Glucosamine use and risk of colorectal cancer: results from the Cancer Prevention Study II Nutrition Cohort

Glucosamine and Cancer Incidence in Osteoarthritis: A Prevalent New-User Cohort Design

OBJECTIVE

Observational studies have associated glucosamine, used to treat joint pain and osteoarthritis, with reductions in cancer incidence, although their study design was affected by selection bias. We assessed this association using a study design that mitigates this selection bias.

METHODS

We used the UK Clinical Practice Research Datalink to identify a cohort of patients diagnosed with osteoarthritis during 1995 through 2017. The prevalent new-user cohort design was employed to match glucosamine initiators with non-users on time-conditional propensity scores, who were observed until cancer incidence. Hazard ratios (HRs) and 95% confidence intervals (CIs) of cancer incidence were estimated to compare glucosamine initiators with non-users.

RESULTS

The study cohort of patients with osteoarthritis included 20,541 glucosamine initiators who were matched to 20,541 non-users. Over an average follow-up of eight years, the overall incidence rate of any cancer was 16.4 per 1,000 per year. The HR of any cancer incidence with glucosamine treatment was 0.97 (95% CI 0.91-1.02) compared with non-users. For lung cancer, the HR with glucosamine treatment was 0.99 (95% CI 0.83-1.18), whereas it was 1.11 (95% CI 0.93-1.33) for colorectal cancer, 1.07 (95% CI 0.93-1.23) for breast cancer in women, and 1.03 (95% CI 0.88-1.22) for prostate cancer.

CONCLUSION

In this large, real-world study of patients with osteoarthritis, designed to emulate a trial, treatment with glucosamine did not reduce the incidence of cancer. This finding reinforces that previous studies, not based on glucosamine initiators, were affected by selection bias. Our study does not support the prescription of glucosamine to prevent cancer in patients with osteoarthritis.

Association between genetically proxied glucosamine and risk of cancer and non-neoplastic disease: A Mendelian randomization study

Introduction

Observational investigations have examined the impact of glucosamine use on the risk of cancer and non-neoplastic diseases. However, the findings from these studies face limitations arising from confounding variables, reverse causation, and conflicting reports. Consequently, the establishment of a causal relationship between habitual glucosamine consumption and the risk of cancer and non-neoplastic diseases necessitates further investigation.

Methods

For Mendelian randomization (MR) investigation, we opted to employ single-nucleotide polymorphisms (SNPs) as instruments that exhibit robust associations with habitual glucosamine consumption. We obtained the corresponding effect estimates of these SNPs on the risk of cancer and non-neoplastic diseases by extracting summary data for genetic instruments linked to 49 varied cancer types amounting to 378,284 cases and 533,969 controls, as well as 20 non-neoplastic diseases encompassing 292,270 cases and 842,829 controls. Apart from the primary analysis utilizing inverse-variance weighted MR, we conducted two supplementary approaches to account for potential pleiotropy (MR-Egger and weighted median) and assessed their respective MR estimates. Furthermore, the results of the leave-one-out analysis revealed that there were no outlying instruments.

Results

Our results suggest divergence from accepted biological understanding, suggesting that genetically predicted glucosamine utilization may be linked to an increased vulnerability to specific illnesses, as evidenced by increased odds ratios and confidence intervals (95% CI) for diseases, such as malignant neoplasm of the eye and adnexa (2.47 [1.34-4.55]), benign neoplasm of the liver/bile ducts (2.12 [1.32-3.43]), benign neoplasm of the larynx (2.01 [1.36-2.96]), melanoma (1.74 [1.17-2.59]), follicular lymphoma (1.50 [1.06-2.11]), autoimmune thyroiditis (2.47 [1.49-4.08]), and autoimmune hyperthyroidism (1.93 [1.17-3.18]). In contrast to prior observational research, our genetic investigations demonstrate a positive correlation between habitual glucosamine consumption and an elevated risk of sigmoid colon cancer, lung adenocarcinoma, and benign neoplasm of the thyroid gland.

