Need For Better Research Grows With Supplements' Popularity – NCCIH

Continued research on non-vitamin and -mineral products' safety is necessary, says National Center for Complementary and Integrative Health Director Josephine Briggs, and improved studies on their effects on users' health are a scientific priority in the center's strategic plan.

US consumer spending on dietary supplements, as shown in the latest National Health Interview Survey's figures for botanicals and herbals, points to continued research on the products' safety, says National Center for Complementary and Integrative Health Director Josephine Briggs.

Improving research on the effects natural products, defined as non-vitamin and -mineral products, have on users' health also is in the National Institutes of Health center's crosshairs. The top scientific priorities stated in NCCIH's latest five-year strategic plan include "Innovative Approaches for Establishing Biological Signatures of Natural Products."

NCCIH on June 22 published findings from an analysis it and the Centers for Disease Control and Prevention conducted on data on complementary health approaches from the 2012 NHIS. CDC's National Center for Health Statistics conducts the survey conducted annually with between 35,000 and 40,000 adult consumers, gathering data on 75,000 to 100,000 individuals' practices; questions on complementary health approaches have been included every five years since 2002.

Consumers in 2012 spent $12.8bn out-of-pocket on natural product supplements, about one-quarter of their out-of-pocket spending on prescription drugs, $54.1bn, according to NCCIH. The mean annual out-of-pocket expenditure for natural product supplements was around $368.

Additionally, total spending on purchases related to self-care approaches, which include homeopathic products as well as self-help materials, such as books related to complementary health topics, was $2.7bn and the mean annual expenditure was $257.

Briggs said consumers' spending and their use of complementary health approaches makes it "extremely important for us to provide the public with evidence-based information to help inform decisions.”

“This underscores the importance of conducting rigorous research to know whether the products and practices being used are safe and effective,” Briggs said in NCCIH's release.

Richard Nahin, NCCIH’s lead epidemiologist and lead author of the analysis, pointed out results from the 2007 NHIS study's questions on consumer spending on complementary health approaches were not directly comparable due to differences in survey design (Also see "CAM Survey May Boost Supplements Research" - Pink Sheet, 3 Aug, 2009.).

“However, globally, in both years, substantial numbers of Americans spent billions of dollars out-of-pocket on these approaches, an indication that users believe enough in the value of these approaches to pay for them,” Nahin said.

As in 2007, the 2012 NHIS showed that herbal and botanical supplements were the most frequently used complementary health approach among US adults and children: almost 18% of adults and about 5% of children used the products in 2012.

While the percentage of consumers using the supplements changed little between 2007 and 2012, the use of certain products increased or decreased dramatically, particularly for adults' use of melatonin, which more than doubled (see charts below).

Overall, during the 12 months prior to the survey consumers spent $30.2bn out-of-pocket on complementary health approaches, $28.3 billion for adults and $1.9 billion for children. The spending accounts for 1.1% of the $2.82tn in total health care expenditures in the US and 9.2% of the $328.8bn out-of-pocket health care spending.

The percentage of consumers using herbals and botanicals changed little from 2007 through 2012, but use of some products increased or decreased dramatically.

2012 National Health Interview Survey

Complexities In The Mix

NCCIH also noted the data show natural products users were twice as likely to identify wellness rather than treatment as reason for using the products, but fewer than 25% of them also said they reduced stress, slept better or felt emotionally better as a result.

The center also notes complexities in studying the efficacy of the products, a point that the supplement industry long has argued in defense of allowing broader health claims for some ingredients (Also see "FDA Health Claims Draft Guidance Should Value Totality Of Evidence – CRN" - Pink Sheet, 3 Sep, 2007.).

The NCCIH's 2016 five-year strategic plan explains that partly because of the variables that complicate establishing links between natural product ingredients and certain biological responses, the research is among its priorities.

"Natural products, whether as herbal supplements or as part of a diet, are frequently consumed as a complex mixture. This complexity is further amplified by potential interactions with endogenous metabolic pathways, including those associated with the microbiome. The result is a collection of natural products and their metabolites that, individually and/or collectively, are associated with a network of biological activity," according to the plan published June 3.

NCCIH said in addition to direct action on biological targets, natural products' activity can be influenced by a person's health and metagenomic background. The center will support research to advance the characterization and categorization of the biologic activity of complex natural products broadly, with an emphasis on determining metabolomic profiles.

In addition to being a strategic plan priority at the center, natural products research is a component of its ongoing mission, particularly to "catalyze advances in natural products methodology," according to the plan.

"Natural products have a long and impressive history as sources of medicine and as important resources for biological research. However, many techniques for studying complex mixtures of natural products have remained unchanged for many years and have yet to leverage advances in biological and chemical methodologies."

To move the research forward, NCCIH says it is renewing emphasis on overcoming methodological and technological hurdles. As an example, the center notes “omics-based” technologies, such as genomics, or other high-throughput procedures in which a large number of measurements can be taken in a fairly short time period that could help researchers evaluate the validity of hypothesized additive or synergistic effects at the core of some traditional herbal medicines.

Additionally, using network pharmacology – the study of the web of biologic targets for any bioactive substance – will enable researchers to investigate the complex effects of natural products on multiple targets in ways that were never before possible.

NCCIH and NIH's Office of Dietary Supplements in September announced grants to five research centers to study the safety of natural products, how the products work within the body and the development of “cutting edge” research technologies. Botanical substances proposed for the studies include black cohosh, bitter melon, chasteberry, fenugreek, grape seed extract, hops, maca, milk thistle, resveratrol, licorice and valerian (Also see "Industry Roundup: Prison For Raw Deal Owner, NIH Funds Botanical Research" - Pink Sheet, 10 Sep, 2015.).

2012 National Health Interview Survey