Athletics and Herbal Supplements
Do current products enhance athletes' health and performance?
David S. Senchina
A
thletes' use of herbal supplements has skyrocketed in the
past two decades. At the top of the
list of popular herbs are echinacea
and ginseng, whereas garlic, St. John's
wort, soybean, ephedra and others
are also surging in popularity or have
been historically prevalent. According to a publication by the American
Botanical Council, herbal supplement
sales grossed $5.3 billion in the United
States during 2011, a 4.5 percent increase from the preceding year. Despite their increasing popularity, recent events have illuminated possible
concerns regarding efficacy and safety
of herbal supplements. Remarkable
sports performances at the end of the
20th century raised suspicions about
supplement use by athletes, prompting the formation of the World AntiDoping Agency, or WADA. Shortly
thereafter, the deaths of two professional athletes raised concerns that
an herbal supplement, ephedra, may
have contributed to their deaths. These
events and others have prompted clinicians and scientists to reevaluate the
role of herbal supplements in athletics.
The meaning of the term herbal supplement is itself nebulous. Some use it
to refer to products derived directly
from plants, whereas others use it to
mean any product containing molecules of botanical origin, such as caffeine pills. Herbal supplements are
David S. Senchina is an associate professor of
medical microbiology and kinesiology at Drake
University in Des Moines, Iowa. He holds two
B.A. degrees from the University of Northern Iowa
(biology and elementary education) and a Ph.D. in
immunobiology from the Kinesiology Department
(formerly Health and Human Performance) at
Ioiva State University. Address: Biology Department, Drake University, 2507 University Ave.,
Drake University, Des Moines, IA 50311. Email:
dssenchina@drake.edu
134
American Scientist, Volume 101
variously called botanicals, phytomedicines, dietary supplements, nutritional supplements or nutraceuticals. In
this article, the term herbal supplement
refers to plant-derived products containing multiple bioactive chemicals,
with some exceptions for products of
fungal or bacterial origin (which are
technically not "herbal" but are often
treated the same).
Although industry has kept pace
with athletes' interests and simultaneously spurred them, research has
lagged behind and many questions
linger. Why do athletes consume
these herbs? Do they use the product
as directed on the label or by a doctor? What claims are made about
these supplements, and does clinical
research support them? How can scientists and sports medicine personnel best design experiments to answer
these questions, and what obstacles do
they encounter?
studies, aerobic endurance exercise or
anaerobic strength training regimens.
But such studies frequently lack information about the chemical contents,
botanical origin or agricultural provenance of the supplements. In addidon,
medical pilot studies are often characterized by small sample sizes, and
a paltry number of studies typically
exist for a given herb. This complex interplay of factors makes results hard to
replicate or interpret and makes it difficult to identify confounding variables
among studies.
Even when every study for an herb
is stalwartly reviewed, one is typically
forced to conclude that the data are
equivocal—for every study that supports efficacy, another refutes it, even
after controlling for demographics,
dosing and so forth. The predictable
outcome is confusion and miscommunicafion within the sports science community.
Dovetailing botany, chemistry and
A Multidisciplinary Framework
medical disciplines from cell biology
Herbal supplement sales, the number to physiology is absolutely crifical to
of available herbs and the number of the advancement of research on herbal
preparation types have all grown in re- supplements in athletic contexts. In adcent years, and many of these are popu- dition to many others' work on this
lar among American athletes (see Figure subject, collaborators fiom Drake and
2). Despite this burgeoning industry, Iowa State Universities Nisarg Shah,
research on supplements' effects on Danielle Doty, Cole Sanderson, Justus
human biology remains inconclusive Hallam and I have developed novel
overall, and athletes are often left to experimental data on previously netrust manufacturers' claims or team- glected preclinical factors. The species of
mates' advice when it comes to makirig plant chosen, the location from which
choices about what supplements to take the plant was gathered, the specific orand whether to take them.
gan extracted or the extracfion method
Early studies of any herbal supple- may in large part explain the heterogement are almost exclusively of the neous clinical outcomes.
clinical variety. They strive to address
One of the biggest challenges such
quesfions of efficacy by testing supple- a multidisciplinary approach presents
ments available for over-the-counter is conceptualizing the myriad prepurchase. Studies often include de- clinical and clinical factors that can
tailed information on subjects' char- potentially influence a trial. In a 2009
acterisfics, dosing regimens, methods article in Exercise Immunology Review,
for assessing efficacy and, in athletic we proposed a conceptual model for
this multidisciplinary approach. We
originally categorized factors in our
model by botanical, chemical and
clinical disciplines. Our revised seedto-stomach model incorporates these
as well as commercial factors to better
reflect the societal context of herbal
supplement research (see Figure 3). The
model discourages the mistaken conclusion that equivocal is synonymous
with ineffectual, moving the field from
simplistic questions of "Does a given
supplement 'work'?" to "Under what
conditions does a given supplement
produce a given outcome?"
