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Antioxidant vitamins supplementation reduce endometriosis related pelvic pain in humans: a systematic review and meta-analysis.
Zheng, SH, Chen, XX, Chen, Y, Wu, ZC, Chen, XQ, Li, XL
Reproductive biology and endocrinology : RB&E. 2023;21(1):79
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Endometriosis is a common gynaecological disorder in reproductive-age women which leads to infertility and pain symptoms. Current pain management approaches involve medications and surgical treatments, but their side effects and risk of recurrence have led to the exploration of alternative options. The aim of this study was to clarify the potential effects of antioxidant vitamins supplementation on endometriosis. This study was a systematic review and meta-analysis of eleven studies, comprising a total of 589 patients. Results showed that antioxidant vitamins supplementation can effectively alleviate endometriosis-related pain and reduce inflammatory markers. Authors conclude that antioxidant vitamins supplementation can be considered as an alternative treatment either on its own or in combination with other methods for managing endometriosis-related pain. However, further research would help to provide a clearer understanding of the role of antioxidant vitamins supplementation in women with endometriosis.
Abstract
OBJECTIVE This study aimed to clarify the effect of antioxidant vitamins supplementation on endometriosis-related pain. METHODS A systematic search of PubMed, Web of Science, Cochrane Library, Scopus, and China National Knowledge Infrastructure (CNK) databases was conducted to identify relevant studies published in English and Chinese up to 16 March 2023. The search terms used were "endometriosis" OR "endometrioma" OR "endometrium" AND "antioxidant" OR "Vitamin C" OR "Vitamin E" OR "Vitamin D" OR "25-OHD" OR "25(OH)D" OR "25-hydroxyvitamin D". Eligible studies were randomized controlled trials (RCTs) that assessed pain scores using the Visual Analogue Scale (VAS). Mean differences or odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to evaluate the effect of antioxidant vitamins supplementation on endometriosis. The quality of the included studies was assessed using the Cochrane Risk of Bias Tool. The study was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. RESULTS A total of 13 RCTs involving 589 patients were included in this meta-analysis. We identified 11 studies that evaluated the effect of antioxidant vitamins supplementation on endometriosis-related pain. The results indicated that the supplementation of antioxidant vitamins can effectively alleviate endometriosis-related pain. Subgroup analysis showed that the supplementation of vitamin E (with or without vitamin C) had a positive effect on improving clinical pelvic pain in patients with chronic pelvic pain. Conversely, supplementation of vitamin D was associated with a reduction in pelvic pain in endometriosis patients, but the difference was not statistically significant compared to the placebo. Additionally, we observed changes in oxidative stress markers following vitamin supplementation. Plasma malondialdehyde (MDA) concentration decreased in patients with endometriosis after antioxidant vitamin supplementation, and the plasma MDA level was inversely correlated with the time and dose of vitamin E and C supplementation. Furthermore, the inflammatory markers in peritoneal fluid, including RANTES, interleukin-6, and monocyte chemoattractant protein-1, significantly decreased after antioxidant therapy. These findings suggest that antioxidant vitamins may alleviate pain in endometriosis patients by reducing inflammation. CONCLUSIONS The included studies support the potential role of antioxidant vitamins in the management of endometriosis. Supplementation with antioxidant vitamins effectively reduced the severity of dysmenorrhea, improved dyspareunia and pelvic pain, and enhanced quality of life in these patients. Therefore, antioxidant vitamin therapy could be considered as an alternative treatment method, either alone or in combination with other approaches, for endometriosis-related pain. TRIAL REGISTRATION PROSPERO registration number: CRD42023415198.
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The Effect of Antioxidants on Sperm Quality Parameters and Pregnancy Rates for Idiopathic Male Infertility: A Network Meta-Analysis of Randomized Controlled Trials.
