Scientific Opinion on principles for deriving and applying Dietary Reference Values

Adherence to the European food safety authority's dietary recommendations and colorectal cancer risk

BACKGROUND/OBJECTIVE

The European Food Safety Authority (EFSA) recently published dietary guidelines for the intakes of carbohydrates, fiber, fats and water. We evaluated their role on the risk of a specific disease, known to be related to diet.

SUBJECTS/METHODS

We used data from an Italian case-control study including 1953 colorectal cancer (CRC) cases and 4154 controls. We developed a so-called EFSA index summing up 1 point for adherence to each EFSA guideline. Odds ratios (ORs) and corresponding 95% confidence intervals (CIs) of CRC and its subsites were derived from unconditional multiple logistic regression models, for both the index and its components.

RESULTS

When each EFSA index component was analyzed separately, we found significant increased risks of CRC for non adherence to the guidelines on linoleic (OR=1.20, 95% CI, 1.07-1.36) and alpha-linolenic fatty acids (OR=1.19, 95% CI, 1.06-1.34). When all the guidelines were included in the same model, no significant association emerged. Compared with minimal adherence, the ORs of CRC for subsequent EFSA index scores were 1.03 (95% CI, 0.72-1.47), 1.05 (95% CI, 0.75-1.48), 1.04 (95% CI, 0.81-1.60), 0.99 (95% CI, 0.69-1.43), and 1.04 (95% CI, 0.67-1.61). No significant association emerged for colon and rectal cancer separately, and for males and females.

CONCLUSIONS

Overall adherence to the EFSA dietary guidelines is not associated to colorectal, colon and rectal cancer risk in our population. Adherence to guidelines on linoleic and alpha-linolenic fatty acids may have a modest beneficial role on CRC risk.

Towards prevention of vitamin D deficiency and beyond: knowledge gaps and research needs in vitamin D nutrition and public health

The North American Institute of Medicine (IOM) recently published their report on dietary reference intakes (DRI) for Ca and vitamin D. The DRI committee's deliberations underpinning this most comprehensive report on vitamin D nutrition to date benefited hugely from a much expanded knowledge base in vitamin D over the last decade or more. However, since their release, the vitamin D DRI have been the subject of intense controversy, which is largely due to the persistence of fundamental knowledge gaps in vitamin D. These can be identified at the levels of exposure, metabolism, storage, status, dose-response, function and beneficial or adverse health effects, as well as safe and effective application of intake recommendations at the population level through sustainable food-based approaches. The present review provides a brief overview of the approach used by the IOM committee to revise the DRI for vitamin D and to collate from a number of authoritative sources key knowledge gaps in vitamin D nutrition from the public health perspective. A number of research topics are outlined and data requirements within these are identified and mapped to the risk assessment framework used by the DRI committee. While not intended as an exhaustive list, it provides a basis for organising and prioritising research efforts in the area of vitamin D, which may offer a perspective on the major areas in need of attention. It is intended to be of use to researchers, national policy makers, the public health community, industry groups and other relevant stakeholders including funding institutions.

State of the art in benefit-risk analysis: food and nutrition

Benefit-risk assessment in food and nutrition is relatively new. It weighs the beneficial and adverse effects that a food (component) may have, in order to facilitate more informed management decisions regarding public health issues. It is rooted in the recognition that good food and nutrition can improve health and that some risk may be acceptable if benefit is expected to outweigh it. This paper presents an overview of current concepts and practices in benefit-risk analysis for food and nutrition. It aims to facilitate scientists and policy makers in performing, interpreting and evaluating benefit-risk assessments. Historically, the assessments of risks and benefits have been separate processes. Risk assessment is mainly addressed by toxicology, as demanded by regulation. It traditionally assumes that a maximum safe dose can be determined from experimental studies (usually in animals) and that applying appropriate uncertainty factors then defines the 'safe' intake for human populations. There is a minor role for other research traditions in risk assessment, such as epidemiology, which quantifies associations between determinants and health effects in humans. These effects can be both adverse and beneficial. Benefit assessment is newly developing in regulatory terms, but has been the subject of research for a long time within nutrition and epidemiology. The exact scope is yet to be defined. Reductions in risk can be termed benefits, but also states rising above 'the average health' are explored as benefits. In nutrition, current interest is in 'optimal' intake; from a population perspective, but also from a more individualised perspective. In current approaches to combine benefit and risk assessment, benefit assessment mirrors the traditional risk assessment paradigm of hazard identification, hazard characterization, exposure assessment and risk characterization. Benefit-risk comparison can be qualitative and quantitative. In a quantitative comparison, benefits and risks are expressed in a common currency, for which the input may be deterministic or (increasingly more) probabilistic. A tiered approach is advocated, as this allows for transparency, an early stop in the analysis and interim interaction with the decision-maker. A general problem in the disciplines underlying benefit-risk assessment is that good dose-response data, i.e. at relevant intake levels and suitable for the target population, are scarce. It is concluded that, provided it is clearly explained, benefit-risk assessment is a valuable approach to systematically show current knowledge and its gaps and to transparently provide the best possible science-based answer to complicated questions with a large potential impact on public health.