New anti-diabetes substance
found in broccoli
Researchers have identified an antioxidant – richly
occurring in broccoli – as a new antidiabetic substance. A patient study shows
significantly lower blood sugar levels in participants who ate broccoli extract
with high levels of sulforaphane.
“There
are strong indications that this can become a valuable supplement to existing
medication,” says Anders Rosengren, Docent in Metabolic Physiology at the
University of Gothenburg.
The
publication in the journal Science Translational Medicine builds on several years’
research at Sahlgrenska Academy and Wallenberg Centre for Molecular and
Translational Medicine, University of Gothenburg, and the Faculty of Medicine
at Lund University.
The
objective was to find new medications against type-2 diabetes by addressing an
important disease mechanism: The liver’s elevated glucose production. The
classic drug metformin works by doing just that, but often causes gastric
side-effects and can also not be taken when kidney function is severely
reduced, which affects many with diabetes.
Lowering blood sugar
The
researchers began by mapping the genetic changes in the liver in diabetes. 50
genes proved to play key roles. These were then matched against different
substances in the search for compounds that could affect these particular key
genes, and thereby attack the disease on a broad front.
Of
2,800 substances investigated through computer-based mathematical analyses,
sulforaphane proved to have the best characteristics for the task. An
antioxidant that was previously studied for the treatment of cancer and
inflammatory disease, but not for diabetes was thereby identified.
Cell
experiments were followed by animal studies on rats and mice with
dietary-induced diabetes. The blood sugar of the animals that received
sulforaphane dropped by 23 percent in four weeks, and by 24 percent in those
given metformin.
“We
tested removing sulforaphane from the extract and the effect disappeared. We
also looked at the genes from the liver of the animals and saw that the 50 key
genes had been changed in the right direction,” says Anders Rosengren.
Mice and men
With
the knowledge that sulforaphane does not hurt people, which was already
documented, a patient study was then done with around hundred patients.
Basically
all were on metformin treatment, but in the group that took sulforaphane every
morning for 12 weeks, the patients with poor glucose control and BMI at 30 or
above (well-known factors associated with elevated glucose production) had
significantly lower blood sugar levels than the placebo group.
In
other words, sulforaphane benefited exactly those patients, totally 17 in the
study, who have elevated glucose production in the liver.
A
daily dose of sulforaphane is extracted from four to five kilograms of
broccoli. The plan is to have a functional food preparation out within two
years. Development is taking place with farmer owned organization Lantmännen.
“Sulforaphane
targets a central mechanism in type 2 diabetes and has a mild side-effect
profile. As functional food, it can reach the patients faster than a
medication, and it is also an interesting concept from a diabetes perspective
where diet is central,” says Anders Rosengren.