Why Athletes Use Herbs
Exercise is a physical stress. If the athlete's body can manage the stress, it
adapts by increasing muscle mass,
optimizing metabolism or improving
motor performance. If the athlete's
body cannot manage the stress, then
muscle soreness, malnutrition or declines in performance may manifest.
Thus exercise can serve as either a positive or negative Stressor.
For example, the J-curve model
proposed by David Nieman of Appalachian State University shows that
individuals who exercise regularly at
moderate intensities have lower incidence of upper respiratory infection
events than their sedentary or rigorously training counterparts (see Figure 4). Individ^uals who train moderately—for example, people who run
three times a week for 30 minutes—
demonstrate decreased incidence of
such infections compared to sedentary
coimterparts. On the other hand, elite
athletes often demonstrate increased
incidence of such infections due to
the stress of their demanding training
schedules. The category "very high"
in Figure 4 includes individuals such
as professional or Olympic athletes,
but from a medical standpoint it could
encompass any athletes who train at
levels beyond what their bodies can
accommodate. These athletes may include college and high school athletes
and even so-called (often erroneously)
amateur recreational athletes.
Herbal supplements appeal to the
sports community because of their potential for improving performance capacity either through conferring ergogenic benefits or through offsetting the
deleterious effects of rigorous training
regimens. Most herbal supplements,
such as ginseng and echinacea, are available over the counter, making them both
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Figure 1. Teammates may be the primary and most frequent source of information about
herbal supplements for "recreational" athletes, such as these city league baseball players, who
do not have access to support systems like professional athletes do. (Photographs courtesy of
the author, unless otherwise noted.)
legal and readily available; others, such
as ephedra or ma huang, are now illegal.
Whether a given supplement is illegal
varies by country and sports regulatory
agency; within the context of sports, illegality is often declared if a supplement
engenders an unfair ergogenic benefit
("doping") or constitutes a health threat.
Ephedra, for example, is banned because
it has no confirmed ergogenic benefits
yet contains toxic alkaloids.
Importantly but not surprisingly,
athletes' rationales for choosing and
using any given supplement are often
discordant with contemporary indications, as evidenced by surveys of U.K.
athletes performed by Andrea Petróczki at Kingston University, in collaboration with colleagues at the University
of Birmingham and Swansea Urüversity. Their work has shown that professional athletes may use supplements
2013 March-April
135
for reasons other than their purported
purpose; ignore advice from medical
professionals despite the fact that athletes consult those professionals for
advice more frequently than coaches
or trainers; misunderstand side effects or assume a supplement is safe
because it is "natural"; and sacrifice
health benefits for perceived performance benefits. Circumstances may be
different for nonprofessional, noncollegiate athletes. Many people assume
that the Food and Drug Administradon regulates herbal supplements, but
in the United States the Dietary Supplement Health and Education Act of
1994 allows most herbal supplements
to be sold without FDA approval.
Vendors position herbal supplements
on store shelves alongside regulated
items such as vitamins, which may
perpetuate this percepdon.
John s wort
ginseng
elderberry
10
15
20
25
30
sales of supplements (millions of dollars)
Figure 2. Sales of selected supplements popular among athletes, including soy (#2 in overall sales),
garlic (#4), echinacea (#7), St. John's wort (#9), ginseng (#10), elderberry (#18) and Siberian ginseng
(#36), are compared to cranberry (#1). (Data from M. Blumenthal et al., HerbalGram 95:60.)
