The Radical Theory That Could Force Us To Rethink Alzheimer’s

Episode 350 What If Alzheimer’s disease starts in the body, not the brain? A radical new theory upends everything we thought we knew about the disease. Alzheimer’s is the most common form of dementia - the leading cause of death in the UK. And for 100 years we believed it all happened in the brain. Despite all of the major symptoms of Alzheimer’s being brain related, scientists studying gene activity have discovered something surprising. Most risk variants for the disease appear in the skin, lungs and gut - not the brain. This could mean the leading suspects of the disease - amyloid plaques and tau proteins - may not be to blame. But if not them, then what? Rowan Hooper is joined by New Scientist’s Australia reporter Alice Klein to discuss the findings. Chapters (00:00) Intro - A radical new understanding of Alzheimer’s (01:23) Why amyloid and tau treatments aren’t proving effective (02:16) How gum and dental health is linked to Alzheimer’s (03:09) Could proteins in the brain be a protective feature? (03:56) Why amyloid and tau really aren’t the full picture (04:35) Why scientists have gone back to the drawing board (05:37) Does Alzheimer’s start in the skin, lungs and gut? (06:14) Alzheimer’s risk genes found in the immune system and barrier tissues (07:12) Where inflammation fits into the puzzle of Alzheimer’s (09:10) The role of the blood brain barrier (10:00) How have scientists responded to these findings? (10:58) What other health conditions are linked to Alzheimer’s? (12:08) Preventative measures you can take to reduce your Alzheimer’s risk (15:03) How reframing diseases leads to better treatments To read more about these stories, visit Read the latest New Scientist CoLab article: Learn more about your ad choices. Visit megaphone.fm/adchoices

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The Radical Theory That Could Force Us To Rethink Alzheimer’s is an episode from New Scientist Weekly by New Scientist.

This episode is 18:23 long.

This episode was published on Mar 11, 2026.

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