Our policy is to share or publish research regardless of the findings. In other words, not to selectively publish results.
We have made a significant investment in research to demonstrate both the safety and efficacy of the SierraSil® mineral complex. The research has been described as a “gold standard” for our industry and cited as an example of “excellence” by a Board member of the Natural Health Products Research Society (of Canada). The minerals have proven to be safe and effective in clinical and lab research as well as in a history of safe use, earning the confidence of experts such as a leading Rheumatologist who wrote that he
“investigated the research.. and .. subsequently recommended (the minerals) to some of his patients with mild to moderate OA and/or RA. It is my observational experience that the minerals have been helpful in the majority of patients. Many of these patients have felt less discomfort and have been more able to resume exercise or enhance their mobility or other activity, improving outcomes and well-being. I note that the onset of such results has typically been within one or two weeks, surpassing my expectations”
The research findings have had reasonably consistent results, verifying safety and efficacy, except perhaps surprisingly, that the heavy metal chelation effect doesn’t result in reduced availability of other nutritional supplements tested.
The studies have been organized here based on relevance for efficacy, mechanism of actions and safety, not chronological order in which they were done.
TITLE:A pilot study to test the safety and efficacy of the mineral supplement SierraSil® in
osteoarthritis of the knee.
OBJECTIVE:A pilot study to evaluate the safety and efficacy of SierraSil® in patients suffering
from osteoarthritis of the knee. The 2003 study was conducted in a randomized fashion to
administer patients diagnosed with moderate osteoarthritis of the knee with SierraSil® alone or
SierraSil® plus a proprietary cat’s claw herbal extract.
METHODS:Baseline WOMAC scores were established after which the patients received one
capsule three times daily of the treatment for 10 days. Post-treatment WOMAC scores and side
effects were also recorded. The parameters of the study included WOMAC scores, OA clinical
symptoms, stair climb ability, pain and stiffness reduction and quality of life.
100% of the subjects reported a significant improvement within one week of
treatment on either SierraSil® alone or SierraSil® with the cat’s claw, with no concomitant
medications (i.e. aspirin, acetaminophen) required or side effects reported.
This pilot study showed that SierraSil® alone or in combination with cat’s
claw provided patients (with previously diagnosed osteoarthritis) benefits that were clinically
measurable. This pilot study therefore warranted further investigation to determine the
biological mechanism of action, the appropriate dosage and SierraSil®’s safety and efficacy
in a larger scale clinical trial.
(c)Open Label Study KCK Synergize
Serving Guidelines for Joint Formula14™
RECOMMENDED DOSE: (ADULTS)
Take 3 capsules once daily with water on an empty stomach.
Persons with larger bodies or BMI of over 25 should consider taking 4 or 5 capsules per day, or
a larger scoop of the powder.
DIRECTIONS FOR USE:
For best results, take SierraSil® Joint Formula14™ (JF14) with water at least
one hour before or after a meal or other beverages such as coffee, pop, tea, juice or milk. Take
critical medications four hours before or after JF14. JF14 has detoxifying properties due to its
clay-like silicate mineral structure, and it is strongly recommended to drink plenty of water for
best results with SierraSil®. Increased water intake assists the body in flushing out toxins and
heavy metals that are eliminated by the body when using SierraSil®.
SPECIAL CONDITIONS:Athletes and active adults participating in high-intensity exercise can
take SierraSil® Joint Formula14™ 1 to 3 hours before activity to aid endurance and recovery
and reduce delayed onset muscle soreness (post-exercise stiffness).
For those in weakened conditions, living with multiple pre-existing medical conditions or
sensitive stomachs, start with one capsule, once per day and gradually work up to the
For those without sensitive stomachs, if results do not manifest within the first 7 days consider
taking a loading dose. A loading dose is double the recommended daily dose for 7 days and can
be taken to help increase results.
CAUTIONS AND WARNINGS
CAUTIONS:For a very small percentage of SierraSil® users, the detoxification process can
cause some transient discomfort at first, known as a healing reaction, while the body adjusts to
SierraSil® Joint Formula14™. A healing reaction is a temporary process that the body endures
as it moves towards optimal balance and function (homeostasis). Symptoms of healing
reactions vary, and may include headache, changes in bowel movements or a slight stiffening
of the joints. These reactions are temporary and normally subside within 1 to 7 days of using
SierraSil® Joint Formula14™. If the symptoms are too uncomfortable, lower the dose to 1
capsule or 667 mg daily and gradually increase to the recommended dose. To facilitate the
detoxification process, it is critical to consume plenty of water (6+ glasses daily) while taking
SierraSil® Joint Formula14™ to assist the body with eliminating toxins. Increased water intake
will also reduce the risk of constipation while taking SierraSil.
