Brain-protecting diet — and the truth about supplements

I see a lot of adverts for 'memory' supplements — omega-3, vitamins, multivitamins. Is it worth taking them to prevent dementia? And what should I change in my diet?

This is an area where WHO guidelines say something that advertising doesn't — and it's worth knowing both sides of the answer.

Supplements: WHO recommends against them

To prevent cognitive decline or dementia, supplementation with B and E vitamins, omega-3, and multivitamins/minerals is not recommended — and this is a strong recommendation, with moderate certainty of evidence. In other words: it's not that 'we don't know yet'; studies have been done and have shown no benefit in preventing dementia in people without diagnosed vitamin deficiencies. If a doctor has identified a specific deficiency (through tests), that's a different conversation — then the supplement treats the deficiency. But buying 'memory' supplements on your own initiative is, in light of the evidence, money poorly spent.

What WHO actually recommends: the dietary pattern

A healthy and balanced diet can be recommended to reduce the risk of cognitive decline and dementia (conditional recommendation, with moderate certainty — one of the most solid in the document). What matters is not a miracle food, but the overall pattern: adequate (sufficient nutrients without excess), balanced (energy and energy sources), diverse (real variety of nutritious foods), and moderate (little of what is proven to be harmful — salt, sugar, processed fats).

In practice, the Portuguese way

The Mediterranean pattern we already know is very close to this: vegetables and fruit every day, legumes, fish, olive oil as the main fat, little processed food, little sugar. No radical diet is needed — it's consistency over the years that protects, not perfection in a month.

The warning sign to remember

Be suspicious of any product sold as 'dementia prevention' — no supplement has such evidence, and WHO states it in black and white. The money spent on supplements is better converted into good food, or a pair of trainers for walking.