Conclusion

Casting doubt on the purported purely beneficial association between glucosamine ingestion and prevention of neoplastic and non-neoplastic diseases, habitual glucosamine ingestion exhibits dichotomous effects on disease outcomes. Endorsing the habitual consumption of glucosamine as a preventative measure against neoplastic and non-neoplastic diseases cannot be supported.

The significance of caloric restriction mimetics as anti-aging drugs

Aging is an intricate process characterized by the gradual deterioration of the physiological integrity of a living organism. This unfortunate phenomenon inevitably leads to a decline in functionality and a heightened susceptibility to the ultimate fate of mortality. Therefore, it is of utmost importance to implement interventions that possess the capability to reverse or preempt age-related pathology. Caloric restriction mimetics (CRMs) refer to a class of molecules that have been observed to elicit advantageous outcomes on both health and longevity in various model organisms and human subjects. Notably, these compounds offer a promising alternative to the arduous task of adhering to a caloric restriction diet and mitigate the progression of the aging process and extend the duration of life in laboratory animals and human population. A plethora of molecular signals have been linked to the practice of caloric restriction, encompassing Insulin-like Growth Factor 1 (IGF1), Mammalian Target of Rapamycin (mTOR), the Adenosine Monophosphate-Activated Protein Kinase (AMPK) pathway, and Sirtuins, with particular emphasis on SIRT1. Therefore, this review will center its focus on several compounds that act as CRMs, highlighting their molecular targets, chemical structures, and mechanisms of action. Moreover, this review serves to underscore the significant relationship between post COVID-19 syndrome, antiaging, and importance of utilizing CRMs. This particular endeavor will serve as a comprehensive guide for medicinal chemists and other esteemed researchers, enabling them to meticulously conceive and cultivate novel molecular entities with the potential to function as efficacious antiaging pharmaceutical agents.

Glucosamine and Chondroitin Use and Mortality Among Adults in the United States from 1999 to 2014

Introduction: Glucosamine and chondroitin are supplements that are often, but not always, used in combination for arthritis and joint pain. Multiple studies have suggested that glucosamine and chondroitin may be associated with reduced risk of several diseases, as well as all-cause, cancer- and respiratory disease-specific mortality. Methods: Nationally representative data from the National Health and Nutrition Examination Survey (NHANES) were used to further evaluate the association between glucosamine and chondroitin with mortality. Participants include 38,021 adults, ages 20+ years and older, who completed the detailed NHANES between 1999 and 2014. Participants were followed for death through linkage with the National Death Index through the end of 2015, over which time 4905 deaths occurred. Adjusted hazard ratios (HRs) for overall and cause-specific mortality were estimated using Cox regression models. Results: Despite glucosamine and chondroitin use appearing to be inversely associated with mortality in the minimally adjusted models, no association was observed in multivariable models (glucosamine: HR = 1.02; 95% confidence interval [CI]: 0.86-1.21, chondroitin: HR = 1.04, 95% CI: 0.87-1.25). No association with cancer mortality or other mortality rate was observed after multivariable adjustment. There was a suggestive, nonsignificant inverse association for cardiovascular-specific mortality (glucosamine HR = 0.72; 95% CI: 0.46-1.15, chondroitin: HR = 0.76; 95% CI: 0.47-1.21). Conclusion: The lack of significant relationship between glucosamine and chondroitin use and all-cause or cause-specific mortality after adjusting extensively for multiple covariates in this nationally representative adult population was in contrast to prior literature. Given the limited power to explore the cause-specific mortality, future well-powered studies will be needed to better understand the potential association with cardiovascular-specific mortality.

Association of regular glucosamine use with incident dementia: evidence from a longitudinal cohort and Mendelian randomization study

BACKGROUND

Emerging data suggests the neuroprotective and anti-neuroinflammatory effects of glucosamine. We aimed to examine the association between regular glucosamine use and risk of incident dementia, including dementia subtypes.

