by Marion Nestle
Feb 13 2023

Industry-funded study of the week: Astaxanthin

Astaxanthin is the dye used by growers of farmed salmon to give the fish a pink color.  They do this by matching the desired amount of the dye to this SalmoFan template.

Astaxanthin, claim its makers, is an antioxidant and, therefore, good for you.

First the public relations: Screen shot: Astaxanthin reduces work-induced visual stress in people aged over 40 – BGG trial: Astaxanthin supplementation has been found to reduce visual display terminal (VDT) work-induced visual stress in people aged over 40, according to a new Japan trial sponsored by supplier BGG Japan. Read more

As for the actual research:

The study: Effects of diet containing astaxanthin on visual function in healthy individuals: a randomized, double-blind, placebo-controlled, parallel study.  Takahiro SekikawaYuki KizawaYanmei LiNaoki Miura. J Clin Biochem Nutr.  https://doi.org/10.3164/jcbn.22-65.

Results:  In participants aged ≥40 years, corrected visual acuity of the dominant eye after visual display terminal work at 6 weeks after intake demonstrated a higher protective effect of astaxanthin in the astaxanthin group vs the control group (p<0.05). In participants aged <40 years, no significant difference was seen between the astaxanthin and control groups. Moreover, no significant difference was found in functional visual acuity and pupil constriction rate between the astaxanthin and control groups [my emphasis].

Conclusion: These results suggest astaxanthin reduces oxidative stress caused by visual display terminal work. Age-related reduction in ciliary muscle strength is likely the main detractor of visual acuity. Correspondingly, astaxanthin reduced visual display terminal work-induced visual stress in the middleaged and elderly.

Conflict of interest: This trial was sponsored by BGG Japan Co., Ltd., which provided all costs for the implementation of the trial. TS and YK are employees of BGG Japan Co., Ltd. YL is an employee of Beijing Gingko-Group Biological Technology Co., Ltd., which belongs to the same company group as BGG Japan Co., Ltd. NM received funding from BGG Japan Co., Ltd. to provide medical services to the trial participants.

Comment: BGG makes astaxanthin products.  This is a company-sponsored study conducted by researchers employed or paid by the company.  It is an excellent example of interpretation bias—putting a positive spin on results that are marginally significant in some groups but not others, or null.

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