President Donald Trump has an idea about soft drinks that’s pretty fringe even by his own eccentric standards.

The president thinks soft drinks can kill cancer cells in the body, and that’s why he constantly guzzles it — with his devotion to fizzy drinks so complete that he had a special button installed in his desk in the White House that summons an aide to bring him Diet Coca Cola whenever he wants.

At least, that’s according to celebrity TV doctor and now-administrator of the Centers for Medicare and Medicaid Services Mehmet “Dr. Oz” Oz, who revealed the eyebrow-raising information on a podcast hosted by Trump’s eldest son Donald Trump, Jr.

“Then comes the diet soda pops, which your dad argues that diet soda is good for him because it kills grass [when] it’s poured on grass, so therefore, it must kill cancer cells inside the body,” Oz told Trump Jr.

Oz recalled once being on Air Force One and becoming appalled when he saw the president drinking an orange soft drink.

“So he starts to sheepishly grin,” Oz said, remembering the moment. “He goes, ‘You know, this stuff is good for me, it kills cancer cells.’ And then he tells me, ‘It’s fresh squeezed, so how bad could it be for you?'”

For the record, orange soda is not “fresh squeezed.” And more fundamentally, soda drinks are actually bad for you because they can cause a cascade of health problems such as obesity, diabetes, high blood pressure, high cholesterol and heart disease. Diet soda is likely not a safe alternative, either, because medical researchers have uncovered evidence that sugar-free versions of fizzy drinks can still lead to weight gain and confuse your body’s response to insulin.

As a point of historical fact, Coca-Cola does have an origin as a medicinal back in the 19th Century; pharmacist John Pemberton invented the elixir back in 1863 and advertised it as a brain tonic and alternative to alcohol. Such claims have been thoroughly debunked by subsequent research, though, soda has been linked to impulsive behavior and poor memory.

But Trump is famously adverse from listening to experts — a common characteristic in his White House, which is full of people with unfounded ideas about health and medicine. Robert F. Kennedy Jr., the Secretary of Health and Human Services, holds dangerous ideas on vaccines, while Oz himself has been ridiculed for touting unproven claims that coffee bean extract can help lose weight.

At the end of the day, Trump’s thirst for soft drinks is par the course for the man, who’s also well known for his love of fast food.

More on soda: Kids Who Drink Lots of Soda Found to Show More Impulsive Behavior, Worse Working Memory