METHODS

We conducted large-scale observational and two-sample Mendelian randomization (MR) analyses. Participants in UK Biobank having accessible data for dementia incidence and who did not have dementia at baseline were included in the prospective cohort. Through the Cox proportional hazard model, we examined the risks of incident all-cause dementia, Alzheimer's disease (AD), and vascular dementia among glucosamine users and non-users. To further test the causal association between glucosamine use and dementia, we conducted a 2-sample MR utilizing summary statistics from genome-wide association studies (GWAS). The GWAS data were obtained from observational cohort participants of mostly European ancestry.

RESULTS

During a median follow-up of 8.9 years, there were 2458 cases of all-cause dementia, 924 cases of AD, and 491 cases of vascular dementia. In multivariable analysis, the hazard ratios (HR) of glucosamine users for all-cause dementia, AD, and vascular dementia were 0.84 (95% CI 0.75-0.93), 0.83 (95% CI 0.71-0.98), and 0.74 (95% CI 0.58-0.95), respectively. The inverse associations between glucosamine use and AD appeared to be stronger among participants aged below 60 years than those aged above 60 years (p = 0.04 for interaction). The APOE genotype did not modify this association (p > 0.05 for interaction). Single-variable MR suggested a causal relationship between glucosamine use and lower dementia risk. Multivariable MR showed that taking glucosamine continued to protect against dementia after controlling for vitamin, chondroitin supplement use and osteoarthritis (all-cause dementia HR 0.88, 95% CI 0.81-0.95; AD HR 0.78, 95% CI 0.72-0.85; vascular dementia HR 0.73, 95% CI 0.57-0.94). Single and multivariable inverse variance weighted (MV-IVW) and MR-Egger sensitivity analyses produced similar results for these estimations.

CONCLUSIONS

The findings of this large-scale cohort and MR analysis provide evidence for potential causal associations between the glucosamine use and lower risk for dementia. These findings require further validation through randomized controlled trials.

Role of Glucosamine and Chondroitin in the Prevention of Cancer: A Meta-Analysis

The anti-inflammatory properties of glucosamine and chondroitin suggest that they may have potential effects in cancer prevention. We performed this meta-analysis to assess the protective function of glucosamine and/or chondroitin intake against cancer risk. We searched the PubMed, Embase, Web of Science, and China National Knowledge Infrastructure (CNKI) databases. The odds ratio (OR), corresponding to the 95% confidence interval (95% CI), was used to assess the association between chondroitin and/or glucosamine intake and cancer risk. Thirteen studies met the inclusion criteria, with 1,690,918 participants and 55,045 cancer cases. Overall, chondroitin and/or glucosamine intake was associated with a lower risk of colorectal cancer (OR = 0.91, 95% CI, 0.87-0.94) and lung cancer (OR = 0.84, 95% CI, 0.79-0.89). Subgroup analysis supported the protective effect of different SYSADOAs (chondroitin and/or glucosamine) intake. However, the protective effect was not observed in the only chondroitin intake group and in the NSAIDs group. Our meta-analysis found that the intake of glucosamine and/or chondroitin decreased the risk of colorectal and lung cancers. Moreover, NSAIDs use may have a synergistic protective effect.

Glucosamine and lower mortality and cancer incidence: Selection bias in the observational studies

BACKGROUND

Glucosamine is a widely used supplement to treat joint pain and osteoarthritis despite inconclusive randomized trial results on its effectiveness. In contrast, observational studies associate glucosamine with significant reductions in mortality and cancer incidence. We evaluated the extent of bias, particularly selection bias, to explain these surprising beneficial effects.

METHODS

We searched the literature to identify all observational studies reporting on the effect of glucosamine use on major outcomes.

RESULTS

We identified 11 observational studies, reporting a mean 16% reduction in all-cause mortality (hazard ratio [HR] 0.84, 95% CI: 0.81-0.87) with glucosamine use, as well as significant reductions in cancer incidence and other major diseases including cardiovascular, respiratory and diabetes. We show that these significant effects can result from selection bias due to collider stratification, as all studies used "prevalent" cohorts, where glucosamine use started before cohort entry, and where subjects agreed to join the cohorts. Our illustration of the bias using the UK Biobank publication involving a half-million subjects shows how a true rate ratio of mortality of 1.0 in the population can result in a biased rate ratio of 0.82 in the prevalent cohort.

