New Delhi, July 9 -- Bryan Johnson, after having spent millions to reverse ageing, has posted an Instagram Reel about the effects of weed (marijuana) on health. The 47-year-old tech entrepreneur is the subject of the Netflix documentary, Don't Die: The Man Who Wants to Live Forever.

Johnson referred to a new study showing that smoking or eating cannabis reduces blood flow, just like tobacco. The study found a 40% drop in blood flow for those who smoke it and 50% in those who consume it in edible form.

The study is based on a marker called flow-mediated dilation (FMD). It measures how well your blood vessels expand. Bryan has clarified he's not against weed. However, he believes it harms heart health and shortens lifespan.

"This is not ...