Johanna T Dwyer

Tufts Medical Center · Department of Medicine

Background Quality of life (QoL) is critical for healthy aging—both for older adults and for healthcare providers/health systems. Eating and nutritious food are essential for older adults to remain healthy/independent and maintain good nutrition status and also provide pleasure and enhance QoL. However, research on nutrition and QoL is limited, inc...

Quality of life (QoL) is important for healthy aging, both for older adults themselves and healthcare providers/systems caring for them. Eating/nutritious food are essential for maintaining good nutrition status, provide pleasure, help older adults remain healthy/independent, and contribute to important QoL domains. Yet research on nutrition and Qo...

Introduction Globally, the number of older adults is growing exponentially. Yet, while living longer, people are not necessarily healthier. Nutrition can positively impact healthy aging and quality of life (QoL). Two decades ago, nutrition and diet were rarely viewed as key QoL domains, were not part of QoL screening, and QoL studies frequently use...

Precise dietary assessment is critical for accurate exposure classification in nutritional research, typically aimed at understanding how diet relates to health. Dietary supplement (DS) use is widespread and represents a considerable source of nutrients. However, few studies have compared the best methods to measure DSs. Our literature review on th...

This paper discusses the rationale for use of proprietary blends on dietary supplement labels, and their implications for researchers and consumers. The Dietary Supplement Health Education Act of 1994 or DSHEA allows the listing of non-nutrient dietary ingredients as proprietary blends on dietary supplement labels for companies to protect their uni...

Background Factors that decrease independence and increase morbidity must be reduced to improve the nutrition, health, and other challenges confronting older adults. In the United States (US), the Older Americans Act (OAA) requires each state/territory develop multi-year aging plans for spending federal funds that foster healthy aging (including su...

Background Dietary supplement (DS) use is widespread in the United States and contributes large amounts of micronutrients to users. Most studies have relied on data from 1 assessment method to characterize the prevalence of DS use. Combining multiple methods enhances the ability to capture nutrient exposures from DSs and examine trends over time....

The increased utilization of metrology resources and expanded application of its’ approaches in the development of internationally agreed upon measurements can lay the basis for regulatory harmonization, support reproducible research, and advance scientific understanding, especially of dietary supplements and herbal medicines. Yet, metrology is oft...

Background Most dietary indices reflect foods and beverages and do not include exposures from dietary supplements (DS) that provide substantial amounts of micronutrients. A nutrient-based approach that captures total intake inclusive of DS can strengthen exposure assessment. Objective To examine the construct and criterion validity of the Total Nu...

Demand for federal nutrition assistance programs is increasing as the older population grows and further accelerated with the COVID-19 pandemic. Older adult nutrition programs are based on federal nutrition guidelines that have traditionally focused on healthy populations, yet many older adults have multiple chronic conditions/advanced age. Some gu...

Background to meet the challenges of an aging population and improve public health it is imperative to reduce factors that decrease independence and increase morbidity. Malnutrition (particularly protein-energy undernutrition), sarcopenia, frailty, and obesity all result in disability but are potentially changeable. The purpose of this study was to...

Background: Nearly a third of young US children take multivitamin/mineral (MVM) dietary supplements, yet it is unclear how formulations compare to requirements. Objective: Describe the number and amounts of micronutrients contained in MVM for young children and compare suggested amounts on product labels to micronutrient requirements. Design:...

Dietary supplements (DS) are widely used and contain many bioactive constituents that are significant to health. Databases of DS ingredients are needed to identify contents, document the prevalence of nutrient inadequacy and excess, evaluate interventions involving DS, and assess the contributions of DS product formulations to health. However, DS c...

Background Sarcopenia, a progressive loss of skeletal muscle mass and strength, can begin in the 4th decade of life. Protein intake predicts skeletal muscle mass and strength among older adults, but knowledge of similar associations among middle-aged adults is lacking. Objectives We aimed to assess associations between protein intake and skeletal...

A priori dietary indices provide a standardized, reproducible way to evaluate adherence to dietary recommendations across different populations. Existing nutrient-based indices were developed to reflect food/beverage intake; however, given the high prevalence of dietary supplement (DS) use and its potentially large contribution to nutrient intakes...

