Besides drinking plain water, here are some alternative methods for staying hydrated:. Be wary of sodas, lemonades, and other drinks that may be hydrating, but contain added sugar.
Alcoholic beverages should also not be used as a source of hydration. Search Contact Share Print. Dining Services NetNutrition. Water Water. There are several other minerals our bodies need in trace amounts. More information on iodine, biotin, copper, and other trace minerals can be found on the National Institutes of Health website. Role in the Body Fuel during high intensity exercise Spares protein to preserve muscle mass during exercise Fuel for the central nervous system your brain!
The alarmingly high incidence of ESCC and its equal sex distribution in Iran highlights the likelihood of a very strong environmental risk factor as the main culprit [ 19 ]. Gross nutritional deficiencies and unbalanced diets have long been suspected to play roles in ESCC risk, particularly in high-risk regions of the world where tobacco smoking and alcohol consumption are not very common [ 7 , 20 ].
Several studies have evaluated the effect of micronutrients, such as beta-carotene, folate, vitamin C and vitamin E on ESCC risk [ 21 - 30 ] and some have proved an inverse association [ 31 - 33 ]. In addition, dietary fat [ 33 - 35 ], butter, eggs [ 28 ], cholesterol [ 36 ] and starchy foods [ 28 , 37 ] have been directly related to the esophageal cancer risk, while dietary fiber is suggested to decrease the risk [ 33 , 34 , 38 ]. Data regarding the role of protein intake in ESCC etiology are conflicting [ 28 , 36 , 39 ].
While previous studies have mostly focused on food items in relation to ESCC risk, studying macro- and micronutrients could offer advantages mainly through providing better understanding of underlying mechanisms of disease [ 40 ].
According to Willet, when an association with overall intake of a nutrient is observed, the association with the etiology of a particular cancer type is strengthened, and hence by conducting analyses at the level of nutrients, maximal information on the cancer etiology will be obtained [ 41 ].
Previous studies in Iran have shown a widespread deficient intake of several nutrients such as riboflavin, vitamin A and vitamin C [ 42 - 44 ]; however, the impact of a wide range of macro- and micronutrient residual intakes in the etiology of ESCC has not been examined in this high-risk population.
The aim of the present study was therefore, to evaluate the effect of major macronutrients, vitamins and minerals intakes on the risk of ESCC in a case-control study in Iran, and to compare the nutritional adequacy of cases and controls. This hospital-based case-control study was conducted in Kurdistan, a high-risk province of Iran.
Cases were patients aged years, who visited major general hospitals and had incident histologically-confirmed ESCC. Cases did not have history of carcinoma of other sites and were interviewed within 6 months after their ESCC was diagnosed. Controls were chosen from individuals admitted to the same hospitals as the cases for a wide spectrum of acute non-neoplastic diseases including traumas Cases and controls were frequency-matched according to the sex and age 5-year groups.
Generally, 50 patients with ESCC and hospital controls were interviewed face-to-face by professionally-trained interviewers using structured pre-tested questionnaires which evaluated socio-demographic characteristics age, sex, education, monthly family income, and place of residence , smoking history status, duration and intensity , eating habits food and beverage temperature, cooking method , medical history, medication use specifically aspirin and non-aspirin non-steroidal anti-inflammatory drugs NSAIDs , gastroesophageal reflux disease GERD symptoms heartburn and acid regurgitation and familial cancer history [ 45 ].
Questions on opium and alcohol consumption were not answered by our participants due to their cultural barriers and religious beliefs, and were hence excluded from the analyses.
No proxy interviews were required. Weight was measured with subjects clothed minimally, standing on digital scales Soehne, Berlin, Germany without shoes and was recorded to the nearest grams.
Height was measured using a non-stretch tape meter fixed to a wall with subjects standing without shoes and was recorded to the nearest 0.
Body mass index BMI was then calculated by dividing weight in kilograms by square of height in meters. Two patients were excluded from the analyses since their reported energy intakes were below or above 3 standard deviations from the mean, indicating errors in reporting dietary intakes [ 49 ].
We further excluded 5 patients due to missing information or due to poor response to dietary questions. Finally data analyses were conducted on 47 ESCC cases and 96 controls for whom the association of dietary patterns and food group intakes with ESCC risk had been documented previously [ 45 , 50 ].
