Salty foods and risk of gastric cancer: overview of the evidence Salted foods and gastric cancer
In most countries, humans consume a large amount of salt (10 g or more per day), although WHO recommendations suggest to limit salt intake to no more than 5 g/day. Gastric cancer is a common neoplasia and dietary factors, especially salt consumption, are considered relevant to its causation. Epidemiological investigations indicated a dose-dependent positive association and, in particular, a meta-analysis of the available prospective studies detected a strong adverse effect of salt intake on the risk of gastric cancer in the general population. Also experimental studies supported this association and suggested an unfavourable synergistic action of high salt intake and Helicobacter pylori infection. This article focuses on the epidemiological evidence concerning the association between excess salt rich-food consumption and risk of gastric cancer, and highlights the potential mechanisms whereby salt excess may favour the development of gastric cancer.
Sodium, the most abundant electrolyte in extracellular fluid, plays a key role in the regulation of cell membrane potential, plasma osmolality and body fluid volume. During the evolution, effective mechanisms were developed by the human body to preserve its sodium and chloride content and to maintain the sodium concentration in the extracellular fluid within a relatively narrow range (1).
In ancient times, the human diet was extremely low in sodium since the salt content of natural foods is quite modest (2). Later on, approximately 5,000 years ago, the discovery that the addition of salt to many foods was functional to preserve them from rapid deterioration (3) caused a progressive huge increase in the habitual salt intake. Although advanced technologies have been developed in the last century allowing drastic reduction in the use of salt for food storage, excess dietary salt intake remains very common. Indeed, in most countries around the world, average of salt intake is comprised between 9 and 12 g/day, and in Asian countries even more than this (4).
Since it is reasonable to assume that humans are genetically programmed ...