Feinberg, Termeh and Kim Innes. University of Maryland.

(Presented at The Future of Ginseng and Forest Botanicals Symposium, July 12-14, 2017, Morgantown, WV)

Introduction

Botanicals (herbs) are grown, harvested, and used by many cultures worldwide for a variety of purposes, including the promotion of health or mitigation of disease. Although crude herbs are harvested within the U.S., consumer use of herbal preparations is largely relegated to dietary supplement status by the Federal Drug Administration. Population-based, epidemiological studies focusing on Nonvitamin, Nonmineral (NVNM) dietary supplement use have been conducted in nationally-representative populations in the U.S., and indicate approximately 17.9% of those in the U.S. consumed a NVNM in 2012 [1].  Limited studies have explored the patterns and correlates of supplement use on specific populations [2-4], while even fewer studies have been conducted to determine the characteristics of populations using specific botanicals [5, 6]. The Appalachian region of the U.S. is a woodland, ecological habitat responsible for a significant portion of U.S. botanical exports. Three woodland botanicals consistently harvested within the Appalachian region are Ginseng, Goldenseal, and Black Cohosh. In addition, Ginkgo grows across the U.S. The goal of this exploratory study was to determine the characteristics of Ginseng, Goldenseal, and Black Cohosh dietary supplement consumers across the U.S. in 2007 and 2012.

Methods

Data Sources and Study Population

Participants for this study were drawn from two nationally-representative samples of 23,501 and 34,525 U.S. adults (National Health Interview Surveys (NHIS), 2007 and 2012, respectively). The NHIS is an annual national, cross-sectional household survey of the non-institutionalized U.S. population and is administered by the Centers for Disease Control and Prevention’s National Center for Health Statistics. Survey details are described elsewhere [7, 8].

Primary outcome variables for this study were reported 30-day use of Ginkgo, Ginseng, Goldenseal, or Black Cohosh products labelled ‘dietary supplements’ and in the form of pills, capsules, tablets or liquids (including tinctures) (Yes/No for each botanical).

Exposure variables included demographics, lifestyle characteristics, health conditions, and medical care-related factors. Demographic factors included age, sex, race/ethnicity, education, employment, income, marital status, geographic region, and place of birth. Lifestyle factors included smoking status, alcohol use, exercise, BMI, and use of Complementary health approaches (CHA) other than NVNMs and prayer, other Natural Products (vitamins, chelation, probiotics, omegas) in the past year. Health conditions included self-reported history of physician-diagnosed diabetes, gastrointestinal disorders (inflammatory bowel disease, irritable bowel, severe constipation, ulcers), respiratory conditions (bronchitis (past year), emphysema, asthma), dyslipidemia, cardiovascular disease (coronary heart disease, angina, and/or heart attack), hypertension, migraine (past 3 months), mental health condition (depression, phobias, anxiety (past year), bipolar disorder), insomnia (past year), cancer, autoimmune condition (rheumatoid arthritis, lupus), and chronic pain condition (migraine or joint pain (previous 3 months), any arthritis). We also assessed number of health conditions (categorized as 0, 1, 2, and 3+ conditions). Medical care-related factors included self-reported health status, insurance status (overall, Medicaid, Medicare, private insurance), annual family out-of-pocket medical costs, and delayed access to care because “could not afford” or “worried about cost” (past year).

We conducted complete-case analyses using SAS 9.4 (Cary, NC, USA) and used sampling weights to account for complex survey procedures. We merged publicly-available NHIS files for each year and measured sample characteristics, including frequencies/prevalence rates of (each) botanical use for 2007 and 2012, respectively; we extrapolated estimates to generate U.S. population estimates using NHIS sampling weights. We considered trends between time points significant if there was no overlap in weighted percentage confidence intervals. In separate models, weighted logistic regressions were used to evaluate the independent associations of Ginkgo, Ginseng, Goldenseal, or Black Cohosh dietary supplement use to demographics, lifestyle factors, health conditions, and medical care-related factors using Rao-Scott Chi-square tests. Multivariate models adjusted for age and geographic region where sample sizes allowed (Ginkgo and Ginseng analyses).

Results

Prevalence and trends in the United States

The consumption of both Ginkgo and Ginseng declined significantly from 2007 to 2012. Ginkgo was consumed by an estimated 1,382,659 adults in 2007 (1.4%, (confidence interval (CI) 1.2, 1.6) vs. 828,340 adults in 2012 (0.8%, CI 0.7, 0.9). Ginseng was used by an estimated 1,559,834 adults in 2007 (1.6%, CI 1.4, 1.8) vs. 857,482 adults in 2012 (0.8%, CI 0.7, 0.9). While small sample sizes precluded statistical comparison, use of Goldenseal and Black Cohosh also appeared to decline from 2007 to 2012.  Goldenseal was consumed by approximately 422,476 adults in 2007 (0.43%) vs. only 13,080 adults in 2012 (0.01%). Black Cohosh was used by an estimated 402,003 adults in 2007 (0.41%) vs. 38,757 adults (0.04%) in 2012.

