Joanne M. Holden

Carotenoid content of fruits and vegetables: An evaluation of analytic data

The test of the association between dietary intake of specific carotenoids and disease incidence requires the availability of accurate and current food composition data for individual carotenoids. To generate a carotenoid database, an artificial intelligence system was developed to evaluate data for carotenoid content of food in five general categories, namely, number of samples, analytic method, sample handling, sampling plan, and analytic quality control. Within these categories, criteria have been created to rate analytic data for beta-carotene, alpha-carotene, lutein, lycopene, and beta-cryptoxanthin in fruits and vegetables. These carotenoids are also found in human blood. Following the evaluation of data, acceptable values for each carotenoid in the foods were combined to generate a database of 120 foods. The database includes the food description; median, minimum, and maximum values for the specific carotenoids in each food; the number of acceptable values and their references; and a confidence code, which is an indicator of the reliability of a specific carotenoid value for a food. The carotenoid database can be used to estimate the intake of specific carotenoids in order to examine the association between dietary carotenoids and disease incidence.

Towards Establishing Dietary Reference Intakes for Eicosapentaenoic and Docosahexaenoic Acids

There is considerable interest in the impact of (n-3) long-chain PUFA in mitigating the morbidity and mortality caused by chronic diseases. In 2002, the Institute of Medicine concluded that insufficient data were available to define Dietary Reference Intakes (DRI) for eicosapentaenoic acid (EPA) or docosahexaenoic acid (DHA), noting only that EPA and DHA could contribute up to 10% toward meeting the Adequate Intake for alpha-linolenic acid. Since then, substantial new evidence has emerged supporting the need to reassess this recommendation. Therefore, the Technical Committee on Dietary Lipids of the International Life Sciences Institute North America sponsored a workshop on 4-5 June 2008 to consider whether the body of evidence specific to the major chronic diseases in the United States--coronary heart disease (CHD), cancer, and cognitive decline--had evolved sufficiently to justify reconsideration of DRI for EPA+DHA. The workshop participants arrived at these conclusions: 1) consistent evidence from multiple research paradigms demonstrates a clear, inverse relation between EPA+DHA intake and risk of fatal (and possibly nonfatal) CHD, providing evidence that supports a nutritionally achievable DRI for EPA+DHA between 250 and 500 mg/d; 2) because of the demonstrated low conversion from dietary ALA, protective tissue levels of EPA+DHA can be achieved only through direct consumption of these fatty acids; 3) evidence of beneficial effects of EPA+DHA on cognitive decline are emerging but are not yet sufficient to support an intake level different from that needed to achieve CHD risk reduction; 4) EPA+DHA do not appear to reduce risk for cancer; and 5) there is no evidence that intakes of EPA+DHA in these recommended ranges are harmful.

The development and application of a carotenoid database for fruits, vegetables, and selected multicomponent foods

A carotenoid database for individual and multicomponent foods has been compiled that contains values for the five most common carotenoids (alpha-carotene, beta-carotene, beta-cryptoxanthin, lycopene, lutein) in 2,458 fruits, vegetables, and multicomponent foods containing fruits and vegetables. The database was used to estimate intakes of specific carotenoids for 19- to 50-year-old women (n = 1,102), using food consumption data obtained from dietary recalls in the US Department of Agriculture Continuing Survey of Food Intake by Individuals, 1986. The major contributors of alpha-carotene were carrots consumed as a single food or as an ingredient in multicomponent foods. Carrots, cantaloupe, and broccoli were the main sources of beta-carotene. Orange juices and blends, oranges, and tangerines were important contributors of beta-cryptoxanthin. Tomatoes and tomato products consumed as single foods or as ingredients in multicomponent foods provided most of the dietary lycopene. Contributors of lutein + zeaxanthin included collard, mustard, or turnip greens; spinach; and broccoli. The per capita consumption of total carotenoids (the sum of the five specific carotenoids) among these women was approximately 6 mg/day.

