Administration's Total Diet Study Research Articles

Update on dietary intake of perchlorate and iodine from U.S. food and drug administration’s total diet study: 2008–2012

The U.S. Food and Drug Administration's (FDA) Total Diet Study (TDS) monitors the US food supply for pesticide residues, industrial chemicals, radionuclides, nutrients, and toxic elements. Perchlorate and iodine intakes based on concentrations in TDS samples collected between 2008 and 2012 were estimated in order to update an earlier TDS dietary assessment. Perchlorate is used as an oxidizing agent in rocket and missile fuel, is formed naturally in the atmosphere, and occurs naturally in some soils. Because of perchlorate's presence in soil, and in irrigation, processing, and source water, it is widely found in food. Iodine was included in the study because perchlorate at high doses interferes with iodide uptake in the thyroid. Iodine (the elemental form of iodide) is essential for growth and development, and metabolism. This study uses a novel statistical method based on a clustered zero-inflated lognormal distribution model to estimate mean and 95th percentile confidence interval concentrations for perchlorate and iodine in US foods. These estimates were used to estimate mean perchlorate and iodine exposures for the total US population and for 14 age/sex groups in the US population. Estimated mean perchlorate intake for the total US population was 0.13 μg/kg bw/day, with mean intakes for the 14 age/sex groups between 0.09 and 0.43 μg/kg bw/day. The estimated mean intakes of perchlorate for all age/sex groups were below EPA's reference dose (RfD) of 0.7 μg/kg bw/day. The estimated mean iodine intake for the total US population was 216.4 μg/person/day, with mean intakes ranging from 140.9 to 296.3 μg/person/day for the 14 age/sex groups, with all age/sex groups exceeding their respective estimated average requirements (EARs).

Current Data on Manganese in Foods and in U.S. Diets from the U.S. Food and Drug Administration's Total Diet Study

The U.S. Food and Drug Administration's Total Diet Study (TDS) program monitors concentrations of manganese, other nutrient minerals, and a variety of toxic substances in foods representative of U.S. diets. These data are available to the public on the TDS website. FDA's most recent TDS‐based intake estimates for manganese, published in 2002, were based on TDS data generated from 1991–1996. We recently initiated a program to update intake estimates for manganese and other TDS analytes using data generated from 2007–2012. Inductively coupled plasma atomic emission spectroscopy (ICP‐AES) was used to determine manganese concentrations in each of 259 foods collected under the TDS program. Of 6143 TDS food samples, 1694 (27.6%) had manganese concentrations below the limit of detection (LOD). We estimated lower bound mean manganese concentrations in TDS foods assuming that samples in which manganese was not detected contained zero manganese, and we estimated upper bound mean manganese concentrations assuming that samples with non‐detected manganese concentrations had concentrations equal to the LOD. We also used a zero‐inflated distribution model to estimate means and confidence intervals for manganese in TDS foods based on clustered data. We merged each set of manganese concentration data with food consumption data from the 2007–2008, 2009–2010, and 2011–2012 cycles of the National Health and Nutrition Examination Survey (NHANES) dietary component, What We Eat In America (WWEIA) and then estimated usual intakes of manganese by U.S. population subgroups using PC‐Side software (v. 1.0, Iowa State University). Proportions of NHANES/WWEIA respondents with manganese intakes greater than the Tolerable Upper Intake Level were low (< 1%) for most subgroups, but high (≥ 5%) among children ages 1 – 3 years and 4 – 8 years. Over 40% of manganese intake was provided by cereals and grain products. Other major contributors to manganese intake were pizza and other mixed dishes (likely due to the grain components) and tea. The updated TDS manganese data and intake estimates based on these data provide key information on manganese in U.S. foods and diets.Support or Funding InformationU.S. Food and Drug Administration