Li, KP, Yang, XS, Wu, T
Frontiers in endocrinology. 2022;13:810242
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Male infertility has gradually increased in recent years and is thought to be an equal contributor alongside female infertility in fertility issues. An imbalance in reactive oxygen species, which can damage sperm cells and the protective antioxidants is thought to be a major contributor to male infertility. This meta-analysis of randomised control trials aimed to determine which antioxidants have the most beneficial effect on sperm quality and count and pregnancy rates. The results showed that 10 antioxidants have been researched; L-carnitine (LC), L-carnitine+L-acetylcarnitine (LAC), coenzyme Q10 (Q10), omega-3 fatty acids (O-3), selenium (Se), zinc (Zn), vitamin E+vitamin C (VEC), folic acid (FAC), and N-acetylcysteine (NAC). LC was the most effective at improving sperm motility and morphology with reducing effectiveness for Q10, O-3, LAC, and Se. Four antioxidants improved sperm concentration starting with the most effective being 0-3, then Q10, Se, and LC. There were no effects of antioxidants on pregnancy rate. It was concluded that LC was the most effective at improving sperm motility and morphology and O-3 was the most effective at increasing sperm concentration, however this did not translate into improvements in pregnancy rate. This study could be used by healthcare professionals to understand that LC and O-3 may help to improve sperm quality and concentration, but this may not be sufficient to improve male fertility.
Expert Review
Conflicts of interest:
None
Take Home Message:
- Consider antioxidant rich diets and increase awareness of the benefits of antioxidants and nutritional interventions in improving fertility rates
- Lifestyle modifications such as maintaining a healthy weight, regular exercise and avoiding harmful substances can enhance the positive effects of antioxidants on fertility
- Patients facing infertility should consider visiting a healthcare professional including nutritional therapists or fertility specialists
- Patients should approach interventions including antioxidant use with a long term perspective.
Evidence Category:
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X
A: Meta-analyses, position-stands, randomized-controlled trials (RCTs)
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B: Systematic reviews including RCTs of limited number
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C: Non-randomized trials, observational studies, narrative reviews
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D: Case-reports, evidence-based clinical findings
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E: Opinion piece, other
Summary Review:
Introduction
The aim of this study was to investigate the impact of antioxidants on sperm quality parameters and pregnancy rates in cases of idiopathic male infertility. The focus was on randomised controlled trials (RCTs) to provide a comprehensive analysis of existing evidence.
Methods
- Utilized a network meta-analysis approach to synthesise data from 23 RCTs with 1917 patients and 10 different antioxidants
- Included studies with a diverse range of antioxidants and placebo/control groups
- Sample size varied across included studies, with a total number of participants analysed for each outcome.
Results
- L-Carnitine, L-carnitine+L-acetylcarnitine, coenzyme-Q10, ω-3 fatty acid, and selenium were more effective than placebo in improving sperm quality parameters
- L-Carnitine showed the most pronounced improvement in terms of sperm motility and sperm morphology (WMD 6.52% [95% CI: 2.55% to 10.05%], WMD 4.96% [0.20% to 9.73%])
- ω-3 fatty acid had the most significant improvement in terms of sperm concentration (WMD 9.89 × 106/ml, [95% CI: 7.01 to 12.77 × 106/ml])
- None of these supplements showed a statistical significant improvement on pregnancy rates compared to placebo.
Conclusion
- L-Carnitine showed significant improvement in terms of sperm motility and morphology
- Omega-3 fatty acids significantly improved sperm concentration
- Co-Q10 has shown to effectively improve sperm motility and concentration
- No statistically significant result was observed in terms of pregnancy rate compared to placebo.
Clinical practice applications:
- Prescribing antioxidants should be considered for patients with idiopathic male infertility
- L-Carnitine can significantly improve sperm motility and morphology
- CoQ10 has shown to improve sperm motility and concentration
- Omega-3 improved sperm concentration
- Considering the patient’s needs, practitioners can tailor the antioxidant for most significant improvement and desired outcomes.
Considerations for future research:
- Investigate the synergistic effects of combining various antioxidants to improve sperm quality and pregnancy rates
- More studies to be conducted to assess the effect of antioxidant combinations on pregnancy outcomes
- Pharmacogenomics investigations could help tailor the interventions to provide individualised medicine
- Investigate the integration of antioxidant formulations with therapeutic interventions, lifestyle modifications, hormonal interventions etc.
