The Crown star Claire Foy reveals ‘gross’ reason that forced her to quit coffee

Claire Foy said she quit coffee after a parasitic infection that she contracted while traveling in Morocco; she shared how she had to overhaul her diet.

Actor Claire Foy has opened up about a five-year health battle in a new podcast, revealing the stomach-churning reason she had to permanently overhaul her diet and lifestyle – she had to give up drinking coffee after discovering she had a parasitic infection.

Claire Foy is a British actor; she played Queen Elizabeth II in the Netflix series The Crown. (Netflix)

The Emmy-winning actor, 41, best known for her portrayal of the young Queen Elizabeth II in The Crown, shared the graphic details of her ordeal during an appearance on the February 4 episode of Table Manners Podcast.

A 'disgusting' discovery

Claire Foy revealed that for half a decade, she unknowingly played host to a parasitic infection. “Quite a few years ago (I gave up caffeine), I had parasites. Gross... I kept losing weight and I didn't know what was going on.”

The actor said that she believes she contracted the infection while travelling in Morocco. When she finally sought medical help, the diagnosis was more unsettling than she expected. Claire shared, “They travel as a pair, I got told by the doctor — gross, absolutely rank. It's disgusting.”

Giving up caffeine

The diagnosis led to immediate and drastic changes to her daily routine. In an effort to avoid 'hardcore antibiotics', Claire said that she opted for a specialised diet and natural remedies to clear the infection. “I basically had to go on this diet... and part of that was giving up caffeine,” she said. Despite having cleared the parasites, the actor stuck with the change, sharing that she still avoided coffee today.

Managing autoimmune health

Beyond the parasitic infection, Claire also shared what she jokingly called her 'big secret' — the fact that she also manages an autoimmune condition. To keep inflammation at bay, she said, she generally follows a strict gluten-free and sugar-free diet.

“I don't actually eat gluten or sugar... except when I go out for dinner,” she admitted, adding, “It’s just because I have an autoimmune condition, so I should avoid anything which causes more inflammation.”

According to UK-based NHS, parasitic infections — often involving various types of worms — can be contracted through contaminated food, water, or surfaces. Symptoms typically include unexplained weight loss, stomach aches, and fatigue. NHS experts recommend regular hand washing and being cautious with food and water when traveling in high-risk areas to prevent similar ‘rank’ experiences.

Note to readers: This article is for informational purposes only and not a substitute for professional medical advice. Always seek the advice of your doctor with any questions about a medical condition.