Epigenetics: A New Link Between Nutrition and Cancer
Emerging studies suggest that dietary components can affect gene expression through epigenetic mechanisms. Epigenetic modifications are heritable and potentially reversible changes in gene expression that do not require changes in the DNA sequence. The main mechanisms of epigenetic control in mammals are DNA methylation, histone modifications, and RNA silencing. The potential reversibility of epigenetic changes suggests that they could be modulated by nutrition and bioactive food compounds. Thus, epigenetic modifications could mediate environmental signals and provide a link between susceptibility genes and environmental factors in the etiology of cancer. Elucidating the impact of nutrition on epigenetic mechanisms may serve as a tool to predict an individuals’ susceptibility to cancer, provide dietary recommendations, or provide therapeutic applications of natural compounds against cancer. The optimal duration and the dose necessary for a chemopreventive effect require further studies. There is limited information about tissue specificity and temporal aspects of dietary treatments. Species differences need to be considered when interpreting results from various models. Importantly, molecular mechanisms of bioactive dietary components should be investigated in greater detail in human intervention studies. Although some of these issues remain controversial, this review mainly focuses on promising data that support the developing field of Nutritional Epigenetics.
Conclusion ....The complex interactions among environmental, genetic, and epigenetic factors during cancer development have not yet been fully identified. Elucidating the epigenetic mechanisms that underlie these modifications may serve as a tool to predict the individuals’ genetic susceptibility to cancer, provide dietary recommendations, or provide therapeutic applications of natural compounds against cancer. Taken together, an increasing number of studies support a role of diet in cancer prevention and treatment....
Lowering the Risk of Rectal Cancer among Habitual Beer Drinkers by Dietary Means Gabriel Kune1 and Lyndsey Watson2
1Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, 41 Power Street, Toorak, VIC 3142, Australia 2Mother and Child Health Research, La Trobe University, Melbourne, VIC 3000, Australia
Abstract Whole-life beer consumption and a quantitative measurement of several dietary micronutrients consumed in adult life were obtained from the dietary and alcohol data of the case-control arm of the population-based Melbourne Colorectal Cancer Study. There was a statistically significant risk, adjusted for other established risk factors, among habitual beer drinkers (AOR 1.75, 95% CI 1.28–2.41) with a significant positive dose-response effect (AOR trend 1.34, 95% CI 1.16–1.55). Among beer consumers the data were interpreted as showing an attenuation of this risk with consumption of the four micronutrients involved in methylation: folate, methionine, vitamins B6 and B12, and the four micronutrients examined with antioxidant properties: selenium, vitamins E, C, and lycopene. The strongest effects were noted with vitamins E, C, and lycopene, and the weakest with methionine and selenium. Whilst not condoning excessive beer drinking, the regular consumption of foods rich in these micronutrients may provide a simple and harmless preventative strategy among persistent habitual beer drinkers and deserves further study with larger study numbers.
Conclusion Habitual longstanding beer drinking was associated with a statistically significant risk for rectal cancer, and there was a significant positive dose-response effect. As measured in this study, the regular consumption of foods containing the micronutrients involved with methylation, folate, methionine, vitamins B6 and B12, and the four micronutrients examined with antioxidant properties, selenium, vitamins E, C, and lycopene, all attenuated this risk among beer drinkers. The strongest effects were noted for vitamins E, C and lycopene, and the weakest for methionine and selenium containing foods. Whilst certainly not encouraging excessive beer drinking, the results support the proposition that the regular consumption of foods containing some of the micronutrients involved in one-carbon metabolism, particularly folate, vitamins B6, B12, and some with antioxidant properties, namely, vitamins E, C, lycopene and selenium, micronutrients that are plentiful in many vegetables, fruits, grains, nuts, and fish, may provide a relatively simple and harmless means of counteracting the excess risk of rectal cancer in habitual and persistent beer drinkers. This conclusion in our view deserves further investigation with larger study numbers and therefore greater statistical power.
Source : Advances in Preventive Medicine Volume 2011 (2011), Article ID 874048, 5 pages doi:10.4061/2011/874048 Link to Full Article
Dietary intake of meat, fruits, vegetables, and selective micronutrients and risk of bladder cancer in the New England region of the United States J W Wu1, A J Cross1, D Baris1, M H Ward1, M R Karagas2, A Johnson3, M Schwenn4, S Cherala5, J S Colt1, K P Cantor1,6, N Rothman1, D T Silverman1 and R Sinha1
1National Cancer Institute, National Institutes of Health, Department of Health and Human Services, 6120 Executive Blvd, Rockville, MD 20852, USA
2Dartmouth Medical School, Section of Biostatistics and Epidemiology, 1 Medical Center Drive, 7927 Rubin Building, Lebanon, NH 03756, USA
3Vermont Cancer Registry, 108 Cherry Street, Burlington, VT 05402, USA
4Maine Cancer Registry, 286 Water Street, Fourth Floor, 11 State House Station, Augusta, ME 04333, USA
5New Hampshire department of Health and Human Services, 129 Pleasant Street, Concord, NH 03301, USA
6KP Cantor Environmental LLC, 708 Bonifant Street, Silver Spring, MD 20910, USA
Background: Despite many studies on diet and bladder cancer, there are areas that remain unexplored including meat mutagens, specific vegetable groups, and vitamins from diet.
