Influence of Nutritional Intakes in Japan and the United States on COVID-19 Infection

Recent advances in nutritional metabolism studies on SARS-CoV-2 infection

In the context of the coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), metabolic research has become crucial for in-depth exploration of viral infection mechanisms and in searching for therapeutic strategies. This paper summarizes the interrelationships between carbohydrate, lipid, and amino acid metabolism and COVID-19 infection, discussing their roles in infection progression. SARS-CoV-2 infection leads to insulin resistance and increased glycolysis, reducing glucose utilization and shifting metabolism to use fat as an energy source. Fat is crucial for viral replication, and imbalances in amino acid metabolism may interfere with immune regulation. Consequently, metabolic changes such as hyperglycemia, hypolipidemia, and deficiency of certain amino acids following SARS-CoV-2 infection can contribute to progression toward severe conditions. These metabolic pathways not only have potential value in prediction and diagnosis but also provide new perspectives for the development of therapeutic strategies. By monitoring metabolic changes, infection severity can be predicted early, and modulating these metabolic pathways may help reduce inflammatory responses, improve immune responses, and reduce the risk of thrombosis. Research on the relationship between metabolism and SARS-CoV-2 infection provides an important scientific basis for addressing the global challenge posed by COVID-19, however, further studies are needed to validate these findings and provide more effective strategies for disease control.

Tannic acids and proanthocyanidins in tea inhibit SARS-CoV-2 variants infection

The COVID-19 pandemic has caused hundreds million cases and millions death as well as continues to infect human life in the world since late of 2019. The breakthrough infection caused from mutation of SARS-CoV-2 is rising even the vaccinated population has been increasing. Currently, the severe threat posed by SARS-CoV-2 has been alleviated worldwide, and the situation has transitioned to coexisting with the virus. The dietary food with antiviral activities may improve to prevent virus infection for living with COVID-19 pandemic. Teas containing enriched phenolic ingredients such as tannins have been reported to be antitumor agents as well as be good inhibitors for coronavirus. This study developed a highly sensitive and selective ultra-high performance liquid chromatography-high resolution mass spectrometric method for quantification of tannic acids, a hydrolysable tannin, and proanthocyanidins, a condense tannin, in teas with different levels of fermentation. The in vitro pseudoviral particles (Vpp) infection assay was used to evaluate the inhibition activities of various teas. The results of current research demonstrate that the tannins in teas are effective inhibitors against infection of SARS-CoV-2 and its variants.

Green Tea Consumption and the COVID-19 Omicron Pandemic Era: Pharmacology and Epidemiology

In spite of the development of numerous vaccines for the prevention of COVID-19 and the approval of several drugs for its treatment, there is still a great need for effective and inexpensive therapies against this disease. Previously, we showed that green tea and tea catechins interfere with coronavirus replication as well as coronavirus 3CL protease activity, and also showed lower COVID-19 morbidity and mortality in countries with higher green tea consumption. However, it is not clear whether green tea is still effective against the newer SARS-CoV-2 variants including omicron. It is also not known whether higher green tea consumption continues to contribute to lower COVID-19 morbidity and mortality now that vaccination rates in many countries are high. Here, we attempted to update the information regarding green tea in relation to COVID-19. Using pharmacological and ecological approaches, we found that EGCG as well as green tea inhibit the activity of the omicron variant 3CL protease efficiently, and there continues to be pronounced differences in COVID-19 morbidity and mortality between groups of countries with high and low green tea consumption as of December 6, 2022. These results collectively suggest that green tea continues to be effective against COVID-19 despite the new omicron variants and increased vaccination.

Are Foods from the COVID-19 Pandemic Lockdown Low in Nutrients? An Analysis of Chinese Psychological Distress Effects

