Jef Geboers

Nutrition and gastric cancer.

Summary Gastric cancer (Gc) is generally conceived as having a multifactorial origin. Different genetic factors, soil, nutritional and socioeconomic factors have all been mentioned in the literature as possible causes. Further research on the causation of Gc has, in fact, been hampered by the large number of hypotheses. A strong geographic association between gastric cancer and stroke mortality was found by chance in 1964; this association could be spurious, but the quantitative analysis of the data showed similar relationships both between countries and within countries (e.g., in countries as different as the US and Japan), a very unlikely situation if due to chance. The same quantitative relationship was maintained using multiple regression analysis of stroke mortality. All this was observed for each sex separately and for both sexes combined. The working hypothesis was set forth in 1965 that salt intake was the predominant linking factor for both types of mortality. Stroke would then be influenced by t...: Gastric cancer (Gc) is generally conceived as having a multifactorial origin. Different genetic factors, soil, nutritional and socioeconomic factors have all been mentioned in the literature as possible causes. Further research on the causation of Gc has, in fact, been hampered by the large number of hypotheses. A strong geographic association between gastric cancer and stroke mortality was found by chance in 1964; this association could be spurious, but the quantitative analysis of the data showed similar relationships both between countries and within countries (e.g., in countries as different as the US and Japan), a very unlikely situation if due to chance. The same quantitative relationship was maintained using multiple regression analysis of stroke mortality. All this was observed for each sex separately and for both sexes combined. The working hypothesis was set forth in 1965 that salt intake was the predominant linking factor for both types of mortality. Stroke would then be influenced by the relationship between salt and blood pressure; Gc would result from the delaying and caustic properties of a hypertonic stomach content. The latter condition could produce atrophic gastritis, a common problem in Japan, Chile and Columbia. Atrophic gastritis favors the synthesis of endogenous nitrites and, henceforth, of nitroso-carcinogens. The salt hypothesis can give an explanation for the geographical and time behavior of Gc and stroke mortality and for the socioeconomic gradient of both diseases. Gc mortality can also be used to provide a rough estimate of the salt intake in a given country and year. The hypothesis was tested in Belgium through a deliberate attempt to lower the salt intake of the population. The observed decreases in Gc and stroke mortality were consistent with the measured decrease in salt excretion. Further research is urgently needed through the monitoring of 24-hour salt and creatinine excretion in different countries and over many years.

Serum lipids in the People's Republic of China. Comparison of Western and Eastern populations.

Serum cholesterol and HDL cholesterol levels were measured in an urban and a rural population of the Peoples Republic of China and compared with cholesterol values obtained in Belgium and in the Republic of Korea, with use of the same methodology. Total cholesterol levels were markedly lower In the Peoples Republic of China than in Belgium and generally lower than in Korea, both in male and female subjects. However, the differences In HDL cholesterol levels among the three populations were small in males and only significantly higher in Belgium in the age classes below 34 years. In women of all age groups, HDL cholesterol values were significantly higher In Belgium than in China and Korea. Total cholesterol levels below 100 mg/dl were found In the Peoples Republic of China in about 2% of the participants. Apolipoprotein B was significantly lower, and the apolipoprotein A,/B ratio was significantly higher, In China and Korea compared to Belgium.

Diet and carcinogenesis

Summary Gastric cancer (Gc) is generally conceived as having a multifactorial origin. Different genetic factors, soil, nutritional and socioeconomic factors have all been mentioned in the literature as possible causes. Further research on the causation of Gc has, in fact, been hampered by the large number of hypotheses. A strong geographic association between gastric cancer and stroke mortality was found by chance in 1964; this association could be spurious, but the quantitative analysis of the data showed similar relationships both between countries and within countries (e.g., in countries as different as the US and Japan), a very unlikely situation if due to chance. The same quantitative relationship was maintained using multiple regression analysis of stroke mortality. All this was observed for each sex separately and for both sexes combined. The working hypothesis was set forth in 1965 that salt intake was the predominant linking factor for both types of mortality. Stroke would then be influenced by t...: Gastric cancer (Gc) is generally conceived as having a multifactorial origin. Different genetic factors, soil, nutritional and socioeconomic factors have all been mentioned in the literature as possible causes. Further research on the causation of Gc has, in fact, been hampered by the large number of hypotheses. A strong geographic association between gastric cancer and stroke mortality was found by chance in 1964; this association could be spurious, but the quantitative analysis of the data showed similar relationships both between countries and within countries (e.g., in countries as different as the US and Japan), a very unlikely situation if due to chance. The same quantitative relationship was maintained using multiple regression analysis of stroke mortality. All this was observed for each sex separately and for both sexes combined. The working hypothesis was set forth in 1965 that salt intake was the predominant linking factor for both types of mortality. Stroke would then be influenced by the relationship between salt and blood pressure; Gc would result from the delaying and caustic properties of a hypertonic stomach content. The latter condition could produce atrophic gastritis, a common problem in Japan, Chile and Columbia. Atrophic gastritis favors the synthesis of endogenous nitrites and, henceforth, of nitroso-carcinogens. The salt hypothesis can give an explanation for the geographical and time behavior of Gc and stroke mortality and for the socioeconomic gradient of both diseases. Gc mortality can also be used to provide a rough estimate of the salt intake in a given country and year. The hypothesis was tested in Belgium through a deliberate attempt to lower the salt intake of the population. The observed decreases in Gc and stroke mortality were consistent with the measured decrease in salt excretion. Further research is urgently needed through the monitoring of 24-hour salt and creatinine excretion in different countries and over many years.

