The World Health Organization's 2026 dementia guidelines recommend adopting a healthy diet as part of reducing dementia risk.
They are noticeably more specific about what they do not recommend.
What WHO does not recommend
This is the part most brain-health content leaves out.
WHO does not recommend vitamin B or vitamin E supplementation, omega-3 polyunsaturated fatty acids, or multivitamin and mineral supplements for reducing dementia risk in people without a diagnosed deficiency.
That is a meaningful gap between the guidance and a great deal of what is sold and written on this subject. If you take a supplement specifically to protect your memory and you have no diagnosed deficiency, current guidance does not support it. Do not change anything you take without speaking to your doctor, who may have prescribed it for an unrelated reason.
We have written about omega-3 ourselves and are reviewing that article against these guidelines rather than quietly leaving it up.
What the evidence does support
Dietary pattern, rather than any single nutrient.
The recommendation is about how you eat overall, and it overlaps almost entirely with advice for cardiovascular health. WHO also recommends managing cardiometabolic conditions including diabetes and high cholesterol, which is the same territory approached from another direction.
What a healthy pattern looks like
Almost every diet studied for cognitive benefit shares the same core, whatever it is called.
- Vegetables, particularly leafy green ones, most days
- Whole grains rather than refined
- Fish, beans and nuts rather than red and processed meat
- Olive oil as the main fat
- Limited added sugar, and limited alcohol
The MIND and Mediterranean patterns are two named versions of that idea. The naming matters less than the pattern, and nobody needs to adopt a branded diet to eat this way.
Why supplements keep being recommended anyway
The gap between the evidence and the marketing is unusually wide here, and it is worth understanding why.
Observational studies often find that people with higher intake of a nutrient have better outcomes. When those nutrients are then given as supplements in controlled trials, the benefit generally does not appear. The most likely explanation is that eating fish is a marker for a whole pattern of living, and a capsule is not.
Supplements are also regulated far more loosely than medicines, which means the incentive to publicise a promising observational finding is large and the obligation to confirm it is small.
None of which means a supplement is harmful. It means that if you are taking one to protect your memory, the current evidence does not support that specific purpose.
Measuring rather than hoping
Dietary change is slow and its effects are invisible day to day.
A repeatable baseline is the only way to see whether your cognition is holding steady over years rather than relying on how you feel about it.