| Literature DB >> 26983608 |
J R Lupton1, J B Blumberg2, M L'Abbe3, M LeDoux4, H B Rice5, C von Schacky6, A Yaktine7, J C Griffiths8.
Abstract
Nutrition is complex-and seemingly getting more complicated. Most consumers are familiar with "essential nutrients," e.g., vitamins and minerals, and more recently protein and important amino acids. These essential nutrients have nutrient reference values, referred to as dietary reference intakes (DRIs) developed by consensus committees of scientific experts convened by the Institute of Medicine of the National Academy of Sciences, Engineering, and Medicine and carried out by the Food and Nutrition Board. The DRIs comprise a set of four nutrient-based reverence values, the estimated average requirements, the recommended dietary allowances (RDAs), the adequate intakes and the tolerable upper intake levels for micronutrient intakes and an acceptable macronutrient distribution range for macronutrient intakes. From the RDA, the US Food and Drug Administration (FDA) derives a labeling value called the daily value (DV), which appears on the nutrition label of all foods for sale in the US. The DRI reports do not make recommendations about whether the DV labeling values can be set only for what have been defined to date as "essential nutrients." For example, the FDA set a labeling value for "dietary fiber" without having the DV. Nutrient reference values-requirements are set by Codex Alimentarius for essential nutrients, and regulatory bodies in many countries use these Codex values in setting national policy for recommended dietary intakes. However, the focus of this conference is not on essential nutrients, but on the "nonessential nutrients," also termed dietary bioactive components. They can be defined as "Constituents in foods or dietary supplements, other than those needed to meet basic human nutritional needs, which are responsible for changes in health status (Office of Disease Prevention and Health Promotion, Office of Public Health and Science, Department of Health and Human Services in Fed Regist 69:55821-55822, 2004)." Substantial and often persuasive scientific evidence does exist to confirm a relationship between the intake of a specific bioactive constituent and enhanced health conditions or reduced risk of a chronic disease. Further, research on the putative mechanisms of action of various classes of bioactives is supported by national and pan-national government agencies, and academic institutions, as well as functional food and dietary supplement manufacturers. Consumers are becoming educated and are seeking to purchase products containing bioactives, yet there is no evaluative process in place to let the public know how strong the science is behind the benefits or the quantitative amounts needed to achieve these beneficial health effects or to avoid exceeding the upper level (UL). When one lacks an essential nutrient, overt deficiency with concomitant physiological determents and eventually death are expected. The absence of bioactive substances from the diet results in suboptimal health, e.g., poor cellular and/or physiological function, which is relative and not absolute. Regrettably at this time, there is no DRI process to evaluate bioactives, although a recent workshop convened by the National Institutes of Health (Options for Consideration of Chronic Disease Endpoints for Dietary Reference Intakes (DRIs); March 10-11, 2015; http://health.gov/dietaryguidelines/dri/ ) did explore the process to develop DVs for nutrients, the lack of which result in increased risk of chronic disease (non-communicable disease) endpoints. A final report is expected soon. This conference (CRN-International Scientific Symposium; "Nutrient Reference Value-Non-Communicable Disease (NRV-NCD) Endpoints," 20 November in Kronberg, Germany; http://www.crn-i.ch/2015symposium/ ) explores concepts related to the Codex NRV process, the public health opportunities in setting NRVs for bioactive constituents, and further research and details on the specific class of bioactives, n-3 long-chain polyunsaturated fatty acids (also termed omega-3 fatty acids) and their constituents, specifically docosahexaenoic acid and eicosapentaenoic acid.Entities:
Keywords: Adequate intake; Bioactives; Docosahexaenoic acid (DHA); Eicosapentaenoic acid (EPA); Nutrient reference values; Omega-3 fatty acids; n-3 long-chain polyunsaturated fatty acids; nonessential nutrients
Mesh:
Substances:
Year: 2016 PMID: 26983608 PMCID: PMC4819601 DOI: 10.1007/s00394-016-1195-z
Source DB: PubMed Journal: Eur J Nutr ISSN: 1436-6207 Impact factor: 5.614
Why it is important to have a DRI-like process for the evaluation of bioactives [39]
| Importance | Example | Benefit for having a DRI-like value |
|---|---|---|
| Bioactives are important to human health | For example, there is strong science behind the relationship between flavanols and decreased risk of cardiovascular disease [ | A major benefit would be that they would be recognized as being important to health and evaluated accordingly. Investigators, regulatory agencies, consumers would all know how strong the science was behind science messaging on these compounds |
| Bioactives are a significant portion of diet and disease research portfolios | Governments, universities, and food manufacturers are supporting studies on bioactives | Standards would be set so that studies could be compared across laboratories |
