Scientists from Tohoku University and Kagome Co., Ltd. report that 12 weeks of supplementation led to significant improvements in processing speed and decreases in negative mood compared to the placebo group.
“These results indicate that nutrition interventions using SFN can have positive effects on cognitive functioning and mood in healthy older adults,” they wrote in the journal Frontiers in Aging Neuroscience.
The potential health benefits of cruciferous vegetables, such as broccoli, cauliflower, and cabbage, are linked to the high levels of the plant chemicals glucosinolates. These are metabolized by the body into isothiocyanates (such as sulforaphane).
When eaten as a raw or lightly-cooked food, an enzyme called myrosinase in the broccoli help to break down the glucosinolates into two valuable compounds of intensive research interest – sulforaphane and erucin. The only sources we have for this enzyme is from the plant itself, or from our own microflora.
The new study provided 30 mg per day of glucoraphanin, which the researchers said was converted by the gut microbiota into sulforaphane.
Significant increases in urinary levels of sulforaphane N-acetyl-L-cysteine (SFN-NAC), a biomarker of sulforaphane absorption, showing that the participants complied with the study protocol and the gut microbiota did convert the glucoraphanin to sulforaphane.
The double-blinded, randomized controlled trial included 144 older adults. The participants were randomly assigned to receive either the sulforaphane supplements or placebo for 12 weeks. SFN group or a placebo group. Cognitive function, mood states, and biomarkers were measured before and after the intervention period.
The results showed that processing speed in a symbol search test increased by about 5%, which was significantly greater than the placebo group.
In addition, total mood disturbance (TMD) scores, a measure of negative mood, improved significantly in the sulforaphane group, compared to placebo.
“The present study can expand existing findings to demonstrate that SFN intake can reduce the TMD score in healthy older adults,” said the researchers.
“Although we did not find any significant changes in antioxidant response, neural plasticity, or the neuroinflammation blood parameter, these results indicate that nutrition interventions using SFN can have positive effects on cognitive functioning and mood in healthy older adults,” wrote the researchers.
Source: Frontiers in Aging Neuroscience
2022, 14:929628. doi: 10.3389/fnagi.2022.929628
“Effects of sulforaphane intake on processing speed and negative moods in healthy older adults: Evidence from a randomized controlled trial”
Authors: R. Nouchi