CONCLUSIONS

The observational studies reporting significant reductions in mortality, cancer incidence and other outcomes with glucosamine were affected by selection bias from collider stratification. In the absence of properly conducted observational studies that circumvent this bias by considering "new users", the studies to date cannot support the prescription of this supplement as a preventive measure for mortality, cancer, and other chronic diseases.

N-Palmitoyl-D-Glucosamine Inhibits TLR-4/NLRP3 and Improves DNBS-Induced Colon Inflammation through a PPAR-α-Dependent Mechanism

Similar to canine inflammatory enteropathy, inflammatory bowel disease (IBD) is a chronic idiopathic condition characterized by remission periods and recurrent flares in which diarrhea, visceral pain, rectal bleeding/bloody stools, and weight loss are the main clinical symptoms. Intestinal barrier function alterations often persist in the remission phase of the disease without ongoing inflammatory processes. However, current therapies include mainly anti-inflammatory compounds that fail to promote functional symptoms-free disease remission, urging new drug discoveries to handle patients during this step of the disease. ALIAmides (ALIA, autacoid local injury antagonism) are bioactive fatty acid amides that recently gained attention because of their involvement in the control of inflammatory response, prompting the use of these molecules as plausible therapeutic strategies in the treatment of several chronic inflammatory conditions. N-palmitoyl-D-glucosamine (PGA), an under-researched ALIAmide, resulted in being safe and effective in preclinical models of inflammation and pain, suggesting its potential engagement in the treatment of IBD. In our study, we demonstrated that micronized PGA significantly and dose-dependently reduces colitis severity, improves intestinal mucosa integrity by increasing the tight junction proteins expression, and downregulates the TLR-4/NLRP3/iNOS pathway via PPAR-α receptors signaling in DNBS-treated mice. The possibility of clinically exploiting micronized PGA as support for the treatment and prevention of inflammation-related changes in IBD patients would represent an innovative, effective, and safe strategy.

Glucosamine Use and Risk of Colorectal Cancer: Results from UK Biobank

BACKGROUND

Use of the dietary supplement glucosamine has been associated with reduced risk of colorectal cancer (CRC); however, it remains unclear if the association varies by screening status, time, and other factors.

METHODS

We therefore evaluated these questions in UK Biobank. Multivariable-adjusted Hazard Ratios (HRs) and 95% Confidence Intervals (95% CI) were estimated using Cox proportional hazards regression.

RESULTS

No association was observed between use of glucosamine and risk of CRC overall (HR: 0.94; 95% CI: 0.85-1.04). However, the association varied by screening status (p-interaction:0.05), with an inverse association observed only among never-screened individuals (HR: 0.86; 95% CI: 0.76-0.98). When stratified by study time, an inverse association was observed in early follow-up among those entering the cohort in early years (2006-2008, HR: 0.80; 95% CI: 0.67-0.95). No heterogeneity was observed by age, sex, body mass index, smoking status, or use of non-steroidal anti-inflammatory drugs.

CONCLUSIONS

While there was no association between glucosamine use and CRC overall, the inverse association among never-screened individuals mirrors our observations in prior exploratory analyses of US cohorts. The National Health Service Bowel Cancer Screening Program started in 2006 in England and was more widely implemented across the UK by 2009. In line with this, we observed an inverse association limited to early follow-up in those surveyed 2006-2008, before screening was widely implemented.

IMPACT

These data suggest that unscreened individuals may benefit from use of glucosamine; however, further studies are needed to confirm the interplay of screening and timing.

Relationship between glucosamine use and the risk of lung cancer: data from a nationwide prospective cohort study

BACKGROUND

Research on glucosamine shows anti-inflammatory and anti-cancer benefits with a minimal adverse effects. We aimed to explore the relationship between use of glucosamine and risk of lung cancer and lung cancer mortality based on data from the large-scale nationwide prospective UK Biobank cohort study.