A validated semi-quantitative food frequency questionnaire FFQ was used by trained dietitians in face-to-face interviews to evaluate the usual dietary intakes of participants during the previous year [ 45 , 50 ]. Habitual dietary intakes of the controls 1 year before interview and the cases one year before diagnosis of ESCC were evaluated. The FFQ consisted of Iranian food items and has previously shown to be a valid and reproducible tool for assessing food and nutrient intakes in Iranian adults [ 51 , 52 ].
Previous studies have revealed good correlations between dietary intakes assessed by this FFQ and those obtained from h dietary recalls [ 52 ]. A comparison of crude, energy-adjusted and deattenuated correlation coefficients for overall nutrient intakes between h dietary recalls and this FFQ have been 0. On the other hand, the mean reliability coefficients, ranged from 0. This FFQ produced exact agreement rates ranging from The validity coefficients, with the sample correlation between the questionnaires and biological markers as the lower limit and the estimates from the triad method as the upper limit were 0.
When using the USDA portion sizes was impossible, household measures e. Patients were asked to report their consumption frequency on a daily, weekly or monthly basis, and data were then converted to the mean daily intakes assuming one month equals Average daily intake of each food item was calculated by multiplying the consumption frequency of each food by its standard item-specific portion size from the exchange list; these scores were then summed to estimate nutrient intakes.
The estimates of nutrient intakes in the present paper are derived from the dietary sources alone. For analyzing the energy and nutrient contents of mixed food items e. For ordinal variables, chi-square test or Fisher's exact test and for continuous variables, Kruskal-Wallis test or t-student test were used to compare case and control groups. Macro- and micronutrient intakes were adjusted for total energy consumption using the residual method as suggested by Willet and Stampfer [ 56 ].
Energy-adjusted nutrients were then categorized into tertiles, due to the appropriateness of tertiles over quartiles for smaller sample sizes in case-control studies [ 57 ]. Tertile 1 served as the reference category for all regression analyses. For comparison purposes, we calculated a base regression model and a fully-adjusted model for each analysis. The base model was adjusted for the matching variables, i.
These factors were selected since they are potentially related to both the disease outcome ESCC risk and also the risk factor nutrient intakes. As a basis for trend testing, scores were constructed from the categorized variables as successive integers and were used in further analyses.
Written informed consents were taken from each subject prior to the interviews. By design, age and sex distributions were similar among cases and controls. Female cases experienced symptoms of GERD significantly more than their control peers Among male participants, Compared to the controls, cases were more likely to consume hot foods and beverages Distribution of cases and controls stratified by sex among selected risk factors in a case-control study of esophageal squamous cell carcinoma in Iran 1.
Relationship between energy-adjusted macronutrient intakes and risk of esophageal squamous cell carcinoma in a case-control study in Iran. In the fully-adjusted model, those in the highest tertile of SFA intake had 2. In the preliminary age- and sex- adjusted analysis original matching criteria , a positive association also emerged with an increased protein intake, which was not significant in the fully-adjusted model.
In the fully-adjusted model, the most protective effects against ESCC risk were associated with higher intakes of folate OR: 0. Being in the highest tertile of sodium intake residual was associated with 1. Relationship between energy-adjusted micronutrients intakes and risk of esophageal squamous cell carcinoma in a case-control study in Iran 1. After mutual adjustment for several potential confounders, the combination of high intakes of both chemicals was associated with a strong protective effect against ESCC risk OR: 0.
Results of the present study suggest that among macronutrients, consuming more carbohydrate, dietary fiber and n-3 fatty acids and among micronutrients, higher intakes of folate, vitamin E and selenium have the most protective effects against ESCC in a high-risk population in Iran. An increased ESCC risk estimate was observed among those with highest intakes of SFA, cholesterol, discretionary calorie, sodium and total fat.
This is the first study in a high-risk population to evaluate the impact of a wide range of macronutrients, minerals and vitamins on risk of ESCC. Similar to previous case-control studies, we found a decreased ESCC risk associated with higher intakes of nutrients with plant origin and an increased risk for intake of several nutrients found primarily in animal-based foods [ 28 , 29 , 58 - 61 ].
In addition to the differences in nutritional composition of animal- and plant-based foods that contribute to this effect, heterocyclic amines that are potent mutagens, and animal carcinogens formed during cooking of meats are also responsible [ 62 ].
The highest level of mutagenic activity is produced during frying, broiling and barbecuing animal products [ 59 ], which could potentially injure the esophageal mucosa [ 63 ].