The mechanism of disappearance of the physiologic third heart sound with age.

To study the mechanism of disappearance of the physiologic third heart sound (S3) with advancing age, combined phonoechocardiographic and phonomechanocardiographic recordings from 165 normal subjects between 6 and 62 years old were quantitatively analyzed. Nearly all individuals under 40 years old had a recordable S3. Although recordable in 38.6% of the 44 subjects over 40 years old, the physiologic S3 found in adults was less intense and occurred later in diastole when compared with that in children and adolescents. Marked changes in left ventricular filling hemodynamics were observed with aging, including an increase in left ventricular wall thickness and mass, a prolongation of the left ventricular isovolumetric relaxation period, a decrease in left ventricular early diastolic filling and wall thinning rates, and a reduction in the height and steepness of the rapid filling wave measured on the calibrated left apexcardiogram (linear correlation with age significant at p less than .001 for all parameters). Although less pronounced, these changes were very similar to the diastolic abnormalities found in patients with pressure overload left ventricular hypertrophy. Therefore, the higher pressure load imposed on the left ventricular wall due to the well-known gradual increase in blood pressure that occurs during normal growth and adulthood appears to be the most likely explanation for the observed changes in diastolic filling. It is concluded that the later occurrence, the diminishing amplitude, and the eventual complete disappearance of the physiologic S3 with age results from a decrease in early diastolic left ventricular filling and subsequent deceleration of inflow caused by the development of relative left ventricular hypertrophy in adulthood as compared with childhood.

Trends in stomach cancer and stroke in Finland. Comparison to northwest Europe and USA.

The mortality rates of stomach cancer and stroke were found to decrease in a similar way over a given time in different countries. The same phenomenon can be observed in Finland for both sexes. Salt is suggested to be the linking factor in the stroke-stomach cancer relationship. Recent studies indicate that salt intake in Finland is very high. Actual salt consumption levels are in Finland as high as they were in Belgium 15 years ago. The same observations can be made for cerebrovascular and stomach cancer mortality, making the salt hypothesis plausible. In contrast from 1972-73 on stroke mortality decreases faster than stomach cancer mortality. This could be observed in other western countries: USA, Austria, England and Wales, Belgium, West Germany, etc. The steeper decline may be the consequence of mass drug treatment of hypertension which started in Finland during the early years of 1970s, and also the conse-quence of changes in dietary habits, especially in fat intake in Finland. Stroke Vol 15, No 5, 1984

A comparative study of serum lipids between Belgium and Korea.

Serum cholesterol values are markedly lower in Korea than in Belgium in both males and females. This is attributed to the much lower consumption of saturated fat in Korea. A mean population serum cholesterol value of about 160 mg/dl appears to be compatible with excellent general health and with the absence of ischemic heart disease or other atheromatous diseases. The influence of age, height and weight on cholesterol between Belgium and Korea is qualitatively similar but quantitatively different. High-density lipoprotein cholesterol values are lower in Korea than in Belgium, particularly in females. Differences in the HDL cholesterol level thus cannot explain the low prevalence of ischemic heart disease in Korea.

Salt and hypertension.

The salt hypothesis states that salt is a necessary condition for the genesis of essential hypertension; however, it is not a sufficient condition. Other factors---primarily genetics--are necessary for the expression of the disease. The arguments in favor of this still controversial subject originate from pathophysiology, evolution, history, pharmacology, experimental and clinical medicine, and epidemiology. Epidemiologic observations favoring the hypothesis mostly relate to comparisons between populations, and much less to comparisons within populations. The arguments against this hypothesis are related mostly to the well known difficulties of proving a within-population relationship of a relatively homogeneously distributed variable to an age-related variable (blood pressure). Mortality data derived from stomach cancer and stroke, compared within and between populations, provide only circumstantial, but nevertheless important, evidence in favor of the salt hypothesis. The strong, consistent, and independent association between stomach cancer and stroke mortality is best explained by the level of salt intake in the population. The observations made in Belgium over the last years are consistent with the salt hypothesis. A decrease in salt intake at the population level correlated with a marked decrease in stroke and stomach cancer mortality, larger than in any other European country, except Finland.