Wednesday, September 20 2006 14:17 Hrs (IST) - World Time -

New York: Eating fatty fish could reduce the risk of developing renal cell carcinoma (RCC), a common form of kidney cancer, says a new study.

RCC accounts for more than 80 percent of all kidney cancers and its incidence rates in the US had increased in the period 1970-1990s, especially among black women and men. More recent data suggest a levelling off in this trend for most racial groups.

Alicja Wolk and colleagues at Karolinska Institute, Stockholm, studied 61,433 women aged 40-76 years without previous diagnosis of cancer at the baseline (March 1987-December 1990), reported Newswise wire.

They found that women who consumed one or more servings of fatty fish per week had a significant 44 percent decreased risk of RCC compared with women who did not consume any fish.

Women who reported consistent long-term consumption of fatty fish at baseline and 10 years later had a significant 74 percent lower risk, the researchers noted.

Previous studies have analysed total fish consumption and have not taken into account that there are large differences between fatty fish and lean fish in the content of omega-3 fatty acids and vitamin D.

Fatty cold-water fish contain marine omega-3 polyunsaturated fatty acids, eicosapentaenoic acid and docosahexaneoic acid up to 20-30 times higher than in lean fish. These acids have been reported to slow down the development of cancer, the report said.

Similarly, fatty fish has three-five times higher vitamin D content than lean fish and lower serum vitamin D levels have been associated with the development and progression of RCC.

"Our results support the hypothesis that frequent consumption of fatty fish may lower the risk of RCC possibly due to increased intake of fish oil rich in eicosapentaenoic acid and docosahexaneoic acid as well as vitamin D," said Wolk.

"Our results, however, require confirmation because this is the first epidemiological study addressing this issue," the researcher added.