Perchlorate in the Feed−Dairy Continuum of the Southwestern United States

Perchlorate has the potential to cause thyroid dysfunction by inhibiting iodide uptake by the sodium iodide symporter. Perchlorate-contaminated waters may lead to human exposure through drinking water and food chain transfer in crops by way of irrigation water. Perchlorate has been found in dairy milk collected nationally and internationally. This study was conducted to evaluate perchlorate in the feed-dairy continuum in the southwestern United States. All feed products collected at dairies in this study had detectable levels of perchlorate as analyzed by ion chromatography-tandem mass spectrometry. The calculated total perchlorate intake across dairies ranged from 1.9 to 12.7 mg/cow per day. The variation in total perchlorate intake across dairies was largely associated with variation in forage and silage products. Alfalfa products were the single most important source of perchlorate intake variability among dairies. The estimated perchlorate intake from drinking water ranged from 0.01 mg per cow per day and was generally less than 2% of the total perchlorate intake. The perchlorate content of milk ranged from 0.9 to 10.3 microg/L and was similar to levels reported by the Food and Drug Administration's Total Diet Study. The perchlorate content of milk was significantly related to the presence of perchlorate in feed but the variation of perchlorate in milk could not be explained by feed intake alone.

US Food and Drug Administration's Total Diet Study: Dietary intake of perchlorate and iodine

The US Food and Drug Administration (FDA) has conducted the Total Diet Study (TDS) since 1961, which designed to monitor the US food supply for chemical contaminants, nutritional elements, and toxic elements. Recently, perchlorate was analyzed in TDS samples. Perchlorate is used as an oxidizing agent in rocket propellant, is found in other items (e.g., explosives, road flares, fireworks, and car airbags), occurs naturally in some fertilizers, and may be generated under certain climatic conditions. It has been detected in surface and groundwater and in food. Perchlorate at high (e.g., pharmacological) doses can interfere with iodide uptake into the thyroid gland, disrupting its function. The National Academy of Sciences (NAS) has identified that "the fetuses of pregnant women who might have hypothyroidism or iodide deficiency as the most sensitive population." This study reports on intake estimates of perchlorate and iodine, a precursor to iodide, using the analytical results from the TDS. Estimated average perchlorate and iodine daily intakes as well as the contribution of specific food groups to total intakes were estimated for 14 age/sex subgroups of the US population. The estimated smallest lower bound to the largest upper bound average perchlorate intakes by the 14 age/sex groups range from 0.08 to 0.39 micrograms per kilogram body weight per day (microg/kg bw/day), compared with the US Environmental Protection Agency (EPA) reference dose (RfD) of 0.7 microg/kg bw/day. Infants and children demonstrated the highest estimated intakes of perchlorate on a body weight basis. The estimated average iodine intakes by the 14 age/sex groups reveal a lower bound (ND=0) and upper bound (ND=LOD) range of average intakes from 138 to 353 microg/person/day. Estimated iodine intakes by infants 6-11 months exceed their adequate intake (AI), and intakes by children and adult age/sex groups exceed their relevant estimated average requirement (EAR).

US Food and Drug Administration's Total Diet Study: intake of nutritional and toxic elements, 1991–96

The Food and Drug Administration (FDA) has conducted the Total Diet Study (TDS) annually since 1961. The TDS is designed to monitor the US food supply for levels of toxic chemical contaminants (pesticide residues, industrial chemicals and toxic elements) and nutritional elements. Foods are generally collected four times a year, once from each of four regions of the country. The foods are prepared table-ready before being analysed. From the results of the TDS, dietary intakes of these analytes are estimated for selected age- sex groups in the US population. This paper reports on the dietary intake of 10 nutritional and four toxic elements based on measurements made in foods collected in the TDS between 1991 and late 1996. Average daily intakes were estimated for 14 age-sex groups in the US population, as well as the contribution of specific food groups to total intakes. For most nutritional elements, teenage boys and adult males had the highest daily intakes. Intakes by infants were below the intake references for seven of 10 nutritional elements, and young girls and women had inadequate intakes of at least half the nutritional elements. Intakes by children between 2 and 10 years of age, teenage boys, and adult males met or exceeded the reference intakes for the majority of nutritional elements. Intakes by all population groups were well below the reference intakes for all toxic elements.

