You may be 40 years old, but could your brain already be showing signs of accelerated aging? New research involving more than 18,000 people suggests that the answer may depend on much more than genetics or your date of birth.

the available scientific evidence.

Certain nutritional deficiencies can affect neurological health.

For example, vitamin B12 deficiency may cause cognitive or neurological symptoms, and appropriate treatment is important.

However, correcting a deficiency is different from taking extra vitamins when nutrient levels are already adequate.

The WHO’s updated 2026 guidance does not recommend routine vitamin B, vitamin E, omega-3, or multivitamin supplementation specifically to reduce cognitive decline or dementia risk in people without a diagnosed deficiency.

No commonly marketed supplement has been convincingly demonstrated to reverse normal human brain aging.

The most reliable approach remains addressing recognized risk factors and maintaining overall