Broccoli tegen blaaskanker.*
Uit een onderzoek blijkt dat een keer per week broccoli eten de kans op blaaskanker met 44% doet dalen. In dit onderzoek is de stof glucosinolaat bekeken. Tijdens de spijsvertering wordt deze stof omgezet in de krachtige voedingsstof isothiocyanaat. Deze stof nu voorkomt het ontstaan van blaaskanker. In broccoli, net zoals in andere kruisbloemige groente, zitten nog veel meer gezonde stoffen welke goed zijn tegen kanker doch die zijn nu niet onderzocht.
Broccoli
Packs Powerful Punch To Bladder Cancer Cells
COLUMBUS
, Ohio – Researchers have isolated compounds from the vegetable broccoli that
they believe may help prevent or slow the progress of bladder cancer.
The current work builds on a major study conducted six years ago by Harvard and
Ohio State universities that found that men who ate two or more half-cup
servings of broccoli per week had a 44 percent lower incidence of bladder cancer
compared to men who ate less than one serving each week.
“We're
starting to look at which compounds in broccoli could inhibit or decrease the
growth of cancerous cells,” said Steven Schwartz, a study co-author and a
professor of food science and technology at Ohio State University .
“Knowing
that could help us create functional foods that benefit health beyond providing
just basic nutrition.”
Some
63,000 people will be diagnosed with bladder cancer this year, according to the
American Cancer Society. And more than 13,000 with the disease will die.
The researchers isolated compounds called glucosinolates from broccoli sprouts.
During chopping, chewing and digestion, these phytochemicals morph into
nutritional powerhouses called isothiocyanates – compounds that the scientists
believed play a role in inhibiting cancer.
Their
hunch was right, at least in the laboratory experiments. There, isothiocyanates
hindered the growth of bladder cancer cells. And the most profound effect was on
the most aggressive form of bladder cancer they studied.
The
researchers presented their findings in New Orleans at the annual Institute of
Food Technologists meeting.
They
first extracted and measured the levels of glucosinolates from broccoli sprouts.
They then used a process that uses enzymes to convert the glucosinolates to
isothiocyanates.
While
young sprouts naturally have higher concentrations of these phytochemicals than
full-grown broccoli spears, eating the spears also provides health benefits,
Schwartz said.
He
and his colleagues treated two human bladder cancer cell lines and one mouse
cell line with varying amounts of glucosinolates and isothiocyanates. Even
though glucosinolates are converted to isothiocyanates, the researchers wanted
to know if the former would have any effect on controlling the growth of cancer
cells.
It
didn't.
However,
the isothiocyanates decreased proliferation in all three cell lines. The
strongest effect was on the most aggressive of these lines – human invasive
transitional cell carcinoma.
The
researchers aren't sure what caused this effect, or exactly how these compounds
keep cancer cells from proliferating. But they are looking into it.
“There's
no reason to believe that this is the only compound in broccoli that has an
anti-cancer effect,” said Steven Clinton, a study co-author and an associate
professor of hematology and oncology at Ohio State. “There are at least a
dozen interesting compounds in the vegetable.
“We're
now studying more of those compounds to determine if they work together or
independently, and what kind of effects they have on cancer cells,” he added.
Broccoli
isn't the only cruciferous veggie with health benefits, the researchers say. The
plant's kin, which include cabbage, cauliflower, Brussels sprouts and kale, may
all contain similar disease-fighting phytochemicals.
It's
too early to suggest just how much broccoli or other cruciferous vegetables
should be eaten to stave off or slow down the progression of bladder cancer.
Still, they are an important part of the diet.
“Cruciferous
veggies have an effect on other types of cancer, too,” Schwartz said. “We
already know that they contain compounds that help detoxify carcinogens. We're
thinking more along the lines of progression and proliferation, such as once
cancer starts, is there a way to slow it down?”
He
and Clinton conducted the study with Ohio State colleagues Robin Rosselot, a
graduate student in food science and technology and Qingguo Tian, a research
associate also in food science and technology. (Sept. 2005)