Evidence-Based Practice Competencies among Nutrition Professionals and Students: A Systematic Review.

BACKGROUND: Evidence-based practice (EBP) promotes shared decision-making between clinicians and patients. OBJECTIVE: The aim was to determine EBP competencies among nutrition professionals and students reported in the literature. METHODS: We conducted a systematic review by searching Medline, Embase, CINAHL, ERIC, CENTRAL, ProQuest Dissertations and Theses Global, BIOSIS Citation Index, and clinicaltrials.gov up to March 2023. Eligible primary studies had to assess one of the 6 predefined EBP competencies: formulating clinical questions; searching literature for best evidence; assessing studies for methodological quality; effect size; certainty of evidence for effects; and determining the applicability of study results considering patient values and preferences. Two reviewers independently screened articles and extracted data, and results were summarized for each EBP competency. RESULTS: We identified 12 eligible cross-sectional survey studies, comprising 1065 participants, primarily registered dietitians, across 6 countries, with the majority assessed in the United States (n = 470). The reporting quality of the survey studies was poor overall, with 43% of items not reported. Only 1 study (8%) explicitly used an objective questionnaire to assess EBP competencies. In general, the 6 competencies were incompletely defined or reported (e.g., it was unclear what applicability and critical appraisal referred to and what study designs were appraised by the participants). Two core competencies, interpreting effect size and certainty of evidence for effects, were not assessed. CONCLUSIONS: The overall quality of study reports was poor, and the questionnaires were predominantly self-perceived, as opposed to objective assessments. No studies reported on competencies in interpreting effect size or certainty of evidence, competencies essential for optimizing clinical nutrition decision-making. Future surveys should objectively assess core EBP competencies using sensible, specific questionnaires. Furthermore, EBP competencies need to be standardized across dietetic programs to minimize heterogeneity in the training, understanding, evaluation, and application among dietetics practitioners. This study was registered at PROSPERO as CRD42022311916.

Supplementation with aged garlic extract improves both NK and γδ-T cell function and reduces the severity of cold and flu symptoms: a randomized, double-blind, placebo-controlled nutrition intervention.

BACKGROUND & AIMS: Earlier studies show that dietary bioactive compounds can modify proliferation of γδ-T cells. Garlic contains numerous compounds that have this potential and, in addition, has been shown to influence NK cell function. Our primary aim was to demonstrate that aged garlic extract could modify these immune cells. METHODS: A randomized, double-blind, placebo-controlled parallel intervention study recruited 120 healthy subjects (60 per group) to determine the effect of aged garlic extract supplementation (2.56 g/d) on immune cell proliferation and cold and flu symptoms. RESULTS: After 45 d of consuming an encapsulated aged garlic extract, γδ-T cells (p = 0.039, n = 56) and NK cells (p = 0.043, n = 56) were shown to proliferate better compared to placebo. After 90 d of supplementation, illness diary entries showed that the incidence of colds and flu, a secondary outcome, were not statistically different; however, the group consuming the aged garlic extract appeared to have reduced severity as noted by a reduction in the number of symptoms reported (21% fewer, p < 0.001, z-test of proportions), a reduction in the number of days (61% fewer, p < 0.001, z-test) and incidences (58% fewer p < 0.001, z-test) where the subjects functioned sub-optimally and the number of work/school days missed due to illness (58% fewer, p = 0.035, z-test). CONCLUSIONS: These results suggest that supplementation of the diet with aged garlic extract may enhance immune cell function and that this may be responsible, in part, for reduced severity of colds and flu.