Element and Radionuclide Concentrations in Food: FDA Total Diet Study 1991–1996

Food purchased throughout the United States during 1991-1997 under the U.S. Food and Drug Administration's Total Diet Study (TDS) program were analyzed for elements and radionuclides. The program is described with emphasis on food analysis and quality control, including independent interlaboratory exercises. Analytical results are summarized for Cd, Pb, Ni, As, Hg, Se, Cu, Zn, Mn, Fe, Mg, Ca, P, K, and Na and for 137Cs, 131I, 106Ru, and 90Sr. Concentration data are provided to expand the information base used to support assessments of the safety and nutritive value of the U.S. food supply and for their potential use in food composition databases. For selected foods, comparisons were made with past TDS results and with those reported in the literature. An extensive listing of the analytical data is available on the FDA CFSAN Website.

Neutron Capture Prompt Gamma-Ray Activation Analysis of Meat Homogenates

Thermal neutron capture prompt gamma-ray activation analysis (PGAA) was used to determine mass fractions of H, B, C, N, Na, Cl, K, and S in 2 meat homogenates. Twelve units of candidate Standard Reference Material (SRM) 1546 Meat Homogenate produced by the National Institute of Standards and Technology (NIST) were analyzed to provide NIST with certification data. This SRM is a realistic processed food matrix, ideal for food analysis programs such as the Food and Drug Administration's Total Diet Study. Another meat homogenate, Certified Reference Material LGC 7002 Pork/Chicken (along with NIST SRMs 1549 Non-Fat Milk Powder and 1571 Orchard Leaves) was analyzed for quality control. Candidate SRM 1546 unit-to-unit heterogeneity was <2% for H, Na, Cl, and K, and 3.5% for N and within-unit heterogeneity was <2% for H, N, Cl, and K, and 2.9% for Na, similar to LGC 7002 homogeneity results. Control material mass fractions agreed well with certificate and consensus values. Protein mass fractions, calculated from N results, were 15.2% and 11.9% for candidate SRM 1546 and LGC 7002, respectively. Protein content calculated for SRM 1549 (36.0%) agreed well with known values for dried non-fat milk powder.

Phylloquinone (Vitamin K1) Content of Foods in the U.S. Food and Drug Administration's Total Diet Study

Two hundred sixty-one foods from the U.S. Food and Drug Administration's Total Diet Study were analyzed for phylloquinone (vitamin K1) using a high-performance liquid chromatographic method that incorporates postcolumn reduction of the quinone, followed by fluorescence detection of the hydroquinone form of the vitamin. Green, leafy vegetables still appear to be the predominant dietary source of this vitamin (113-440) micrograms of phylloquinone/100 g of vegetable), followed by certain vegetable oils that are derived from vegetables or seeds containing large concentrations of phylloquinone. Some mixed dishes contain moderate amounts of phylloquinone that are attributable to the vegetable oils used in their preparation. Other foods, such as certain meats, brewed beverages, soft drinks, and alcoholic beverages, contained negligible amounts of phylloquinone. These data expand and improve the quality and quantity of the phylloquinone food composition table and will be used to prioritize future analyses

The 1990 revision of the FDA total diet study

Information from the 1987–88 USDA Nationwide Food Consumption Survey (NFCS) was used to revise the food list and diets of the Food and Drug Administration's Total Diet Study. The 1990 Total Diet Study contains 265 core foods that will be used to estimate contaminant and nutrient intakes for 14 age-sex categories. The core foods were selected by aggregating the foods consumed by the selected age-sex categories into 265 groups. A food within each group was selected to represent the group. For each age-sex category, the daily gram weight intake of each food within each group was assigned to the core food. These estimates of daily intakes of the 265 foods represent approximately the same weight and caloric intake of average diets for the 14 age-sex categories using 3,571 foods of the NFCS database. Nutrient intakes of diets calculated on the basis of the 3,571 foods and the 265 Total Diet Study foods were similar.