WARNINGS:Pregnant or nursing women and persons with known medical conditions (such
as cardiovascular diseases) should consult with their health care practitioner prior to using
SierraSil® Joint Formula14™. SierraSil® Joint Formula14™ should be kept out of reach of
children. SierraSil® has not been clinically tested for these population groups.
CONTRAINDICATIONS:SierraSil® Joint Formula14™ should not be taken at the same time of day as
critical medications. The absorptive mineral complex in SierraSil® Joint Formula14™ may bind
with medications due to its highly absorptive and adsorptive properties.
TITLE: Early relief of osteoarthritis symptoms with a natural mineral supplement and a
herbo-mineral combination: A randomized controlled trial [ISRCTN38432711]
OBJECTIVE:This study was designed to determine if a natural mineral supplement, SierraSil®,
alone and/or in combination with a cat’s claw herbal extract (Uncaria guianensis), Vincaria®,
has therapeutic potential in mild to moderate osteoarthritis of the knee.
METHODS: 107 patients with mild to moderate osteoarthritis of the knee were randomly
assigned to one of 4 groups in a double-blinded fashion: 1) high dose SierraSil® (3 g/day), 2)
low dose SierraSil® (2 g/day), 3) low dose SierraSil® (2 g/day) + Vincaria® (100 mg/day) or 4)
placebo, administered for 8 weeks. Primary efficacy variables were WOMAC scores. Secondary
variables were: Visual Analog Score (VAS) for pain; consumption of rescue medication
(paracetamol); and tolerability. Safety measures included vital signs and laboratory-based assays.
RESULTS: SierraSil® was able to produce significant improvement in WOMAC and VAS scores
after 8 weeks (P < 0.001) either alone or in combination with Vincaria®. SierraSil® groups
also produced a faster onset of benefits (at week 1, 2, and 4) in reference to baseline values
when compared to placebo group. At 4 weeks, all the SierraSil groups displayed a 38–43%
CONCLUSION:SierraSil® alone and in combination with cat’s claw extract improved joint health
and function within 1–2 weeks of treatment. SierraSil® may offer an alternative therapy in
subjects with joint pain and dysfunction. See PMID: 16242032 PMCID: PMC1276811 for the
peer reviewed, published paper. Journal of Inflammation. J Inflamm (Lond). 2005;2:11.
Cross-over Study of the Efficacy and Safety of SierraSil Joint Formula 14 in Osteoarthritis of the Knee (11SOHS)
Efficacy of a natural mineral complex in North American adults with osteoarthritis of the knee: a randomized double-blind placebo-controlled study
(e)Double-blind, placebo controlled, cross-over Osteoarthritis study
TITLE:A randomized, double blind, placebo controlled cross over study to explore the efficacy
and safety of SierraSil® Joint Formula14™ in adults with osteoarthritis of the knee.
OBJECTIVE:The primary objective of this study was to assess the efficacy of SierraSil® at 2 g/
day on the symptoms of osteoarthritis as assessed by WOMAC™ Pain subscale in Canadian
subjects with osteoarthritis of the knee. Secondary objectives of the study were to determine
changes in WOMAC™ osteoarthritis index physical function and stiffness subscales, SF-36
questionnaire scores, inflammatory markers such as hsCRP, TNF, and IL-6, onset of analgesia,
amount of rescue medication used, safety parameters including vital signs, adverse events, and
METHODS:In this randomized, double-blind, placebo controlled, cross over study, a total of 230
subjects were screened and 150 were found to be eligible to participate in the study. 75 subjects
went on the SierraSil® treatment and the other 75 on placebo. Of the 150 subjects 25% were of
healthy weight while 75% were large or obese by BMI measurement.
RESULTS:Subjects with a WOMAC™ Pain score between 16 and 33.3 mm at baseline showed
a decreasing trend in Pain score from baseline to week 4. During the washout period, these
subjects’ Pain scores increased suggesting efficacy of SierraSil®. Though subjects on placebo
had an initial decrease in Pain score from baseline to week 2, an increase was seen by week 4.
