Epidemiological studies have demonstrated inconsistent associations between tea consumption and mortality of all cancers, CVD and all causes. To obtain quantitative overall estimates, we conducted a dose–response meta-analysis of prospective cohort studies. A literature search in PubMed and Embase up to April 2015 was conducted for all relevant papers published. Random-effects models were used to calculate pooled relative risks (RR) with 95 % CI. In eighteen prospective studies, there were 12 221, 11 306 and 55 528 deaths from all cancers, CVD and all causes, respectively. For all cancer mortality, the summary RR for the highest v. lowest category of green tea and black tea consumption were 1·06 (95 % CI 0·98, 1·15) and 0·79 (95 % CI 0·65, 0·97), respectively. For CVD mortality, the summary RR for the highest v. lowest category of green tea and black tea consumption were 0·67 (95 % CI 0·46, 0·96) and 0·88 (95 % CI 0·77, 1·01), respectively. For all-cause mortality, the summary RR for the highest v. lowest category of green tea and black tea consumption were 0·80 (95 % CI 0·68, 0·93) and 0·90 (95 % CI 0·83, 0·98), respectively. The dose–response analysis indicated that one cup per d increment of green tea consumption was associated with 5 % lower risk of CVD mortality and with 4 % lower risk of all-cause mortality. Green tea consumption was significantly inversely associated with CVD and all-cause mortality, whereas black tea consumption was significantly inversely associated with all cancer and all-cause mortality.

Experimental models showed consistently a modulation of carcinogenesis by omega 3 polyunsaturated fatty acids (ω3 PUFA). Fish intake is often described as part of a beneficial dietary pattern. However, observational epidemiological studies on the relationship between ω3 PUFA reported conflicting results. The objective of this systematic review is to determine whether there exists any progress in the evaluation of the causal relationship between dietary ω3 PUFA and cancers since the previous FAO/OMS expert consultation and whether it is possible to propose preventive and/or adjuvant therapeutic recommendations. Prospective and case-control observational studies published since 2007 and meeting validity criteria were considered together with RCT. Experimental studies are mentioned to provide for biological plausibility. When evaluating the level of evidence, a portfolio approach was used, weighted by a hierarchy giving higher importance to prospective studies followed by RCT if any. There is a probable level of evidence that ALA per se is neither a risk factor nor a beneficial factor with regards to cancers. Observational studies on colorectal, prostate and breast cancers only provided limited evidence suggesting a possible role of LC-ω3PUFA in cancer prevention because insufficient homogeneity of the observations. Explanation for heterogeneity might be the inherent difficulties associated with epidemiology (confounding and dietary pattern context, measurement error, level of intake, genetic polymorphism). The role of LC-ω3PUFA as adjuvant, might be considered of possible use, in view of the latest RCT on lung cancers even if RCT on other cancers still need to be undertaken.

The immune system is able to protect the host from tumor onset, and immune deficienciesare accompanied by an increased risk of cancer. Immunology is one of the fields in biologywhere the role of computational and mathematical modeling and analysis were recognized theearliest, beginning from 60s of the last century. We introduce the two most common methodsin simulating the competition among the immune system, cancers and tumor immunologystrategies: differential equations and rule-based models. Several specific implementationsare presented, describing in details how they work and how they advance or contribute thefield of tumor immunology.

Several dietary factors have been associated with the occurrence of cancers of the oral cavity and oropharynx, larynx and oesophagus, collectively called upper aerodigestive tract (UADT) cancers, but the evidence is considered as inconclusive. We hypothesised that the traditional Mediterranean dietary pattern may be more strongly inversely associated with UADT cancer risk than individual dietary components, and may explain the unexpectedly low incidence of these cancers in Greece. In the context of the European alcohol-related cancers and genetic susceptibility in Europe project, we have conducted a hospital-based case–control study in Athens, Greece, comparing 239 incident UADT cases and 194 hospital controls with admission diagnoses unrelated to tobacco, alcohol or diet. Adherence to Mediterranean diet was assessed through a widely used score, which ranges from 0 (minimal adherence) to 9 (maximal adherence) and increases with high consumption of plant foods and olive oil and low consumption of meat, dairy products and saturated lipids. Stricter adherence to the Mediterranean diet was associated with a substantial and significant decrease in UADT cancer risk (30 % for a two-unit increase in score), whereas after mutual adjustment, no individual dietary component of this diet was significantly associated with this risk. Adherence to the traditional Mediterranean diet is associated with reduced risk of UADT cancers, and may explain the lower incidence of UADT cancers in Greece, in spite of the smoking and drinking habits of this population.