Epidemiological studies have shown a positive association between total fat, cholesterol and SFA intakes with ESCC and esophageal adenocarcinoma risk [ 33 , 39 , 57 , 64 - 67 ].
In the present study, more than one-thirds of total energy intake among ESCC cases was derived from dietary fat and those with higher intakes of total fat, SFA, cholesterol and discretionary calories had an increased risk of ESCC. Since all our analyses were adjusted for usual adult BMI, the risk-enhancing effect of high fat diet on ESCC observed in the present study was independent of adiposity, which is a strong risk factor for carcinogenesis. However, this effect is likely to have been underestimated since ESCC patients tend to decrease their dietary fat intake in an effort to prevent exacerbation of reflux symptoms, and hence our result is likely to have been distorted through underestimation of magnitude of true association for dietary fat.
Although some studies have shown an inverse association between EC risk and intakes of added oil and PUFAs [ 33 ], we failed to show a significant relationship. Findings of previous studies have been inconclusive regarding the role of protein intake in esophageal cancer risk with some classic studies suggesting an inverse relationship [ 28 , 69 ]. We observed a positive association between protein intake and ESCC risk, which is in line with more recent studies [ 33 , 38 , 39 , 57 , 67 , 70 ]; however, this effect was only statistically significant in the age- and sex-adjusted model.
Although few studies have questioned the role of dietary fiber in cancer protection [ 71 - 74 ], most have proved a strong inverse association between fiber intake and risk of ESCC, esophageal adenocarcinoma and stomach cancer [ 33 , 34 , 38 , 57 , 59 , 60 , 67 , 70 , 75 , 76 ].
The role of carbohydrate intake in esophageal cancer risk is not yet clear with some studies showing a negative association [ 57 ], but not all [ 77 - 79 ]. In the present study, participants with higher carbohydrate intakes had markedly reduced ESCC risk. Previously we showed an inverse association between fruit and vegetable consumption and risk of ESCC in the same population [ 50 ], and in the present study, after adjustment for fruit and vegetable intake, the association of dietary folate, vitamin E and selenium with ESCC risk remained significant, suggesting an independent protective role for these nutrients.
Epidemiological evidence regarding the role of folate intake in ESCC risk are scanty [ 21 , 67 , 84 , 85 ]. Findings of the present research are in agreement with those of the previous studies showing a strong inverse association between dietary folate intake and risk of ESCC [ 21 , 22 , 57 , 67 , 85 ]. However, it is likely that we have more clearly observed an inverse relationship between folate intake and ESCC compared to other studies [ 22 ], since in Iran there is no mandatory folate fortification and the use of dietary supplements is very uncommon; hence, folate is mainly taken from diet in this population.
In populations with mandatory folate fortification and frequent supplement use, most of the population may have sufficient folate intakes to prevent cancer from these sources and little further benefit may be seen for dietary folate intake.
Folate is an important cofactor in DNA metabolism and its deficiency has been linked to higher risk of epithelial tumors [ 22 , 23 , 25 , 70 , 87 ]. Several mechanisms have been proposed to explain the protective effect of folate, which are mainly focused on prevention of hypomethylation and maintenance of the DNA repair system by influencing the nucleotide pool for DNA replication and repair [ 88 - 90 ].
Similar to folate, vitamin B 2 , B 6 , B 12 and methionine have major roles in one-carbon metabolism. Previous studies in Iran have reported inadequate riboflavin intakes among patients with esophageal cancer [ 44 ].
This is in line with findings from this research and those of previous studies, which have shown protective effects for this nutrient against the risk of EC [ 28 , 69 , 82 , 91 ].
In this study, we failed to observe a significant association between vitamin B 12 intake and ESCC risk. However, it has been suggested that the positive relationship between vitamin B 12 and EC risk observed in some studies [ 67 ], could be explained by the fact that vitamin B 12 is derived exclusively from animal sources and hence may be simply a marker for consumption of animal protein and other factors or nutrients in these foods [ 67 ].
It has also been documented that individuals living in the high ESCC risk regions have significantly lower vitamin B 9 and B 12 intakes, compared to those living in the low risk areas [ 93 ] and those with vitamin B 12 deficiency disorders e. Overall, causal relationship between vitamin B 12 intake and ESCC risk is not yet clear and evidence in this regard is lacking. In the present study, high methionine intake was inversely associated with ESCC risk, which might be explained through its involvement in SAM production, which is necessary for retaining folate in body [ 96 ].
