Enthusiasts claim it cures nearly everything, sceptics believe it cures nothing, and, as usual, the actual evidence is hanging around somewhere politely between them.
The short answer
The short answer is that it depends, though less than the internet would have you believe. For most healthy adults, the sensible middle ground turns out to be the correct one, and the sharp claims you have seen online tend to come from small studies or from people with something to sell.
You will certainly feel something, but that does not mean it is working.
What the research says
Researchers have followed large groups over many years, and the effect appears real, if modest. It is important to keep the scale in view: a change that sounds dramatic in percentage terms may translate into a very small difference for any one individual in everyday life.
When to see someone
A few groups should take extra care, particularly anyone who is pregnant, on regular medication, or managing a long-term condition. This article is general information and not medical advice. If something has changed in your body and has stayed changed for a few weeks, see a clinician.
What should you actually do? The dull advice remains the best: move most days, sleep regularly, eat plenty of plants and keep up with the people you love. None of this will trend. It has, however, been the consistent finding of nearly every long-term study for about fifty years.