| Consumers are interested in optimal health and are purposefully purchasing foods containing bioactives | This was part of the rationale for setting DRI values for bioactives in China | Consumers would benefit from strengthened knowledge that they were making decisions based on science and they would also have a target to aim for in terms of intake |
| Having a DRI value elevates the status of a bioactive and makes it part of nutrition public policy | Substances that have DRI values are regularly evaluated in populations to see whether that population is meeting established DRI values | If the bioactive is part of the intake assessment of nutrients/foods, then we will learn whether or not that population is actually meeting the DRI value, or if it is an “at risk” nutrient |
| The process by which a bioactive is evaluated would set standards which would raise the level of science | Such requirements as having a formal definition, and an approved method of analysis would help comparing studies across laboratories | Using common methods of analysis and a common definition would allow studies to build on each other and advance the science more rapidly |
| With a transparent process for evaluation the results would provide science-based recommendations for improving diets | Health professionals such as doctors, dietitians, and educators would be more comfortable making diet recommendations | Messaging on intake of bioactives would be science-based |
| Having an intake value would set a goal for incorporating bioactives into diets | Consumers would know whether a food was a good source of that bioactive, or how much one would need to eat in order to reach the intake value | Having a target intake value would discourage messaging on products that suggest they are a good source of a specific bioactive when they only contain a negligible amount |
Proposed criteria for a bioactive to qualify for evaluation [39]
| Criterion | Additional information | Rationale for criterion |
|---|---|---|
| A definition of the substance which is commonly accepted | Definition should match the method of analysis | Makes it easier to build a database of efficacy of bioactive if substances with the same definition are compared |
| A method of analyzing the substance which is consistent with the definition | Preferably backed up by a multicenter analysis such as an AOAC method | Facilitates comparing studies across laboratories. Need a definition and an approved method of measuring so that intake values can be determined, and if populations are meeting recommended intake values |
| Database of the amount of the bioactive in foods | Preferably global and updated on a regular basis as new foods come on the market | To determine the amount of this bioactive currently in the food supply and enable determining how much people are consuming. Also necessary for baseline data for clinical trials and input into epidemiological studies |
| Prospective cohort studies | Both sexes, showing decreased risk of a disease such as CVD with increased intake of the bioactive. Must be able to isolate the specific bioactive vs other bioactives. Best if the bioactive is also measured in blood/urine, etc., in subset of population and supports food intake data. Relationship to the disease should be consistent with clinical trials | Dose response data or at least highest quintile vs lowest quintile for the bioactive will help to set level of efficacy |
| Clinical trials on digestion, absorption, activation, transport, excretion of the substance | Important to understand the level of absorption and what substances interfere with that absorption, also what the active molecule is and how long it stays in the blood | This information is useful for determining intake and factors that affect intake, transport, activation, etc. |
| Clinical trials on efficacy and dose response data | Conducted in healthy populations. Bioactive must be measured. Accepted endpoint linked to decreased risk of the particular disease. If surrogate marker, must be “accepted” by regulatory agencies | Need dose response data to determine the efficacious level, and determine intake values |
| Safety data at the level of intake that might be anticipated | Ideally would include safety data for special populations such as children, pregnant or lactating women | Need this information even if the bioactive is considered generally regarded as safe (GRAS). GRAS means “safe for intended use” |
| Systematic reviews and/or meta-analyses showing efficacy | In the US, the Institute of Medicine now requires systematic reviews for setting DRI values (most recent was calcium and vitamin D). The US Dietary Guidelines now requires these also | Having a systematic review that shows efficacy is a real plus and may be necessary, e.g., a Cochrane review. These reinforce the need to have major prospective epidemiological studies and randomized clinical trials |
| A plausible biological explanation for efficacy | This is not required but is a very large plus if it is available | Scientists/evaluators of the research are more comfortable if there is an explanation, particularly if that explanation is accepted by the scientific community |