Use Of Table Salt Research Articles

The importance of salt in the athlete’s diet

Salt consists of sodium and chloride, and is important for normal physiologic function. High sweat rates in athletes result in loss of both fluids and sodium. Fluid replacement with hypotonic solutions will lead to incomplete rehydration and possible complications such as hyponatremia, decreased performance, heat cramps, or other heat-related illness. There is significant individual variation in sodium loss during activity. In some the losses can be replaced by normal dietary intake, whereas in others the losses can be dramatic and increased dietary intake is essential. There are various methods to increase sodium intake, such as increased use of table salt on foods, salty snacks, adding salt to sports drinks, and use of salt tablets. Emphasis on replacement of fluids is also important, but care must be taken to avoid overhydration. Simple measures such as recording daily pre- and postexercise body weight can aid in making fluid and sodium ingestion decisions; in some cases, a comprehensive evaluation is necessary.

The Importance of Salt in the Athleteʼs Diet

Salt consists of sodium and chloride, and is important for normal physiologic function. High sweat rates in athletes result in loss of both fluids and sodium. Fluid replacement with hypotonic solutions will lead to incomplete rehydration and possible complications such as hyponatremia, decreased performance, heat cramps, or other heat-related illness. There is significant individual variation in sodium loss during activity. In some the losses can be replaced by normal dietary intake, whereas in others the losses can be dramatic and increased dietary intake is essential. There are various methods to increase sodium intake, such as increased use of table salt on foods, salty snacks, adding salt to sports drinks, and use of salt tablets. Emphasis on replacement of fluids is also important, but care must be taken to avoid overhydration. Simple measures such as recording daily pre- and postexercise body weight can aid in making fluid and sodium ingestion decisions; in some cases, a comprehensive evaluation is necessary.

Short-term effectiveness of mandatory iodization of table salt, at an elevated iodine concentration, on the iodine and goiter status of schoolchildren with endemic goiter

Goiter rates and iodine deficiency usually show marked improvement in efficacy studies of mandatory iodization of salt, but little is known about the short-term effectiveness of mandatory iodization. The aim of the study was to evaluate, after 1 y, the effectiveness of mandatory iodization of salt at an iodine concentration higher than that occurring under optional iodization on the goiter rates and iodine status of schoolchildren living in an endemically goitrous area. Goiters, measured by palpation, and urinary iodine concentrations of children in grades 4-7 in 4 schools in a known goitrous area in South Africa were assessed before and 1 y after the introduction of mandatory iodization at a higher iodine concentration than occurred with optional iodization. Estimates of the iodine concentration of iodized salt and the proportion of households using iodized salt were also made. Iodine concentration in table salt and household use of iodized salt improved within 1 y. Goiter rates, which varied at baseline from 14. 3% to 30.2% in the 4 schools, remained unchanged, with an overall mean (+/-SE) prevalence of 25.6 +/- 2.5% at baseline and of 27.5 +/- 2.7% 1 y later. The distribution of urinary iodine concentrations in the 4 schools improved substantially from the baseline deficient range. The overall median urinary iodine concentration increased from 0.17 to 1.47 micromol/L. Mandatory iodization of salt virtually eradicated iodine deficiency within 1 y in South African schoolchildren, but the goiter rate in these children did not decline. Measurement of goiters by palpation may not be appropriate in short-term evaluations of mandatory iodization programs.

Prevalence of Health Behaviors Related to Hypertension in 3 Blood Pressure Treatment Groups: The Minnesota Heart Health Program

