Eating fatty fish -- but not lean fish or shellfish -- cuts women's risk of kidney cancer, a Swedish study shows.
A recent overview of all existing dietary studies recently found no proof that eating fish fights cancer. But that study didn't differentiate fatty fish -- which are full of healthy omega-3 fatty acids and vitamin D -- from lean fish.
Alicja Wolk, DMSc, of the Karolinska Institute in Stockholm, Sweden, and colleagues looked at more than 15 years of data on 61,433 women aged 40 to 76. The women filled out food-frequency questionnaires.
Women who ate fatty fish at least once a week had a 44 percent lower risk of kidney cancer than those who ate no fish. Those who consistently ate lots of fatty fish over a 10-year period had a 74 percent lower risk of kidney cancer.
"Our study suggests that consumption of fatty fish may reduce the occurrence of [kidney cancer] in women," Wolk and colleagues conclude. "In contrast, consumption of lean fish or other seafood was not associated with the risk of [kidney cancer]."
Fatty fish, in the Wolk study, included salmon, herring, sardines, and mackerel. Lean fish included cod, tuna, and fresh-water fish.
Of course, this study simply finds a link between lower kidney-cancer risk and eating fatty fish. It doesn't prove fatty fish prevents cancer. But eating fatty fish once or twice a week is good for you. So there's no harm in making sure it's part of your diet.
The study appears in the Sept. 20 issue of The Journal of the American Medical Association.
By Daniel J. DeNoon, reviewed by Louise Chang, MD
SOURCES: Wolk, A. The Journal of the American Medical Association, Sept. 20, 2006; vol: 296 pp 1371-1376. MacLean, C.H. The Journal of the American Medical Association, Jan. 25, 2006; vol 295: pp 403-415.