As 69% of adults between the ages of 40 and 79 are prescribed at least one medication, and 22.4% use at least five prescription medications, scientific and regulatory experts from the U.S. and Canada argue that a fundamental change is needed to include more participants in clinical trials.
“The current constraints and limitations are frustrating in identifying ‘healthy populations’ when concepts and definitions of the term have changed over the years, and it is no longer possible to choose the best population for a study, resulting in data that [cannot be generalized] to the national population,” Dr Malkanthi Evans, an author on the study, told NutraIngredients-USA. “Consumers’ expectations have changed due to longer lifespans. Therefore, there is an [onus on] researchers to challenge the use of outdated markers of health and more importantly the traditional classifications of disease.”
Regular access to medical care and lifestyle management can mean most chronic conditions such as hypertension, diabetes, hypercholesterolemia, arthritis and osteoporosis, as examples, may be managed well. This allows most individuals to consider themselves in good health, and even without symptoms. Instead of pursuing ‘absence’ of disease, a more innovative definition of health is required as the definition of ‘healthy’, the paper noted.
The researchers argue that ‘physiologically stable’ or ‘apparently healthy’ are better terms to replace the ‘healthy’ descriptor in order to better represent the population. Supplements are sold and taken by the general population, and the clinical trials scientists conduct need to represent the markets in which they are sold, they added.
“Nutrients/supplements are major players in the big picture of health optimization, and well-designed science to support structure-function claims is pertinent,” said Dr Evans.
Broadening disease definitions
Over the last few decades, the number of people with chronic disease in the United States has increased, as scientists and physicians have broadened disease definitions, the researchers noted. Now, 75% of the adult population is classified as having a chronic illness.
For example, the diagnostic thresholds for hypertension have expanded after the redefinition of systolic and diastolic blood pressure levels, making the prevalence of cardiovascular disease risk now higher among adults with previously low risk.
When it comes to obesity, there are also challenges for researchers. The authors on the perspective take issue with body mass index as an eligibility criterion for structure-function claims, which has its challenges.
“Under these conditions, evaluating weight loss supplements only in those who are normal or overweight and not on medication excludes participants with obesity who may best benefit from such interventions, highlighting some of the contraindications in the use of BMI as an eligibility criterion in S/F claims evidence,” they noted.
A better definition might include ‘metabolically healthy obese’ consisting of individuals who are obese based on their BMI classification but who are not at an increased risk for cardiovascular disease, the researchers wrote.
Pushing the FDA forward
Despite long-standing demands—from both inside and outside the dietary supplement industry—to revise and update the Dietary Supplement Health and Education Act (DSHEA) of 1994, an interim change to the FDA definition of ‘healthy’ could substantially advance clinical research approaches and study designs.
“While we are still waiting for implementation of the broader FDA draft guidance for modernizing the design and conduct of clinical trials, our single suggestion would allow sooner new innovation in claims substantiation,” said Jeff Blumberg, Research Professor in the Friedman School of Nutrition Science and Policy and Professor Emeritus in the School of Graduate Biomedical Sciences at Tufts University, and co-author on the new perspective. “There is a broad recognition that the current FDA regulatory framework regarding ‘healthy’ is outdated, inconsistent with proposed definitions by others, fails to support innovative research and ultimately ill-serves public health.”
Updating FDA’s current definition of healthy would make a significant difference for advancing nutrition science, innovative research approaches and claims substantiation, he added.
The binary concept of health—that one is either in ‘good’ or ‘poor’ health—doesn’t fit into contemporary biomedical science which now shows the relationship between illness, disease, health and wellness are part of a continuum, Prof. Blumberg said.
Source: Journal of Dietary Supplements
Published online ahead of print, doi: 10.1080/19390211.2023.2301383
“Revisiting the Definition of ‘Healthy’ Participants in Substantiation of Structure/Function Claims for Dietary Supplements"
Authors: M. Evans et al.