METHODS

Participants were enrolled between the year 2006 and 2010 and followed up to 2020. Cox proportion hazards model were used to assess the relationship between glucosamine use and risk of lung cancer and lung cancer mortality. Subgroup analyses and sensitivity analyses were performed to explore the potential effect modifications and the robustness of main findings.

RESULTS

A total of 439,393 participants (mean age: 56 years; 53% females) with a mean follow-up of 11 years were included for analyses. There were 82,603 (18.80%) participants reporting regular use of glucosamine at baseline. During follow-up, there were 1,971 (0.45%) lung cancer events documented. Glucosamine use was significantly associated with a decreased risk of lung cancer (hazard ratio=0.84, 95% CI: 0.75-0.92, p<0.001) and lung cancer mortality (hazard ratio=0.88, 95% CI: 0.81-0.96, p=0.002) in fully-adjusted models. A stronger association between glucosamine use and decreased lung cancer risk was observed in participants with a family history of lung cancer when compared to those without a family history.

CONCLUSION

Regular use of glucosamine was significantly related with decreased risk of lung cancer and lung cancer mortality, based on data from this nationwide prospective cohort study.

Impact of Glucosamine Supplementation on Gut Health

Glucosamine (GLU) is a natural compound found in cartilage, and supplementation with glucosamine has been shown to improve joint heath and has been linked to reduced mortality rates. GLU is poorly absorbed and may exhibit functional properties in the gut. The purpose of this study was to examine the impact of glucosamine on gastrointestinal function as well as changes in fecal microbiota and metabolome. Healthy males (n = 6) and females (n = 5) (33.4 ± 7.7 years, 174.1 ± 12.0 cm, 76.5 ± 12.9 kg, 25.2 ± 3.1 kg/m2, n = 11) completed two supplementation protocols that each spanned three weeks separated by a washout period that lasted two weeks. In a randomized, double-blind, placebo-controlled, crossover fashion, participants ingested a daily dose of GLU hydrochloride (3000 mg GlucosaGreen®, TSI Group Ltd., Missoula, MT, USA) or maltodextrin placebo. Study participants completed bowel habit and gastrointestinal symptoms questionnaires in addition to providing a stool sample that was analyzed for fecal microbiota and metabolome at baseline and after the completion of each supplementation period. GLU significantly reduced stomach bloating and showed a trend towards reducing constipation and hard stools. Phylogenetic diversity (Faith's PD) and proportions of Pseudomonadaceae, Peptococcaceae, and Bacillaceae were significantly reduced following GLU consumption. GLU supplementation significantly reduced individual, total branched-chain, and total amino acid excretion, with no glucosamine being detected in any of the fecal samples. GLU had no effect on fecal short-chain fatty acids levels. GLU supplementation provided functional gut health benefits and induced fecal microbiota and metabolome changes.

Oral and Intravenous Iron Therapy Differentially Alter the On- and Off-Tumor Microbiota in Anemic Colorectal Cancer Patients

Iron deficiency anemia is a common complication of colorectal cancer and may require iron therapy. Oral iron can increase the iron available to gut bacteria and may alter the colonic microbiota. We performed an intervention study to compare oral and intravenous iron therapy on the colonic tumor-associated (on-tumor) and paired non-tumor-associated adjacent (off-tumor) microbiota. Anemic patients with colorectal adenocarcinoma received either oral ferrous sulphate (n = 16) or intravenous ferric carboxymaltose (n = 24). On- and off-tumor biopsies were obtained post-surgery and microbial profiling was performed using 16S ribosomal RNA analysis. Off-tumor α- and β-diversity were significantly different between iron treatment groups. No differences in on-tumor diversity were observed. Off-tumor microbiota of oral iron-treated patients showed higher abundances of the orders Clostridiales, Cytophagales, and Anaeroplasmatales compared to intravenous iron-treated patients. The on-tumor microbiota was enriched with the orders Lactobacillales and Alteromonadales in the oral and intravenous iron groups, respectively. The on- and off-tumor microbiota associated with intravenous iron-treated patients infers increased abundances of enzymes involved in iron sequestration and anti-inflammatory/oncogenic metabolite production, compared to oral iron-treated patients. Collectively, this suggests that intravenous iron may be a more appropriate therapy to limit adverse microbial outcomes compared to oral iron.