The World Health Organization's Decade of Healthy Aging began in 2020. This article focuses on nutrition's role in healthy aging with examples of older adult nutrition programs in Canada, the European Union, and the United States, including work of the Canadian Malnutrition Task Force, the European Malnutrition in the Elderly Knowledge Hub, and the...

Launched in 2008, NIH’s DSLD (https://dsld.nlm.nih.gov/dsld/) currently catalogs information printed on over 125,000 (historical and current) labels of dietary supplement products sold in the U.S. The database is maintained and updated continuously, and new versions deployed regularly. The new home page includes a prominent search bar and counter t...

Both undernutrition and frailty adversely affect the health and functional outcomes of the older adult population. Timely and accurate national data are necessary to assess those at risk of these debilitating but often preventable conditions, to correct them and support healthy aging. The objective was to identify relevant measures in undernutritio...

Background Food insecurity is associated with poorer nutrient intakes from food sources and lower dietary supplement use. However, its association with total usual nutrient intakes, inclusive of dietary supplements, and biomarkers of nutritional status among US children remains unknown. Objective The objective was to assess total usual nutrient in...

Integrating ingredients in databases of dietary supplements (DS) involves harmonizing terminology describing ingredients, expressing amounts in a common fashion, and using interoperable description systems to link ingredients to related drug, food and other DS databases. Harmonizing ingredient descriptions facilitates calculation of bioactives in D...

We conducted a Web-based survey of Commission on Dietetic Registration members to identify opportunities and challenges related to malnutrition and frailty screening among older adults (≥65 years old). Of the 9279 surveys sent out in emails, 903 registered dietitian nutritionists (RDNs) returned the surveys (10% response rate), and of those who res...

Background: Potential safety concerns relative to impaired cognitive function may exist when high folic acid exposures are combined with low vitamin B-12 status. Objectives: We aimed to examine the relation of the coexistence of high folate and low vitamin B-12 status with cognitive function, utilizing various definitions of "high" folate status...

Objectives: Most prenatal supplements available in the US contain synthetic folic acid. We compared the labeled amounts of folic acid in prenatal supplements with: 1) the Recommended Dietary Allowance (RDA) of 360 mcg and Tolerable Upper Intake Level (UL) of 1000 mcg for pregnant women established by National Academies of Science, Engineering and...

Objectives: US national surveys report that pregnant women are at risk of dietary deficiency for several key nutrients, including calcium, iron, folate, and vitamin D. Most pregnant women take prenatal multivitamins (MVM). However intake studies have used only product label information, which may lead to incorrect estimates of their impact on nutr...

Objectives: To estimate total mean usual micronutrient intakes (inclusive of dietary supplements (DS)), Dietary Reference Intakes (DRI) adherence, and the % contribution of DS to total usual micronutrient intakes for U.S. adults (≥19y) using data from the 2011-2014 National Health and Nutrition Examination Survey (NHANES, n = 9474), by sex, age, a...

Objectives: The purpose was to evaluate nutritional status, food security, and related health factors of older adults who were overweight or obese compared to those with a healthy weight. Methods: Data from 2969 adults aged ≥60 years from NHANES 2011-2014 were analyzed. Participants were categorized by sex and body weight status as healthy weigh...

A Scientific Integrity Consortium developed a set of recommended principles and best practices that can be used broadly across scientific disciplines as a mechanism for consensus on scientific integrity standards and to better equip scientists to operate in a rapidly changing research environment. The two principles that represent the umbrella unde...

Adult MVMs are the most commonly reported dietary supplements in the US, with ~30% reporting their use. The analytically determined content of these products is ingredient specific, with some ingredients close to labeled levels and others significantly higher. The DSID ( http://dsid.usda.nih.gov ) reports analytically derived national estimates for...

The bioactivity of dietary supplements (DSs) is determined by the active ingredient (AI), amount of AI and by the design and performance of the dosage form into which the AI is incorporated. As a part of the Botanical Initiative for the Dietary Supplement Ingredient Database (DSID; http://dsid.usda.nih.gov ), DSs containing green tea (GT) extract a...

Background Dietary fibers promote gut health and reducerisk for diseases, including cancer. Few Americans consume enough high fiberfoods to meet their requirements without consuming fiber‐containing dietary supplements (FCDS). Differing fibers may exert differing effects on health and disease risk. Fermentability of these fiber components may also...

