However, the way the analysis has been conducted has provoked heated debate.
The research team says all the drugs they reviewed remove amyloid from the brain so their analysis tells you if that approach works.
However, other experts say differences in the way each drug works are important and it’s unfair to group older experimental drugs with newer ones proven to work.
Prof Bart De Strooper, from the UK Dementia Research Institute at UCL, said the review “does not clarify the evidence, it blurs it” and added that “the flaw in this review is fundamental”.
“Many early programmes failed, but newer antibodies have delivered modest yet real clinical benefit,” he said.
Dr Richard Oakley, from the Alzheimer’s Society, said: “It’s essential that we interpret this review with nuance and avoid taking a sledgehammer to decades of pioneering scientific study.”
At the moment the only way to get these drugs in the UK is by paying for them privately, which puts them out of reach of most people.
The National Institute of Health and Care Excellence – which decides on the drugs the NHS will pay for – has rejected them in the past, but is reviewing the evidence, external again to account for the burden placed on unpaid carers.