Popular Herbs
The extent of athletes' herbal supplement use is unclear. Part of the problem
5.. consumer factors
4 . postproduction factors
a. storage
3. production factors
a. harvest
1. planning factors
Figure 3. The seed-to-stomach model identifies preclinical factors that may impact clinical trial outcomes. Each factor in an herbal supplement's production introduces mounting variation. Generally, these preclinical factors are not accounted for. Planning factors (1) occur prior to
planting (selection of species and seed supplier). Field factors (2) are introduced as the crop grows, such as ecological factors (hydration, soil,
sunlight exposure, pathogen infections and time grown). Production factors (3) include harvest factors (a), or how the plants were removed
and transported to the processing site, and manufacturing facility factors (b), or how the herb was processed and packaged, such as the plant
organs, solvents, procedures or bottling used. Postproduction factors (4) cover warehouse factors (a), market factors (b) and household factors
(c), because storage conditions such as temperature, oxidation and expiration often vary across these sites. Consumer factors (5) include demographics, supplement dosing, preexisting health status and psychological or societal contexts of those individuals enrolled in the study.
136 American Scientist, Volume 101
is that few studies address this topic.
Surveys of athletes' supplement use
exist, but herbal supplements are often
relegated to a category called "other."
And when supplements are idenñfied
as a separate category, the specific supplements used are often unreported. In
the United States alone, 17 to 61 percent of athletes reported usüig herbal
g.
supplements, although the categorization of herbal supplement varied
across surveys, and this likely explains
the huge discrepancy. Although these
numbers should be interpreted cautiously, it appears safe to conclude that
athletes' use of herbal supplements is
higher than in the general public.
very high
moderate
sedentary
Purportedly performance-enhancing herbs include those that benefit
total exercise workload
both endurance and strength athletes,
such as ginseng (Panax species or Eleii- Figure 4. Individuals who exercise regularly at moderate intensities have lower incidence
therococcus senticosus), ephedra (Ephedraof upper respiratory infections than sedentary or rigorously training counterparts. (Figure
sinica) and arctic root (Rhodiola rosea). adapted from D. C. Nieman, Journal of Athletic Training, 32:344.)
They also include herbs such as caltrop
(Tribulus terrestris) that may primarily as having more specialized functions, chemical compounds produced by
benefit strength athletes (see Figure 5). such as the supposed metabolism-en- living organisms but not required for
Ephedra and ginseng are also consid- hancing fungus, Cordyceps sinensis. Still their primary functions. Many herbs
ered central nervous system sümulaiits others are treated as multipurpose food used in sports supplements or energy
along with guaraná (Paullinia ciipana). ingredients, for example, the cyanobac- drinks contain alkaloids—small, nitrogen-based compoxinds that encompass
Herbs taken primarily to boost im- terium Spirulina (Spirulina species).
many notorious naturally derived molThe
organisms
mentioned
above
mune function include echinacea (Echinacea speciesj, elderberry (Sambucus demonstrate that these supplements ecules, from morphine to cocaine—that
nigra) and milk vetch (Astragalus spe- are taxonomically diverse and include act as stimulants. Examples include
cies). Other herbs, such as caltrop, soy ñowering, seedless vascular and non- caffeine from the kola plant (Cola spe(Glycine max) and sarsaparilla (Smilax vascular plants, fungi and algae with cies), ephedrine and pseudoephedrine
species), are believed to contain plant- distinct evolutionary liistories. The bio- from ephedra, guaranine from guaraproduced compotmds capable of mod- active moleciües attributed to each tax- ná, and theobromine and theophylline
ulating anabolic steroidal pathways. on are equally diverse, although most from the chocolate plant (Theobroma
And some supplements are promoted are classified as secondary metabolites. cacao).
Figure 5. Herbs popular with athletes include supplements from the above plants, clockwise from top left, arctic root (Rhodiola rosea), echinacea (Echinacea purpurea), caltrop (Tribulus terrestris), ginseng (Panax ginseng) and elderberry (Sambucus nigra). (Photographs courtesy of Wikimedia Conunons.
Top right photograph by Forest & Kim Starr [http://www.hear.0rg/starr/I.)
www.americanscientist.org
2013
March-April
137
or after a scheduled bout of exercise.