Background: The city-wide COVID-19 lockdown has resulted in psychological anguish, which may have an impact on dietary consumption. This study’s dual goals are to show how Chinese food consumption was altered before and after the lockdown, and to examine the nutrient density for the psychologically affected group. Methods: A cross-sectional study involving 652 people from Mainland China, Taiwan, and Macao was conducted with the aid of a web-based questionnaire. Sociodemographic characteristics, related environmental factors, nutrient consumption, food recommendations, and psychological distress were all measured. 516 trustworthy data revealed that two nutrient-poor foods were consumed less frequently during the lockdown than they were before to the COVID-19 outbreak (i.e., salty snacks and alcoholic beverages). People who endured high levels of psychological distress in particular tended to consume more. Particularly, those who experienced high levels of psychological distress had a tendency to consume far more alcohol than people who only experienced low levels of stress. Comparing the time before the COVID-19 to the present, there has statistically been an increase in the frequency of family members recommending diets. According to research, by food advice, individuals who experience psychological distress should consume more nutrient-dense foods (78.7%) than nutrient-poor ones (61.9%). Thus, food advice plays a role in mediating the relationship between psychological distress and dietary decisions for nutrient-rich (b = 0.186, p < 0.001) or nutrient-poor (b = 0.187, p < 0.001) food groups. This study provides insights for lowering psychological distress through dietary consumption, where the exact mechanisms underlying these connections have not been thoroughly elucidated. It encourages nutrition research by recommending practical nutrition education from family and environmental activities. Chronic psychological anguish may have a crucial relationship to secure access to food and a balanced diet. Along with nutrition instruction, it is critical to develop skills in interventions such as food procurement and culinary knowledge.

Anti-SARS-CoV-2 activity of various PET-bottled Japanese green teas and tea compounds in vitro

The outbreak of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a serious threat to global public health. The emergence of SARS-CoV-2 variants is a significant concern regarding the continued effectiveness of vaccines and antiviral therapeutics. Thus, natural products such as foods, drinks, and other compounds should be investigated for their potential to treat COVID-19. Here, we examined the in vitro antiviral activity against SARS-CoV-2 of various polyethylene terephthalate (PET)-bottled green Japanese teas and tea compounds. Six types of PET-bottled green tea were shown to inhibit SARS-CoV-2 at half-maximal inhibitory concentrations (IC50) of 121- to 323-fold dilution. Our study revealed for the first time that a variety of PET-bottled Japanese green tea drinks inhibit SARS-CoV-2 infection in a dilution-dependent manner. The tea compounds epigallocatechin gallate (EGCG) and epicatechin gallate showed virucidal activity against SARS-CoV-2, with IC50 values of 6.5 and 12.5 µM, respectively. The investigated teas and tea compounds inactivated SARS-CoV-2 in a dose-dependent manner, as demonstrated by the viral RNA levels and infectious titers. Furthermore, the green teas and EGCG showed significant inhibition at the entry and post-entry stages of the viral life cycle and inhibited the activity of the SARS-CoV-2 3CL-protease. These findings indicate that green tea drinks and tea compounds are potentially useful in prophylaxis and COVID-19 treatment.

Effects of a New Multicomponent Nutritional Supplement on Muscle Mass and Physical Performance in Adult and Old Patients Recovered from COVID-19: A Pilot Observational Case-Control Study

Objective: The purpose of the present study was to assess the effect of a specific oral nutritional supplement among patients recovered from COVID-19 but suffering symptoms of fatigue. Methods: This is an observational case–control study involving a sample of 66 COVID-19 survivors divided in two groups, 33 subjects in the intervention group who received the nutritional supplement and 33 subjects in the control group. The nutritional supplement received by subjects in the active group was based on amino acids; vitamin B6 and B1; and malic, succinic and citric acids. After an 8-week follow-up, the main outcomes considered were skeletal muscle index (measured by bioelectrical impedance analysis), physical performance measures (handgrip strength, one-minute chair–stand test, six-minute walking test), and quality of life (using EuroQol visual analogue scale). Results: All the considered areas increased significantly in the subjects receiving the active treatment with oral nutritional supplement in comparison with the baseline values. After adjusting for age, gender, and baseline values, skeletal muscle index, handgrip strength test, the one-minute chair–stand test, and six-minute walking test values were higher among participants in the treatment group compared with subjects in control group. The oral nutritional supplement significantly improved the handgrip strength; similarly, participants in the active group showed a higher improvement in skeletal muscle index, the one-minute chair–stand test, the six-minute walking test, and in quality of life. Conclusion: The nutritional supplement containing nine essential amino acids plus cysteine; vitamin B6 and B1; and malic, succinic and citric acids had a positive effect on nutritional status, functional recovery, and quality of life in COVID-19 survivors still suffering from fatigue. Additional controlled clinical trials are required to corroborate these results.