Evidence for the nutrtional benefits of bioactives is steadily accumulating, and the time has come engage regulators in a process of determining dietary reference intakes (DRIs) for the best-researched substances, said Jim Griffiths, vice president of scientific and reglatory affairs for the Council for Responsible Nutrition.
Griffiths’ comments came in the wake of the release of a report from a meeting sponsored by CRN’s international arm. The report, titled Exploring the benefits and challenges of establishing a DRI-like process for bioactives , was published in the peer reviewed journal European Journal of Nutrition . The report, now available in eight languages, deals with three categories of bioactives: flavanols, lycopene and other tomato carotenoids and soybean isoflavones.
Bioactives are defined in US reglations 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.’’ As the evidence of the efficaciousness of various compounds in moving that health status needle accumulates, problems remain in obtaining any sort of official recognition of those effects.
One of the key issues is that while many of these compounds have been shown to have benefit, they cannot as yet be labeled as “essential,” despite what some promoters might claim. DRIs exist for vitamins, minerals, essential fatty acides and essential amino acids. In the case of vitamins and minerals, they exist for a specific purpose, to prevent the deficiency conditions that have been identified and studied through more than a century of nutritional research. The bioactives disussed in the paper have more complicated effects, unlike the well-recognized relationship of vitamin C and scury, for example. Therefore, a consumer whose diet is deficient in certain flavanols might be in a state of health that is below his or her optimum, but that situation doesn’t easily equate to the idea of a ‘deficiency disease.’
“Although every dietary supplement ingredient and putative bioactive may wish to be awarded a dietary reference intake (DRI), the road would be arduous and only those that have the scientific data to meet a high standard would gain entrance into such a process,” Griffiths told NutraIngredients-USA.
Benefits of official recognition
Having a DRI for these substances, and others that might be able to clear the accumulated evidence bar, would be manifold, the authors said. A DRI would make those compounds part of public nutrition policy, and could mean inclusion in large-scale publically-funded surveys such as the NHANES (National Health and Nutrition Examination Survey).
Dietary fiber is an example of a bioactive that does have a DRI. The recognition of this bioactive’s effects means that more public messaging is possible. “Dietary fiber is a non-essential nutrient, but extensive scientific information has allowed for an official DRI value to be adopted and called out on fact-based food labels throughout the world,” Griffiths said.
Rather than preventing deficiency states, bioactives’ point of entry into the DRI world lies in the idea of demonstrated effects in preventing chronic diseases. While not a literature review per se, the paper does discuss the connection of flavanols on decreased risk of cardiovascular disease and associated risk factors. It also looks at the connection of lycopene and other carotenoids in decreasing blood pressure in pre-hypertensive patients as well as reducign post-prandial blood-oxidized low-density lipoproteins. And the paper looks as isoflavones in association with a lower risk of several chronic disease including breast and prostate cancer and, in women, a lowered risk of coronary heart disease and osteopororsis.
Griffiths said a helpful notion might be to look at these substances in terms of their effects on helping users live longer, healthier lives.
“I like the term that the Chinese are using for these bioactives that like some other nutrients (vitamins & minerals) are considered essential for reaching the full (genetically-determined) lifespan. They are calling these bioactives ‘life span essential,’ ” Griffiths said.
“In contrast to classic nutrients, i.e., vitamins and minerals, these bioactives are not required for vital body functions in humans such as growth, reproduction, wound repair, and development. However, there is compelling clinical and epidemiological evidence that some bioactive-rich plant sources and/or isolated bioactive constituents significantly reduce the risk of chronic diseases. Bioactives that are beneficial, yet not critical, to human health, may play a role on where on the bell-shaped curve our individual morbidity and mortality might lie,” he said.
The paper lays out criteria that the bioactives would have to meet to meet regulators’ scrutiny. Many of the substances currently being promoted will not be able to meet those standards, Griffiths said.
“There are nine proposed criteria, and if met, would minimize the effort of the evaluator (scientific, independent, regulatory), and would also drive research to address the elements needed for that eventual evaluation. Those criteria range from specifications, to analytical methods, to presence in food, to clinical trials and safety. I don’t think anyone ever stated that all dietary supplements / supplement ingredients are the same when it comes to the completeness and persuasiveness of their respective safety and efficacy knowledge databases,” he said.
Source: European Journal of Nutrition
Published online, 25 Feb. 2014, doi 10.1007/s00394-014-0666-3
“ Exploring the benefits and challenges of establishing a DRI-like process for bioactives"
Authors: Joanne R. Lupton et al