The Role of Diet and Supplements in the Prevention and Progression of COVID-19: Current Knowledge and Open Issues.

A healthy diet and dietary supplements have gained attention as potential co-adjuvants in managing and preventing coronavirus disease 2019 (COVID-19). This paper critically reviews the current evidence regarding the impact of diet and supplements on the prevention and progression of COVID-19. According to available data, a healthy diet and normal weight are considered protective factors. Regarding dietary supplementation, the most robust results from human studies are for vitamin C, which appears to decrease inflammatory markers and suppress cytokine storm. A small, randomized trial showed that a high dose of vitamin D significantly reduced the need for intensive care unit treatment of patients requiring hospitalization for COVID-19. According to retrospective human studies, there is limited evidence for vitamin E and selenium supplements. Animal studies have investigated the effects of green tea and curcumin. Xanthohumol and probiotics, interesting for their antiviral, anti-inflammatory, and immunoregulatory properties, need formal clinical study. In summary, there is promising evidence supporting the role of diet and supplements as co-adjuvants in the treatment of COVID-19. Further studies and properly designed clinical trials are necessary to draw more robust conclusions; however, it is not unreasonable to take a pragmatic approach and promote the use of appropriate diet and supplements to counter the effects of COVID-19, ideally with a mechanism to assess outcomes.

Diagnosis and treatment of nutritional deficiencies in alcoholic liver disease: Overview of available evidence and open issues.

Malnutrition is common in alcoholic liver disease and is associated with high rates of complications and mortality. In this article, the current literature was reviewed to highlight the relevance of proper nutritional management providing levels of evidence, when available. A PubMed search was performed for English-language publications from 1980 through 2014 with the keywords: alcoholic liver disease, nutritional deficiencies, nutritional support, enteral nutrition, parenteral nutrition, and protein-energy malnutrition. Manuscripts focused on nutritional approach in patients with alcoholic liver disease were selected. Although nutritional support for malnourished patients improves the outcome of hospitalization, surgery, transplantation and reduces the complications of liver disease and the length of hospital stay, specific guidelines are scanty. Both enteral and parenteral nutrition appear to improve nutritional parameters and liver function; however data on survival is often conflicting. As micronutrient depletion is common in alcoholic liver disease and each deficiency produces specific sequelae, all cirrhotic patients should be screened at baseline for deficiencies of micronutrient and supplemented as needed. In summary, protein-energy malnutrition and micronutrient depletion are clinical concerns in alcoholic liver disease. Nutritional therapy, including enteral nutrition, parenteral nutrition and micronutrient supplementation should be part of the multidisciplinary management of these patients.

The role of dietary factors in prevention and progression of breast cancer.

BACKGROUND/AIM: Breast cancer (BC) is the leading global cause of cancer-related death in women. There is growing evidence for a role for dietary factors in BC pathophysiology. The aim of the present review was to evaluate the impact of dietary factors in BC risk. MATERIALS AND METHODS: Bibliographical searches were performed in PubMed, using the following terms: "nutrition and breast cancer", "nutrition and breast carcinoma", "dietary factors and breast cancer", "risk factors and breast cancer", "diet and breast cancer, "breast cancer epidemiology", "breast cancer and prevention". RESULTS: Consumption of well-done red meat appears to be associated with increased risk of BC, whereas fish may be protective. Total cholesterol, triglyceride levels and glycaemic load should be monitored and controlled in at risk populations because they may be associated with increased risk of BC, although the exact mechanisms involved are not clear. Alcohol intake should be minimized since it is a risk factor for BC. High intake of polyphenol/phyto-oestrogen -rich food (i.e. flavonoids, soya products), as well as fibres, fruits and vegetables, may have potential protective effects against BC occurrence but the results might vary according to hormonal status. Vitamin D supplements appear protective against BC development and similarly other vitamins and oligo-elements might decrease BC risk, although further large prospective studies are required. CONCLUSION: There exist increasing evidence that dietary factors can play an important role in both the development and prevention of BC. Large randomized clinical and epidemiological studies are required but are difficult to design due to the number of variable factors.

Prostate cancer and the influence of dietary factors and supplements: a systematic review.