The reduced incidence of infections
was corroborated by molecular immunological data from blood, saliva
Immunoglobulins are
and urine samples, demonstrating inmolecules produced by white
creases in circulating concentrations of
blood cells. In mucus and
certain antibodies and changes in cirsaliva, they serve as the first
Cytokines are important
culating concentrations of several sigline of immune defense. One
signaling molecules in
type, immunoglobulin A,
naling molecules important in regulatthe immune system and
increased In saliva.
ing infiammafion (see Figure 6). White
are produced by white
blood cells are the cells associated with
blood cells. Some types
the immune system, but no changes
of cytokine increase;
others decrease.
in
white blood cell subsets or counts
Aerobic performance,
Because these molecules
were identified. Taken together, the
as
measured
by
have complex functions,
findings suggest that echinacea may
V02max and running
it Is difficult to conclude
economy,
increased.
reduce
incidence and severity of upper
whether such changes
are good or bad for
respiratory infections by changing the
athletic performance.
quantities of immune molecules produced by white blood cells, rather than
Two hormones
changing other aspects of white blood
Red blood cell
increased: cortisol,
function, as measured
related to stress and
cells, such as their rate of multiplicaby cell counts,
metabolism, and
tion or specific functions. In further
hematocrit and
erythropoetin, which
support of the link between echinacea,
hemoblobin, did not
controls red blood
exercise and upper respiratory infecchange.
cell production.
tions, Roland Schoop and colleagues
Figure 6. Immunological and physiological effects of Echinacea purpurea supplementation in aero- at Bioforce AG in Switzerland reportbic athletes, summarized from five studies, and based on illness rates and blood, saliva and urine ed reduced incidence and duration of
analyses. Athletes supplemented with echinacea reported reduced incidence or duraHon of upper self-reported upper-respiratory-infecrespiratory infections, perhaps because of changes in circulating concentrations of immune system tion symptoms in athletes dosed in a
signaling molecules (cytokines) and antibodies. However, more studies are needed to understand similar manner to those in the previthe full gamut of possible outcomes. Pictured: Erin Poss, Drake University cross-country.
ous two studies, when compared to a
control group generalized from control
Current research on the dozens of It is important to differentiate these data in previous studies.
botanical dietary supplements used by molecules because the body processes
Looking at physiological paramathletes all suffer from the problems them differently and they have differ- eters important in athletic perforoutlined above. Two of the most well ent effects. Alkamides move from gut mance, Malcolm Whitehead, now at
known of these supplements, echina- to bloodstream apparently unmodified Stephen F. Austin State University in
cea and ginseng, will serve as repre- within an hour. Complex carbohydrates Texas, published two reports with colsentative examples.
have largely been discounted by mul- leagues from Troy University, College
tiple studies due to their inability to of Charleston and the University of
Echinacea
move fiom gut to bloodstiream without Southern Mississippi on a recreational
Echinacea is purported to boost de- modification. Roots contain the highest group of athletes, dosed with £. purfense against upper respiratory ir\fec- levels of these compounds, but often- purea for four weeks and compared to
tions, so athletes use it primarily to times manufacturers will instead har- placebo-treated controls. They found
offset the deleterious effects of intense vest aboveground parts, such as leaves that common measures of aerobic pertraining on immunity. Although the and stems, to allow the plants to regrow formance—maximal oxygen consumpgeneral public uses the genus name and thus provide multiple harvests per tion (VO2max), running economy (oxas the common name, genus Echinacea planting. In North America, echinacea
ygen use efficiency) and erythropoietin
is comprised of nine species (some di- is most widely consumed as capsules
(a hormone that controls red blood
vided into subspecies). The three spe- or tablets.
cell genesis)—were higher among the
cies most often used commercially are
Only five studies have been pub- echinacea-treated group than among
Echinacea angustifolia, E. pallida and E. lished concerning in vivo dosing of athcontrols. However, the authors reportpurpurea.
letes with echinacea supplements (Fig- ed no differences in total red blood
Bioactive molecules produced by ure 6). Studies by Aloys Berg of Albert cell count, hemoglobin (the molecule
these species include alkamides, or- Ludwigs University and collaborators within red blood cells that carries oxyganic molecules made of fatty acids and Heather Hall of Elmhurst College gen) or hematocrit (packed red blood
often found in plants, and phenols, an- and collaborators reported reduced cell volume) between the two groups.
other class of organic molecules also incidence or duration of upper respi- The fact that there were no changes in
dubbed carbolic acids that are known ratory infection events after intense red blood cell-associated parameters
for their acidity. Phenols encompass exercise (such as competitive sprint but there were changes in performance
caffeic acid derivatives, echinacoside triathlons or laboratory sprint cycling) parameters is difficult to interpret but
and ketones; distributions and quanti- in athletes dosed with E. purpurea sup- may suggest that echinacea suppleties of these molecules vary by species. plements for four weeks either before mentation influences performance by
White blood cells
are involved in fighting
disease; counts of
these immune system
cells did not change
across studies.
