NEW YORK (Reuters Health) - In a study of more than 1,000
Chinese women, those who ate the most cruciferous vegetables had
substantially less inflammation than those who ate the fewest.
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 cancer.
Based on their findings, the study authors say the health
benefits of these vegetables may be at least partly a result of
their anti-inflammatory effects.
"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 said.
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 Dietetics.
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 cruciferous vegetables.
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
"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
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
"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 the colors."
SOURCE: http://bit.ly/OUoCsL Journal of the Academy of
Nutrition and Dietetics, online March 17, 2014.