Background. Lifestyle modifications have the potential to bring blood pressure under control or reduce the need for potentially harmful medications and, most importantly, to prevent high blood pressure from developing. Evaluation of the contribution of primary and secondary prevention efforts requires monitoring risk factors for hypertension among those with and without a history of the condition. Methods. This study in the Minnesota Heart Health Program describes the prevalence of the major lifestyle risk factors for hypertension and other cardiovascular disease. Data are from men and women age 25-74 over a period of about 10 years (1980-1990). The study involved six communities, three received an education intervention, and three were used as comparison groups. Irrespective of observed blood pressure values, risk factor levels and time trends are compared among persons taking antihypertensive medication, persons with a history of hypertension but not currently medicated, and a general population, nonhypertensive group who report they were never told they were hypertensive. Analysis was done at the level of the city rather than the individual and involved a subset of the cross-sectional survey data. Results . Significant differences were found between groups for knowledge about and control of high blood pressure, for body mass index, intent to lose weight, physical activity, sodium and fat intake, and total serum cholesterol level. No differences were found in intent to increase physical activity, in alcohol intake, or smoking prevalence. A group by time interaction was found only for frequent use of table salt and percentage of total kilocalories from fat. Most time trends were significant and in a favorable direction for prevention. Means for all groups indicated failure to meet national recommendations for dietary sodium, percentage of calories from fat, total cholesterol level, smoking, and possibly exercise. Conclusions. Efforts to prevent, treat, and control hypertension will require more intensive intervention. Continued monitoring of the knowledge and behaviors of hypertensives and the general population is needed to inform primary and secondary prevention efforts, especially in more diverse populations than this study represents.

Respiratory symptoms and bronchial responsiveness are related to dietary salt intake and urinary potassium excretion in male children

To investigate whether dietary salt intake and urinary sodium and potassium levels are related to respiratory symptoms and bronchial responsiveness, a cross-sectional study among 2593 subjects aged 9 to 16 was conducted in four communities of the Latium region (Italy). Questionnaires were administered to the parents, urine samples were collected, lung function, methacholine challenge tests and prick tests were performed. Information about familial and personal dietary salt use and respiratory health was collected from the parents of 2439 (94%) subjects. A total of 2020 methacholine challenge tests and 916 urinary sodium and potassium levels were available for analysis. Personal table salt use was strongly related to cough and phlegm apart from colds (adjusted odds ratios, OR, 1.87, 95% confidence intervals, CI, 1.20-2.90), wheezing apart from colds (OR, 2.19, 95% CI, 1.27-3.77), wheezing with dyspnoea (OR, 1.45, 95% CI, 0.98-2.12) and wheezing after exercise (OR, 2.16, 95% CI, 1.35-3.44). These associations were mainly found in boys. Use of familial table salt and canned food showed no relation to respiratory symptoms. Increased bronchial responsiveness was associated with a higher urinary potassium excretion in boys, but not with urinary sodium. In conclusion, personal table salt use is related to an increased prevalence of bronchial symptoms; an increase in bronchial responsiveness among those with higher potassium excretion also seems to be implied. Although it is difficult to interpret the results of this study in causal terms, the findings might be relevant to the distribution of bronchial symptoms and diseases in the population.

Dietary risk factors in intestinal and diffuse types of stomach cancer: a multicenter case-control study in Poland

A hospital-based, multicenter, case-control study has been performed in Poland covering 741 incident stomach-cancer cases (520 males and 221 females) and the same number of controls. All stomach-cancer diagnoses were evaluated for histologic type according to the Lauren criteria. Fifty-one percent were of the intestinal type, 35 percent of the diffuse type, and 8.5 percent of the mixed type. The frequency of consumption of individual food items and several food groups was analyzed and the association of various foods with stomach cancer risk was evaluated after controlling for sex, age, occupation, education, and residency. Increased consumption of sausages was related significantly to gastric cancer risk, whereas increased consumption of cheese products, nonwhite bread, vegetables, and fruit was associated with decreased risk. A particularly strong decrease in risk was associated with consumption of radishes and onions. When consumption of fruits and vegetables, sausages, nonwhite bread, and cheese were introduced simultaneously in a multivariate model, independent effects were found only for fruit and vegetables, sausages, and nonwhite bread. The use of table salt, the frequency of eating hot meals, and an irregular eating pattern were also associated with increased risk, while additional consumption of fruit between meals showed reduced risk. If a reduction in vegetable and fruit consumption took place after marriage, an increased risk for stomach cancer was found, whereas augmented consumption of these food items after marriage decreased the risk. Separate risk models were calculated for stomach cancer of the intestinal and diffuse types, but both histologic varieties showed the same pattern of associations with dietary risk factors.

Dietary sodium reduction for hypertension prevention and treatment.

