Claire Foy unable to drink caffeine after five-year parasite infection

Claire Foy, the acclaimed actress known for her portrayal of Queen Elizabeth II in The Crown, has revealed she suffered from a parasitic infection for five years, leading her to eliminate caffeine from her diet. The 41-year-old star believes she contracted the parasites during a trip to Morocco.

Speaking candidly on the Table Manners with Jessie and Lennie Ware podcast, Foy described the unsettling experience. "Quite a few years ago, I had parasites. Gross," she shared, adding, "I kept losing weight and I didn’t know what was going on." She endured the condition for approximately half a decade. "They travel as a pair. I got told by the doctor, gross, absolutely rank. It’s disgusting."

The prolonged illness prompted significant dietary changes. Foy explained: "I basically had to go on this diet and because I didn’t want to take really hardcore antibiotics and stuff like that, I took all this little gross stuff, and part of that was giving up caffeine."

Parasites are organisms that reside in or on a host, such as a human, feeding off them. The NHS website details various types of worms that can infect people, some acquired domestically and others abroad. Common symptoms include an itchy, worm-shaped rash, persistent sickness or stomach aches lasting over two weeks, and unexplained weight loss.

Infections can occur through contact with contaminated objects or surfaces, consuming food or drink containing worm eggs, or eating raw or undercooked meat or fish. The NHS advises that worm infections are treatable with prescribed medication. Prevention methods include regular handwashing, especially before preparing food, drinking bottled or boiled water in high-risk regions, routine deworming of pets, and thoroughly washing garden produce.

Beyond the parasitic ordeal, Foy also disclosed that she avoids gluten and sugar to manage an autoimmune condition, steering clear of foods that could exacerbate inflammation. "This is my big secret, I feel like I’m in The Traitors or something, and I’m letting everyone know that I’m related to someone," she quipped. "I don’t actually eat gluten or sugar… except when I go out for dinner. It doesn’t have an impact on me. It’s just because I have an autoimmune condition, so I should avoid anything which causes more inflammation."

Foy’s distinguished career includes roles in BBC’s Wolf Hall and A Very British Scandal. Her iconic performance in The Crown earned her significant accolades, including two Emmy awards and a Golden Globe. More recently, she featured in 2022’s Women Talking and the biographical drama H Is For Hawk.