Subjects with a WOMAC™ Pain score between 66.7 and 100 mm at baseline showed a
decreasing trend in Pain score from baseline to week 2 and plateaued by week 4 for both
Placebo and SierraSil®. Within groups, subjects on SierraSil® demonstrated statistically
significant improvements in SF-36 scores from baseline to week 4 for the domains: Physical
Function, Role Limitation due to Physical Health, Vitality/Energy, Social Functioning, and
Bodily Pain. Furthermore, subjects on SierraSil® showed statistically significant improvements
in Total SF-36 scores, Total Physical Activity and Total Mental Health.
CONCLUSION: The study found that SierraSil® was effective in relieving pain associated with
osteoarthritis as indicated by both WOMAC scores and SF-36 scores. SierraSil® was found in
this study to be effective in temporary relief of joint pain, with more profound effect in subjects
with normal body weight (BMI < 25.00 Kg/m2), suggesting that larger bodies would benefit
from a larger dose than 2 g/day. This study was published in the following Dove Press Journal:
Open Access Rheumatology: Research and Reviews 3, Oct 2014.
TITLE: SierraSil as an ergogenic aid to performance in athletes.
OBJECTIVE:The purpose of this study was to examine whether Sierrasil® could improve anaerobic power in a group of well-trained athletes. A secondary purpose was to examine the effect
of Sierrasil® on the severity of delayed onset muscle soreness (DOMS).
METHODS: 10 male, varsity football players were studied in a double-blind, cross-over design.
The athletes (mean age= 22 years; height= 183.6 cm; weight = 90.3 kg) performed three
Wingate cycle ergometer tests 5 minutes apart as a test of peak power, average power and
fatigue index. They recorded DOMS on a 0-10 visual analogue scale (VAS) at 24, 48 and 72
hours post-exercise. Prior to exercise and 5 minutes following the last Wingate test, blood was
taken for analysis of selected cytokines. The athletes were randomly assigned to Sierrasil® or
placebo groups for three weeks and, following a three-week washout period, the experimental treatments were reversed. The products were dispensed according to the manufacturer’s
RESULTS:All athletes completed the trial. Sierrasil® was well tolerated by highly trained male
athletes. There were no adverse effects reported. Following Sierrasil® supplementation the
peak power increased by 33.8 W (a 3% increase) and mean power by 6.7 W (a 1% increase). In
the placebo group the peak power decreased by 11.2 W (-2.6%) and the mean power decreased
by 17.2 W (-1%). DOMS values on the VAS were higher in the placebo group at 24, 48 and 72
hrs post-exercise (P= 3.2, 2.2, 1.3 vs. Sierrasil®= 2.5, 1.6, 0.6). There were no statistically
significant changes in the performance measures between the two groups however (p>0.05).
There were no significant changes in the cytokine measures following supplementation with
either Sierrasil® or placebo.
CONCLUSION: The results showed that Sierrasil® is safe to use in highly trained athletes and
resulted in improvements in anaerobic power and in reducing the level of DOMS post-exercise
that the researchers, Dr. Don McKenzie and Dr. Jack Taunton describe as “sport significant”.
N of 1 Study assessing soreness in a healthy adult male.
Dr. James McCormack, UBC Title, offered to supervise a double blind, placebo
controlled, multiple cross over N of 1 Study to assess the efficacy of SierraSil JF14 in a healthy
SierrraSil customer, challenging placebo effects and speed of benefits.
Eight bottles of a two week supply (4 each of placebo and treatment) were randomized on a double blind basis. The adult male patient kept a log of activity and noted soreness
on a scale of 1 to 7 with definitions for each as established by Dr. McCormack. For example 1,
represented no soreness to 7 which represented very severe soreness, cannot be ignored and
markedly limits daily activity and often requires rest.
The patient soreness scores ranged from 1 (no soreness) to 4 (moderate soreness -
cannot be ignored but does not influence my daily activities). The average soreness score (per
bottle/2 week blocks) on treatment was 1.29 and the average soreness score on placebo was
2.13, a difference of 0.84 (placebo soreness 65% higher than treatment). All treatment score
averages were lower than any of the placebo score averages. This is significant given the nature
of the study, with what turned out to be 5 transitions from either placebo to treatment or treatment to placebo in the 16 week period, suggesting that the onset of benefits was rapid when on
treatment, but there was similarly short ‘tail’ to the benefits.
