And the benefits may be even more pronounced amongst smokers, with a risk reduction of over 59 per cent, said lead author Ute Nöthlings from the German Institute of Human Nutrition Potsdam-Rehbruecke. According to the US National Cancer Institute almost 38,000 new cases of pancreatic cancer are diagnosed every year in the US, with almost 34,000 deaths from the disease. British charity Cancer Research UK states that the pancreatic cancer has a poor prognosis overall since most cases are diagnosed quite late. Indeed, only one in every 50 cases will still be living five years after diagnosis, highlighting the importance of prevention for this type of cancer. The new study, part of the Multiethnic Cohort Study of 183,518 residents of California and Hawaii, reports that subjects with the highest consumption of flavonols from the diet had significant risk reductions, compared to the lowest consumption, with smokers particularly benefiting from flavonol-rich diets. "The effect was largest in smokers, presumably because they are at increased pancreatic cancer risk already," said Nöthlings. Smoking is the only established risk factor for pancreatic cancer, and "short of stopping tobacco use, it has been difficult to consistently show lifestyle factors that might help protect against this deadly cancer," she added. The researchers, led by Laurence Kolonel from the Cancer Research Center of Hawaii, used food frequency questionnaires to assess dietary intakes and followed them for an average of eight years, with 529 incident cases of pancreatic cancer documented in the study population. The researchers also stated that theirs is the first study to examine prospectively specific classes of flavonols (quercetin, found in onions and apples; kaempferol, found in spinach and some cabbages; and myricetin, found mostly in red onions and berries) and pancreatic cancer risk. Of the three individual flavonols, they report that kaempferol was associated with the largest risk reduction (22 per cent) across all participants. The interaction with smoking status was statistically significant for total flavonols, quercetin and kaempferol. The extended benefits afforded to smokers did not appear to extend to former smokers, said Nöthlings. While no mechanistic study was performed by the researchers, Nöthlings stated: "Anti-carcinogenic effects of flavonoids in general have been attributed to the ability of these constituents to inhibit cell cycle, cell proliferation and oxidative stress, and to induce detoxification enzymes and apoptosis." "Further epidemiological studies in other populations and geographic regions are needed to confirm our findings," she said. Interest in flavonoids is growing rapidly and a mounting body of science, including epidemiological, laboratory-based and randomised clinical trials, continues to report the cancer-fighting potential of a number of different flavonoids, such as isoflavones, anthocyanidins and flavonols. According to Business Insights, the market potential for flavonoids in the dietetic and nutritional supplement market is in excess of €670m ($862m) for 2007, with annual increases of 12 per cent. Source: Annual Meeting of the American Association for Cancer Research April 2007, Abstract 856 "Flavonols and pancreatic cancer risk: The Multiethnic Cohort Study" Authors: U. Nöthlings, S.P. Murphy, L.R. Wilkens, B.E. Henderson, L.N. Kolonel.