A voluminous body of epidemiological research concerning the potential role of antioxidant nutrients in the prevention of cancers has accumulated over the past few decades. However, results of large recent intervention trials do not support a preventive effect against cancer for supplementation with antioxidant nutrients. Seemingly contradictory results between observational studies and randomised trials can be explained by the fact that doses used in clinical trials were much higher than the highest levels attained by the usual dietary intake which, in observational studies, were found to be associated with the lowest risk of cancer. Recently, the Supplementation en Vitamines et Mine´raux Antioxydants (SU.VI.MAX) study, a randomised, double-blind, placebo-controlled primary prevention trial, tested the efficacy of supplementation with a combination of antioxidant vitamins and minerals, at nutritional doses, in reducing the cancer incidence in a general population not selected for risk factors. After 7·5 years, low-dose antioxidant supplementation lowered the total cancer incidence in men only. This may be explained by a lower baseline status of certain antioxidants in men compared to women. Finally, the effect of antioxidant supplementation on the incidence of cancer could depend on baseline antioxidant status (which differs from gender and/or nutritional status) and the health status of subjects (healthy v. cancer high-risk subjects). Antioxidant supplementation may have a beneficial effect upon cancer incidence only in healthy subjects who are not exposed to cancer risk and who have a particularly low baseline status. High doses of antioxidant supplementation may be deleterious in subjects in whom the initial phase of cancer development has already started, and they could be ineffective in well-nourished subjects with adequate antioxidant status.

The SUpplementation en VItamines et Mineraux AntioXydants (SU.VI.MAX) study, a randomised double-blind, primary-prevention trial showed that after 7·5 years, low-dose antioxidant supplementation lowered the total cancer incidence in men, but not in women. To explain this difference in the impact of antioxidant supplementation in men and women, we hypothesised that the effect of supplementation is dependent on initial antioxidant status; 12 741 French adults (7713 females aged 35–60 years; 5028 males aged 45–60 years) received daily antioxidant supplementation (120 mg vitamin C, 30 mg vitamin E, 6 mg β-carotene, 100 μg Se, 20 mg Zn daily) or a matching placebo. Cut-off limits for baseline serum concentrations of the different antioxidant vitamins and minerals were defined as follows for both men and women: 0·3 μmol/l for β-carotene, 11·4 μmol/l for vitamin C, 15 μmol/l for vitamin E, 0·75 μmol/l for Se and 10·7 μmol/l for Zn. The percentage of men with serum concentrations under cut-off limits was higher for vitamins C and E and β-carotene in those who developed a cancer than in those who did not. The risk of cancer was higher in men with baseline concentrations of serum vitamin C or vitamin E under cut-off limits, but not in women. The effect of supplementation was greater in men with baseline serum concentrations of vitamin C, vitamin E and β-carotene below the cut-off limits compared with those above it. This effect was maintained only for vitamin E after adjustment for age, tobacco, and alcohol consumption and BMI. No effect of supplementation could be seen in women. Baseline antioxidant status is related to the risk of cancer in men but not in women and therefore does not entirely explain the differences observed in the effect of antioxidant supplementation on cancer risk between sexes in the SU.VI.MAX study.

The importance attributed to dietary change as a means of helping to achieve the major goals of the UK's public health policy as articulated in the Health of the Nation White paper (Department of Health, 1992) is less apparent in the most recent strategy document (Department of Health, 1999). Greater emphasis is given to amelioration of the socio-economic circumstances that are believed to contribute to inequalities in health. Better understanding of the elements of foods and diets which help protect health together with better evidence of effective dietary interventions are essential if the opportunities to use diet to reduce the burden of noncommunicable diseases are to be realised. This is likely to need new research strategies that take advantage of emerging information from genomics and proteomics to produce evidence of safety, efficacy and applicability. Ethical exploitation of the rapid growth in interest in ‘functional foods’ by the food industry will require a level of investment in biomedical research unusual in the past.