This analysis characterizes use of dietary supplements (DS) and motivations for DS use among U.S. children (≤18 years) by family income level, food security status, and federal nutrition assistance program participation using the 2011–2014 National Health and Nutrition Examination Survey data. About one-third (32%) of children used DS, mostly multi...

The objective of this study was to estimate the prevalence of use and types of dietary supplements (DS) used by U.S. adults (≥19 years) by sociodemographic characteristics: family income-to-poverty ratio (PIR), food security status, and Supplemental Nutrition Assistance Program (SNAP) participation using NHANES 2011–2014 data (n = 11,024). DS use w...

Many of the scientific and regulatory challenges that exist in research on the safety, quality and efficacy of dietary supplements are common to all countries as the marketplace for them becomes increasingly global. This article summarizes some of the challenges in supplement science and provides a case study of research at the Office of Dietary Su...

This chapter reviews the rationale and methodology for including assessment of dietary supplements in total dietary assessment. Tools for assessing supplement use are discussed, and informational resources for learning more about supplement assessment are provided.

This chapter provides an overview of tools for evaluating dietary intakes of individuals and provides dietary recommendations. Such recommendations have been given by government and other groups for over 100 years (Fig. 2.1). The chapter describes the concepts of dietary status, nutritional status, and the available methods for measuring them. The...

Background: Dietary supplements (DSs) have the potential to be both beneficial and harmful to health, especially in adults aged ≥60 y, and therefore it is important to monitor the patterns of their use. Objective: This study evaluated DS use by adults aged ≥60 y to characterize the use of DSs, determine the motivations for use, and examine the asso...

This chapter asks whether there is a role for enrichment/fortification and/or dietary supplements in highly industrialized countries today, and what challenges and opportunities exist regarding their use. It considers fortification and supplementation together because both affect total nutrient exposures and both are popular in developed countries....

This chapter discusses the human right to food and nutrition security. Sustainable food and nutrition security has four key components: the nutritional quality of foods and diets, their cost, cultural acceptance, and their impact on the environment. Sustainable diets call for foods that are healthy and safe, nutrient-rich, affordable, culturally ac...

This book is the first of its kind to tackle in detail the nutritional requirements of the industrialized, so-called developed world. It discusses the link between socio-economic status and food security, focusing especially on the relationship between income and food security in different age groups. The authors calculate the actual levels of esse...

Serious mental illnesses and their treatments often have adverse nutritional effects, but little is known about the effective nutritional counseling to use with those who suffer from them. The therapeutic challenges involved include finding medications that control symptoms while minimizing their adverse effects on weight gain and on other metaboli...

I came of age as a nutrition scientist during the best of times-years that spanned a rapidly changing world of food and nutrition science, politics, and policy that greatly broadened the specialty and its influence on public affairs. I followed the conventional route in academe, working my way up the academic ladder in Boston from a base first in a...

Background Prenatal supplements are often recommended to pregnant women to help meet their nutrient needs. Many products are available, making it difficult to choose a suitable supplement because little is known about their labeling and contents to evaluate their appropriateness. Objective To determine differences between prescription and nonpresc...

This article, part 2 of the series on polyphenols, examines some of the evidence for the roles of specific foods rich in polyphenols in reducing the risk of 3 common health conditions: urinary tract infections, cardiovascular disease, and type 2 diabetes. Although the research remains emerging rather than settled science, polyphenols may have benef...

Scientific integrity is at the forefront of the scientific research enterprise. This paper provides an overview of key existing efforts on scientific integrity by federal agencies, foundations, nonprofit organizations, professional societies, and academia from 1989 to April 2016. It serves as a resource for the scientific community on scientific in...

The 2015 to 2020 Dietary Guidelines for Americans reports that calcium, vitamin D, potassium, and dietary fiber are still nutrients of public health concern. This article describes ways to make children’s micronutrient adequacy a reality with a combination of nutrition education, enrichment, fortification, and, in some instances, dietary supplement...

Dietary reference intakes (DRIs) are nutrient standards used within the United States and Canada as references for many purposes, including assessment and planning of diets for both individuals and groups. The process by which the DRIs are established is reviewed, including an overview of the functional criteria used to determine requirements and e...

This article describes nutrition policy and influences on it. The scope of nutrition policy and evidence needed for making nutrition policy are summarized, and the challenges to scientists involved in nutrition policy making are discussed. The process of science-based nutrition policy making that involves nutritional risk assessment, nutritional ri...