For the patient in this double blind, placebo controlled multiple cross-over study,
SierraSil JF14 significantly reduced soreness associated with activity such as running and other
(h) Mechanism of Action Study
Suppression of Human Cartilage Degradation and Chondrocyte Activation by a Unique
Mineral Supplement (SierraSil®) and a Cat’s Claw Extract, Vincaria®.
This study investigated the hypothesis that the unique clay-based mineral
supplement SierraSil® alone, and in combination with an extract of cat’s claw, Vincaria®,
could limit human cartilage degradation-activated chondrocytes.
The investigative model used was human cartilage tissue, obtained at the time
of knee surgery. SierraSil® was subjected to neutral, alkali, and acid washes, followed by
neutralization before addition to cartilage explants or cultured chondrocytes (0.05, 0.1, and
0.2 μg/ml). Vincaria®, an alkaloid depleted aqueous extract of cat’s claw (Uncaria Guianensis)
was studied in combination with SierraSil® (2.5, 5 and 10 ng/ml).
Chondrocytes were activated with the addition of the inflammatory cytokine interleukin-1 (5 ng/ml). Measured outcomes were media nitrate/nitrite levels as an index
of nitric oxide production, and media glycosaminoglycan (GAG) concentrations as an index
of matrix breakdown. Following neutral or alkali washes, a small reduction in GAG release
was observed with neutral extracts (p<0.05). The combination of SierraSil® + Vincaria®
significantly reduced both GAG and nitric oxide release under these conditions. Following an
acid wash to mimic passage of the material through the stomach, SierraSil® alone significantly
reduced IL-1-induced GAG release by 68–73% (p<0.01) and SierraSil® + Vincaria® by 58–77%
(p<0.01). Production of NO by human chondrocytes was also reduced by acid-washed SierraSil®
alone (p<0.05) and was more pronounced with the SierraSil® + Vincaria® combination (p<0.01).
IL-1-induced nitric oxide production and GAG release is known to reflect the activation of
inducible pathways (inducible nitric oxide synthase and matrix metalloproteases).
The attenuation of these events suggests that SierraSil alone or in this herbo-mineral combination limits cartilage destruction by curtailing these transcriptional events in
chondrocytes. Results suggest that this nutraceutical-based therapeutic agent may offer a new
approach to limiting joint destruction and immobility associated with arthritis.
(i)Radiation protection study
Effect of SierraSil® hydrothermal mineral complex (HMC317) on [3H-Methyl] Thymidine
uptake in human liver (THLE-2), human normal skin (NHEM) and human melanoma skin
This study was to investigate the effect of SierraSil® on [3H-Methyl] Thymidine
uptake as a measure of radiation absorption by various human cells.
An in vitro assay was designed to measure the uptake of [3H-Methyl] Thymidine
by three human cell lines: human liver (THLE-2), human normal skin (NHEM) and human
melanoma skin cells (A375). SierraSil® powder dissolved in complete growth media
provided ~2.4% soluble solids in the filtrate that were used in the assay. [3H-Methyl] Thymidine
at concentrations of 0.5, 0.1 and 0.05 μCi were tested at 24, 48 and 72 hours after incubation
with the test product.
After 24 hours of incubation there was a significant decrease in the amount
of radiation detected in THLE-2 cells exposed to all three concentrations of [3H-Methyl]
Thymidine in the presence of SierraSil® compared to control liver cells. After 24 hours of
incubation there was a significant decrease in the amount of radiation detected in NHEM cells
exposed to 0.05 μCi of [3H-Methyl] Thymidine in the presence of SierraSil® compared to control
normal skin cells. After 72 hours of incubation, there was a significant decrease in the amount
of radiation detected in A375 cells exposed to 0.05 μCi of [3H-Methyl] Thymidine in the presence of SierraSil® compared to control melanoma cells.
Analysis of the data showed that cells cultured in the presence of SierraSil®
powder demonstrated lower incorporation of [3H-Methyl] Thymidine compared to cells
cultured in the absence of SierraSil®. The study also established that the absorption of
radiation in the form of [3H-Methyl] Thymidine is dose, time and cell type dependent.
