What actually slows cognitive decline?

This review concerns brain performance and the outcomes named below. It is educational information, not medical advice. Helibrain sells none of the supplements or treatments rated here.

Evidence at a glance

How to read the table. The grade is our GRADE-style certainty in the stated outcome, using the existing Helibrain evidence base: High means strong confidence, Moderate means the conclusion is likely to hold, Low means it may change with better research, and Very low means it is very uncertain. A high grade can support little or no benefit. Grades apply to the named population, comparator and outcome, not to an ingredient or habit in every setting. [3]

Size and certainty are different. Hedges’ g, Cohen’s d and SMD express a difference in units of the variation between people. Around 0.2 is conventionally small, 0.5 moderate and 0.8 large; these are descriptions, not thresholds for a worthwhile personal benefit. A g of 0.2 does not mean 20% improvement. We preserve the source metric: a z-score difference, risk ratio (RR), odds ratio (OR) or hazard ratio (HR) is labelled separately. These measures cannot be ranked as though they were all the same. Intervals are 95% unless marked otherwise. Statistical intervals do not capture every source of bias. [4]

Better test scores and fewer diagnoses are not interchangeable

FINGER, US POINTER and Maintain Your Brain studied specified combinations of behaviour change and support. Their cognitive outcomes can inform practical prevention research, but the result belongs to the whole programme, not to each ingredient separately. [18] [19] [1]

MAPT, preDIVA and the Cochrane multidomain review make the uncertainty clear: interventions and endpoints differ, and prevention of diagnosed dementia has not consistently followed cognitive-score improvement. [20] [21] [6]

Vascular health is a clinical opportunity, not a supplement claim

The blood-pressure individual-data review and the larger prevention meta-analysis support a modest cognitive-risk benefit in people for whom treatment is indicated. SPRINT’s combined MCI/dementia endpoint was positive; probable dementia alone was less certain. Longer follow-up provides additional context rather than a universal target for everyone. [8] [22] [2] [23]

The rural Chinese trial is especially relevant because it tested delivery of better hypertension care at scale. It does not justify self-adjusting medication. Decisions depend on the clinical indication, tolerability and the person’s other conditions. [9]

Hearing treatment is worthwhile without a prevention guarantee

ACHIEVE’s overall result was null, with a more encouraging prespecified higher-risk subgroup. A later risk-based analysis explores that heterogeneity, while hearing-loss cohorts establish an association rather than the effect of treatment. [10] [24] [25]

The Cochrane hearing-aid review supports improved hearing-related participation in everyday life. That benefit has value even while the dementia-prevention question remains open. It should not be relabelled a large cognitive effect. [11]

Avoid turning risk-factor lists into promises

The Lancet Commission describes potentially modifiable risks at the population level. Its estimates are not a personal guarantee and do not mean that every associated exposure has a proven treatment effect. Anticholinergic burden reviews illustrate the difference between a risk marker and evidence that deprescribing prevents dementia. [26] [27] [28]

Sleep and diet cohorts are useful signals, but they cannot by themselves establish that changing those exposures prevents decline. The randomized MIND and omega-3 findings are important counterweights. [29] [30] [14] [31]

Ginkgo prevention trials and aspirin’s bleeding results show why taking more products is not a safe substitute for addressing an established clinical risk. None of this is a claim about extending lifespan or reversing ageing. [16] [32] [33]

Frequently asked questions

Can cognitive decline be prevented completely?

No intervention guarantees prevention. Some clinical and lifestyle interventions modestly change risk or test trajectories in selected populations; that is different from eliminating risk.

Should I buy brain games to prevent dementia?

The evidence does not establish that commercial games as a class prevent dementia. Long-term results from a specified research programme cannot validate unrelated games.

What should I do if my memory is getting worse?

Arrange a clinical assessment when decline persists or affects daily life. A browser test or supplement cannot identify the cause or replace assessment; medication and hearing or sleep problems may need review.

Explore related pages

Explore long-term memory, use the brain health habits check, and read brain performance across age. The exam sleep planner can support planning; these pages and checks do not diagnose cognitive decline.

These activities can help you observe or organise a task. Repeated scores are affected by practice and conditions; they are not a diagnosis or proof that an intervention improved your brain.

How we reviewed the evidence

We started with the Helibrain evidence base and research library, checked the original study or review behind each estimate, and compared supportive and contrary findings. The tables retain the existing outcome-specific grades. Some outcomes have only abstract-level access; access limits and study-quality concerns are recorded in the review notes. We do not treat lack of access alone as a reason to lower a grade. Sources below support different parts of the review and are not all independent studies. Last reviewed: 5 November 2026.