Sunday night's Academy Awards — said she is recovering from a bout of mercury poisoning, which she suggested was a result of her new fish-heavy diet; a spokesperson for Monáe said no additional information was available on her illness at press time.

The "Take a Byte" singer told the magazine that the switch to a mostly plant-based diet that includes some aquatic elements had her "feeling my mortality." Given the scare, Billboard reached out to the University of Chicago's associate director of adult nutrition, Dr. Edwin McDonald, a gastroenterologist (and trained chef) to find out more about mercury poisoning.

"Mercury in fish has been a concern for many years, since [1956] when there was an industrial accident in Japan in Minamata where a factory dumped wastewater with a lot of mercury in it into the water supply and a lot of people, including pets and animals, developed neurological symptoms that they called 'Minamata Disease.' It caused shaking and twitching," explains McDonald, who does not have first-hand knowledge of Monáe's case, but was speaking in general terms about the effects of mercury on humans.

McDonald explains that mercury is a neurotoxin that sometimes leeches into the water from coal plants where it can build up in fish, leading to absorption into humans who consume those fish. And though he could only recall one true case of mercury poisoning that he's observed in his practice — which involved an octogenarian who had an old-school style of dental fillings that contained mercury — he says that fish are the most common current route of exposure to the silvery, metallic element.

"The wastewater pollution gets into the water and the smaller fish start to consume it, then the larger fish consume the smaller fish and it builds up," he says. "One of the reaaons why larger fish like sharks, mackerel and large tuna have the most mercury is because the smaller fish don't live long enough to accumulate higher levels." Though a switch to a pescatarian diet can cause mercury to build up in the body, he notes that fish are also rich in the essential mineral selenium, which can offer some protection from mercury poisoning. 

"Mercury poisoning is extremely rare," he says. "It's something we should all be aware of and I'm not sure what symptoms Monáe had, but mercury toxicity makes it so you can barely walk and you can't control your limbs … and for Janelle, I've seen some of her recent performances and it seems like it was probably not at such high levels."

McDonald says that unless you are eating large quantities of tuna three times a day every day for years, the chances of suffering from severe mercury poisoning are pretty slim. Long periods of chronic exposure can, however, cause neurological symptoms as well as heart disease, numbness and tingling. Low-level toxicity typically has less obvious effects, which he speculates is what Monáe may have suffered from. That said, he notes that pregnant women and women who are breast-feeding should definitely avoid fish that are high in mercury, as well as raw sushi, because developing fetuses are very sensitive to even small amounts.

"A pescatarian diet is very healthy unless you're eating fish that is not cooked properly," he says, adding that a diet rich in vegetables with some fish is associated with a decreased risk of heart disease, diabetes and obesity. "Her concern is a valid one because there is mercury in fish and chronic exposure to low levels is not the healthiest thing for your body." He suggests eating a variety of fish and sticking to smaller, shorter-lived fish as part of a diverse diet.

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