The finding of a strong inverse association between ESCC with vitamin D intake in this study is consistent with some studies [ 97 , 98 ], although in contrast with others [ 67 ].
This contradiction could be explained by the fact that dietary and supplemental vitamin D intakes only comprise a relatively small proportion of the variation in hydroxy vitamin D levels in the body, and sunlight exposure, skin pigmentation, geographic region of residence, season, BMI, and differences in vitamin D receptor expressions genetic differences are the major predictors of 25 OH D levels in the body [ 99 , ]. Dietary antioxidants also play major roles in prevention of damage to the mucosa of the upper aerodigestive tract caused by oxidative stress of smoking and alcohol consumption.
Dietary selenium is inversely associated with cell cycle predictors of neoplastic progression and the ESCC risk [ - ]. The potential of combined supplementation in the Linxian trial in reducing the EC risk has been mainly attributed to the effect of selenium, which has a highly deficient intake in Chinese population.
Our inability to detect a significant relationship may be due to considering vitamin A intakes from both plant and animal origins together, while it has been suggested that vitamin A of plant origin is associated with decreased ESCC risk, whereas vitamin A of animal origin increases the level of risk [ 67 , ]. In addition, the protective effect of high carotene intake observed in some of the previous studies could have been mediated through high intakes of plant-based foods, which contain different micronutrients and hence contribute to the general effect [ 59 , 61 , 98 ].
Vitamin C, as an important antioxidant and inhibitor of endogenous synthesis of N-nitroso compounds [ - ] prevents carcinogenesis of esophageal cells [ ]. Some epidemiological studies have suggested a role for higher salt intake in carcinogenesis.
Although salt is not a carcinogen per se, it acts as an irritant to the esophageal protective mucosal layer, which results in inflammatory regenerative response, increased DNA synthesis and cell proliferation [ 23 ] and may also enhance carcinogenesis induced by other carcinogens [ ]. However, supplemental calcium intake has previously failed to show beneficial effects on EC risk, which could been explained by the confounding effect of higher calcium supplement intakes in the form of GERD medication by cases compared to the controls [ 67 ].
This study has several limitations. Firstly, as with other case-control studies, recall bias and selection bias were inevitable. In case-control studies, there is the possibility that cases may recall their diets differently after a cancer diagnosis.
However, our participants were generally of low literacy and socioeconomic status with little knowledge about the role of diet and nutrients in the cancer risk, which should have reduced the possibility of recall bias.
Moreover, using hospital controls and administering validated FFQs by trained interviewers in a hospital setting might have further reduced the recall bias and improved comparability of information of cases and controls [ , ]. Not having data on participants' alcohol consumption was yet another barrier. Our subjects refrained from reporting their alcohol intake due to the fact that consuming alcohol is legally prohibited in Iran [ , ]. In addition, since the import of alcoholic beverages is banned in Iran, the contents of alcoholic beverages that Iranians consume may differ from those consumed in other countries [ , ].
On the other hand, the Iranian FCT does not provide data on any type of alcoholic beverages [ 54 ]. Opium use was also not answered by our participants due to the cultural barriers and sensitivity of this issue among Iranian population [ 10 ], which could have resulted in confounded estimates in the present study due to the possible role of opium in ESCC risk.
However, it has been suggested that opium contributes to ESCC development only in a subgroup of patients and not in the majority [ 6 , 19 ]. In contrast to low-incidence regions for EC, a much smaller proportion of esophageal cancer cases are attributed to alcohol, tobacco and opium use in high-risk regions [ 9 , 13 , 19 , ].
This suggests a more prominent role for nutritional deficiencies in EC development in high-risk areas, such as Iran and China, where a larger number of cases could be attributed to insufficient nutritional intakes [ 19 , 28 , 42 , 44 , 75 , , ]. The third limitation is the possibility of some micronutrient misclassification due to not having data on supplement use.
However, it has been suggested that dietary supplements and fortified foods, mask the beneficial effect of food intakes in reducing the cancer risk [ ] and some of them have independent positive association with esophageal cancer risk [ 85 ]. In addition, supplement intake is very uncommon among our population since the majority of participants in the present study were rural dwellers with little or no education and low socioeconomic status.
