Vette
vis (omega-3 vetzuren) tegen prostaatkanker.*
Zweedse onderzoekers hebben gekeken naar de voedingsgewoonte van 2.600 mannen waarvan 1.500 met en 1.100 zonder prostaatkanker. Zij die gemiddeld 1x keer per week vette vis, zoals zalm eten hebben 43% minder kans op het ontwikkelen van prostaatkanker vergeleken met zij die geen vette vis eten. De onderzoekers denken ook dat een bepaald gen een belangrijke rol speelt bij de groei van prostaatkanker. Mannen met dat bepaalde (60% van alle mannen) Cox-2 gen hebben zelfs ruim 70% minder kans op prostaatkanker dan mannen zonder dat gen. Deze studie laat zien dat er een wisselwerking is tussen voedingsstoffen, zoals in dit geval omega-3 vetzuren en genen, maar hoe die wisselwerking precies werkt is niet altijd duidelijk.
Association
of frequent consumption of fatty fish with prostate cancer risk is modified by
COX-2 polymorphism
Maria
Hedelin 1 *, Ellen T. Chang 1 2,
Fredrik Wiklund
1 3, Rino
Bellocco
1 4, Åsa Klint
1, Jan Adolfsson
5, Katarina
Shahedi
3, Jianfeng Xu
6, Hans-Olov
Adami
1 7, Henrik Grönberg
1 3, Katarina
Augustsson Bälter
1
1Department of Medical Epidemiology and Biostatistics, Karolinska
Institute, Stockholm, Sweden
2Northern
California Cancer Center, Fremont, CA
3Department
of Radiation Sciences/Oncology, Umeå University, Umeå, Sweden
4Department
of Statistics, University of Milano-Bicocca, Milan, Italy
5Oncologic
Center, CLINTEC, Karolinska University Hospital, Stockholm, Sweden
6Center
of Human Genomics, Wake Forest University, School of Medicine, Winston-Salem, NC
7Department
of Epidemiology, Harvard University, Boston, MA
email:
Maria Hedelin (maria.hedelin@ki.se)
Correspondence
to Maria Hedelin, Department of Medical Epidemiology and Biostatistics,
Karolinska Institute, Box 281, SE-171 77 Stockholm, Sweden
Fax:
+46-8-31-49-57.
Funded by:
Swedish Cancer Foundation (Cancerfonden); Grant Number: 05 0158
NIH; Grant Number: 1R01CA105055
Dietary intake of marine fatty acids from fish may protect against prostate cancer development. We studied this association and whether it is modified by genetic variation in cyclooxygenase (COX)-2, a key enzyme in fatty acid metabolism and inflammation. We assessed dietary intake of fish among 1,499 incident prostate cancer cases and 1,130 population controls in Sweden. Five single nucleotide polymorphisms (SNPs) were identified and genotyped in available blood samples for 1,378 cases and 782 controls. Odds ratios (OR) and 95% confidence intervals (CI) were estimated by multivariate logistic regression. Multiplicative and additive interactions between fish intake and COX-2 SNPs on prostate cancer risk were evaluated. Eating fatty fish (e.g., salmon-type fish) once or more per week, compared to never, was associated with reduced risk of prostate cancer (OR: 0.57, 95% CI: 0.43-0.76). The OR comparing the highest to the lowest quartile of marine fatty acids intake was 0.70 (95% CI: 0.51-0.97). We found a significant interaction (p < 0.001) between salmon-type fish intake and a SNP in the COX-2 gene (rs5275: +6365 T/C), but not with the 4 other SNPs examined. We found strong inverse associations with increasing intake of salmon-type fish among carriers of the variant allele (OR for once per week or more vs. never = 0.28, 95% CI: 0.18-0.45; ptrend < 0.01), but no association among carriers of the more common allele. Frequent consumption of fatty fish and marine fatty acids appears to reduce the risk of prostate cancer, and this association is modified by genetic variation in the COX-2 gene. © 2006 Wiley-Liss, Inc. (Okt. 2006)