This 2020 rodent study demonstrated benefits from daily cooked broccoli intake, even when it contained no myrosinase enzyme and no sulforaphane:
Rats fed a broccoli diet exhibited an enhanced Nrf2-Nqo1 pathway by day 4:
Amino acid synthesis and glutathione (GSH) synthesis pathways were upregulated by Day 7. Fatty acid synthesis pathways, specifically α-linoleic acid synthesis pathways, were downregulated by Day 14.
Glucosinolate (GSL) metabolite sulforaphane alters liver GSH metabolism. It might be that consumption of any brassica, since all have GSLs, may lead to plasma glutamine and S-methyl-L-cysteine (SMC) as biomarkers. Future studies are needed to confirm whether glutamine and SMC are broccoli-specific or GSL-specific biomarkers.
Dietary broccoli caused plasma metabolite changes that correlate with:
- Improved GSH status, suggesting protection from oxidative stress; and
- Diversity and abundance of gut microbiota, suggesting that changes in gut microbiome may contribute to health benefits caused by dietary broccoli.”
https://www.mdpi.com/2072-6643/12/9/2514/htm “Biomarkers of Broccoli Consumption: Implications for Glutathione Metabolism and Liver Health”
I came across this study as a result of it citing the second study of A pair of broccoli sprout studies:
“A human clinical study reported changes in plasma fatty acids and GSH/GSH component levels after even a single meal of broccoli sprouts, similar to pathways we report here for rat plasma. We saw levels drop initially, then rise.
In that 2-day study, levels dropped like ours, but it was not sufficiently long to see the recovery and overshoot that we saw by 14 days when glutamine abundance and liver Nrf2 and NQO1 expression were all increased, suggesting increased GSH production, which might provide protection of liver from reactive oxygen species.”
Maybe a better comparison would have been against 0, 1-day, and 2-day rodent measurements, since the human study sampled at 0, 3, 6, 12, 24, and 48-hour intervals? People ate fresh broccoli sprouts only at time 0, though, whereas rodents ate a 10% cooked broccoli diet (0.11 mg/g glucoraphanin) ad libitum.