The English singer and songwriter—who first rose to fame in the ‘90s pop group Take That—is said to be making the transition back to veganism after a hiatus in light of a recent health scare per the UK’s Daily Star.

Though the musician was plant-based for a period of time, he had reintegrated animal products like fish into his lifestyle until a recent check-up at his doctor's office revealed abnormally high mercury levels in his system.

"His recent check-up returned the highest mercury poisoning levels his doctor had ever seen,” a source told the outlet. "[Williams] guesses it was from fish but as a result, he's now gone back to being plant-based again." While a representative for Williams declined to comment for the piece, a quick perusal of his Instagram account includes several fish dishes on his feed. (It also reveals Williams striking a pose at the end of 2019 with Simon Cowell who ditched his plant-based ways following an electric bike accident.)

So, how, exactly does mercury leap from land to water to the human body? Erin Wagner, RD, CDCES breaks it down: “Mercury gets into fish mainly from burning coal for energy. Inorganic mercury is released with coal emissions, ending up either on land or in water. Small organisms in the water turn inorganic mercury into a toxic material,” she explains. “Small fish eat these plants and then the larger predators (i.e. shark, swordfish, some large varieties of tuna) can end up with high levels of toxic mercury.”

While there’s no denying that the consumption of fish is bad for the environment, animal welfare, and when they contain high mercury levels, our health, omega-3 fatty acids—which are found in a variety of fish—are known to fight inflammation, protect your brain and ticker, and may even safeguard your mental health.

While you may have to get a little creative, it’s easier than you think to incorporate these good-for-you fats into a plant-based diet through seeds, nuts, and soy foods like edamame.

“Flaxseeds are one of the highest sources of omega-3s, with one tablespoon containing a little over seven grams of these healthy fats. Chia seeds and walnuts are honorable mentions for their content and convenience,” says Wagner, who suggests adding any of these foods to oatmeal, smoothies, or atop a salad.

Who’s gonna pass the message along to Mr. Williams?