Recent advances in the field of caloric restriction mimetics and anti-aging molecules

Caloric restriction (CR) mimetics are molecules that produce beneficial effects on health and longevity in model organisms and humans, without the challenges of maintaining a CR diet. Conventional CR mimetics such as metformin, rapamycin and spermidine activate autophagy, leading to recycling of cellular components and improvement of physiological function. We review here novel CR mimetics and anti-aging compounds, such as 4,4'-dimethoxychalcone, fungal polysaccharides, inorganic nitrate, and trientine, highlighting their possible molecular targets and mechanisms of action. The activity of these compounds can be understood within the context of hormesis, a biphasic dose response that involves beneficial effects at low or moderate doses and toxic effects at high doses. The concept of hormesis has widespread implications for the identification of CR mimetics in experimental assays, testing in clinical trials, and use in healthy humans. We also discuss the promises and limitations of CR mimetics and anti-aging molecules for delaying aging and treating chronic diseases.

Glucosamine and Chondroitin Use in Relation to C-Reactive Protein Concentration: Results by Supplement Form, Formulation, and Dose

Objectives: Glucosamine and chondroitin supplements have been associated with reduced inflammation, as measured by C-reactive protein (CRP). It is unclear if associations vary by formulation (glucosamine alone vs. glucosamine+chondroitin), form (glucosamine hydrochloride vs. glucosamine sulfate), or dose. Design, Subjects, Setting, Location: The authors evaluated these questions using cross-sectional data collected between 1999 and 2010 on 21,917 US adults, surveyed as part of the National Health and Nutrition Examination Survey (NHANES). Exposures: Glucosamine and chondroitin use was assessed during an in-home interview; exposures include supplement formulation, form, and dose. Outcome/Analysis: CRP was measured using blood collected at interview. Survey-weighted linear regression was used to evaluate the multivariable-adjusted association between exposures and log-transformed CRP. Results: In early years (1999-2004), use of glucosamine (ratio = 0.87; 95% confidence interval [CI] = 0.79-0.96) and chondroitin (ratio = 0.83; 95% CI = 0.72-0.95) was associated with reduced CRP. However, associations significantly varied by calendar time (p-interaction = 0.04 and p-interaction = 0.01, respectively), with associations nonsignificant in later years (ratio = 1.09; 95% CI = 0.94-1.28 and ratio = 1.16; 95% CI = 0.99-1.35, respectively). Consequently, all analyses have been stratified by calendar time. Associations did not significantly differ by formulation in either set of years; however, significant associations were observed for combined use of glucosamine+chondroitin (ratioearly = 0.82; 95% CI = 0.72-0.95; ratiolate = 1.16; 1.00-1.35), but not glucosamine alone. Associations also did not significantly differ by supplement form. Even so, a significant inverse association was observed only for glucosamine sulfate in the early years (ratio = 0.78; 95% CI = 0.64-0.95); no significant association was observed for glucosamine hydrochloride. No significant trends were observed by dose. Conclusions: Although a significant inverse association was observed for glucosamine and chondroitin and CRP in early years, this association did not hold in later years. This pattern held for combined use of glucosamine+chondroitin as well as glucosamine sulfate, although associations did not significantly vary by supplement form, formulation, or dose. Further study is needed to better understand these associations in the context of calendar time.

Glucosamine and Chondroitin Supplements and Risk of Colorectal Adenoma and Serrated Polyp

BACKGROUND

Studies have shown an inverse association between use of glucosamine and chondroitin supplements and colorectal cancer risk. However, the association with the precursor lesion, colorectal adenoma and serrated polyp, has not been examined.

METHODS

Analyses include 43,163 persons from the Nurses' Health Study (NHS), Health Professionals Follow-up Study (HPFS), and NHS2 who reported on glucosamine/chondroitin use in 2002 and who subsequently underwent ≥1 lower gastrointestinal endoscopy. By 2012, 5,715 conventional (2,016 high-risk) adenomas were detected, as were 4,954 serrated polyps. Multivariable logistic regression for clustered data was used to calculate OR and 95% confidence intervals (CI).

