Drugs that were once hailed as possible breakthroughs in the battle to treat Alzheimer’s have no meaningful clinical effect on the disease’s progression, a new Cochrane review found.
Cochrane reviews have a reputation in the medical and life sciences fields as a gold-standard, independent analysis of the evidence for and against specific health interventions or treatments. The drugs assessed in the new review, published on Thursday, target beta-amyloid proteins, which form plaques that seem to accumulate in the brains of people with Alzheimer’s. Some research suggests they may play a role in the disease. The proteins can be detected before other symptoms appear, so researchers had theorized that drugs designed to eliminate them could slow or prevent the disease, for which there is no cure. Early trials of some of these drugs suggested they might do just that, but further research just hasn’t corroborated those preliminary results.
The drugs not only seem to have no beneficial effect but also increase the risk of brain bleeding and swelling, the review found.
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“Unfortunately, the evidence suggests that these drugs make no meaningful difference to patients,” said the review’s lead author Francesco Nonino, a neurologist and epidemiologist at the IRCCS Institute of Neurological Sciences of Bologna in Italy, in a statement.
The review included 17 clinical trials with a total of 20,342 participants. Nonino and his co-authors argue that future clinical trials of drugs designed to remove amyloid proteins are unlikely to have benefits for patients, and they instead recommend other avenues of research.
One emerging theory is that inflammation associated with lifestyle factors may drive Alzheimer’s disease, and there is a growing body of research suggesting a link between inflammation elsewhere in the body and cognitive decline.

