Whether on Twitter, Facebook or in the news, clinical research published in ASN Journals generates discussion around the world, keeping nutrition scientists, clinicians, and policymakers current with groundbreaking findings and setting the stage for new advances in nutrition science and practice.  Recently, the four ASN Journal Editors posted a new collection, “Most Discussed Clinical Research of 2021,” presenting the top Altmetric-scoring clinical research that was published in their journals last year.  This collection is available free online to everyone until May 31, 2022.

Below are highlights from each of our four journals:

Avocado Consumption Alters Gastrointestinal Bacteria Abundance and Microbial Metabolite Concentrations among Adults with Overweight or Obesity: A Randomized Controlled Trial
The Journal of Nutrition, April 2021

Working with a group of 163 overweight or obese adults, aged 25 to 45, Sharon V. Thompson et al. conducted a randomized controlled trial to determine the impact of avocado consumption on the gastrointestinal microbiota and microbial metabolite.  Participants were divided into two groups.  Both groups consumed the exact same number of meals and the exact same number of calories per day over a 12-week period, with the one exception that the experiment group consumed avocado once daily (175 grams for men and 140 grams for women), whereas the control group did not consume any avocado during the trial period.  Following the trial period, the authors discovered that “daily avocado consumption resulted in lower fecal bile acid concentrations, greater fecal fatty acid and short-chain fatty acids, and greater relative abundances of bacteria capable of fiber fermentation.”  According to the authors, “these findings provide valuable insight regarding the impact of avocado intake on the intestinal microbiota and have important implications for dietary interventions conducted among the growing at-risk population of adults with overweight or obesity.”

Growth, Body Composition, and Cardiovascular and Nutritional Risk of 5- to 10-y-Old Children Consuming Vegetarian, Vegan, or Omnivore Diets
The American Journal of Clinical Nutrition, June 2021

Plant-based diets are increasingly recommended for personal health and planetary health; however, evidence on the health effects of plant-based diets, particularly vegan diets, on children has been limited.  Working with a group of Polish children, aged 5 to 10 (63 vegetarians, 52 vegans, and 72 omnivores), Małgorzata A. Desmond et al. conducted a cross-sectional study to quantify the differences in body composition, cardiovascular risk, and micronutrient status between these three groups.  Compared to omnivore children, study results suggest that vegan children had healthier cardiovascular risk profiles, but, at the same time, had an increased risk of nutritional deficiencies.  Vegetarian children showed less pronounced nutritional deficiencies but, unexpectedly, a less favorable cardiometabolic risk profile.  The authors recommend that public health recommendations customize “the advice to vegans compared with vegetarians and different age groups so that the established benefits of these diets are maximized and the risks minimized in the pediatric population.”

Association of Vitamin D Status with SARS-CoV-2 Infection or COVID-19 Severity: A Systematic Review and Meta-analysis
Advances in Nutrition, September 2021

Asma Kazemi et al. assessed the evidence to determine any associations between vitamin D status and COVID-19 disease risk and outcomes.  The authors reviewed 36 studies, including 17 from Europe, 2 from North America, 2 from South America, 17 from Asia, and 1 from Africa.  Although these studies were heterogeneous in their methodological and statistical approach, the authors did find that “most of them indicated a significant relation between vitamin D and SARS-CoV-2 infection, COVID-19 composite severity, and mortality.”  For example, the authors pointed to studies which observed a higher risk of COVID-19 infection among individuals who were vitamin D deficient.  Moreover, vitamin D deficient individuals were more likely to experience a more severe course of the disease.  “For ICU admission, inflammation, hospitalization, and pulmonary involvement,” the authors observed, “the evidence is currently inconsistent and insufficient.”  The authors have called for future studies to “investigate the association of COVID-19 with vitamin D in subgroups of age and sex.”

A Whole-Grain Diet Increases Whole-Body Protein Balance Compared with a Macronutrient-Matched Refined-Grain Diet
Current Developments in Nutrition, November 2021

Jacob T. Mey et al. conducted a randomized controlled trial to determine the effects of a whole-grain diet on whole-body protein turnover.  Fourteen adults with overweight or obesity ranging in age from 33 to 47 were recruited.  Participants were randomly assigned to either a whole-grain–enriched or refined-grain diet for an eight-week period.  Diets were matched for macronutrient composition and calories.  Only the whole grain content of the two diets differed: participants assigned to the whole-grain diet consumed 50 grams of whole grains per 1,000 kilocalories, whereas those assigned to the refined-grain diet consumed no whole grains at all.  Following the eight-week trial, findings “revealed that when adults with overweight/obesity consume a whole-grain diet, whole-body protein turnover and 24-hour integrated net protein balance are increased compared with a carefully matched refined-grain diet.”  To support these findings, the authors obtained in vitro evidence that a whole-grain wheat extract increases skeletal muscle global protein synthesis rates in response to anabolic stimuli.  “Taken together,” the authors believe, “these data implicate a novel role for whole-grains in human protein metabolism and related health outcomes.”

We invite you to peruse the entire collection, consisting of 21 articles that captured the attention of social and traditional media worldwide in 2021.  As a reminder, the collection is available free online to everyone until May 31, 2022.