BACKGROUND: Prostate cancer is the second most common cause of cancer worldwide after lung cancer. There is increasing evidence that diet and lifestyle plays a crucial role in prostate cancer biology and tumourigenesis. Prostate cancer itself represents a good model of cancer in which to look for chemopreventive agents due to the high disease prevalence, slowly progressive nature, and long latency period. Dietary agents have gained considerable attention, often receiving much publicity in the media. AIM: To review the key evidence available for potential chemopreventive nutrients. METHODS: The methodology for this review involved a PubMed search from 1990 to 2013 using the key-words "diet and prostate cancer", "nutrition and prostate cancer", "dietary factors and prostate cancer", "prostate cancer epidemiology", "prostate cancer prevention", "prostate cancer progression". RESULTS: Red meat, dietary fat and milk intake should be minimised as they appear to increase the risk of prostate cancer. Fruit and vegetables and polyphenols may be preventive in prostate cancer, but further studies are needed to draw more solid conclusions and to clarify their role in patients with an established diagnosis of prostate cancer. Selenium and vitamin supplements cannot be advocated for the prevention of prostate cancer and indeed higher doses may be associated with a worse prognosis. There is no specific evidence regarding benefits of probiotics or prebiotics in prostate cancer. CONCLUSIONS: From the wealth of evidence available, many recommendations can be made although more randomised control trials are required. These need to be carefully designed due to the many confounding factors and heterogeneity of the population.

Nutrition and pancreatic cancer.

BACKGROUND: Pancreatic cancer is the fourth leading cause of cancer death in men and women. Prognosis is poor with a 5-year survival rate of less than 5%. As there is no effective screening modality, the best way to reduce morbidity and mortality due to pancreatic cancer is by effective primary prevention. AIM: To evaluate the role of dietary components in pancreatic cancer. MATERIALS AND METHODS: Bibliographical searches were performed in PubMed using the terms "pancreatic cancer", together with "nutrition", "diet", "dietary factors", "lifestyle", "smoking", "alcohol" and "epidemiology". RESULTS: Fruits (particularly citrus) and vegetable consumption may be beneficial. The consumption of whole grains has been shown to reduce pancreatic cancer risk and fortification of whole grains with folate may confer further protection. Red meat, cooked at high temperatures, should be avoided, and replaced with poultry or fish. Total fat should be reduced. The use of curcumin and other flavonoids should be encouraged in the diet. There is no evidence for benefit from vitamin D supplementation. There may be benefit for dietary folate. Smoking and high Body Mass Index have both been inversely associated with pancreatic cancer risk. CONCLUSION: The lack of randomized trials and the presence of confounding factors including smoking status, physical activity, distance of habitat from the equator, obesity, and diabetes may often result in inconclusive results. There is evidence to encourage the use of whole grain in the staple diet and supplementation within the diet of folate, curcumin and other flavanoids. Carefully designed randomized trials are required to further elucidate these important matters.

Nutritional deficiencies in inflammatory bowel disease: therapeutic approaches.

BACKGROUND & AIMS: Malnutrition is common in inflammatory bowel diseases (IBD), mainly in Crohn's disease (CD) because the small bowel is primarily affected. We reviewed the literature to highlight the importance of proper nutrition management. METHODS: A PubMed search was performed for English-language publications from 1999 through 2012. Manuscripts comparing nutritional approaches for IBD patients were selected. RESULTS: We identified 2025 manuscripts: six meta-analyses, 170 clinical-trials, 692 reviews. The study findings are discordant. In adult CD, enteral nutrition plays a supportive role, steroid therapy remaining the first choice treatment. In CD children enteral nutrition may represent the primary therapy. As regards parenteral nutrition, there are no large randomized studies, although mild improvements in morbidity have been described as a result of parenteral nutrition in malnourished surgical IBD patients. Specific micronutrient deficiencies are common in IBD. A number of factors may contribute to micronutrient deficiencies, and these include: dietary restriction, disease activity and surgery. The possible therapeutic roles of omega-3 fatty-acids, probiotics and prebiotics have been studied, but the results are still preliminary. CONCLUSION: Protein-energy malnutrition and micronutrient depletion are clinical concerns in IBD patients. Enteral nutrition, parenteral nutrition and micronutrient supplementation are cornerstone of the multidisciplinary management of IBD patients.