This might relate to the sampling method in the present research which was performed in general hospitals of one of the high-risk regions of Iran. Generally, lack of information on supplement use would most likely have negligible effects on our estimates and if anything, would likely results in underestimation of association between ESCC and nutrient intakes. Another limitation of the present study was using a semi-quantitative FFQ, which despite its common use for characterizing the habitual dietary intakes, is well-recognized for its weakness in quantification of nutrient intakes [ ].
Using a semi-quantitative dietary assessment tool limits our conclusions mostly to comparisons between cases and controls and hence conclusions about adequacy of diet are relative and should be interpreted by caution, since these types of comparisons generally overestimate the true effect of exposure on the outcome.
However, the theoretical basics that formed the food frequency method have been based on the good correlation of "frequency" of food intake and the "total weights" of the same foods consumed over a several-day period [ , ].
The fundamental concept behind the calculation of nutrients from FCTs is that the nutrient contents of specific foods are relatively constant, and their variability might not be large enough to distort calculations [ ]. In addition, much of the errors relating to sample-to-sample variation in nutrient composition of foods are reduced by using the estimates of long-term nutrient intakes obtained from the FFQs [ ]. Another drawback of this study was using nutrient values in the statistical analyses without directly referring to the foods which contributed most to the nutrient intake and its variation.
According to Willet, an optimal approach to epidemiologic analysis is to employ both foods and nutrients to represent diets [ ]; in this way the case for causality is strengthened when an association is observed both with the overall intake of a nutrient and also with more than one source of that nutrient, especially when the food sources are different. Previously we evaluated the role of food group intakes in the etiology of esophageal squamous cell carcinoma ESCC among the same population [ 50 ]; by conducting the present study, we aimed at providing preliminary evidence on the extent to which certain nutrients could influence the ESCC risk in such a high-risk region.
Another potential source of error is that several naturally continuous variables e. BMI, physical activity were categorized for the purpose of analysis, which might have increased the possibility of residual confounding and decreased the precision and power of the study.
However, we compensated for this limitation by choosing categories with multiple sufficiently narrow intervals to decrease the residual confounding and heterogeneity of subjects within intervals. Additionally, availability of B-vitamins is influenced by diet, supplement use, alcohol consumption and generic polymorphism and B-vitamins are all involved in one-carbon metabolism which requires vitamin B 2 , B 6 , B 9 and B This complexity added to the problems of using estimated intake of nutrients obtained at one point in time must be considered when interpreting the results of this study.
Small sample size is also a limitation which might have resulted in unstable results and extreme relative risk estimates observed in some of the subgroups, although this is one of the largest sample series in an Iranian population and a number of strong consistent findings have emerged from this sample [ 45 , 50 ]. Fats Role in the Body Fats provide energy during endurance exercise, in between meals, and in times of starvation. They constitute an essential component of cell membranes, insulate and act as a shock absorber for bones and organs.
Fats are not necessarily bad for you, but you only need a small amount. Fats have 9 calories per gram. Saturated fats those that are solid at room temperature: butter, shortening, etc.
Trans fats the really bad fats! Micronutrients: Vitamins and Minerals Water-Soluble Vitamins Water-soluble vitamins travel freely through the body and excess amounts are usually excreted by the kidneys. Contact Us. Frank Dining Hall.
Facebook Twitter. Search Search Mobile Search. All nutritious food contain moderate amounts, especially pork, whole-grain or enriched breads and cereals, legumes, nuts and seeds. Part of an enzyme needed for energy metabolism; important for nervous system, digestive system, and skin health. Meat, poultry, fish, whole-grain or enriched breads and cereals, vegetables especially mushrooms, asparagus, and leafy green vegetables , peanut butter.
Leafy green vegetables, legumes, seeds, orange juice, and liver; now added to most refined grains. Antioxidant; part of an enzyme needed for protein metabolism; important for immune system health; aids in iron absorption.
Found only in fruits and vegetables, especially citrus fruits, vegetables in the cabbage family, cantaloupe, strawberries, peppers, tomatoes, potatoes, lettuce, papayas, mangoes, kiwifruit. Needed for vision, healthy skin and mucous membranes, bone and tooth growth, immune system health. Animal sources retinol : fortified milk, cheese, cream, butter, fortified margarine, eggs, liver Plant sources beta-carotene : leafy, dark green vegetables; dark orange fruits apricots, cantaloupe and vegetables carrots, winter squash, sweet potatoes, pumpkin.
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