Rice protein matrix and xanthohumol absorption from hops
What it found
In a small trial in people, taking spent hops with a rice protein matrix led to higher levels of xanthohumol and its breakdown products in the blood than taking spent hops alone.
The two treatments did not give equivalent blood levels.
What they found
Studies in people
Blood levels higher
Blood levels of xanthohumol and its metabolites, measured as area-under-the-curve, were greater after the spent hops-rice protein matrix preparation than after the control spent hops preparation.
Not equivalent
The circulating xanthohumol and metabolite response to each treatment was not bioequivalent, meaning the two preparations did not produce the same blood levels.
Metabolites measured
The study measured xanthohumol and its major metabolites isoxanthohumol, 6-prenylnaringenin and 8-prenylnaringenin in plasma.
What the authors conclude
“Compared to a standard spent hops powder, a protein-rich spent hops matrix demonstrates enhanced plasma levels of XN and metabolites following acute oral intake.”
Also in their conclusions
- They conclude that compared to a standard spent hops powder, a protein-rich spent hops matrix demonstrates enhanced plasma levels of xanthohumol and metabolites following acute oral intake.
How it was done
Xanthohumol, a compound found in hops, has anti-inflammatory and antioxidant properties, but it is poorly absorbed, which may limit its use. Food components are known to affect how polyphenols are absorbed, so the authors wanted to see whether a protein matrix could improve xanthohumol absorption after eating.
Six healthy people took part in a randomised, double-blind, crossover study. They consumed 12.4 mg of xanthohumol either in a spent hops-rice protein matrix preparation or in a control spent hops preparation, and their blood was measured for xanthohumol and its main metabolites over 6 hours.
What it can’t tell you
- We summarised it from the abstract only.
- This was a small study with only 6 healthy participants, so the results may not apply to other people.
- The study only looked at a single dose and 6 hours after intake, so it cannot show what happens with longer use.
- It did not test whether the higher blood levels lead to any health benefit.
Who paid
- Authors work at
- Oregon State University, USA
The paper
- Title
- Rice Protein Matrix Enhances Circulating Levels of Xanthohumol Following Acute Oral Intake of Spent Hops in Humans
- Type
- Randomised controlled trial
- Evidence
- Studies in people
- Summarised from
- Abstract only
- Cite
- O'Connor A, Konda V, Reed RL, Christensen JM, Stevens JF, Contractor N (2018). Rice Protein Matrix Enhances Circulating Levels of Xanthohumol Following Acute Oral Intake of Spent Hops in Humans. Molecular nutrition & food research. doi:10.1002/mnfr.201700692PubMed 29322620DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error