Nutritional-nonpharmacological approaches for the treatment and prevention of hypertension are of great interest. Sodium reduction is one of the primary methods recommended for these purposes. The general public is interested in the reduction of dietary sodium intake and has responded with a decrease in table salt use, the purchase of lowered sodium food products, and the use of food labels to help guide food purchases. Countervailing trends in the use of convenience foods and dining out increase the difficulty for individuals to lower sodium intake. Clinical trials that have used sodium reduction alone or in combination with other lifestyle therapies have demonstrated the feasibility of reducing dietary sodium intake from 30% to 50% for up to 4 years, in a variety of populations. Trials that used lifestyle and weight loss interventions have also achieved significant reductions in body weight and alcohol consumption and increases in physical activity. A variety of studies indicate that long-term sodium reduction is feasible and that it is acceptable to patients. No negative consequences of these interventions have been observed, and in some cases improvement in the intake of other nutrients has occurred. Nonpharmacological interventions have resulted in hypertension control in significant proportions of the trial populations. These studies demonstrate that the foregoing types of interventions can significantly contribute to hypertension treatment and prevention.

Nutritional and Sensory Beliefs in Food Choice

Food choice is influenced by a range of factors, including sensory attributes and beliefs about the nutritional value of the foods. It is difficult to determine the relative importance of beliefs about nutritional and sensory attributes to foods. It is necessary to examine these within an overall framework. The attitudes model developed by Fishbein and Ajzen is presented as a framework within which such comparisons can be made. It has been shown to be useful in a variety of studies of food choice. The relative importance of different types of beliefs can be assessed within this approach by examining the relationship between individual beliefs (or groups of beliefs) and either attitude or behaviour. In a number of studies sensory attributes have been found to be more important for table salt use, snack food consumption and consumption of foods contributing highly to fat in the diet. In the case of low‐fat milk consumption, however, nutritional beliefs were found to be more important than beliefs about the sensory attributes of the milks or their suitability for different uses.

The effect of manipulation of salt pot hole size on table salt use

Daily use of table salt was measured for 10 weeks in a staff canteen serving approximately 2400 meals. During the study the size of the holes in the salt pots was manipulated, and the corresponding amount of table salt used was measured. Staff also completed a questionnaire on salt use, which was used to calculate the percentage of staff using the salt pots. Results indicate that, despite a 10 day exposure to each new hole size, individuals used significantly more table salt when the salt pots with the largest holes were supplied. However, when the ‘shaking’ time was estimated by relating the amount used to the flow rate, the salt pots with the largest holes were shaken for a shorter time. This finding suggests that the adding of table salt to food is subject to both sensory and habitual control.

Dietary and weight control practices among persons with hypertension: Findings from the 1986 Behavioral Risk Factor Surveys

The National Heart, Lung, and Blood Institute has concluded that reducing sodium intake, controlling weight, and moderating alcohol consumption can help patients with hypertension control their blood pressure. To determine whether such patients have adopted recommended dietary practices, we analyzed data collected in 1986 from telephone surveys of adults in 26 states (no. = 34,395). The self-reported dietary practices that we evaluated were: use of table salt, alcohol consumption, and weight control practices. In comparison with persons who did not have hypertension (no. = 26,848), those with hypertension who were receiving pharmacological therapy ("treated hypertensives," no. = 5,025) were more likely to report limiting their use of table salt (odds ratio [OR] = 2.5) and were less likely to have their weight controlled (OR = 0.4). Although overweight persons with hypertension were more likely than persons with normal blood pressure to attempt to lose weight, most have not included exercise in their weight loss efforts. There was no difference between persons who do not have hypertension and treated patients with hypertension in their use of alcohol. Untreated persons with hypertension (no. = 2,378) were less likely to limit their use of table salt and less likely to moderate their use of alcohol than treated persons with hypertension but otherwise reported similar dietary practices. Dietetic practitioners may need to emphasize moderation of alcohol use and the use of physical activity to lose weight when counseling patients with hypertension.

Salt intak assessment by questionnaire and urinary sodium excretion

A questionnaire designed to assess salt intake was distributed to a sample of 113 healthy female subjects. The questionnaire was validated with 36 subjects collecting complete 24-h urine samples (analysed for sodium) for 7 days, along with sing pre-weighed table and cooking salt pots. Intake was well predicted for table salt use (r=0.67), cooking use (r=0.57), nondiscretionary intake (r=0.65), and total salt intake (r=0.61). The test-retest reliability for the estimate of total intake was good (r=0.75). Measured total salt intake for the 36 subjects was found to be 7.4g NaCl/day, with only 11% from discretionary salt use. Mean questionnaire estimates agreed closely with the measured values.

