소금과 암 발병Salt and Cancer Risk Kiwon Kim, Nephrology Clinic, National Cancer Center
IntroductionAmerican Institute for cancer Research :Food, Nutrition, Physical Activity, and the Prevention of Cancer 2007
Introduction• Salt intake was first reported as a possible risk factor for stomach cancer in 1959 Bull Inst Public Health 1959; 8: 187-198• In some early studies, using refrigerators for food storage, which may be an indicator of less salted food consumption or decreased salt intake, was found to be correlated with a reduction in stomach cancer rates Br J Cancer 1990; 62: 136-137• A nearly linear correlation between the cumulative mortality rate of stomach cancer and the median 24 h urine salt excretion level J Epidemiol 1992; 2: 75-81
Animal Studies• In general, salt alone has no apparent effect on the development of gastric carcinogenesis,• But administration of salt in rats induced a concentration-dependent damage of surface mucous cell layer, and also increased replicative DNA synthesis Carcinogenesis 1996; 17: 401-406
Role in the pathogenesis of Gastric Cancer• Direct damage of the gastric mucosa causing excessive cell replication• Indirect effect by increasing of the mutagenic potential of N-nitroso compounds (Correa, 1992)• Damage caused by salt may also increase gastric H. pylori colonization (Fox et al., 1999; Nozaki et al., 2002), which is also supportive of an early role in the pathway
Potential Mechanisms• High dietary salt alters viscosity of mucous, hence facilitating exposure to carcinogenic agents such as nitrates• Persistent inflammation may promote cell proliferation and endogenous mutations• In the presence of H. pylori infection and atrophic gastritis, high salt exacerbates mucosal damage
Salt Intake and Intestinal MetaplasiaMeta-analyses on the association between salt intake and intestinal metaplasia, and gastriccancer (Dias-Neto et al., 2010; World Cancer Research Fund & American Institute for CancerResearch, 2007)
Global Stomach Cancer Statistics • Regional variations in part reflect differences in dietary patterns, particularly in European countries, and the prevalence of Helicobacter pylori infection. • CA: A Cancer Journal for Clinicians Volume 61, Issue 2, pages 69-90, 4 FEB 2011 DOI: 10.3322/caac.20107
Global rates of Stomach Cancer in 2002Maps courtesy of The International Agency for Research on Cancer (IARC)
Cancer incidence rate in Korea Reference: Central cancer registry in Korea, Annual report of the central cancer registry in Korea, 2000
Relationship between salt intake as judged by 24h urinary salt excretion and stomach cancer mortality in 24 countries Dietary salt, nitrate and stomach cancer mortality in 24 countries. European Cancer Prevention (ECP) and the INTERSALT Cooperative Research Group. Int J Epidemiol. 1996;25:494-504
Dietary factors and stomach cancer: a case-control study in Korea• A case-control investigation involving 213 incident cases of histologically confirmed stomach cancer and an equal number of controls, matched by age (within 2 years) and sex, was conducted from June 1990 to October 1991.• An increased risk of stomach cancer was noted among those with high consumption of stewed foods such as soybean paste stew and hot pepper-soybean stew, broiled fish, and those who liked salty food. Int J Epidemiol. 1995 Feb;24(1):33-41. Lee JK, Park BJ, Yoo KY, Ahn YO.
Stomach Cancer among Korean-AmericanCancer incidence among Korean-American immigrants in the UnitedStates and native Koreans in South Korea.Cancer Control. 2007 Jan;14(1):78-85.
Gastric cancer and salt preference: a population-based cohort study in Korea• Design: Participants were Korean government employees, school faculty members, and their unemployed dependents, aged 30–80 y, who underwent health examinations between 1996 and 1997. In 2003, information on the gastric cancer incidence in these participants was obtained during the 6–7-y follow-up period. The final data analysis included 2,248,129 study subjects• Result : showed evidence of an increased risk of gastric cancer with salt preference. The HRs were 1.10 (95% CI: 1.04, 1.16) and 1.10 (95% CI: 1.03, 1.17) for the overall total population Am J Clin Nutr 2010;91:1289–93.
Stomach cancer in 67 Chinese countiesAfter stratification, positively significant correlations were observed betweensodium and stomach cancer mortality in counties with high H. pylori prevalence(≥71.6%) and between H. pylori and stomach cancer mortality in counties withhigh urinary sodium (≥5.0 mg/mg.creatinine/12-hour)
• 422 gastric cancer cases and 649 community controls. Salt exposure was estimated in the year before the onset of symptoms through: sodium intake (estimated by a food frequency questionnaire (FFQ)); main food items/groups contributing to dietary sodium intake; visual analogical scale for salt intake preference; use of table salt; and duration of refrigerator ownership
British Journal of Cancer (2011) 104(1), 198 – 207
Other Cancers ass. with Salt?• Colon cancer• Breast cancer• Pancreas cancer No sufficient evidence
Conclusion• Most published epidemiological studies provide positive evidence for an association between salt or salted food consumption and stomach cancer risk• Ideally, dietary modification of salt intake, as well as eradication of H. pylori infection, is a promising strategy for gastric cancer prevention throughout the world
Benefits of a Reduction in Salt Intake Reduces Reduces Reduction in Fluid CVD Salt Intake RetentionReduces L.V.H. Reduces Reduces Glomerular Blood Hyperfiltration Pressure Reduces ReducesOsteoporosis Urinary Calcium May reduce Reduces Asthma Bone Attacks Mineral Loss Reduces Reduces Reduces Kidney Stomach Fractures Stones Cancer