138 American Scientist, Volume 101
changes observed in aerobic athletes
supplemented with echinacea
1. plants are grown in common gardens
where field conditions are controlled
6. white blood cells are isolated
and stimulated in vitro
2 . extracts are produced and stored
\ under controlled conditions,
with a portion being subjected to
phytochemical analysis
5. a postexercise
blood sample is
obtained
3. a pre-exercise
• blood sample is
obtained
4 . the athlete
_-{II|l.performs an acute
exercise bout
Figure 7. Putting the seed-to-stomach model into action reduces variation introduced by preclinical factors. (1) Plants are grown in common gai^
dens, where field conditions are controlled. (2) Extracts are produced and stored under controlled conditions and analyzed for bioactive chemicals.
These first two steps account for many preclinical factors that are ignored in many studies. (3) A pre-exercise blood sample is obtained. (4) The
athlete performs an acute exercise bout. Using metabolic monitoring, intensity is standardized. (5) A postexercise blood sample is obtained. (6)
White blood cells are isolated and treated in vitro with the plant extracts from steps 1 and 2. Measurements such as cell proliferation rates or signaling molecule production are used as markers of immune function.
modulating oxygen dynamics or metabolism at body sites distinct from
the red blood cells themselves. Other
scientific teams report relatively good
tolerability and low side effects from
echinacea supplements, although interactions with certain prescription
medications have been documented.
In contrast to studies in athletes, studies of echinacea supplementation in the
general population have yielded conflicting findings, likely due to the confounding factors discussed previously.
Our team has endeavored to reduce
the problem of preclinical factor variation by translating the concepts from
our seed-to-stomach model into an experimental design adapted for athletic
applications (Figure 7). We opted for an
ex vivo approach, where white blood
cells were taken from study participants
before and after an acute exercise bout
and then treated with echinacea extracts
in the laboratory. This method, although
less representative of the organismal
context, allows us to more tightly control some variables.
www.americansciendst.org
60-1-
E. simulata
E. pallida
Figure 8. Different species of echinacea may result in different immime system effects. White blood
cells isolated from the blood of male soccer athletes, both before (rest) and after (post) a two-hour
aerobic exercise bout, were cultured in vitro with Echinacea pallida tincture, £. simulata tincture or
a solvent vehicle control. After 72 hours, cell cultures were assayed for a cytokine important during
infection, called iitterleukin-10 (IL-10). E. simulata extract, but not E. pallida extract, improved IL-10
production. (Figure adapted from D. S. Senchina et al.. Exercise Immunology Review 15:66.). Inset,
Drake University soccer player Logan North.
2013
March-April
139
changes observed in anaerobic athletes
supplemented with ginseng
White blood celi
counts did not show
a consistent change
across studies.
Cytokines did not
consistent trends in
changes in concentration.
Some studies demonstrated no difference in
cytokine concentrations
from controls.
An immunoglobulin that
serves as the immune system's
first line of defense, called salivary
immunogiobuiin A, increased.
An enzyme
controlling muscle
energy dynamics,
called creatine kinase,
decreased in the two
studies that measured
it. This enzyme is
important to ballistic
movement, so such a
decrease could
reduce performance
in athletes needing
spurts of high energy.
9. Summarized from eight different studies on the effects of ginseng on immime function
in strength athletes, research remains inconclusive and contradictory. Preclinical factors could account for some of the wide variation in results. For example, four different ginseng prepaiiations
were used across these eight studies. Pictured: Travis Merritt, Drake University football.
We inifially worked with white blood
cells from resting donors to establish
the effects of key preclinical factors.
Several interesting findings accrued;
for example, our lab and others have
repeatedly demonstrated that different
echinacea species vary in the way they
modulate the immune system, probably because of differences in plant
chemistry. We showed how deliberate
choices in species, plant organ, solvent
and extracfion method influenced cell
growth rates and production rates of
immune system signaling molecules.