THE DOMINANCE OF SALT IN MANUFACTURED FOOD IN THE SODIUM INTAKE OF AFFLUENT SOCIETIES

Statistical analyses suggest that 25-50% of the salt intake of Western populations is derived from the discretionary use of cooking and table salt. Yet direct estimates of discretionary salt use by a lithium technique show that in one community in Britain this source contributed only 15% to total intake. The estimates of discretionary salt use in Finland, the United States, and Britain have been exaggerated because salt losses in cooking water were not considered. Only about a quarter of cooking salt actually enters the consumed food; allowance for this in statistical calculations makes data on dietary intake similar to those assessed from urinary sodium excretion. Daily salt intake in Britain averages about 10·7 g for adult men and 8·0 g for women, figures similar to those from countries in northern Europe. The natural salt content of food provides about 10% intake, the remaining 75% being derived from salt added by manufacturers; drinking water provides a negligible amount. Any programme for reducing the salt consumption of a population should therefore concentrate primarily on a reduction in the salt used during food processing.

An assessment of the sources of dietary salt in a British population.

An epidemiological study was conducted in the market town of March, Cambridgeshire, to assess the quantitative importance of cooking and table salt to total dietary salt intake by the use of a fused mixture of lithium carbonate and sodium chloride. Men and women aged 20-60 participated in a 12 day study with sequential 24 h urine collections to assess salt sources over a 7 day period. Total salt consumption estimated from urinary chloride excretion amounted to 10.6 +/- 0.55 (SEM) g in 33 men and 7.4 +/- 0.29 (SEM) g in 50 women. The cooking salt eaten was only 0.45 +/- 0.09 (SEM) g in men and women, with men eating more table salt (0.77 g/day) than women (0.46 g/day). Discretionary sources, i.e. cooking and table salt use, contributed only 15% to the total intake. Salt from manufacturing foods and catering in purchased food therefore provided on average 85% of total salt intake. These results are consistent even when an allowance is made for the slightly poorer pouring quality of the lithium-tagged salt. The importance of food as a source of salt was reflected in the significant relationship between the weight of the individual and the amount of salt eaten (for males P less than 0.05 and for females P less than 0.001). Cooking salt consumption did not relate to the amount of salt derived from purchased food nor did table salt use relate to the amount of salt in cooked foods.(ABSTRACT TRUNCATED AT 250 WORDS)

Attitudes and personality related to salt intake

A predominantly middle-class female sample of British adults completed questionnaires designed to estimate salt intake and to assess attitudes towards adding table salt to food, along with Cattell's 16PF personality inventory. The attitudes questions were based on the approach suggested by Fishbein and Ajzen, and proved to be good predictors of table salt use. The person's own feeling about table salt use was a better predictor than perceived pressure from other people. Beliefs about adding table salt were closely related to the person's attitude, but only beliefs about taste (not beliefs about health consequences) predicted usage. Beliefs about pressure from doctors and nutritionists/dietitians, but not family, were also related to usage. There was lower usage and more negative attitudes in respondents under 35 years old. Two of the second-order personality factors from the 16PF correlated with salt intake, but appeared to act through attitudes: tough poise (i.e. given to rapid action with insufficient thought) correlated positively with estimated table and cooking salt use; anxiety correlated positively with cooking use, with salt consumed in foods and with estimated total intake. The results suggest that any attempt to reduce salt intake might best be directed at satisfying taste, and not exclusively at augmenting anxiety about the health consequences of salt intake.