RESULTS

Glucosamine/chondroitin use was inversely associated with high risk and any conventional adenoma in NHS and HPFS: in the pooled multivariable-adjusted model, glucosamine + chondroitin use at baseline was associated with a 26% (OR = 0.74; 95% CI, 0.60-0.90; P _{heterogeneity} = 0.23) and a 10% (OR = 0.90; 95% CI, 0.81-0.99; P _{heterogeneity} = 0.36) lower risk of high-risk adenoma and overall conventional adenoma, respectively. However, no association was observed in NHS2, a study of younger women (high-risk adenoma: OR = 1.09; 95% CI, 0.82-1.45; overall conventional adenoma: OR = 1.00; 95% CI, 0.86-1.17), and effect estimates pooled across all three studies were not significant (high-risk: OR = 0.83; 95% CI, 0.63-1.10; P _{heterogeneity} = 0.03; overall conventional adenoma: OR = 0.93; 95% CI, 0.85-1.02; P _{heterogeneity} = 0.31). No associations were observed for serrated polyps.

CONCLUSIONS

Glucosamine/chondroitin use was associated with lower risks of high-risk and overall conventional adenoma in older adults; however, this association did not hold in younger women, or for serrated polyps.

IMPACT

Our study suggests that glucosamine and chondroitin may act on early colorectal carcinogenesis in older adults.

Chondroitin Sulphate and Glucosamine Use Depend on Nonsteroidal Anti-inflammatory Drug Use to Modify the Risk for Colorectal Cancer

BACKGROUND

A safe and effective colorectal cancer chemoprevention agent remains to be discovered. There is little evidence regarding the protective effect of chondroitin sulphate and glucosamine on colorectal cancer. We aimed to assess the association between colorectal cancer risk and the use of chondroitin sulphate and glucosamine using a large cohort with dispensed data.

METHODS

We performed a population-based case-control study in Catalonia using primary care reimbursed medication records (SIDIAP database). The study included 25,811 cases with an incident diagnosis of colorectal cancer and 129,117 matched controls between 2010 and 2015.

RESULTS

The prevalence of ever use was 9.0% (n = 13,878) for chondroitin sulphate, 7.3% (n = 11,374) for glucosamine, and 35% for regular use of nonsteroidal anti-inflammatory drugs (NSAID; n = 45,774). A decreased risk of colorectal cancer was observed among chondroitin sulphate use [OR: 0.96; 95% confidence interval (CI), 0.91-1.01], glucosamine use (OR: 0.92; 95% CI, 0.87-0.97), and concurrent use of chondroitin sulphate and glucosamine (OR: 0.83; 95% CI, 0.70-0.98). Especially for glucosamine, there was a dose-response association regarding duration and cumulative dose. The analysis stratified by simultaneous use with other NSAIDs showed that these drugs used without other NSAIDs do not reduce risk (OR: 1.06; 95% CI, 0.74-1.51). However, they may have a synergistic protective effect when used with other NSAIDs (OR: 0.80; 95% CI, 0.72-0.88).

CONCLUSIONS

This study does not provide strong support for an independent protective association of chondroitin sulphate or glucosamine on colorectal cancer risk in our population. However, these drugs may have a synergistic beneficial effect among NSAID users.

IMPACT

Chondroitin sulphate or glucosamine may contribute to the protective effect of NSAID use in colorectal cancer.