After the work in resting subjects we
incorporated an acute exercise component, still controlling for the preclinical
factors as we had in our previous studies. Early work conducted on teams of
wrestlers and soccer players showed
that the different species of echinacea
plant, given in tincture form to the
players' white blood cells cultured under laboratory conditions, resulted in
different effects on signaling molecules
important during infecfion (Figure 8).
We also showed that acute exercise
changed how echinacea supplements
interacted with the white blood cells.
However, we have since switched to
testing athletes individually on treadmills and stationary bicycles so we can
better ensure that the amount of exercise is more consistent across subjects.
140 American Scientist, Volume 101
Collectively, data from studies of echinacea in athletes suggest that different
species of echinacea have different effects on the human body, that exercise
changes these effects and that effects are
cell- and body site-specific. The work
also suggests that preclinical factors
have not been adequately accounted for
across studies; further, preclinical factors
are expected to vary greatly between
manufacturers and even between batches from the same manufacturer. Given
that awareness, and the understanding
that so few studies have been conducted
and often with smaO sample sizes, one
cannot conclusively argue for or against
the use of echinacea by athletes.
Ginseng
Like echinacea, ginseng is taken to
augment immunity, but its primary
indication is to improve performance.
The name ginseng refers to any of approximately a dozen species within the
genus Panax, three of which are used
most often commercially (P. ginseng is
used most frequently, but also P. pseudoginseng and P. quinquefolius). Ginsensosides, from the plant steroids' saponin
subgroup (plant-derived chemicals that
in solution produce soaplike foaming
when shaken), are the classically recognized bioactive molecules in ginseng.
Roots are used most often, typically
in dried or powdered form. So-called
Siberian ginseng, Eleutherococcus senticosus, is sometimes confused with
ginseng and is also frequently used
by athletes, although it has different
bioactive molecules and may be less
effecfive in the context of performance
enhancement.
Unlike echinacea, studies of ginseng
or Siberian ginseng in athletic contexts
have yielded conflicting results owing
to differences in experimental design
or outcomes measured. Systemafic reviews by Johannah Shergis and colleagues at Royal Melbourne Institute
of Technology University, and Michael Bahrke of Human Kinefics along
with collaborators at University of
Wisconsin-Madison, have concluded
that human studies have not convincingly demonstrated any ergogenic
benefits of ginseng supplementation
in athletes, although supplementafion
may transiently alter cardiological or
pulmonary funcdon. Side effects and
prescription drug interactions appear
to be more severe and extensive than
those associated with echinacea and
may include insomnia, gastrointestinal
upset and heart palpitations.
Less contentious but more complicated are findings regarding the effects of ginseng supplements on immune function in athletes (Figure 9).
From eight different studies that used
no fewer than four different ginseng
preparations along with a spectrum
of exercise modalifies, no clear overall
patterns emerge. This lack of clarity
is probably due to interexperimental
variability. Indicators of immune sys- .
tem activity including wliite blood cell
counts, subsets and acfivifies, as well
as interactions with signaling molecules associated with the immune
system, were variously upregulated,
downregulated or unaffected. Conservatively, these facts together indicate
ginseng is likely a modulator of immune system acfivity, but the specific
effects that different preclinical factors
have on clinical outcomes are poorly
understood. Thus, although ginseng
is a much more popular herbal supplement than echinacea in the United
States and globally, experimental data
supporting its use in athlefic contexts
are currently weak.
Contrasting echinacea studies with
ginseng studies reveals that immunological findings from the echinacea
studies were more consistent, whereas
those from the ginseng studies were
more variable (see Figures 6 and 9).
There are fewer studies of echinacea's
effects on athletes than ginseng's effects
on athletes, so variation in the effects
of ginseng may be better documented
than the variation in echinacea's effects.
Echinacea studies mostly focus on aerobic performance, whereas ginseng studies mostly focus on anaerobic, strength
athletes' performance. Although the
names echinacea and ginseng encom- •
pass multiple species each, studies of
them in the context of athletic performance focus on one species each (E.
purpurea and P. ginseng, respectively).
Why a clearer pattern emerges from
the literature on echinacea's effects on
athletes is not known, but the difference in variability may be because the
echinacea studies used herbal preparations that were more consistent in species, plant part used and other preclinical factors. Both the echkiacea and the
ginseng studies drew their participants
from diverse populations in terms of
age, gender and physical activity levels.
