The evaluation contained in this study published in Neuroscience & Biobehavioral Reviews (2018) by Solfrizzi et al. was a systematic review involving 32 randomized controlled trials (RCTs) conducted from 2014 to 2017, which tested nutritional interventions aimed at cognitive functioning in older adults (60+) with mild cognitive impairment (MCI) or Alzheimer's disease (AD).

Can Nutritional Interventions Improve Cognitive Function in Late-Life Cognitive Disorders? A Systematic Review

Interesting News . Apr 05, 2025

The evaluation contained in this study published in Neuroscience & Biobehavioral Reviews (2018) by Solfrizzi et al. was a systematic review involving 32 randomized controlled trials (RCTs) conducted from 2014 to 2017, which tested nutritional interventions aimed at cognitive functioning in older adults (60+) with mild cognitive impairment (MCI) or Alzheimer’s disease (AD).

The primary conclusions arrived are:

  • Medical food and nutraceutical supplementation improved biomarkers of cognitive function; however, they had reportedly no clear effect on cognition in mild Alzheimer’s disease and mild cognitive impairment.
  • Antioxidant-rich foods (i.e., nuts, grapes, cherries) do improve some cognitive functioning in small-sample studies of mild cognitive impairment and mild-to-moderate dementia.
  • Omega-3 polyunsaturated fatty acids (PUFA) supplementation has improved some cognitive domains and cognition-related biomarkers in MCI and Alzheimer’s disease.
  • Antioxidants vitamins and trace elements improved biomarkers of cognition, but they could not be demonstrated to enhance cognition directly.
  • High-dose B vitamin supplementation did improve cognitive function only in those individuals who had above-average baseline omega-3 PUFA levels.
  • Folic acid supplementation improved specific cognitive functions, especially in patients with elevated homocysteine levels.

Nutrients Supportive of Cognitive Well-Being in Last-Life Disorders

If one is thinking of nutritional intervention in cognitive support for MCI and AD, the supplements that one should take are:

  • Omega-3 PUFA (DHA & EPA)—It is supporting brain function, especially for MCI-diagnosed patients and AD.
  • Foods rich in antioxidants—Nuts, grapes, and cherries might improve very specific aspects of cognitive functioning.
  • B Vitamins (B6, B9/Folic Acid, B12)—They’re good for both high-homocysteine patients and in combination with omega-3 PUFA.
  • Antioxidant Vitamins (Vitamin C & Vitamin E)—These support cognitive biomarkers but have not been shown to enhance cognition directly.
  • Trace Elements (Zinc, Selenium, Copper)—May assist in improving cognition-relevant biomarkers.

Level of Evidence: How Strong Is the Science?

This study was based on:

  • 32 randomized controlled trials (RCTs)→ Level 1B (high quality individual RCTs)
  • Systematic review of RCTs→ Level 1A (most highly recognized level of evidence)

As strong as systematic reviews of RCTs are, the study notes shortcomings, especially with population size and direct cognitive improvement for some interventions.

Can-Nutritional-Interventions-Improve-Cognitive-Function-in-Late-Life-Cognitive-Disorders-A-Systematic-Review_FRL-

Final Verdict: Does Science Support It?

The results indicate that nutrition interventions might improve cognitive-related biomarkers but their direct effect on cognitive functioning mostly remains uncertain in mild AD and MCI. Some interventions, namely omega-3 PUFA, folic acids, and B vitamins, might be able to benefit specific subgroups but not all patients generally.

What’s Next?

Future research should consider the following:

  • Larger, long-term RCTs to confirm cognitive benefits that go beyond biomarker improvement.
  • Identifying subgroups that best respond to nutritional interventions, for instance, those high in omega-3 PUFA or homocysteine levels.
  • The most beneficial combinations, optimal doses, and interactions of nutritional interventions with genetic and lifestyle factors.

Nutritional support may provide brain health benefits in late life cognitive disorders, but further investigation is warranted before definitive clinical recommendations can be made. A proper diet with essential nutrients is still the best option for cognitive maintenance.