Spirulina Extract Improves Visual Learning and Visual Working Memory in Older Adults

by | Nov 21, 2022 | 2022, Aging, Brain Health, Cognitive Health, Spirulina

Written by Taylor Woosley, Staff Writer. 12-week supplementation of a Spirulina maxima 70% ethanol extract (SM70EE) resulted in statistically significant improvements in visual learning (p=0.007) and visual working memory tests (p=0.024). 

spirulinaThe populations of most countries are aging rapidly, and with advancing age, elderly people usually experience a decline in cognitive functions1. The spectrum of cognitive decline in the elderly ranges from normal cognitive decline with aging to subjective cognitive impairment to mild cognitive impairment (MCI) to dementia2. MCI is a condition in which individuals demonstrate cognitive impairment with minimal impairment of instrumental activities of daily living3. The conversion rate from MCI to dementia is reported to be about 10% per year4.

It is known that dietary factors can contribute to maintaining neuronal functions and synaptic plasticity, through the activation of biological mechanisms underlying brain health and mental functions5. Spirulina is a fresh-water blue-green algae that contains various nutrients such as protein, B vitamins, vitamin E, chlorophyll, beta-carotene, and iron, and has been previously studied for its beneficial neuroprotective effects6. It also provides health benefits which include antibacterial, antioxidant, and anti-inflammatory properties7. It is also a rich source of phycocyanobilin, an inhibitor of NADPH oxidase, which is implied to be a contributor to oxidative stress in a variety of neurodegenerative diseases8.

Choi et al. conducted a randomized, double-blind, placebo-controlled clinical trial to report the effects of spirulina on cognitive function in older adults (aged over 60 years) with memory impairment. The spirulina used in the study was SM70EE, a Spirulina maxima 70% ethanol extract, which also contained chlorophyll at a concentration of 15.68 ± 0.76 mg/g. Placebo used in the trial was identical in appearance to the treatment product and contained gardenia pigments and caramel color. Subjects (n=74) were randomized into two groups of 37 individuals and were allocated to consume either 1 g of an active SM70EE product or a placebo, three times a day for 12 weeks.

Subject inclusion consisted of being age 60 years or older and with a score of 25-28 on the Korean mini-mental status examination (K-MMSE). Every 6 weeks participants underwent tests related to memory improvement, vital signs, the Korean version of the Montreal Cognitive Assessment (MoCA-K) and a computerized neurocognitive function test (CNT). Blood samples were obtained to evaluate biomarkers. Amyloid-β (Aβ) was measured in the plasma samples using an enzyme-linked immunosorbent assay (ELISA) using the Human Aβ Assay Kit. Brain-derived neurotrophic factor (BDNF) was measured using a BNDF rapid ELISA kit and total antioxidant capacity (TAC) was measured using the ferric reducing antioxidant power method.

An independent t-test was used to evaluate the efficacy for differences in changes in primary validation indicators (visual working memory, visual learning, verbal learning tests) and secondary validation indicators (MoCA-K, BDNF, Aβ, and TAC) between the test and control groups, before and after 12 weeks of treatment. Furthermore, a paired t-test was utilized to analyze the difference in changes in the results of the 7 tests in the test and control groups, before and after 12 weeks of product consumption. Study participants consisted of 59 women and 21 men, with an average age of 68.26 ± 4.68 years. The mean K-MMSE score was 26.38 ± 1.06, with no significant difference between the two groups, and no other variables were found to be statistically significant between the groups (p>0.05). Significant results of the 12-week study are as follows:

  • There was a statistically significant difference between the groups after 12 weeks regarding their visual learning (p=0.007) and visual working memory (p=0.024) when comparing the amount of change before and after 12 weeks of SM70EE intake.
  • There was a statistically significant difference between the two groups in vocabulary (p=0.043).
  • Although the increase in TAC was not significant (p>0.066), the efficacy increased to a level that will need to be verified through further studies.

Findings of the randomized, double-blind, placebo-controlled clinical trial show that 12-week supplementation of SM70EE significantly improved scores related to visual learning and visual working memory tests. Therefore, SM70EE use resulted in an enhanced memory improvement effect. Further studies should continue to explore the neuroprotective effects of SM70EE, along with learning more about its potential to improve TAC levels.

Source: Choi, Woon-Yong, Won-Kyu Lee, Tae-Ho Kim, Yong-Kyun Ryu, Areumi Park, Yeon-Ji Lee, Soo-Jin Heo, Chulhong Oh, Young-Chul Chung, and Do-Hyung Kang. “The Effects of Spirulina maxima Extract on Memory Improvement in Those with Mild Cognitive Impairment: A Randomized, Double-Blind, Placebo-Controlled Clinical Trial.” Nutrients 14, no. 18 (2022): 3714.

© 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/).

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Posted November 21, 2022.

Taylor Woosley studied biology at Purdue University before becoming a 2016 graduate of Columbia College Chicago with a major in Writing. She currently resides in Glen Ellyn, IL.

References:

  1. Yu S, Wei M. The Influences of Community-Enriched Environment on the Cognitive Trajectories of Elderly People. Int J Environ Res Public Health. Aug 23 2021;18(16)doi:10.3390/ijerph18168866
  2. Jongsiriyanyong S, Limpawattana P. Mild Cognitive Impairment in Clinical Practice: A Review Article. American journal of Alzheimer’s disease and other dementias. Dec 2018;33(8):500-507. doi:10.1177/1533317518791401
  3. Petersen RC, Lopez O, Armstrong MJ, et al. Practice guideline update summary: Mild cognitive impairment: Report of the Guideline Development, Dissemination, and Implementation Subcommittee of the American Academy of Neurology. Neurology. Jan 16 2018;90(3):126-135. doi:10.1212/wnl.0000000000004826
  4. Sakurai K, Shen C, Ezaki Y, et al. Effects of Matcha Green Tea Powder on Cognitive Functions of Community-Dwelling Elderly Individuals. Nutrients. Nov 26 2020;12(12)doi:10.3390/nu12123639
  5. Sorrenti V, Castagna DA, Fortinguerra S, Buriani A, Scapagnini G, Willcox DC. Spirulina Microalgae and Brain Health: A Scoping Review of Experimental and Clinical Evidence. Mar Drugs. May 22 2021;19(6)doi:10.3390/md19060293
  6. Spirulina. Drugs and Lactation Database (LactMed). National Library of Medicine (US); 2006.
  7. Piovan A, Battaglia J, Filippini R, et al. Pre- and Early Post-treatment With Arthrospira platensis (Spirulina) Extract Impedes Lipopolysaccharide-triggered Neuroinflammation in Microglia. Front Pharmacol. 2021;12:724993. doi:10.3389/fphar.2021.724993
  8. Trotta T, Porro C, Cianciulli A, Panaro MA. Beneficial Effects of Spirulina Consumption on Brain Health. Nutrients. Feb 5 2022;14(3)doi:10.3390/nu14030676