Kristi M. Crowe

Position of the Academy of Nutrition and Dietetics: Functional Foods

It is the position of the Academy of Nutrition and Dietetics to recognize that although all foods provide some level of physiological function, the term functional foods is defined as whole foods along with fortified, enriched, or enhanced foods that have a potentially beneficial effect on health when consumed as part of a varied diet on a regular basis at effective levels based on significant standards of evidence. The Academy supports Food and Drug Administration-approved health claims on food labels when based on rigorous scientific substantiation. All food is essentially functional at some level as it provides energy and nutrients needed to sustain life. However, there is growing evidence that some food components, not considered nutrients in the traditional sense, may provide positive health benefits. Foods containing these food components are called functional foods. Functional food research holds many promises for improving the quality of life for consumers; however, to achieve such outcomes, scientific research must effectively establish the bioavailability and efficacy of these compounds at levels that are physiologically achievable under typical dietary patterns. This Position Paper reviews the complexities of defining functional foods; categories of foods marketed as functional; regulation of functional foods; the scientific substantiation of and advancement of functional food research; as well as a message to registered dietitians and dietetic technicians, registered, on how to remain current in their knowledge of functional food research and the translation of this information to consumers.

Oxidative stress responses of gulf killifish exposed to hydrocarbons from the Deepwater Horizon oil spill: Potential implications for aquatic food resources

Ecosystem effects of polycyclic aromatic hydrocarbons (PAHs) remain under investigation following the Gulf of Mexico Deepwater Horizon oil spill. Fundulus grandis, an established indicator of aquatic ecosystem health, was investigated because this species shares genes and biochemical pathways with higher trophic-level fish and plays an important role in the gulf food chain. Oxidative stress responses including hepatic cytochrome P4501A (CYP1A) and serum antioxidant capacity were evaluated in fish exposed to PAHs. Fish were exposed to water-accommodated fractions (WAFs) of crude oil (7.0  ± 0.10 mg/L C6-C28) after which solutions were diluted below the level of detection over 8 h using 15 ppt aerated artificial seawater. Before euthanasia, fish remained in aquaria for 12 h, 24 h, or 48 h. Three replicate experiments were conducted at each time point using unexposed fish as experimental controls. Significant differences (p < 0.05) in CYP1A induction were observed in exposed versus control fish at 24 h. Expression of CYP1A increased by 25%, 66%, and 23% in exposed fish at 12 h, 24 h, and 48 h, respectively. Significant increases were observed in antioxidant capacity of nonenzymatic antioxidants in exposed versus control fish at each time point. Given the activity of CYP1A, radicals formed during PAH detoxification likely resulted in increased oxidant load requiring elevated antioxidant defenses. Research is needed to determine the duration of oxidative stress responses considering the potential for lipid oxidation in exposed fish or species feeding on exposed fish.

Deconstructing a Fruit Serving: Comparing the Antioxidant Density of Select Whole Fruit and 100% Fruit Juices

Research suggests phytonutrients, specifically phenolic compounds, within fruit may be responsible for the putatively positive antioxidant benefits derived from fruit. Given the prominence of fruit juice in the American diet, the purpose of this research was to assess the antioxidant density of fresh fruit and 100% fruit juice for five commonly consumed fruits and juices and to compare the adequacy of 100% juice as a dietary equivalent to whole fruit in providing beneficial antioxidants. Antioxidant density was measured using an oxygen radical absorbance capacity method on six samples assayed in triplicate for each fruit (grape, apple, orange, grapefruit, pineapple), name-brand 100% juice, and store-brand 100% juice. One-way analysis of variance and Tukeys honestly significant difference or Student t test were used to assess significance (P<0.05). Antioxidant density (mmol TE/100 g) of apple, orange, and grapefruit was 23% to 54% higher than the mean antioxidant density of name-brand and store-brand juices for each fruit; however, only apple and grapefruit exhibited significantly greater (P<0.05) antioxidant density than either of their name-brand or store-brand juices. In contrast, the mean antioxidant density of name-brand grape and pineapple juice was higher than fresh grape or pineapple fruit; however, both fresh grapes and commercial grape juice contained significantly more (P<0.05) antioxidants than store-brand grape juice. Regardless of the convenience of fruit juice, results support the recommendations of the 2010 Dietary Guidelines for Americans for increasing fruit servings in the whole fruit form due to their provision of beneficial antioxidants and fiber with approximately 35% less sugar.

Low birth weight outcomes: why better in Cuba than Alabama?

