Some of the most popular promote high-fat, low-carbohydrate “ketogenic” diets and suggest they are effective in fighting cancer, despite no clinical trials backing up the claims.
Some claim they restrict calorie consumption and therefore the amount of fuel that cancer cells receive.
But health experts said following them could cause harm and urged patients to steer clear.
Martin Ledwick, of Cancer Research UK, said: “There is no evidence ketogenic diets can help to treat cancer, so any app that makes claims this or any other unproven therapy may help should not be promoted. This is misleading for patients and could result in harm.”
The charity added: “Apps that allow you to track and monitor your health could help you lead a healthier life.
“But when health apps start claiming that they can diagnose cancer from a selfie, warning bells start going off. When apps claim to give you a diagnosis, be wary and remember there’s no technological replacement for seeing your GP.”
Professor Helen Stokes-Lampard, chairwoman of the Royal College of GPs, added: “Health advice should always be based on robust scientific evidence, so it is deeply concerning to hear that some apps that offer spurious advice are being given such a prominent platform by some web giants.”
