For decades, Alzheimer's disease had no disease-modifying treatments at all — only drugs that masked symptoms for a time. That has begun to change. A wave of approvals and near-approvals has given patients and families new options. But the picture is still far from complete, and the limitations of each approach reveal something important about where the field needs to go.
This post is our attempt to lay out the landscape clearly — what is available, what the evidence shows, and how a probiotic food supplement like 1C-01 fits into a picture dominated by blockbuster biologics.
Lecanemab (brand name Leqembi, developed by Eisai and Biogen) and donanemab (Kisunla, developed by Eli Lilly) are the most prominent disease-modifying drugs to reach approval in recent years. Both are monoclonal antibodies that target amyloid-beta plaques — the protein deposits long considered a hallmark of Alzheimer's.
The clinical evidence is real but modest. In the phase III CLARITY AD trial, lecanemab slowed cognitive decline by around 27% over 18 months compared to placebo, as measured by the CDR-SB scale. Donanemab showed similar results — roughly 35% slowing in early-stage patients in the TRAILBLAZER-ALZ 2 trial. These are genuine signals. For a disease that has resisted drug development for so long, they represent a meaningful step.
But the practical picture is complicated.
It is also worth noting that these drugs do not reverse Alzheimer's — they slow it, in a specific population, at considerable complexity and cost. The question of what happens beyond the trial period, and whether the slowing is durable, remains open.
Souvenaid is a medical food — a drink rather than a drug — developed by Danone Nutricia and marketed primarily in Europe. It contains a proprietary blend called Fortasyn Connect: uridine monophosphate, choline, DHA (an omega-3 fatty acid), B vitamins (including B6, B12, and folate), vitamin C, vitamin E, and selenium.
The rationale is that these nutrients support synapse formation and maintenance. The LipiDiDiet randomised trial showed that Souvenaid slowed structural brain changes (hippocampal atrophy) and reduced progression on composite cognitive measures in people with mild cognitive impairment — though the primary cognitive outcomes at two years were not statistically significant.
Souvenaid is not a licensed medicine and makes no disease treatment claims. It is prescribed or recommended by clinicians in some countries as a supportive nutritional intervention, particularly in early-stage disease. Its main strengths are its safety profile and ease of use — it is a daily drink. Its main limitation is that the magnitude of effect is modest and the evidence base, while promising, remains contested.
The supplement market for brain health is vast and largely unregulated in terms of efficacy claims. Products containing omega-3s, B vitamins (particularly B6, B12, and folate), vitamin D, and various botanical extracts are widely sold with implied cognitive benefits. The evidence for most of them — at the doses and formulations sold — is weak to absent for Alzheimer's specifically.
B vitamins are a partial exception: the VITACOG trial from Oxford showed that B12, B6, and folic acid supplementation significantly slowed brain atrophy in people with mild cognitive impairment who had elevated homocysteine levels. But this effect appears specific to that subgroup and does not generalise broadly.
The fundamental challenge with vitamins and dietary supplements in this space is bioavailability and specificity. A multivitamin delivers folate systemically — but the liver processes and distributes it broadly. The concentrations reaching the brain, and the downstream metabolic effects, are hard to target with a pill or capsule designed primarily for nutritional adequacy.
1C-01 is a food-grade probiotic supplement. It is not a drug, it has not been approved to treat or prevent any disease, and we are not claiming it is equivalent to or a replacement for any licensed medicine. Anyone with Alzheimer's or a diagnosis of mild cognitive impairment should be under the care of a physician and should discuss any supplement with them.
With that said, the research behind 1C-01 starts from a different place than either the anti-amyloid drugs or the vitamin-based approaches.
Our co-founder Dr Yizhou Yu's work at Cambridge focused on why some neurons survive Alzheimer's while others do not. The answer pointed to the one-carbon metabolic pathway — a cellular process consistently impaired in Alzheimer's brains. Restoring its activity in animal models was neuroprotective.
1C-01 takes a probiotic approach to supporting this pathway. The details of how it works are the subject of ongoing scientific and intellectual property development — more will be published as our research progresses.
We are currently running the PROFILE Phase I trial to assess safety and biomarker effects in healthy adults aged 50–65. We do not yet have clinical evidence of cognitive benefit in humans. What we have is a peer-reviewed scientific rationale, animal model data, and an ongoing trial to generate the human evidence.
The summary of where we are in 2026 is this: the anti-amyloid drugs are real but narrow in their applicability, expensive, and require a clinical infrastructure that most people cannot easily access. Nutritional approaches like Souvenaid are safe and accessible but modest in effect. Vitamins and supplements vary enormously in quality and evidence. And the fundamental biology of Alzheimer's — why neurons die, what cellular processes fail first, and how to interrupt them early — is still being worked out.
The field needs approaches that are safe, scalable, and that address the disease's biology upstream of the point at which amyloid has already accumulated for decades. That is the space we are trying to work in — not as a replacement for any existing treatment, but as part of a broader picture of brain health that the current landscape does not yet adequately address.
For more on the science behind 1C-01, see our Research page.
1C-01 is a food supplement. It has not been approved by the MHRA or any regulatory authority to diagnose, treat, cure, or prevent any disease. This article is for informational purposes only and does not constitute medical advice. If you have concerns about your cognitive health, please consult a qualified healthcare professional.