USDA Food and Nutrient Databases Provide the Infrastructure for Food and Nutrition Research, Policy, and Practice

The USDA food and nutrient databases provide the basic infrastructure for food and nutrition research, nutrition monitoring, policy, and dietary practice. They have had a long history that goes back to 1892 and are unique, as they are the only databases available in the public domain that perform these functions. There are 4 major food and nutrient databases released by the Beltsville Human Nutrition Research Center (BHNRC), part of the USDAs Agricultural Research Service. These include the USDA National Nutrient Database for Standard Reference, the Dietary Supplement Ingredient Database, the Food and Nutrient Database for Dietary Studies, and the USDA Food Patterns Equivalents Database. The users of the databases are diverse and include federal agencies, the food industry, health professionals, restaurants, software application developers, academia and research organizations, international organizations, and foreign governments, among others. Many of these users have partnered with BHNRC to leverage funds and/or scientific expertise to work toward common goals. The use of the databases has increased tremendously in the past few years, especially the breadth of uses. These new uses of the data are bound to increase with the increased availability of technology and public health emphasis on diet-related measures such as sodium and energy reduction. Hence, continued improvement of the databases is important, so that they can better address these challenges and provide reliable and accurate data.

Summary of an NIH Workshop to Identify Research Needs to Improve the Monitoring of Iodine Status in the United States and to Inform the DRI

The Office of Dietary Supplements (ODS) at the NIH sponsored a workshop on May 12-13, 2011, to bring together representatives from various NIH institutes and centers as a first step in developing an NIH iodine research initiative. The workshop also provided an opportunity to identify research needs that would inform the dietary reference intakes for iodine, which were last revised in 2001. Iodine is required throughout the life cycle, but pregnant women and infants are the populations most at risk of deficiency, because iodine is required for normal brain development and growth. The CDC monitors iodine status of the population on a regular basis, but the status of the most vulnerable populations remains uncertain. The NIH funds very little investigator-initiated research relevant to iodine and human nutrition, but the ODS has worked for several years with a number of other U.S. government agencies to develop many of the resources needed to conduct iodine research of high quality (e.g., validated analytical methods and reference materials for multiple types of samples). Iodine experts, scientists from several U.S. government agencies, and NIH representatives met for 2 d to identify iodine research needs appropriate to the NIH mission.

A nationwide study of the selenium contents and variability in white bread

Abstract Bread is a major source of dietary selenium (Se) in the United States. As part of a nationwide survey of Se contents in more than 100 foods, 90 composite samples of white bread, representing major brands, were prepared from products purchased in large cities in nine different geographical divisions of the U.S. during 3 calendar years (1986–1988). Thirty-five additional samples (7 production plants × 5 samples each in 1 year) of a single major brand were collected. Limited numbers of bread flour samples provided by the plants were also prepared. Samples were analyzed by two laboratories, each using a modified Se hydride generation procedure. Before the sample analyses began, methods were validated by analyses of National Institute of Standards and Technology (NIST) Standard Reference Material SRM 1549 (Nonfat Milk Powder) and SRM 1567 (wheat Flour). Accuracy of analytical results was monitored by repeated analyses of NIST SRMs and an USDA in-house control sample. The city means for white bread range from a high of 46 μg/100 g in Boston to a low of 17 μg/100 g in Los Angeles. The coefficient of variation for the nationwide mean was 49%.

The copper content of foods based on a critical evaluation of published analytical data

Abstract Increasing interest in the copper (Cu) intake of Americans has generated a need for the compilation, evaluation, and improvement of data for Cu in foods. In order to estimate dietary Cu intake, accurate and precise Cu values for foods are needed. A system of criteria developed to evaluate the quality of published selenium data has been adapted to evaluate analytical data for Cu in foods. Mean Cu values for each food were calculated from the evaluated data and combined with USDA frequency of consumption data, resulting in a list of 218 major contributors of dietary Cu. The richest sources of Cu are legumes, wheat bran cereals, organ meats, shellfish, and grains. Confidence codes, indicators of the relative degree of confidence the user of the data can have in that mean value, were included. More than half of the mean values for the foods listed are of limited quality or result from a limited quantity of data, indicating a need for improvement in food Cu data. This proposed dynamic system for the compilation and evaluation of Cu data can be used to generate Cu data bases for specific purposes, provide a ranked list of foods which are significant contributors of that nutrient, and establish priorities for further improvements in the database.