Of participants who reported consuming a botanical, 65% (Ginseng, 2012) to 87% (Black Cohosh, 2007) were white. Across all botanicals, 4% (Black Cohosh, 2007) to 15% (Ginseng, 2012) were consumed by black participants. Twenty-seven (Black Cohosh, 2007) to 34% (Goldenseal, 2007) of consumers resided in the Western U.S. and 27% (Black Cohosh, 2007) to 35% (Ginseng, 2007) resided in the South, with only 9% (Ginseng, 2007) to 30% (Goldenseal, 2012) located in the Northeast. Middle-aged consumers (45-64 years) represented 43% (2007) to 46% (2012) of Ginkgo users, 35% (2007) to 44% (2012) of Ginseng users, 82% (2007) to 93% (2012) of Black Cohosh users, and 48% (2012) to 89% (2007) of Goldenseal users. In contrast, 13% (Black Cohosh) to 42% (Goldenseal) of consumers were aged 25-44 years. Ginseng users were predominantly male (55-57%; 2007 and 2012, respectively), while Ginkgo (51-54%), Goldenseal (59%), and Black Cohosh (92%) users were largely female.

Over 70% of all botanical consumers in both years were non-obese (BMI<30); 71% (Ginseng, 2007) to 80% (Goldenseal, 2007) reported at least some college education. Overall, 42% (Ginkgo, 2007) to 50% (Black Cohosh, 2007) of consumers were married/cohabitating, with 37% (Ginkgo, 2007) to 48% (Black Cohosh, 2007) indicating an annual income of under $45,000. The percentage of consumers reporting annual household out-of-pocket medical cost(s) under $2000 ranged from 64% (Ginkgo, 2007) to 71% (Black Cohosh, 2007).  Approximately 90% of all botanical consumers reported positive health status (range: 88% (Black Cohosh) to 90% (all others)).

Between 46% (Ginseng, 2007) and 68% (Black Cohosh, 2007) of participants consuming botanicals reported at least one chronic pain condition, with 38% (Black Cohosh, 2007) to 45% (Goldenseal, 2007) indicating recent low back pain, 34% (Ginkgo, 2007) to 53% (Goldenseal, 2012) indicating recent joint pain, and 18% (Goldenseal, 2007) to 29% (Ginkgo, 2012) reporting arthritis. Twenty-five (Black Cohosh, 2007) to 29% (Ginseng, 2012) reported recent neck pain, 14% (Black Cohosh, 2012) to 28% (Black Cohosh, 2007) had recent migraine, and 8% (Goldenseal, 2012) to 25% (Black Cohosh, 2012) had headache in the past year. Further, 6% (Ginseng, 2007) to 15% (Black Cohosh, 2012) had ever received a cancer diagnosis, 13% (Goldenseal, 2007) to 32% (Ginkgo/Black Cohosh, 2012) had a respiratory condition, and 26% (Goldenseal, 2012) to 38% (Ginseng, 2012) reported mental illness. Those undergoing menopause within the previous year represented 5% (Ginseng, 2007) to 66% (Black Cohosh, 2012) of participants using a botanical.

While there were no significant differences in Ginkgo or Goldenseal use by sex, males were 1.4 (2007) to 1.6 (2012) times more likely to use Ginseng than were females. In contrast, males were 90% less likely to use Black Cohosh compared to women (Table 1). Those separated or formerly married were 2 times as likely to use Gingko, or nearly 3 times as likely to use Black Cohosh, compared to those who were single. Those born in the U.S. were 60% (Ginseng) to over 300% (Goldenseal) more likely to use botanicals compared to those not born in the U.S.

Table 1. Association of Woodland Herb and Ginkgo use to demographic, lifestyle, and health-related factors. National Health Interview Surveys 2007 and 2012, United States

Those with an annual income of $45,000-$74,999 were 1.6-2 times as likely to use Ginseng or Goldenseal in 2007 as those with an income of <$25,000, while those with an annual income of <$25,000 were nearly 2 times as likely to use Ginseng in 2012 (Table 1).  Additionally, those unemployed were less likely to use any botanical, with the exception of Ginseng in 2012 or Black Cohosh (2007), for which there were no differences by employment status.

Lifestyle and Medical-related Characteristics of Botanical Users in the United States

Relative to never smokers, former smokers had 60-90% higher odds of using Ginkgo and Ginseng (2007); current smoking was also positively associated with Ginseng use, but was unrelated to consumption of other botanicals (Table 1). Those exercising over 10 minutes per week were 1.9-2.4 times more likely to consume Ginkgo, Ginseng, Black Cohosh, or Goldenseal compared to those who engaged in no weekly exercise in 2007. Likewise, those exercising in 2012 were 2 times as likely to use Ginkgo or Ginseng. In both 2007 and 2012, those consuming moderate to heavy amounts of alcohol had 2.3 to 2.6 fold higher likelihood of using Gingko, Ginseng, or Goldenseal compared to alcohol abstainers.

