While the 98-year-old retiree turns his nose up at tea, he is reportedly a fan of drinking black coffee, which he no doubt enjoys while spending his days at the royal Sandringham estate.
According to Carrie Ruxton, a public health nutritionist from King's College London, the Duke is likely missing out on a host of nutritional benefits from not sipping black tea.
Carrie explained that drinking tea is actually better for you than drinking water, as it works to replace essential electrolytes that are lost through perspiration.
“Tea replaces fluids and contains antioxidants, so it's got two things going for it,” Carrie said.
“Also, a cup of tea contains fluoride, which is good for the teeth."
Prince Philip’s shocking revelation comes after a royal insider revealed the Queen is a big “fan” of Kate Middleton, the Duchess of Cambridge.
Speaking to Vanity Fair, the source explained the Queen admired Kate's "unflappable" nature.
"[The Duchess of Cambridge's] mantra is very like the Queen’s 'keep calm and carry on' approach in life, and she has the added benefit of making the royal family seem almost normal and in touch," the insider said.