By Amy Norton
NEW YORK (Reuters Health) – Eating plenty of leafy greens,
broccoli and Brussels sprouts may help ward off the blood
cancer non-Hodgkin’s lymphoma, research findings suggest.
In a study of more than 800 U.S. adults with and without
non-Hodgkin’s lymphoma (NHL), researchers found that those who
ate the most vegetables had a 42 percent lower risk of the
cancer than those with the lowest intakes.
In particular, leafy greens like spinach and kale, and
cruciferous vegetables like broccoli, Brussels sprouts and
cauliflower, seemed to be protective.
Similarly, the study found, two nutrients found in green
vegetables — lutein and zeaxanthin — were related to a lower
NHL risk. The same was true of zinc, a mineral obtained through
meat, nuts and beans.
The “working hypothesis” is that the antioxidant activity
of these vegetables and nutrients explains the connection, said
study co-author Dr. James R. Cerhan of the Mayo Clinic College
of Medicine in Rochester, Minnesota.
NHL begins in the lymphatic system, a component of the
immune system that carries disease-fighting white blood cells
called lymphocytes. The cancer arises when these cells become
abnormal and begin to divide uncontrollably.
Antioxidants help protect cells from such damage by
neutralizing molecules called reactive oxygen species. These
substances are byproducts of normal body processes, as well as
environmental exposures like cigarette smoke, and in excess
they can damage body tissue and lead to disease.
The new findings, published in the American Journal of
Clinical Nutrition, suggest “yet another benefit” of eating
your vegetables, Cerhan told Reuters Health.
Vegetables and fruits are probably the best way to get
antioxidants, he said, because these foods have a host of other
nutrients that may all work together to bestow health benefits.
The study included 466 adults with NHL who were enrolled in
a national cancer registry, along with 391 cancer-free adults
who were matched to patients by age, race and sex. Both groups
answered questions about their diet and other health and
lifestyle factors.
In general, those who ate more than 20 servings of
vegetables a week had a 42 percent lower risk of NHL than those
who ate eight weekly servings or fewer. When the researchers
looked at specific nutrients, lutein and zeaxanthin stood out;
people with the highest intakes were about half as likely as
those with the lowest to develop NHL.
This makes sense, Cerhan noted, given that the major
vegetable sources of these antioxidants, including spinach,
kale and broccoli, also seemed particularly protective against
the cancer.
Zinc, a mineral important to immune function, was also
linked to a lower lymphoma risk. But Cerhan said this has not
been seen in previous studies, and more research is needed to
know what to make of it.
SOURCE: American Journal of Clinical Nutrition, June 2006.
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