(j) Toxicology and chelation study
TITLE: The Toxicology and Potential Chelating Effect of SierraSil®
OBJECTIVE:A pilot study led by Dr. James Lavalle designed to assess potential for accumulation
of toxic minerals in humans and to reveal if SierraSil® has a chelating effect on toxic metal
METHODS:12 subjects entered the study designed to examine the effects of SierraSil® on 16
potentially toxic metals and 19 essential elements over a 6-month period.
RESULTS:7 subjects completed the study. The data reveals that arsenic levels appear to rise from
T0 to T3 (and from T0 to T6). However, they declined from T3 to T6, although this change was
not statistically significant. All the measurements for arsenic levels remained within the normal reference range. If the arsenic in SierraSil® was bioaccessible, then the levels should have
continued to rise. As a natural chelating agent, ingestion of SierraSil® caused a 56.9% decrease
in lead between T0 and T6, and a 62.7% decrease between T3 and T6, both of which were statistically significant at the 5% level.
CONCLUSION: It appears that daily ingestion of SierraSil® at 4 g/day may have a profound effect
on the lowering of lead levels and may have the potential to lower the risk of the adverse health
effects associated with lead exposure.
(k) Long term user medical analysis
Long term user medical analysis by Dundarave Medical Clinic, West Vancouver,
OBJECTIVE:: This laboratory analysis was conducted to examine the blood chemistry and other
health indicators of patients who have been taking SierraSil® over a long period of time
(2 to 5 years).
METHODS:A full laboratory analysis was conducted on 9 patients with a mean age of 60.1
years with the range of 41–85 years old. The average use of SierraSil® in this study was 2–4
capsules per day for a minimum of 2 years. Haematology, general blood chemistry, adrenal
function and serum proteins were included in the laboratory analysis.
RESULTS:Lab analysis showed that these patients have normal to low-normal profiles of
parameters described above, for instance, the cortisol is averaging 350.38 nmol/L when the
normal range is 140 – 690 nmol/L, showing that adrenal function of the 9 patients was healthy.
A more important and more relevant testing was the C - reactive protein (CRP) as it relates to
inflammatory processes in the body. The average CRP level of the 9 patients was
2.2 mg/L where the normal range is < 5.0 mg/L. this again shows that SierraSil® may have
anti- inflammatory properties in patients suffering from osteoarthritis; however OA markers
were not included in this lab analysis.
Patients who are on long term use of SierraSil® were found to have a healthy and
normal biochemistry profile when compared to the established normal ranges.
(l)Long-term user heavy metal analysis
(m)Bacterial Reverse Mutation (AMES) test
Review of SierraSil® Bacterial Reverse Mutation (AMES) Test.
SierraSil® mineral was tested in bacterial reverse mutation assay for its potential to
induce point mutations in S. typhimurium strains TA-98, TA-100, TA-1535, TA-1537 and E. coli
strain WP2 uvrA. The experimental design followed the OECD guideline for testing of
chemicals– 471, bacterial reverse meutation test (1997).
The powder was stored at room temperature during the study. A large portion of it
was insoluble in common solvents that were compatible with the assay. The insoluble material
precipitated in the testing agar plates and interfered with colony counting. In the main studies,
the sample was prepared in DMSO and water by shaking at 45oC for two days. Exposure
concentrations were expressed in “mg eq. per plate”. “Mg eq.” represented the number of
mg from which the extract was prepared. DMSO extracted SierraSil® was tested in a plate
incorporation assay; water extract, in pre-incubation assay.
Bacterial toxicity was observed in all strains exposed to DMSO extracts with S9.
This limited the maximum exposure concentrations to 2.07 mg eq. per plate for this part of the
study. With the addition of S9, exposure to as high as 56.00 mg eq. per plate of DMSO extract
did not cause obvious toxicity. Water extract was largely non-toxic with or without S9.
Maximum extractable concentration was in this case included in the exposure concentrations
that ranged from 0.55 to 44.40 mg eq. per plate. All tester strains showed only background
level of reversion at any exposure concentration with either extract. The observed means for
triplicate plates of each concentration was largely within the range of the means ± 2 SD of the
corresponding solvent controls.
It was concluded that the mineral was not mutagenic to S. typhimurium strains
TA-98, TA-100, TA-1535, TA-1537 and E. coli strain WP2 uvrA under the test conditions.