Future studies of ginseng and Siberian
ginseng preparations may elicit stronger and more consistent findings if both
preclinical and clinical factors are controlled better.
and nonathletes alike, and most of
those substances have not been clinically tested. Those herbs need to be explored further. For instance, elderberry
is an herbal supplement that is increasingly popular in sports contexts, and it
appears to have immune-modulating
attributes similar to those of ecliinacea
and may provide similar benefits. Compounds associated with anüoxidant activities, called lectins and anthocyanins,
are found in elderberry and may interfere with influenza binding to human
cells. One report by Sepp Porta from
the University of Graz and colleagues
suggested elderberry extracts may lower exercise-induced lactate levels.
Many herbal supplements have
the potential to improve both human
health and athletic performance, but as
the examples show, the potential benefits are greatly influenced by preclinical factors, necessitafing an interdisciplinary approach to studies of herbal
supplements. Scientists and sports
medicine professionals are taking steps
toward such an approach, which we
hope will improve our understanding
of how supplements work, or don't
work, to aid human performance.
Bibliography
Full Speed Ahead
Promising strides have been made in
our understanding of herbal supplements in exercise and sport contexts.
However, several irksome and perhaps insoluble problems remain. It
would be quixotic to expect a single
investigative team or lone experiment
to address each individual factor—
aiid some factors may not be possible
to accurately measure or may be beyond manufacturers' control. Preparations containing several herbs and
other ingredients, such as those used
in traditional Chinese medicine, may
compound the difficulty of identifying preclinical factors. And analytical
chemists have shown repeatedly that
the contents of retail herbal supplements are often inconsistent with
their own product labels in terms of
ingredients or quantities, even when
manufacturers make claims of standardization. Given these realities, even
the most diligent clinical or bench scientists cannot accurately report their
findings and may imwittingly report
false data.
Directions for future research are innumerable. Hundreds of herbal supplements are currently used by athletes
www.americanscientist.org
Bahrke, M. S., W. P. Morgan and A. Stegner.
2009. Is ginseng an ergogenic aid? International Journal of Sport Nutrition & Exercise
Metabolism 19:298-322.
Berg, A., et al. 1998. Influence of Echinacin
(EC31) treatment on the exercise-induced
immune response in athletes, journal of
Clinical Research 1:367-380.
Blumenthal, M., A. Lindstrom, C. Ooyen and
M. E. Lynch. 2012. Herb supplement sales
increase 4.5% in 2011 despite still-weak
economy, herb sales continue multi-year
growth. HerbalGram 95:60-64.
Castell L. M., L. M. Burke, and S. J. Stear, eds.
2010-2013. A-Z of nutritional supplements
(series). British Journal of Sports Medicine,
44-47.
Goulet, E. D. B. and 1. J. Dionne. 2005. Assessment of the effects of Eleutherococcus
senticosus on endurance performance. International Journal of Sport Nutrition & Exercise
Metabolism 14:75-83.
Hall, H., M. M. Fahlman and H. J. Engels.
2007. Echinacea purpurea and mucosal immunity. Internationnl Journal of Sports Medicine 28:792-797.
Schoop, R., S. BUechi and A. Suter. 2006. Open,
multicenter study to evaluate the tolerability and efficacy of Echinaforce Forte tablets
in athletes. Advances in Therapy 23:823-833.
Senchina, D. S., J. E. Hallam and D. J. Cheney.
2013. Multidisciplinary perspectives on
mechanisms of activity of popular in^nuneenhancing herbal supplements used by athletes. Frontiers in Biology. 8:78-100.
Sencliina, D. S., J. E. Hallam, A. S. Dias and
M. A. Perera. 2009. Human blood mononuclear cell in vitro cytokine response before and after two different strenuous exercise bouts in the presence of bloodroot and
Echinacea extracts. Blood Cells, Molecules, &
Diseases 43:298-303.
Senchina, D. S., et al. 2012. Alkaloids and endurance athletes: A research review and
some demonstrations using bloodroot extracts and white blood cells from cyclists
and runners. Track & Cross Country Journal
2:2-18.
Sencl-iina, D. S., N. B. Shah, D. M. Doty, C. R.
Sanderson and J. E. Hallam. 2009. Herbal
supplements and athlete immune function—what's proven, disproven, and unproven? Exercise Immunology Review 15:66106.
