"Clinical Trial to Evaluate if Balenine, A Major Component of Whale Meat Extract, Improves Cognitive Function in Subjects with Symptoms of Increasing Forgetfulness"

Abstract

Background: Balenine (beta-alanyl-N tau-methyl histidine), an imidazole dipeptide reported to have antioxidant and anti-fatigue effects in animal models and humans, is present in abundant amounts in whale meat. Previously, we reported that long-term consumption of whale meat extracts containing balenine improve cognitive function in a mouse model of Alzheimer's disease. To test whether this cognition-improving effect of balenine can also be observed in humans, we conducted a double-blind clinical trial in subjects with symptoms of increasing forgetfulness. Methods:This study was a randomized, placebo-controlled, double-blind study. We recruited men and women aged 60 to 79 who felt that levels of forgetfulness had increased as a subjective symptom. Fourteen subjects were allocated into two groups, and one group received balenine and the other placebo, both of which were given in capsule form for 12 weeks. We performed the Mini Mental State Examination (MMSE), MCI screening, Zung self-rating depression scale (SDS), Uchida-Kraepelin test and assay for antioxidative potential and cortisol in saliva after the 6-week and 12-week consumption of capsules.Results: There were no significant changes in the MMSE, MCI screening between the two groups. Results on balenine-and placebo-treated subjects showed that the group taking balenine for 12 weeks tended to show reduced levels of depression compared to the placebo group. Uchida-Kraepelin test results showed that the 12-week balenine treatment significantly improved cognitive function, work efficiency and concentration compared to placebo. In addition, salivary cortisol, a biomarker of psychological stress, tended to be lower in the balenine treatment group compared to the placebo group, although differences were not statistically significant.Conclusions: Long-term consumption of whale meat extract containing balenine may reduce the effects of dementia or inhibit its progression of dementia by reducing psychological stress in humans.