Silicon in foods and diets

Information on the silicon content of foods and diets is summarized from published literature, and the silicon content of US diets is calculated based on the Food and Drug Administration's Total Diet Study model and literature values for silicon in foods. Silicon levels tend to be higher in foods derived from plants than in foods from animal sources. Foods highest in silicon include grains, especially oats, barley and some rice fractions. Average daily intakes of silicon probably range from about 20 to 50 mg/day with the lower values for animal-based diets and the higher values for plant-based diets. The silicon content of adult US diets, based on the Total Diet Study model, is 19 mg/day for women and 40 mg/day for men.

Iodine Concentrations in US Milk: Variation Due to Time, Season, and Region

The iodine content of milk is influenced primarily by the iodine added to animal feed and by iodophor sanitizing solutions used in the dairy industry. Variability of these practices may result in variation of iodine concentrations in milk. Some seasonal and perhaps regional variation in iodine concentrations in milk may reflect the amount of indoor feeding (i.e., iodine supplemented feed) during the colder months versus outdoor pasture feeding during the warmer months. The proportion of indoor versus outdoor feeding depends upon the climate of the particular geographical area. Milks and other dairy products from the Food and Drug Administration's Total Diet Study were analyzed for iodine quarterly from 1982 to 1990. The iodine concentrations in fluid milks were evaluated over time, by season (summer, spring, winter, and fall), and by region (East, South, Central, and West). Iodine in fluid milks averaged 23μg/100g and ranged from 16μg/100g in the summer and fall in the East to 34μg/100g in the winter in the East. Iodine was highest in the winter (27μg/100g) and lowest in the summer (19μg/100g) and higher in western and central states (25 and 27μg/100g, respectively) than in eastern states (18μg/100g).

Zinc: Consumption patterns and dietary recommendations

Two important factors that determine zinc nutriture are the amount of zinc provided by the food supply and the zinc content of the foods individuals eat. The amount of zinc provided by the U.S. food supply has varied between 11 and 13 mg/day/person since the beginning of the century. Currently, it is estimated that the U.S. food supply provides 12.3 mg zinc per person per day. Data from the Food and Drug Administration's Total Diet Study and the U.S. Department of Agriculture's Nationwide Food Consumption Survey of Individuals and year-long Beltsville diet study indicate that adult males select diets that contain 90% or more of the 1989 Recommended Dietary Allowance (RDA) for zinc, whereas women select diets that have less than 81% of the RDA for zinc. Zinc densities of the diets for men and women were similar, which suggests that the difference in total zinc intake is attributable to a difference in energy consumption. Consumption patterns that meet the RDA for zinc can be compatible with the recent National Academy of Sciences diet and health recommendations. The dietetic practitioner should encourage consumption patterns that include using zinc-rich foods in the form of poultry and lean meats and low-fat or nonfat dairy products; using grain products and legumes, particularly whole grains, which can make an important contribution to total zinc intake; and increasing physical activity to a moderately active level to increase energy and zinc intake.

Organic nutrient content of the US Food and Drug Administration's Total Diet and its possible use as a standard reference material

Mixed diet composites containing 201 different foods from the United States Food and Drug Administration's Total Diet Study have been prepared to represent the intake of a 25- to 30-year-old male in the US. To date, foods from ten different collections have been received and composites representing six collections have been prepared and assayed. Each composite, representing one of four different geographical areas of the US (West, South, Northeast, North Central), was assayed for proximates (fat, protein, moisture, carbohydrates, and ash), elemental composition and organic nutrient content. The elemental content is reported separately. This paper deals with the proximate and organic nutrient content. The organic nutrients determined were thiamin, riboflavin, vitamin B6, vitamin B12, niacin, pantothenic acid, folic acid and biotin. The results to date show no significant variations in the contents among the individual collections. Portions of the collections have been freeze-dried and mixed to prepare a total diet reference material. Analytical results for nutrient content of the dry material are equivalent to those of the original composite.