Vitamin D content and variability in fluid milks from a US Department of Agriculture nationwide sampling to update values in the National Nutrient Database for Standard Reference

This study determined the vitamin D(3) content and variability of retail milk in the United States having a declared fortification level of 400 IU (10 μg) per quart (qt; 1 qt=946.4 mL), which is 25% daily value per 8 fluid ounce (236.6 mL) serving. In 2007, vitamin D(3) fortified milk (skim, 1%, 2%, whole, and 1% fat chocolate milk) was collected from 24 statistically selected supermarkets in the United States. Additionally, 2% milk samples from an earlier 2001 USDA nationwide collection were reanalyzed. Vitamin D(3) was determined using a specifically validated method involving HPLC with UV spectroscopic detection and vitamin D(2) as an internal standard. Quality control materials were analyzed with the samples. Of the 120 milk samples procured in 2007, 49% had vitamin D(3) within 100 to 125% of 400 IU (10 μg)/qt (label value), 28% had 501 to 600 IU (12.5-15 μg)/qt, 16% had a level below the label amount, and 7% had greater than 600 IU (15 μg)/qt (>150% of label). Even though the mean vitamin D(3) content did not differ statistically between milk types, a wide range in values was found among individual samples, from nondetectable [<20 IU (0.5 μg)/qt] for one sample to almost 800 IU (20 μg)/qt, with a trend toward more samples of whole milk having greater than 150% of the labeled content. On average, vitamin D(3) in 2% milk was higher in 2007 compared with in 2001 [473 vs. 426 IU (11.8 vs. 10.6 μg)/qt].

The USDA's National Food and Nutrient Analysis Program: update 2002

Abstract The National Food and Nutrient Analysis Program (NFNAP) was designed in 1997 to develop robust and nationally representative estimates of the mean nutrient content of important foods in the food supply and significantly improve the quality of food composition data in the US Department of Agricultures National Nutrient Databank. The underlying aims defining the process behind the NFNAP are: (1) evaluation of existing data; (2) identification of Key Foods and nutrients for analysis; (3) development of nationally based sampling plans; (4) analysis of samples; and (5) compilation and calculation of representative food composition data. Supported by a self-weighting stratified sampling design, the NFNAP approach has been applied to other sampling programs for the analysis of specific nutrients (e.g., fluoride-containing beverages and foods) and ethnic foods (e.g., American Indian foods). For select nutrients of potential health significance, additional sampling approaches allow for the estimation of serving-to-serving variability (e.g., highly processed foods). Under NFNAP, over 500 foods of the targeted 1000 important foods in the US food supply have been analyzed. Unrivaled research on food sampling, sample handling, and analytical methodology (e.g., for study of perishable nutrients in fresh produce) is integral to this effort. The NFNAP data are current, reflective of the market and nationally representative of the US food supply and therefore a crucial resource to health researchers, architects of nutrition policy, the nutrition and medical communities, and the food industry. They are released through the Web site: www.nal.usda.gov/fnic/foodcomp

Selex : an expert system for evaluating published data on selenium in foods

Abstract Providing consistent and objective evaluation of published data on nutrient composition is critical for planning future analytical studies and for effective use of data. Based on a commercial expert system shell, a computer system of approximately 200 rules has been created to evaluate and ratre quantitatively published data on selenium in foods. The evaluation scheme uses five general categories for its rule-making process: number of samples, analytical method, sample handling, sampling plan, and analytical quality control. For each selenium value to be evaluted, rating ar assigned in each category by the expert system based on input which is derived from the information reportedin a given paper. A quality index, which is derived from the ratings, is a measure of the reliability of a given selenium value over all categories for a given study. The concepts used in developing SELEX have the potential of establishing criteria for evaluation of proposed analytical methods prior to their publication.