Background: Multivitamin/mineral products (MVMs) are the dietary supplements most commonly used by US adults. During manufacturing, some ingredients are added in amounts exceeding the label claims to compensate for expected losses during the shelf life. Establishing the health benefits and harms of MVMs requires accurate estimates of nutrient inta...

Context: Dietary supplements are widely used by military personnel and civilians for promotion of health. Objective: The objective of this evidence-based review was to examine whether supplementation with l-arginine, in combination with caffeine and/or creatine, is safe and whether it enhances athletic performance or improves recovery from exhau...

This brief overview of polyphenols describes what they are, where they are found in foods, and why some may be important to human health. Polyphenols are widely diverse and ubiquitous non-nutrient compounds in plant foods that may have physiological effects on the human body. Sources of polyphenols include fruits and vegetables, whole grains, herbs...

Cinnamon (Cinnamomum sp) has been suggested to help patients with type 2 diabetes mellitus (T2DM) achieve better glycemic control, although conclusions from meta-analyses are mixed. To evaluate whether the use of cinnamon dietary supplements by adults with T2DM had clinically meaningful effects on glycemic control, as measured by changes in fasting...

This article explores the risks and benefits of 2 therapies for adults with severe or morbid obesity and type 2 diabetes: bariatric surgery (with special attention to the Roux-en-Y gastric bypass) or conventional medical therapy,which relies on nutrition, physical activity, lifestyle changes, and hypoglycemic medication. The Roux-en-Y gastric bypas...

Background: Food-composition tables typically give measured nutrient concentrations in foods as a single summary value, often the mean, without providing information as to the shape of the distribution. Objective: Our objective was to explore how the statistical approach chosen to describe the iodine concentrations of foods affects the proportion o...

Background: Prevalences of iodine inadequacy and excess are usually evaluated by comparing the population distribution of urinary iodine concentration (UIC) in spot samples with established UIC cutoffs. To our knowledge, until now, dietary intake data have not been assessed for this purpose. Objective: Our objective was to compare 2 methods for...

The US Food and Drug Administration (FDA) and the Nutrient Data Laboratory (NDL) of the USDA Agricultural Research Service have worked independently on determining the iodine content of foods and dietary supplements and are now harmonizing their efforts. The objective of the current article is to describe the harmonization plan and the results of i...

Strategic translational research is designed to address research gaps that answer specific guidance questions. It provides translational value with respect to nutrition guidance and regulatory and public policy. The relevance and the quality of evidence both matter in translational research. For example, design decisions regarding population, inter...

Some adults with type 2 diabetes mellitus (T2DM) believe that chromium-containing supplements will help control their disease, but the evidence is mixed. This narrative review examines the efficacy of chromium supplements for improving glycemic control as measured by decreases in fasting plasma glucose (FPG) or hemoglobin A1c (HbA1c). Using systema...

Background More than 50% of all U.S. adults consume dietary supplements (DS) contributing to an estimated $35 billion in sales in 2015. Among these are DS often recommended by oncology practitioners for the reduction of disease risks, including risk of colorectal cancer. The Dietary Supplement Label Database (DSLD) contains over 50,000 DS labels re...

Management of type 2 diabetes mellitus (T2DM) emphasizes glucose control with diet, hypoglycemic drugs, lifestyle modification, and reduction in cardiovascular risk factors. In 2011–12, the estimated prevalence of T2DM in U.S. adults was 12.4%, up from 10.8% in 2001–2. Recently, cinnamon (Cinnamomum sp. ) has been suggested to help T2DM patients ac...

Chromium (Cr)‐containing dietary supplements are claimed to improve glycemic control in T2DM. We conducted a systematic literature search of randomized clinical trials (RCT) of adults with T2DM to document changes in glycemic control from pre‐ to post‐supplementation with Cr. The search included studies from 1/1991–1/2014 with the following terms:...

Dietary supplement (DS) consumption plays an important role in achieving recommended nutrient levels for a large part of the U.S. population, and MVM are the most commonly consumed DS. Knowledge of DS composition based on chemical analysis rather than label declarations has become critical for more complete dietary intake assessment and for deciphe...