Nutritional elements in U.S. diets: Results from the Total Diet Study, 1982 to 1986

Through the Food and Drug Administration's Total Diet Study, the levels of 11 nutritional elements (sodium, potassium, calcium, phosphorus, magnesium, iron, zinc, copper, manganese, selenium, and iodine) in the diets of eight age-sex groups were determined for the 4 years between 1982 and 1986. The 234 Total Diet Study foods, which are representative of the U.S. food supply, were purchased, prepared for consumption, and analyzed for the elements four times each year. The results were combined with national food consumption data to estimate intakes for 6- to 11-month-old infants, 2-year-old children, 14- to 16-year-old boys and girls, 25- to 30-year-old men and women, and 60- to 65-year-old men and women. Six elements (calcium, magnesium, iron, zinc, copper, and manganese) were low (less than 80% of the Recommended Dietary Allowance or below the low end of the Estimated Safe and Adequate Daily Dietary Intake range) for three or more of the age-sex groups. Six elements were of concern for teenage girls and adult women, five for older women, three for 2-year-old children, two for teenage boys and older men, and only one for infants and adult men. Sodium levels (which did not include discretionary salt) were elevated for 2-year-old children and teenage boys, and iodine was elevated for all age-sex groups. A significant trend was noted only for iodine, the intake of which decreased during the 4-year period.(ABSTRACT TRUNCATED AT 250 WORDS)

Molybdenum, nickel, cobalt, vanadium, and strontium in total diets

The 234 foods from a 1984 collection of the Food and Drug Administration's Total Diet Study were analyzed for the trace elements molybdenum, nickel, cobalt, vanadium, and strontium by plasma emission spectrometry. Daily intakes of these elements were then estimated for eight age-sex groups on the basis of results from national food consumption surveys. The contribution of food commodity groups to the daily intake of the five elements and the distribution of the elements in the 234 foods were also determined. Results from this study were compared with those reported earlier from other laboratories.

Mineral content of market samples of fluid whole milk

Results from the Food and Drug Administration's Total Diet Study on the nutrient element content of fluid whole cow's milk are presented and compared with previously published values. Whole milk was collected and analyzed yearly from 1975 through 1985. Yearly and overall means were similar for all elements except iron and iodine. The iron content of milk was generally low, but several samples had high levels. The distribution of iodine in whole milk was quite wide (0.002 to 0.094 mg/100 gm). The iodine content of milk is affected by the level of iodine added to cattle feed and by the use of iodophor sanitizing solutions used by the dairy industry. Overall mean levels of the elements in milligrams per 100 gm whole milk were: sodium, 42; potassium, 134; calcium, 106; phosphorus, 83; magnesium, 9.8; iron, 0.07; zinc, 0.37; copper, 0.009; manganese, 0.004; iodine, 0.034; and selenium, 0.001. Coefficients of variation were high (67% to 117%) for iron, copper, manganese, selenium, and iodine but ranged from 18% to 26% for the other elements. An 8-fl oz serving of whole milk is an excellent source of iodine, calcium, phosphorus, and potassium. It also provides some sodium, magnesium, zinc, and selenium but is not a reliable source of iron, copper, or manganese.

Purge and Trap Method for Determination of Volatile Halocarbons and Carbon Disulfide in Table-Ready Foods