A method to assess sodium intake in populations

Dietary sodium measurement in populations has severe limitations whether assessment is based on urinary excretion or on food intake methods. We have validated a simple instrument to determine total dietary sodium intake of populations in a pilot study of 10 women, 20 to 36 years old. Sodium intake determined by means of the sodium measurement instrument was correlated with sodium intake from food analysis, sodium intake calculated from food composition tables, and measurement of 24-hour urinary sodium excretion. Sodium values obtained with the instrument are based on regression equations, which incorporate information as follows: an average measure of 7 days' actual table salt use, the average sodium contribution of 17 high-sodium foods from a food frequency checklist maintained for 7 days, a calculation of drinking water sodium, and measurements of height and weight to establish 24-hour energy needs, a surrogate estimate of sodium found in all foods not included in the food frequency checklist. Participants were studied for 16 days: 7 consecutive days on either a 2,000-mg or a 3,500-mg sodium diet, 2 days' adjustment, and 7 days' crossover. Participants were allowed to select foods from a diverse menu, eat at fast-food restaurants, and consume alcohol if desired. Mean of 7-day sodium intake obtained with the instrument was significantly correlated with mean of 7-day sodium intake determined by food analysis (r = .80), from food composition tables (r = .62), and from urinary excretion (r = .56).

Estimation of salt intake by questionnaire

A questionnaire designed to assess salt intake was tested. This involved principal components analysis of responses from 155 subjects to find the underlying components related to the questions. Validation of the questionnaire used 7-day urinary sodium excretion for 33 subjects, along with table and cooking salt usage over 7-days. This gave comparatively good prediction for total intake (r = 0.66) and table salt use (r = 0.70) but not for cooking salt use (r = 0.17). Test-retest reliability for the estimate of total intake was r = 0.75. This method would therefore offer a useful estimate of total intake, especially where group means are required rather than accurate estimates of individual intakes.

Contemporary table salt practices and blood pressure.

Salt intake of 978 subjects when compared to 1954 data demonstrated a trend toward the decreased use of table salt. When hypertensives in treatment were excluded, persons reporting low salt use had higher mean systolic and diastolic blood pressures than those reporting high salt use. These findings were the reverse of the relationships found in 1954.

The relationship between salt intake and preferences for different salt levels in soup

Two experiments are reported with subjects divided according to questionnaire responses into low and high total sodium intake, and low and high table salt use. The stimuli were tomato soup with varying salt concentrations. In Experiment 1 these were rated for salt intensity, pleasantness and intensity relative to ideal. In Experiment 2 the stimuli were presented in restricted concentration ranges or using a method designed to minimise range bias; relative-to-ideal intensity rating was again used. Subjects with a high total intake were found to prefer higher concentrations of salt assessed both with the hedonic and relative-to-ideal intensity ratings, though not with restricted stimulus ranges. Subjects with high table salt use were found to prefer higher concentrations only when assessed using the hedonic ratings. Sensitivity to salt taste was not found to differ between the groups.

Preference and Sensitivity to Salt Taste as Determinants of Salt-intake

Total salt-intake was estimated in 33 normal subjects using urinary sodium excretion over 7 days, and table and cooking salt use were measured over the same period. Sensitivity to salt taste was measured for 31 of these subjects using a seven-category rating scale for intensity of saltiness with five concentrations of salt in water, bread and mashed potato. Preferences were assessed using a nine-category hedonic rating scale with the bread and mashed potato to determine the maximally-preferred concentration. No differences were found in the taste measures between subjects divided into high and low intake in terms of total salt-intake or total intake divided by body weight. However, differences were found in sensitivity and preferences between groups divided into high and low table salt use. This may be because the major proportion of total salt-intake arose from salt present in foods and this would not be so open to voluntary control as table salt use.

Sodium intake from meals and snacks consumed by college students

This investigation was designed to compute the total sodium intake from meals and snacks consumed by selected college students. Most students used carbonated beverages, candies, gums, cookies, and salted snack items. They consumed salted snack items mostly as evening snacks. Mean sodium intake was found to be 3,904 mg. for men and 2,628 mg. for women, without taking into consideration the use of table salt. Sodium density per kilocalorie per day was 1.40 and 1.41 for men and women, respectively, suggesting that the differences in intakes were due to women's lower caloric intake. Sodium intake was greater from regular meals than from snack foods. Evening snacks contributed more to the daily sodium intake than morning and afternoon snacks. It can be concluded that sodium intake of college students needs careful assessment. According to the Food and Nutrition Board, the most effective way to maintain intake within the suggested range is to reduce the amount of salt added at table or in cooking and to reduce moderately the selection of obviously salty foods (9). College students need to be made aware of the sodium content of foods they select for lunch, dinner, and evening snacks, as well as the amount of salt they add at the table.