Abstract
PURPOSE Male infertility is a global public health issue recognized by the WHO. Recently, antioxidants are increasingly used to treat idiopathic male infertility. However, the lack of available evidence has led to the inability to rank the effects of antioxidants on the sperm quality parameters and pregnancy rate of infertile men. This network meta-analysis studied the effects of different antioxidants on the sperm quality and pregnancy rate of idiopathic male infertility. METHODS We searched PubMed, Embase, Web of Science, and Cochrane Library databases for randomized controlled trials (RCTs). The weighted mean difference (WMD) and odds ratio (OR) were applied for the comparison of continuous and dichotomous variables, respectively, with 95% CIs. The outcomes were sperm motility, sperm concentration, sperm morphology, and pregnancy rate. RESULTS A total of 23 RCTs with 1,917 patients and 10 kids of antioxidants were included. l-Carnitine, l-carnitine+l-acetylcarnitine, coenzyme-Q10, ω-3 fatty acid, and selenium were more efficacious than placebo in sperm quality parameters. l-Carnitine was ranked first in sperm motility and sperm morphology (WMD 6.52% [95% CI: 2.55% to 10.05%], WMD 4.96% [0.20% to 9.73%]). ω-3 fatty acid was ranked first in sperm concentration (WMD 9.89 × 106/ml, [95% CI: 7.01 to 12.77 × 106/ml]). In terms of pregnancy rate, there was no significant effect as compared with placebo. CONCLUSIONS l-Carnitine was ranked first in sperm motility and sperm morphology. ω-3 fatty acid was ranked first in sperm concentration. Coenzyme-Q10 had better effective treatment on sperm motility and concentration. Furthermore, high-quality RCTs with adequate sample sizes should be conducted to compare the outcomes of different antioxidants.
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An updated systematic review and meta-analysis on adherence to mediterranean diet and risk of cancer.
Morze, J, Danielewicz, A, Przybyłowicz, K, Zeng, H, Hoffmann, G, Schwingshackl, L
European journal of nutrition. 2021;60(3):1561-1586
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The development of cancer is associated with a number of risk factors, including smoking, obesity, sedentary lifestyles, alcohol consumption, infections, pollution, and dietary imbalances. Based on previous research, optimal consumption of fruits, vegetables, and whole grains, along with reduced consumption of red and processed meat, reduces cancer risk. According to this systematic review and meta-analysis, adherence to the Mediterranean diet is associated with lower cancer mortality and site-specific cancer development. A Mediterranean diet includes fruits, vegetables, nuts, legumes, fish, whole grains, extra virgin olive oil, and low amounts of red meat, processed meat, egg, and dairy, along with moderate amounts of red wine. According to this systematic review and meta-analysis, adherence to the Mediterranean diet reduces the risk of cancer mortality and the risk of developing cancers specific to the site, such as colorectal cancer, bladder cancer, gastric cancer, and lung cancer. Among the components of the Mediterranean diet, fruits, vegetables, and whole grains have been shown to reduce cancer risk. Bioactive substances found in Mediterranean diet components require additional robust studies to evaluate their benefits. A healthcare professional can use the results of this study to make clinical decisions and recommend therapeutic interventions to cancer patients.