A method developed for the determination of ethylene dibromide in table-ready foods has been modified and expanded to include 7 other volatile halocarbons and carbon disulfide. Samples are stirred with water and purged with nitrogen for 0.5 h in a water bath at 100 degrees C. The analytes collected on a duplex trap composed of Tenax TA and XAD-4 resin are eluted with hexane and determined by gas chromatography with electron capture detection or Hall electrolytic conductivity detection. Flame photometric detection in the sulfur mode is used to determine carbon disulfide. Thick-film, wide-bore capillary columns are used exclusively in both the determination and confirmation of the halogenated analytes. The higher levels of analytes are also confirmed by full scan gas chromatography mass spectrometry (GC/MS). Samples are analyzed for carbon disulfide, methylene chloride, chloroform, 1,2-dichloroethane, methyl chloroform, carbon tetrachloride, trichloroethylene, 1,2-dibromoethane, and tetrachloroethylene. Initially, 19 table-ready foods from the Food and Drug Administration's Total Diet Study were analyzed by this method. A limited survey of those food items exhibiting high levels of analytes was conducted. Samples exhibited levels up to 3300 ppb (methyl chloroform in Parmesan cheese). Recoveries of all 9 analytes from fortified samples ranged from 83 to 104%. Chromatograms from this purge and trap method are clean, enabling quantitation levels of low parts per billion and sub-parts per billion to be achieved for the halogenated analytes. The quantitation limit for carbon disulfide is 12 ppb. Two compounds found in drinking water were identified by GC/MS as bromodichloromethane and chlorodibromomethane. Drinking water from several cities was analyzed for these trihalomethanes as well as for bromoform. Levels of up to 17 ppb bromodichloromethane were found. Recoveries ranged from 96 to 103%.

Preparation of a mixed human diet material for the determination of nutrient elements, selected toxic elements and organic nutrients: A preliminary report

Using 201 foods from the United States Food and Drug Administration's Total Diet Study (FDA TDS), a mixed diet composite (USDIET-I) was prepared to represent the intake of 25–30-year-old males in the United States. Proximate analyses, phytate determination, and assays for nutrient elements and selected toxic elements, as well as organic nutrients were carried out on this composite. As part of a quality control exercise for a coordinated research program, atomic absorption spectrophotometry, inductively coupled atomic emission spectrometry, colorimetry and neutron activation analysis were used to determine up to 30 elements in this diet material. A comparison of the daily intakes of As, Ca, Cd, Cu, Fe, Hg, K, Mg, Mn, Na, P, Se and Zn from the composite USDIET-I shows excellent to good agreement with FDA TDS values calculated from results of single food analyses. These USDIET-I results demonstrate the feasibility of the mixed diet concept as a viable approach for a reliable assessment of daily intakes, especially for a number of elements such as Cd, Cr, Hg and Mo that occur at low concentrations in individual food products. Simultaneously, stability of some organic nutrients during storage was also investigated. Initial findings suggest that this program may also be useful in the development of reference materials for organic nutrients, for which there is a great need. These aspects are discussed.

Pentachlorophenol: health and environmental effects profile.

Pentachlorophenol is used as an industrial wood preservative for utility poles, crossarms, fence posts, and other purposes (79%);for NaPCP (12%); and miscellaneous, including mill uses, consumer wood preserving formulations and herbicide intermediate (9%) (CMR, 1980). As a wood preservative, pentachlorophenol acts as both a fungicide and insecticide (Freiter, 1978). The miscellaneous mill uses primarily involve the application of pentachlorophenol as a slime reducer in paper and pulp milling and may constitute ∼6% of the total annual consumption of pentachlorophenol (Crosby et al., 1981). Sodium pentachlorophenate (NaPCP) is also used as an antifungal and antibacterial agent (Freiter, 1978). Pentachlorophenol also is used as a general herbicide (Martin and Worthing, 1977).Photolysis and microbial degradation are the important chemical removal mechanisms for pentachlorophenol in water. In surface waters, pentachlorophenol photolyzes rapidly (ECETOC, 1984; Wong and Crosby. 1981; Zepp et al., 1984); however,...

Multiresidue Method for Quantitative Determination of Organophosphorus Pesticides in Foods

A multiresidue method for the quantitative determination of organophosphorus pesticides in foods from the Food and Drug Administration's Total Diet Study is described. The organophosphorus pesticides are separated on the basis of polarity and determined in both fatty and nonfatty foods with a minimum of interferences. The foods analyzed included raw and cooked individual foods as well as combination dishes, water, and whiskey. Recoveries of 17 organophosphorus pesticides in 41 foods ranged from about 80 to 118%.