(n)Acute oral Toxicity Test (AOT)
Review of SierraSil® acute oral toxicity test.
The acute oral toxicity study completed on SierraSil® found that the acute oral LD50
of SierraSil® to be in excess of 2000.0 mg/Kg body weight. No effects of toxicity or mortality
were observed at any point during the 14 days of testing. The animals gained weight during
the test. Post-testing examination showed no gross pathological findings in any of the five rats.
(o)SubAcute Oral Toxicity Test (OECD Protocol 408)
Repeated dose 90-day oral toxicity study with 28-day recovery period of SierraSil® in
Sprague Dawley rats (OECD Protocol 408).
The study was to assess the toxicological profile of SierraSil® when rats are exposed
daily to the test article over a period of 90 days, by oral gavage.
Groups of 10 male and 10 female Sprague Dawley rats were administered SierraSil®
by oral gavage daily at the doses of 100 mg, 550 mg or 1000 mg per kg body weight for 90 days
and were sacrificed on day 91 to evaluate its toxicity. Concurrent control group receiving vehicle
at 10 ml/kg was also maintained. Additionally, groups of 5 rats per sex receiving vehicle at 10
ml/kg and the test article at 1000 mg/kg levels were further observed for a period of 28 days
following 90 day exposure, for assessment of reversibility, persistence or delayed occurrence
There was no treatment related mortality among rats exposed to SierraSil® at all three
doses. No findings indicative of neurotoxic potential of the treatment were reported. Body
weight gain by treatment group was found to be comparable to that by the control group. Food
consumption was also comparable between the treatment group and control group. Haematology, clinical chemistry, urinalysis, organ weights, gross pathology and histopathology all
revealed no significant difference between treatment group and placebo group.
Based on the findings of this study, the no-observed-adverse-effect-level (NOAEL)
of SierraSil® in Sprague Dawley rats, following oral administration for 90 days was found to
be more than 1000 mg/kg body weight (equivalent to about 35 times the recommended
(p)SubAcute Oral Toxicity Test (SAOT) Liver Analysis
Repeated dose 90-day oral toxicity study with 28-day recovery period of SierraSil® in
Sprague Dawley rats.
The study was to address body weight and liver chemistry analysis of rats that had
been fed SierraSil® over a period of 90 days by oral gavage.
In the same study as described previously, liver samples for rats treated with
SierraSil® were prepared and analyzed as it is a safe assumption that hepatic metal content
is reflective of levels in other tissues of the animal.
Total iron content of the liver, total lead content of the liver, total arsenic content of the
liver and total aluminum content of the liver were analyzed in 10 rats from the control group
and 10 rats from the high dose group (1000 mg/kg body weight of SierraSil®). The weight of
the liver was also compared between control and high dose groups. No statistically significant
difference was found in any of the above liver analyses.
Even at very high dosages there was no accumulation of metals tested in the liver,
even a trend to lower lead levels.
(q)Bio-accesibility Dissolution Test (USP711)
Dissolution Testing of SierraSil® USP <711>
This experiment is conducted to determine if metals from the SierraSil® product are
bioaccessible following digestion with simulated gastric and intestinal fluids at physiological
The test protocol follows the Dissolution method <711> described in USP 24 NF-19.
The experiment was conducted in a water bath at 37 ± 2°C. All materials were cleaned and
rinsed according to standard procedure. Both digestive solutions – gastric fluid and intestinal
fluid – were prepared according to the USP 24 NF-19 method. The bioaccessibility of metals in
the test sample was estimated using the equation: [concentration of a given metal determined
in the chime] / [concentration of the given metal determined in the SierraSil® sample before
digestion x 100%].
The mean concentration of mercury was 0.213 ± 0.004 μg/0.667g. However, the mean
bioaccessibility of mercury was 1.4%. The concentration of lead in the test sample was 4.3 ±
0.04 μg/0.667g, while the bioaccessibility was 0%. The bioaccessibility of cadmium was 108%,
however, the concentration of cadmium in the test sample, 0.03 ± 0.002 μg/0.667g, was very
close to the limit of detection (0.02 μg/0.667g).
The estimated daily intake for elements of potential concern, based on an
expected consumption of three 0.667g-capsules per day (containing a total of 2g of SierraSil®),
showed that the concentrations of mercury, lead and cadmium in the sample were extremely
low and came well within the limits of Health Canada regulations.