Identification of longevity compounds with minimized probabilities of side effects

It is hypothesized that treating the general aging population with compounds that slow aging, geroprotectors, could provide many benefits to society, including a reduction of age-related diseases. It is intuitive that such compounds should cause minimal side effects, since they would be distributed to otherwise healthy individuals for extended periods of time. The question therefore emerges of how we should prioritize geroprotectors discovered in model organisms for clinical testing in humans. In other words, which compounds are least likely to cause harm, while still potentially providing benefit? To systematically answer this question we queried the DrugAge database—containing hundreds of known geroprotectors—and cross-referenced this with a recently published repository of compound side effect predictions. In total, 124 geroprotectors were associated to 800 unique side effects. Geroprotectors with high risks of side effects, some even with risk for death, included lamotrigine and minocycline, while compounds with low side effect risks included spermidine and d-glucosamine. Despite their popularity as top geroprotector candidates for humans, sirolimus and metformin harbored greater risks of side effects than many other candidate geroprotectors, sirolimus being the more severe of the two. Furthermore, we found that a correlation existed between maximum lifespan extension in worms and the likelihood of causing a side effect, suggesting that extreme lifespan extension in model organisms should not necessarily be the priority when screening for novel geroprotectors. We discuss the implications of our findings for prioritizing geroprotectors, suggesting spermidine and d-glucosamine for clinical trials in humans.

Modulation of Gut Microbiota by Glucosamine and Chondroitin in a Randomized, Double-Blind Pilot Trial in Humans

Glucosamine and chondroitin (G&C), typically taken for joint pain, are among the most frequently used specialty supplements by US adults. More recently, G&C have been associated with lower incidence of colorectal cancer in human observational studies and reduced severity of experimentally-induced ulcerative colitis in rodents. However, little is known about their effects on colon-related physiology. G&C are poorly absorbed and therefore metabolized by gut microbiota. G&C have been associated with changes in microbial structure, which may alter host response. We conducted a randomized, double-blind, placebo-controlled crossover trial in ten healthy adults to evaluate the effects of a common dose of G&C compared to placebo for 14 days on gut microbial community structure, measured by 16S rRNA gene sequencing. Linear mixed models were used to evaluate the effect of G&C compared to placebo on fecal microbial alpha and beta diversity, seven phyla, and 137 genera. Nine genera were significantly different between interventions (False Discovery Rate < 0.05). Abundances of four Lachnospiraceae genera, two Prevotellaceae genera, and Desulfovibrio were increased after G&C compared to placebo, while Bifidobacterium and a member of the Christensenellaceae family were decreased. Our results suggest that G&C affect the composition of the gut microbiome which may have implications for therapeutic efficacy.

Population-based case-control study: chemoprotection of colorectal cancer with non-aspirin nonsteroidal anti-inflammatory drugs and other drugs for pain control

BACKGROUND

Inflammation and overexpression of cyclooxygenase-2 (COX-2) have been described to play a key role in the progression from nonpathologic intestinal mucosa to colorectal cancer (CRC).

AIMS

To assess the chemoprotective effect of non-aspirin nonsteroidal anti-inflammatory drugs (NA-NSAIDs) under different patterns of use in a Mediterranean population and to explore the potential effect of symptomatic slow-acting drugs for osteoarthritis (SYSADOAs; chondroitin sulfate and glucosamine) and metamizole (or dipyrone), also reported to influence COX-2 activity.

METHODS

We performed a case-control study nested in a cohort extracted from the primary care database, BIFAP. From 2001 to 2014, we included 15 491 incident cases and 60 000 random controls. To estimate the association between the drugs of interest and CRC, we built logistic regression models to compute the adjusted-odds ratios (AOR) and 95% confidence intervals (CI).

RESULTS

NA-NSAIDs use was associated with a reduced risk of CRC (AOR = 0.67; 95% CI: 0.63-0.71) and increased linearly with duration of treatment (p for trend <0.001). The effect diminished upon discontinuation but persisted statistically significant up to 1 year. All individual NA-NSAIDs examined showed a decreased risk. The concomitant use of proton-pump inhibitors (PPI) had no impact on the protective effect of NA-NSAIDs; AOR_{PPI + NSAID}  = 0.64; 0.58-0.71. SYSADOA use was associated with a reduced risk (0.79; 0.69-0.90) but disappeared after the exclusion of NSAID users during the previous 1 or 3 years (0.85; 0.70-1.04 and 1.00; 0.76-1.31 respectively). Metamizole did not show a chemoprotective effect.

CONCLUSIONS

NA-NSAID use is associated with a duration-dependent risk reduction of CRC not shared by SYSADOAs or metamizole.