Reducing the incidence of low birth weight (LBW), a major predictor of infant mortality and morbidity in developed and developing countries, is an important worldwide goal, yet interventions to reduce this incidence have been disappointingly unsuccessful. Despite its low per capita income, Cuba has managed to significantly reduce the prevalence of LBW in recent decades. To date, minimal research has been conducted to comparatively evaluate risk factors associated with birth weight outcomes between countries with significantly differing rates of LBW. For this reason, we traveled to Havana to study the Cuban model of prenatal care and compare risk factors associated with LBW in Cuba, the United States, and, in particular, Alabama. This article describes the community-based approaches to prenatal care provided within the Cuban healthcare system and their influence on rates of LBW. As a result of these successfully integrated health services, the Cuban healthcare model will be used to evaluate and compare Alabamas current prenatal care system, in particular the implementation of strategies such as community-based clinics and maternity homes for high-risk pregnancies.

Obesity-Related Inflammation: Implications for Older Adults

The combination of age-related increases in obesity and inflammation can lead to chronic disease, decreased strength, and physical disability. Lifestyle interventions that include moderate caloric restriction along with aerobic and resistance exercise have shown improvements in metabolic outcomes, strength, and physical function in obese older adults. Although few weight loss studies have addressed diet quality, evidence summarized in this review suggests that encouraging intake of antioxidant-rich fruits and vegetables, high-quality protein, low-glycemic index carbohydrates, and omega-3 fatty acids may further ameliorate obesity-related inflammation. Future controlled trials are indicated to examine the effects of incorporating these foods into multimodal weight loss interventions.

Evaluating Bioactive Food Components in Obesity and Cancer Prevention

Research into bioactive food compounds (BFC) continues to evolve albeit with shared challenges among scientists in the fields of obesity and cancer treatment and prevention. Given the diversity of scientific disciplines involved in evaluating BFC, multidisciplinary conferences provide opportunities to update the state of the science and critically discuss conceptual and methodological challenges encountered in studying BFC in both preclinical and clinical trials. This overview is an introduction to presentations given at a conference sponsored by the National Cancer Institute of the National Institutes of Health and the University of Alabama at Birmingham, which convened a multidisciplinary group of researchers evaluating BFC in obesity and cancer prevention. Full presentations can be viewed in video format at http://www.norc.uab.edu/courses/conferences/conference2013.

Optimizing protein precipitation efficiency for assessing the contribution of low molecular weight compounds to serum antioxidant capacity

UNLABELLED Antioxidant capacity testing is commonly used in clinical investigations to provide an estimate of in vitro antioxidant capacity of biosamples. Although beneficial to measure the synergistic contribution of all compounds with antioxidant functionality, assessing the capacity of non-protein fractions or small molecules like ascorbic acid with primary antioxidant functionality may be more beneficial in specific populations. Thus, efficacy of solvent/s to precipitate serum proteins is critical to assessing the antioxidant contribution of these compounds. OBJECTIVES To compare protein precipitation efficiency of a validated precipitating solvent system to acetone, the commonly utilized precipitating solvent in the oxygen radical absorbance capacity (ORAC) assay, and to evaluate antioxidant contribution of small molecular weight compounds in serum from 20 adults aged 65 and older with stage I or stage II obesity, yet who were otherwise healthy. DESIGN AND METHODS Precipitating solvent/s included acetone (1:8 (v/v)) or methanol/acetonitrile/acetone (MAA) (1:1:1, v/v/v) in a ratio of 1:4 (v/v). Protein concentration and antioxidant capacity were measured by the Biuret and ORAC assay, respectively. RESULTS Significant differences (p<0.001) were observed in protein precipitation efficiency such that the protein content of serum remaining after acetone deproteination was 2.30±0.76mg/mL compared to 0.85±0.60mg/mL with MAA. Antioxidant capacity of whole serum was significantly greater (p<0.001) than that of serum deproteinated with MAA or acetone. Small molecular weight compounds contributed 6.18±2.46% to antioxidant capacity of whole serum. CONCLUSIONS Precipitation by MAA is more effective than acetone alone in precipitating high molecular weight proteins, thus allowing for assessment of antioxidant capacity of small molecules in serum.

Protein-enhanced soups: a consumer-accepted food for increasing dietary protein provision among older adults

Abstract Protein-enhanced soups (PES) may improve protein intake among older adults. This study examined sensory attributes (aroma, texture, taste, and overall acceptability) and preferences of PES (chicken noodle and cheddar broccoli) compared with flavor-matched control soups (FCS) among older adults (≥65 years) and evaluated dietary profile changes of a standard menu based on the substitution of one PES serving/d for a standard soup. Modified paired preference tests and 5-point facial hedonic scales were administered to participants (n = 44). No significant differences in sensory attributes between either PES compared with FCS were identified, but significant gender- and age-related differences (p < 0.05) were observed. About Sixty-one percent of participants preferred protein-enhanced chicken noodle soup while only 38% preferred protein-enhanced cheddar broccoli soup to their respective FCS. Substituting one PES serving for one non-fortified soup serving per day resulted in significantly higher (p < 0.001) protein profile. Results suggest that all attributes of PES were consistent with sensory expectations and PES substitution could improve protein provision.