According to the 2007–10 NHANES, 7.5% of the US population reports botanical dietary supplement (DS) use. The DSID provides analytically‐derived estimates of the ingredient contents of DS. Commonly consumed and frequently studied, green tea (GT) DS were chosen as the first botanical DS for the DSID botanical initiative. The most abundant GT constit...

Dried plant parts used as culinary spices (CSs) in food are permitted as dietary ingredients in dietary supplements (DSs) within certain constraints in the United States. We reviewed the amounts, forms, and nutritional support (structure/function) claims of DSs that contain CS plants listed in the Dietary Supplement Label Database (DSLD) and compar...

Elsie M. Widdowson CH, CBE, FRS, PhD (1906–2000), was one of the outstanding nutrition scientists of the 20th century. It is less well appreciated that she trained in dietetics after her earlier training in chemistry. Her original work on carbohydrates in fruits led to the most comprehensive food composition tables ever produced. She and her longti...

During 3 months in 1936, a young Dr Elsie Widdowson undertook a trip to the United States to discuss mutual research interests with colleagues there. This article picks out highlights from Elsie’s personal diary, focusing on the contributions her US colleagues were making to the study and practice of dietetics and to nutrition research. Virtually a...

NHANES is the cornerstone for national nutrition monitoring to inform nutrition and health policy. Nutritional assessment in NHANES is described with a focus on dietary data collection, analysis, and uses in nutrition monitoring. NHANES has been collecting thorough data on diet, nutritional status, and chronic disease in cross-sectional surveys wit...

Vegetables are an important part of a healthy diet for infants and young children, but they are poorly accepted and underconsumed. This paper highlights major themes and research needs for understanding how to raise children to consume and enjoy vegetables as part of a healthful diet. A range of factors impedes US infants and young children from ea...

The Dietary Reference Intakes (DRIs) are reference values to guide the planning and assessing of nutrient intakes in the United States and Canada. The DRI framework was conceptualized in 1994, and the first reports were issued from 1997–2004, based on work by expert panels and subcommittees under the guidance of the Food and Nutrition Board of the...

It is complicated to ascertain the composition and prevalence of the use of highly fortified food and supplement products (HFPs) because HFP foods and HFP supplements have different labeling requirements. However, HFPs (energy bars, energy drinks, sports drinks, protein bars, energy shots, and fortified foods/beverages) are popular in the United St...

This study examines the relationship between long-term intake of six flavonoid classes and incidence of CVD and CHD, using a comprehensive flavonoid database and repeated measures of intake, while accounting for possible confounding by components of a healthy dietary pattern. Flavonoid intakes were assessed using a FFQ among the Framingham Offsprin...

The effects of patient characteristics on reported adherence to dietary self-care behaviours in 184 Taiwanese outpatients 40 years or older with type 2 diabetes was assessed. Patient characteristics included the presence of predisposing factors affecting diabetes adherence (knowledge and attitudes about the disease, self-efficacy, and the absence o...

We examined the influences of patients' background characteristics on the frequency of performing five diabetes self-care behaviours that 185 Taiwanese outpatients reported. All patients had type 2 diabetes diagnosed for more than a year and attended an outpatient clinic at a large university hospital where they had received at least one dietitian-...

The incidence of kidney stones is common in the United States and treatments for them are very costly. This review article provides information about epidemiology, mechanism, diagnosis, and pathophysiology of kidney stone formation, and methods for the evaluation of stone risks for new and follow-up patients. Adequate evaluation and management can...

The Dietary Supplement Ingredient Database (DSID) provides analytically-derived estimates of the ingredient content in dietary supplements (DS). DSID 3.0 now includes 4 categories of DS: adult, children's and non-prescription prenatal multivitamin/mineral products (MVM), and omega-3 fatty acid DS. Green tea was chosen for analysis in the pilot stud...

Imprecision in estimating intakes of non-nutrient bioactive compounds such as flavonoids is a challenge in epidemiologic studies of health outcomes. The sources of this imprecision, using flavonoids as an example, include the variability of bioactive compounds in foods due to differences in growing conditions and processing, the challenges in labor...

Although growing evidence from trials and population-based studies has supported a protective role for flavonoids in relation to risk of certain chronic diseases, the underlying mechanisms remain unclear. Several previous studies focused on individual inflammatory biomarkers, but because of the limited specificity of any individual marker, an asses...