Abstract
PURPOSE The aim of current systematic review was to update the body of evidence on associations between adherence to the Mediterranean diet (MedDiet) and risk of cancer mortality, site-specific cancer in the general population; all-cause, and cancer mortality as well as cancer reoccurrence among cancer survivors. METHODS A literature search for randomized controlled trials (RCTs), case-control and cohort studies published up to April 2020 was performed using PubMed and Scopus. Study-specific risk estimates for the highest versus lowest adherence to the MedDiet category were pooled using random-effects meta-analyses. Certainty of evidence from cohort studies and RCTs was evaluated using the NutriGrade scoring system. RESULTS The updated search revealed 44 studies not identified in the previous review. Altogether, 117 studies including 3,202,496 participants were enclosed for meta-analysis. The highest adherence to MedDiet was inversely associated with cancer mortality (RRcohort: 0.87, 95% CI 0.82, 0.92; N = 18 studies), all-cause mortality among cancer survivors (RRcohort: 0.75, 95% CI 0.66, 0.86; N = 8), breast (RRobservational: 0.94, 95% CI 0.90, 0.97; N = 23), colorectal (RRobservational: 0.83, 95% CI 0.76, 0.90; N = 17), head and neck (RRobservational: 0.56, 95% CI 0.44, 0.72; N = 9), respiratory (RRcohort: 0.84, 95% CI 0.76, 0.94; N = 5), gastric (RRobservational: 0.70, 95% CI 0.61, 0.80; N = 7), bladder (RRobservational: 0.87, 95% CI 0.76, 0.98; N = 4), and liver cancer (RRobservational: 0.64, 95% CI 0.54, 0.75; N = 4). Adhering to MedDiet did not modify risk of blood, esophageal, pancreatic and prostate cancer risk. CONCLUSION In conclusion, our results suggest that highest adherence to the MedDiet was related to lower risk of cancer mortality in the general population, and all-cause mortality among cancer survivors as well as colorectal, head and neck, respiratory, gastric, liver and bladder cancer risks. Moderate certainty of evidence from cohort studies suggest an inverse association for cancer mortality and colorectal cancer, but most of the comparisons were rated as low or very low certainty of evidence.
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Olive oil intake is inversely related to cancer prevalence: a systematic review and a meta-analysis of 13,800 patients and 23,340 controls in 19 observational studies.
Psaltopoulou, T, Kosti, RI, Haidopoulos, D, Dimopoulos, M, Panagiotakos, DB
Lipids in health and disease. 2011;10:127
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Dietary fat, both in terms of quality and quantity, has been implicated in cancer development, either positively or negatively. The aim of this systematic review and meta-analysis of 19 studies (13,800 cancer patients; 23,340 controls) was to evaluate whether raw olive oil intake was associated with various types of cancer. Overall, the authors concluded that olive oil consumption was associated with lower odds of cancer development. The most prominent results were observed for breast cancer and cancer of the digestive tract. The authors call for more studies to investigate whether higher olive oil intake facilitates higher vegetable intake, thus maximising potential beneficial effects on cancer prevention and whether it is the mono-unsaturated fat component of olive oil or the anti-oxidant components that are responsible for the beneficial effects. Nutrition practitioners may want to incorporate olive oil intake into their client protocols as a preventative health measure.
Abstract
Dietary fat, both in terms of quantity and quality, has been implicated to cancer development, either positively or negatively. The aim of this work was to evaluate whether olive oil or monounsaturated fat intake was associated with the development of cancer. A systematic search of relevant studies, published in English, between 1990 and March 1, 2011, was performed through a computer-assisted literature tool (i.e., Pubmed). In total 38 studies were initially allocated; of them 19 case-control studies were finally studied (13800 cancer patients and 23340 controls were included). Random effects meta-analysis was applied in order to evaluate the research hypothesis. It was found that compared with the lowest, the highest category of olive oil consumption was associated with lower odds of having any type of cancer (log odds ratio = -0.41, 95%CI -0.53, -0.29, Cohran's Q = 47.52, p = 0.0002, I-sq = 62%); the latter was irrespective of the country of origin (Mediterranean or non-Mediterranean). Moreover, olive oil consumption was associated with lower odds of developing breast cancer (logOR = -0,45 95%CI -0.78 to -0.12), and a cancer of the digestive system (logOR = -0,36 95%CI -0.50 to -0.21), compared with the lowest intake. The strength and consistency of the findings states a hypothesis about the protective role of olive oil intake on cancer risk. However, it is still unclear whether olive oil's monounsaturated fatty acid content or its antioxidant components are responsible for its beneficial effects.