(r)In-vitro Bio-accessibility and Bio-availability study
TITLE:In-vitro bioaccessibility and bioavailability of heavy metals in mineral clay complex used in
natural health products
OBJECTIVE:This study evaluates in vitro bioaccessibility and bioavailability of Arsenic, Cadmium,
and Lead in mineral clay samples from the Sierra Mountains using the UBM method and the
Caco-2 permeability assay, respectively.
METHODS:Clay samples were air-dried, then sieved and screened to guarantee only particles
smaller than 250 μm. Ten clay samples were digested and analyzed using synthetic digestive
fluids to simulate human digestion to determine bioaccessibility of metals present in clay.
Sodium arsenate dibasic heptahydrate (As), cadmium acetate (Cd), lead acetate trihydrate (Pb)
were used as references to test the bioavailability of free minerals.The bioavailability f the heavy
metals was analyzed using Caco-2 cell culture.
Following the UBM-gastric digestion As and Pb were lower than the Cd and decreased
more after the UMB-gastrointesinal assay. The initial heavy metals ranged from 3.8–17 ppm for
As, 0.024–0.061ppm for Cd, and 5.8–20 ppm Pb. However, the bioavailability was reduced to
non-detectable values of As, <0.007ppm of Cd, and <0.1ppm of Pb using the Caco-2 cell
Based on the combined bioaccessibility and bioavailability results, consumption of
these mineral clays poses low probability of risk if an amount of 11-15mg per lb body weight
recommendation is followed
(s)Tart Cherry and SierraSil In-vitro Bio-accessibility and Bio-availability study
TITLE:In-vitro bioaccessibility of tart cherry anthocyanins in a health supplement mix containing
OBJECTIVE:This study was conducted to determine if the presence of a cationic based mineral
clay will inhibit the bioaccesibility of anthocyanin and its antioxidant capacity.
METHODS:Clay mineral mixtures were disaggregated and screened to remove particles greater
than 250 μm. Mineral clay was mixed with tart cherry extract. Synthetic digestive fluids were
used for the 2-step in vitro digestion method used to simulate gastric and gastriuntestinal
digestions of the clay samples. The antioxidant capacities of fresh and digested extracts were
determined using the oxygen radical absorption capacity assay (ORAC).
Based on the study results, after gastric digestion, tart cherry anthocyanins are stable
and bioaccessible, but after gastrointestinal digestion they were largely transformed and
degraded by upwards of 70%. The total antioxidant capacity of the tart cherry extract increased
almost 2-fold after GI digestion. In the presence of the cationic-based mineral clay, anthocyanin
recovery displayed no significant difference when compared with the control, thus the cationic-
based mineral clay was not a factor in reducing anthocyanin bioaccessibility, or associated
The presence of the cationic-based mineral clay was not a factor in reducing
anthocyanin bioaccessibility, or associated antioxidant capacity due to no significant difference
between anthocyanin recovery when present with the mineral clay formulation when compared
(t)Glucosamine and SierraSil In-vitro Bio-accessibility and Bio-availability study
TITLE:Effect of a clay-mineral matrix on in vitro bioaccessibility and bioavailability of
OBJECTIVE:The purpose of the present study was to determine the in-vitro bioaccessibility and
bioavailability of glucosamine sulfate using a health supplement that consisted of a mineral base
METHODS:Glucosamine sulfate was analyzed using AOAC Official Method 2005.01. For the in
vitro bioaccessibility measurement, synthetic gastric and gastrointestinal fluids were prepared.
The in vitro bioavailability of heavy metal was analyzed using Caco-2 cell culture.
Results showed that the fraction of ingested glucosamine that can potentially be made
available for absorption was very close to 100%. Following gastric digestion different mineral
clay-glucosamine samples exhibited bioaccessibility that ranges from 92.3-105.2% and 87.1-
97.2% after gastrointestinal digestion. The bioavailability of the glucosamine obtained from the
mineral clay matrix varied between 18-28.8%, which is similar to the absorption of pure
glucosamine sulfate which was found to be 22%.
The results confirmed that glucosamine sulfate remains stable during gastric and
gastrointestinal phase digestion and retains high bioaccessibility when present in a clay mineral