Shergis, J. L., A. L. Zhang, W. Zhou and C. C.
Xue. 2012. Panax ginseng in randomized
controlled trials: A systematic review. Phytotherapy Research, doi: 10.1002/ptr.4832.
Whitehead, M. T., T. D. Martin, T. P Scheet and
M. J. Webster. 2008. The effect of 4 wk of
oral echinacea supplementation on serum
erythropoietin and indices of erythropoietic
status. International Journal of Sport Nutrition
and Exercise Metabolism 17:378-390.
Whitehead, M. T., T. D. Martin, T. P Scheet
and M. J. Webster. 2012. Running economy
and maximal oxygen consumption after 4
weeks of oral Echinacea supplementation.
Journal of Strength & Conditioning Research
26:1928-1933.
For relevant Web links, consult this
issue of American Scientist Or^line:
http://www.americanscientist.ora/
issues/id. 101 /past.aspx
Nieman, D. C. 1997. Risk of upper respiratory
tract infection in athletes: An epideniiologic
and immunologie perspective. Journal of
Athletic Training 32:344-349.
Petróckzi, A., et al. 2008. Nutritional supplement use by elite young U.K. athletes: Fallacies of advice regarding efficacy. Journal
of the biternational Society of Sports Nutrition
5:22.
2013
March-April
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Criteria
NonBasic
performance
Proficient
Describe the main points presented
about supplements, including specific
areas of research and the findings.
20%
Identifies but
does not
describe the
main points
Does not
presented
identify the
about
main points
supplements,
presented
or does not
about
include
supplements.
specific areas
of research
and the
findings.
Describes and
analyses the
Describes
main points
the main
presented
points
about
presented
supplements,
about
including
supplements,
specific areas
including
of research
specific areas
and the
of research
findings, and
and the
provides
findings.
personal
interpretation.
Explain the role of supplements and
athletics, including why supplements
are currently unregulated, and if
supplements should undergo more
stringent testing.
20%
Identifies but
does not
explain the
role of
supplements
and athletics,
or does not
include
Does not
information
identify the
on why
role of
supplements
supplements
are currently
and athletics.
unregulated,
or if
supplements
should
undergo
more
stringent
testing.
Explains the
role of
supplements
and athletics,
including why
supplements
are currently
unregulated,
and if
supplements
should
undergo more
stringent
testing, and
analyzes the
cost of
monitoring
supplements.
Compare article with multiple sources
of information about the same
Does not
compare
Explains the
role of
supplements
and athletics,
including
why
supplements
are currently
unregulated,
and if
supplements
should
undergo
more
stringent
testing.
Compares
Compares
article with a article with
Distinguished
Compares
article with
Criteria
concepts.
20%
Evaluate sources by answering the
questions in the source evaluation
forms and provide an analysis within
the paper.
20%
Write coherently to support a central
idea in appropriate format with correct
grammar, usage, and mechanics,
including correct APA format and
citations.
20%
NonBasic
performance
Proficient
Distinguished
multiple
sources of
information
about the
same
concepts.
multiple
sources of
information
about the
same
concepts, and
provides an
analysis of the
similarities
and
differences.
Does not
describe
sources by
answering
the
questions in
the source
evaluation
forms.
Describes
but does not
evaluate
sources by
answering
the
questions in
the source
evaluation
forms or
does not
provide an
analysis
within the
paper.
Evaluates
sources by
answering
the
questions in
the source
evaluation
forms and
provides an
analysis
within the
paper.
Evaluates
sources by
answering the
questions in
the source
evaluation
forms and
provides a
clear, concise,
and deep
analysis within
the paper.
Does not
write to
support a
central idea.
Writes to
support a
central idea
but the
format is
inconsistent
and there
are errors in
grammar,
Writes
coherently to
support a
central idea
in
appropriate
format with
correct
grammar,
usage, and
Writes
coherently to
support a
central idea in
appropriate
format with
correct
grammar,
usage, and
mechanics,
article with
other
sources of
information.
single source
of
information
or does not
focus on the
same
concepts.
Criteria
NonBasic
performance
usage, and
mechanics.
Proficient
Distinguished
mechanics,
including
correct APA
format and
citations.
including
correct APA
format and
citations, and
in addition,
uses concise,
clear, and
thorough
language.
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