Tau is a structural protein that helps build the skeleton, much like pipes, through which nutrients and nerve signals are delivered to different parts of the brain. Our brains contain a balance of tau protein and phosphorylated-tau, abbreviated to p-tau. An abnormal accumulation of p-tau makes these tubular channels tangled and dysfunctional and triggers brain-cell death.1
Too much p-tau also messes up the mitochondria, the cells’ energy factories, potentially leading to brain fatigue. The more p-tau accumulates, the greater the risk of cognitive problems and Alzheimer’s dementia. Also, those with memory decline have been shown to have relatively more p-tau to tau protein.
The next target for dementia drugs is reducing p-tau. Consequently, drugs are being developed and tested that block the kinase enzyme and activate the phosphatase enzyme,2 which is exactly what the homocysteine-lowering B vitamins do. But so far, there are no human clinical trials reporting significant benefit.
The critical prevention question is what stops too much of the tau protein from turning into the potentially harmful p-tau in the first place and what helps restore p-tau to normal tau protein.
The answer is remarkably simple – a lack of B vitamins raises the blood levels of homocysteine, which activates an enzyme, Cdk5 kinase, which adds the bad ‘p’ to tau and blocks another enzyme, protein phosphatase A2, which removes the dangerous ‘p’.3,4 High homocysteine levels also damage the tiny blood vessels in the brain, leading to ‘mini strokes’ or transient ischemic attacks (TIAs), which further raise the levels of p-tau. Homocysteine not only raises the levels of the dangerous p-tau,5 but can also bind to tau,6 further generating the neurofibrillary tangles that then trigger brain-cell death.
So, the simplest way to stop the formation of p-tau, and neurofibrillary tangles, and keep your brain healthy, is to keep your plasma homocysteine level below 10mcmol/l. Half of those above 65 have a homocysteine level higher than this.
By now you’re surely wondering why, if these natural approaches are at least as good, if not better, than drug treatments, and without adverse effects, why this isn’t common knowledge and common practice, especially if the cost is a fraction of the drug treatments. For example, supplementing B vitamins and omega-3 fish oils might cost you £100 a year while anti-amyloid drugs are pitched at around £20,000 a year.
I’m convinced that it is exactly this last point that explains the anomaly. Naturally occurring nutrients cannot be patented; only a man-made invention, such as a drug, can be. Holding a patent means only the company making that product can sell it, and they can determine the price. The price of a drug will include a hefty margin for marketing the drug and creating all the hype to get you, the media and the medical profession to buy into it. Once the patent expires, the price plummets. The price of a leading branded statin dropped by 93 per cent, from close to £30 down to just over £2 a month,7 That’s a lot of margin for marketing. By then, the manufacturers are on to the next ‘new’ patented drug. Up to 2022 $45 billion8 has been spent so far developing the latest ineffective dementia drugs, but the real cost, including the most recent trials and marketing, could be double this. That’s a lot of money to recoup. The first stage is to develop a test that convinces you and your doctor that you ‘need’ the drug. That’s what these tests in the £10 million trial are all about. If you test high, instead of taking an ineffective drug why not do prevention? That’s what the free Cognitive Function Test at foodforthebrain.org is all about.
Extract, used with permission, from Patrick Holford’s Upgrade Your Brain (Thorsons 2024)
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REFERENCES
1. Balasu S et al. Science14 Sep 2023 Vol 381, Issue 6663 pp. 1176-1182 DOI: 10.1126/science.abp9556
2. Xia, Y., Prokop, S. & Giasson, B.I. “Don’t Phos Over Tau”: recent developments in clinical biomarkers and therapies targeting tau phosphorylation in Alzheimer’s disease and other tauopathies. Mol Neurodegeneration 16, 37 (2021). https://doi.org/10.1186/s13024-021-00460-5.
3. Smith AD, Refsum H. Homocysteine, B Vitamins, and Cognitive Impairment. Annu Rev Nutr. 2016 Jul 17;36:211-39. doi: 10.1146/annurev-nutr-071715-050947. PMID: 27431367.
4. LiJ-G,ChuJ,BarreroC,MeraliS,Pratico`D.2014.Homocysteine exacerbatesβ-amyloid, tau pathology, and cognitive deficit in a mouse model of Alzheimer’s disease with plaques and tangles. Ann. Neurol. 75:851–63.
5. Shirafuji N et al Homocysteine Increases Tau Phosphorylation, Truncation and Oligomerization. Int J Mol Sci. 2018 Mar 17;19(3):891. doi: 10.3390/ijms19030891. PMID: 29562600; PMCID: PMC5877752.
6. Bossenmeyer-Pourié C et al. N-homocysteinylation of tau and MAP1 is increased in autopsy specimens of Alzheimer’s disease and vascular dementia. J Pathol. 2019 Jul;248(3):291-303. doi: 10.1002/path.5254. Epub 2019 Mar 19. PMID: 307349
8. Cummings JL, Goldman DP, Simmons-Stern NR, Ponton E. The costs of developing treatments for Alzheimer’s disease: A retrospective exploration. Alzheimers Dement. 2022 Mar;18(3):469-477. doi: 10.1002/alz.12450. Epub 2021 Sep 28. PMID: 34581499; PMCID: PMC8940715.