There were no differences in overall insurance status for Ginkgo, Ginseng, and Goldenseal (p range >0.08). However, there was a borderline-significant decrease in Black Cohosh use among those uninsured compared to participants who were insured (Table 1). Those spending over $2000 per year were over 9 times as likely as those with no out-of-pocket costs to use Black Cohosh, and those delaying medical care due to cost were 3 times as likely to use Black Cohosh. Comparatively, those delaying medical care due to cost were 2.1-2.4 times as likely to use Ginkgo, Ginseng, or Goldenseal and were only about 2 times as likely to spend over $2000 per year on out-of-pocket medical costs (Ginkgo 2012, Ginseng 2007). Participants who had ever used any other Complementary Health Approaches (CHAs) besides herbs and prayer were over 8 times as likely to use Black Cohosh, 10-11 times as likely to use Ginseng, 18-36 times as likely to use Ginkgo, and over 30 times more likely to use Goldenseal compared to those not using these approaches; estimates remained unchanged after additional adjustment for variations in use by region.

Reproductive History, Obesity, and Health Status

After controlling for geographical region and age, chronic pain was significantly and positively associated with use of all botanicals. As illustrated in Table 1, this association was most pronounced with consumption of Black Cohosh; participants who reported a chronic pain condition were more than 3 times as likely to use this herb relative to those without chronic pain.  Participants who reported recent migraine were approximately 1.5-3 times more likely to use Ginkgo (2012), Ginseng (2007, 2012), and Black Cohosh (2007).  Likewise, those indicating headache in the past year were also more likely to use Ginseng and Black Cohosh (ORs 1.5-1.8).

As indicated in Table 1, participants who reported insomnia in the past year were more likely to indicate using Ginkgo (AOR’s 1.4-2.2), Ginseng (AOR’s 1.8-2.0), Black Cohosh (OR 1.9), and Goldenseal (OR 1.9).  Similarly, those indicating a history of mental illness were 1.4 to 2.2 times as likely to use Ginseng (AOR’s 1.8-1.9), Ginkgo (AOR’s 1.4-1.9), Black Cohosh (OR 2.2) and Goldenseal (OR 2.0).

After adjusting for age and region, participants who reported three or more health conditions were nearly twice as likely to use Ginseng (2012), and 3 times as likely to use Black Cohosh (2007; no additional adjustment) related to those with no medical conditions (Table 1).  Among female participants, those experiencing menopause in the previous year were 1.7-2.2 times as likely to use Ginkgo (AOR’s 1.7-2.2), Ginseng (2012 AOR 2.0), and Goldenseal (2007 OR 3.0). Alternately, those experiencing menopause in the previous year were nearly 12 times as likely to use Black Cohosh (2007), compared to those not experiencing relatively recent menopause.

Discussion

In our study, a number of demographic, lifestyle, and health-related factors were associated with the use of Ginkgo, Ginseng, Goldenseal, and Black Cohosh. The average botanical consumer in our samples largely mirrored factors associated with the use of (overall) natural product consumption in the U.S., particularly higher supplement use among white, middle-aged consumers with higher levels of education. All botanicals were used more often by those with chronic pain, insomnia, or mental health conditions. Further, those using Black Cohosh had higher out-of-pocket medical costs, and presence of chronic pain, headache, migraine, and mental health conditions compared to Ginkgo, Ginseng, and Goldenseal. Yet, those using Black Cohosh were more likely to report no health conditions, comparatively, but had much higher rates of menopause. Ginkgo was not associated with the presence of headache, and was only positively associated with recent migraine in 2012.

It is possible that all botanicals measured in this study reflected only a piece of the potentially health-protective behaviors utilized by participants for general health, as all botanical users had an increased, positive association with weekly exercise and former smoking. Alternately, the use of these botanicals may reflect a behavior associated with riskier health behaviors, as current smokers also maintained positive (but decreased) rates of botanical use, as did those consuming moderate to heavy amounts of alcohol. Thus, botanical use in the context of factors associated with coping mechanisms in the presence of health conditions should be further explored.

The major strength of this study is its use of large datasets to explore patterns and correlates of botanicals previously unexamined in epidemiological studies. There were, however, some limitations. First, there was no geographic harvest origin data available for dietary supplements in the dataset; thus, we analyzed data with the assumption that at least some of it derived from the U.S. In addition, there were no Latin names available in the NHIS dataset. Our reliance on common names may have increased the chances of outcome misclassification. Despite our use of the largest US dataset containing information on a variety of NVNMs, our sample sizes were quite small for outcomes Goldenseal and Black Cohosh, demonstrated by wide confidence intervals. Replication of these analyses in larger sample sizes also including the use of crude herbs for health purposes are needed to confirm characteristics of specific botanical use and to lay the foundation for efficacy studies related to the use of woodland and other botanicals for specific conditions.

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