Methods: We conducted a population-based case–control study of bladder cancer in Maine, New Hampshire, and Vermont. A total of 1171 cases were ascertained through hospital pathology records and cancer registries from 2001 to 2004. Overall, 1418 controls were identified from the Department of Motor Vehicles (<65 years) and Center for Medicaid and Medicare Services (65–79 years) and were frequency-matched to cases by state, sex, and age (within 5 years). Diet was assessed with a self-administered Diet History Questionnaire. Unconditional logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (CI).
Results: Processed meat intake was positively associated with bladder cancer (highest vs lowest quartile OR: 1.28; 95% CI: 1.00–1.65; Ptrend=0.035), with a stronger association for processed red meat (OR: 1.41; 95% CI: 1.08–1.84; Ptrend=0.024). There were no associations between intake of fruits or vegetables and bladder cancer. We did, however, observe an inverse association with vitamin B12 intake (OR: 0.77; 95% CI: 0.61–0.99; P=0.019).
Conclusion: Vitamin B12 from diet may be protective against bladder cancer, whereas consuming processed meat may increase risk.
Natural sources as potential anti-cancer agents: A review Abhishek Bhanot, Rohini Sharma, Malleshappa N. Noolvi
Abstract Natural products remain an important source of new drugs, new drug leads and new chemical entities. The plant based drug discovery resulted mainly in the development of anticancer agents including plants (vincristine, vinblastine, etoposide, paclitaxel, camptothecin, topotecan and irinotecan), marine organisms (citarabine, aplidine and dolastatin 10) and micro-organisms (dactinomycin, bleomycin and doxorubicin). Beside this there is numerous agents identified from fruits and vegetables can used in anticancer therapy. The agents include curcumin (turmeric), resveratrol (red grapes, peanuts and berries), genistein (soybean), diallyl sulfide (allium), S-allyl cysteine (allium), allicin (garlic), lycopene (tomato), capsaicin (red chilli), diosgenin (fenugreek), 6-gingerol (ginger), ellagic acid (pomegranate), ursolic acid (apple, pears, prunes), silymarin (milk thistle), anethol (anise, camphor, and fennel), catechins (green tea), eugenol (cloves), indole-3-carbinol (cruciferous vegetables), limonene (citrus fruits), beta carotene (carrots), and dietary fiber. In this review active principle derived from natural products are offering a great opportunity to evaluate not only totally new chemical classes of anticancer agents, but also novel lead compound and potentially relevant mechanisms of action.
Source : Internation Journal of Phytomedicine Link to Abstract or Google "Natural sources as potential anti-cancer agents: A review" and download Full Article - PDF
Nutrition and cancer: A review of the evidence for an anti-cancer diet
It has been estimated that 30–40 percent of all cancers can be prevented by lifestyle and dietary measures alone. Obesity, nutrient sparse foods such as concentrated sugars and refined flour products that contribute to impaired glucose metabolism (which leads to diabetes), low fiber intake, consumption of red meat, and imbalance of omega 3 and omega 6 fats all contribute to excess cancer risk. Intake of flax seed, especially its lignan fraction, and abundant portions of fruits and vegetables will lower cancer risk. Allium and cruciferous vegetables are especially beneficial, with broccoli sprouts being the densest source of sulforophane. Protective elements in a cancer prevention diet include selenium, folic acid, vitamin B-12, vitamin D, chlorophyll, and antioxidants such as the carotenoids (α-carotene, β-carotene, lycopene, lutein, cryptoxanthin). Ascorbic acid has limited benefits orally, but could be very beneficial intravenously. Supplementary use of oral digestive enzymes and probiotics also has merit as anticancer dietary measures. When a diet is compiled according to the guidelines here it is likely that there would be at least a 60–70 percent decrease in breast, colorectal, and prostate cancers, and even a 40–50 percent decrease in lung cancer, along with similar reductions in cancers at other sites. Such a diet would be conducive to preventing cancer and would favor recovery from cancer as well.
Timothy J Key, Naomi E Allen, Elizabeth A Spencer, Ruth C Travis
Diet-related factors are thought to account for about 30% of cancers in developed countries. Obesity increases the risk of cancers in the oesophagus, colorectum, breast, endometrium, and kidney. Alcohol causes cancers of the oral cavity, pharynx, larynx, oesophagus, and liver, and causes a small increase in the risk of breast cancer. Adequate intakes of fruit and vegetables probably lower the risk for several types of cancer, especially cancers of the gastrointestinal tract. The importance of other factors, including meat, fibre, and vitamins, is not yet clear. Prudent advice is to eat a varied diet including plenty of fruit, vegetables, and cereals; to maintain a healthy bodyweight with the help of regular physical activity; and to restrict consumption of alcohol.