Large-scale, long-term human trials are needed to confirm the limited risk-benefit findings of fasting.
Johnson also has weekly acid peels (which use mild acid to exfoliate the skin) to maintain a “youthful glow”. But you cannot smooth sagging facial skin or remove deep scars or wrinkles. Acid peels also come with risks, including organ damage, infection, scarring and swelling.
Perhaps the most bizarre youth-inducing procedure Johnson has attempted is receiving blood transfusions from his 17-year-old son.
US biotech companies have explored plasma infusions to tackle age-related diseases in humans for decades. But there are no proven clinical benefits. Side effects from blood transfusions include blood-borne infections, fever and allergic reactions.
HISTORICAL ATTEMPTS TO STAY YOUTHFUL
Humans have been experimenting with anti-ageing methods for centuries. These have included all sorts of behavioural and lifestyle practices that are quirky, questionable, and even sadistic.
Ancient practices included crocodile dung face masks, which the Greeks and Romans used to brighten their complexions.
Romans also used donkey milk and swan fat to minimise wrinkles, due to their acclaimed rejuvenating properties.
Cleopatra apparently took daily baths in sour donkey milk. To sustain this lavish habit, she had a herd of 700 donkeys. Sour milk contains lactic acid, a naturally occurring alpha-hydroxy acid (AHA) that exists in many modern-day exfoliants. So this idea was grounded in basic science, at least.