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.

The impact of diet and nutrition in the prevention and progression of hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is the third leading cause of cancer mortality worldwide. There is growing evidence for a chemopreventive role of nutrition in the development of HCC in at risk populations. Bibliographical searches were performed in PubMed for the terms 'nutrition and hepatocellular carcinoma', 'nutrition and liver cancer', 'nutrition and hepatic cancer', 'diet and hepatocellular carcinoma', 'diet and liver cancer'. High dietary sugar intake should be discouraged in at risk populations. Coffee, polyphenols, vanadium, dietary fibre, fruits and vegetables show encouraging results in terms of chemoprevention. Red meat intake may be associated with increased risk of HCC. The evidence for fatty acids is inconclusive, but they might exert anti-cancer effects. Inconclusive results are available on vitamins, selenium probiotics and prebiotics. There is increasing evidence that diet may play an important role in the development of HCC, and may also have a chemopreventive role in at risk populations.

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.

Diet and supplements and their impact on colorectal cancer.

BACKGROUND: Colorectal cancer is the third commonest cancer and the third leading cause of cancer death among men and women. It has been proposed that dietary factors are responsible for 70-90% of colorectal cancer and diet optimization may prevent most cases. AIM: To evaluate the role of dietary components and supplements in colorectal cancer. METHODS: Bibliographical searches were performed in Pubmed for the terms "diet and colorectal cancer", "diet and colon cancer", "diet and rectal cancer", "nutrition and colorectal cancer", "probiotics and colorectal cancer", "prebiotics and colorectal cancer", "alcohol and cancer" and "colorectal cancer epidemiology". RESULTS: Consumption of processed or red meat, especially when cooked at high temperatures may be associated with increased risk of colorectal cancer. The evidence for dietary fibre is unclear but foods that contain high amounts of fibre are usually rich in polyphenols which have been shown to alter molecular processes that can encourage colorectal carcinogenesis. Meta-analyses provide evidence on the benefits of circulating, diet-derived and supplemented, vitamin D and Calcium. We also found that diets rich in Folate may prevent colorectal carcinoma. The evidence on dietary micronutrients such as Zinc and Selenium in association with colorectal cancer is not conclusive. It has been suggested that there may be a direct association between alcohol intake and colorectal cancer. In vitro and in vivo studies have highlighted a possible protective role of prebiotics and probiotics. CONCLUSIONS: The lack of randomized trials and the presence of confounding factors including smoking, physical activity, obesity and diabetes may often yield inconclusive results. Carefully designed randomized trials are recommended.