Cruciferous vegetables include cabbage, broccoli,
bok choy, Brussels sprouts, kale and cauliflower, and eating them is
often encouraged as a way to lower risk for heart disease and
Based on their findings, the study authors say the health benefits
of these vegetables may be at least partly a result of their
"Our group and others have found that consumption of fruits and
vegetables, particularly cruciferous vegetables, was associated with
lower total mortality and cardiovascular disease mortality — however, the potential mechanisms behind this association are not
well understood," Dr. Gong Yang told Reuters Health by email.
Yang is a researcher at Vanderbilt University Medical Center in
Nashville, Tennessee, and senior author of the study.
"Chronic inflammation is implicated in the pathogenesis of
cardiovascular and other chronic diseases — we therefore examined
whether cruciferous vegetable intake may relate to inflammation," he
In animal studies, high intake of cruciferous vegetables or certain
key compounds within them has been found to lower inflammation,
Yang's team writes in the Journal of the Academy of Nutrition and
To see whether that is the case in people too, Yang and colleagues
analyzed signs of inflammation in the blood of 1,005 middle-aged
Chinese women who filled out questionnaires about their diets as
part of the Shanghai Women's Health Study.
The participants included in the new analysis were generally
healthy, and had an average age of 58. Yang and his colleagues
divided the women into five groups based on their daily intake of
The median intake of cruciferous vegetables was just under one cup
per day, with women in the lowest fifth consuming about half that
amount. The women in the top fifth of consumption took in about 1.5
cups of cruciferous vegetables every day.
The researchers then measured levels of signaling molecules involved
in causing inflammation in the women's blood. Blood levels of three
important inflammatory molecules — tumor necrosis factor-alpha (TNF-a),
interleukin-1beta (IL-1b) and interleukin-6 (IL-6) were lowest among
women with the highest intakes of cruciferous vegetables.
The women who consumed the most cruciferous vegetables had, on
average, 13 percent less TNF-a, 18 percent less IL-1b, and 25
percent less IL-6 than women who ate the fewest.
The researchers found a similar inverse relationship between the
inflammation markers and intake of all vegetables combined, but not
when they looked strictly at non-cruciferous vegetables.
"Cruciferous vegetables may have health benefits through modulating
inflammation," Yang said. "However, it is premature to make any
dietary recommendation on the basis of this single observational
[to top of second column]
"It's an important message — we always hear people saying 'eat
your vegetables,' but it's also important to know that these aren't
just theoretically good — we know that they really do have important
health effects," Dr. Neil Barnard told Reuters Health.
Barnard is president of the Physicians Committee for Responsible
Medicine and an advocate of plant-based diets. Also an adjunct
assistant professor of medicine at George Washington University, in
the District of Columbia, Barnard was not involved in the new study.
Inflammation is thought to be part of a cycle that promotes heart
disease, and heart disease in turn promotes more inflammation.
"Bottom line, if you're eating a lot of cruciferous vegetables your
health is better, and specifically, inflammation markers are
diminished," he said. "That means you're going to have a healthier
heart and you're going to live longer."
Barnard added that cruciferous vegetables are good in other ways
beyond reducing inflammation.
"They happen to be a source of a highly available calcium — the
absorption of calcium from Brussels sprouts in something like 60
percent, whereas for milk it's only 30 percent," he said. "They also
provide iron in a really good form, and provide a little protein."
Barnard offered a couple of practical tips for consumers. "I think
it's a good idea to cook cruciferous vegetables rather than just
have them raw because they're more digestible that way," he said.
"Generally speaking, you can eat raw carrots and raw celery, but
it's best to cook broccoli and cauliflower."
He also suggests eating more than one serving of vegetables at a
meal. "Instead of thinking about just one little modest vegetable
serving at a meal, why not have two?" he said. "And a really great
combination is green and orange, so you might have broccoli and
sweet potato or you could have Brussels sprouts with carrots or
cauliflower with carrots, something like that, so that you're mixing
Journal of the Academy of Nutrition and
Dietetics, online March 17, 2014.
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