Methodological Challenges and Confounders in Research on the Effects of Ketogenic Diets: A Literature Review of Meta-Analyses.

Several meta-analyses have found a positive association between a popular type of "fad diet", ketogenic diets, and their effect on anthropometric and blood parameters. However, the non-specific inclusion criteria for meta-analyses may lead to incorrect conclusions. The aim of this literature review is to highlight the main confounders and methodological pitfalls of meta-analyses on ketogenic diets by inspecting the presence of key inclusion criteria. The PubMed, Embase, and Web of Science databases and the Cochrane Database of Systematic Reviews were searched for meta-analyses. Most meta-analyses did not define the essential parameters of a ketogenic diet (i.e., calories, macronutrient ratio, types of fatty acids, ketone bodies, etc.) as inclusion criteria. Of the 28 included meta-analyses, few addressed collecting real, re-measured nutritional data from the ketogenic diet and control groups in parallel with the pre-designed nutritional data. Most meta-analyses reported positive results in favor of ketogenic diets, which can result in erroneous conclusions considering the numerous methodological pitfalls and confounders. Well-designed clinical trials with comparable results and their meta-analyses are needed. Until then, medical professionals should not recommend ketogenic diets as a form of weight loss when other well-known dietary options have been shown to be healthy and effective.

Is Balneotherapy Protective Against Oxidative Stress? A Pilot Study.

BACKGROUND/AIM: This study aimed to research the effects of Harkány healing water on oxidative stress. The study was performed in a randomized, placebo-controlled, double-blind setup. PATIENTS AND METHODS: Twenty patients with psoriasis who underwent a 3-week-long inward balneotherapy-based rehabilitation were enrolled. Psoriasis Area and Severity Index (PASI) score and Malondialdehyde (MDA) - a marker of oxidative stress - were determined, on admission and before discharge. Patients were treated with dithranol. RESULTS: The mean PASI score - determined on admission and before discharge - decreased significantly after the 3-week-long rehabilitation 8.17 vs. 3.51 (p<0.001). The baseline MDA value of patients with psoriasis was significantly higher compared to controls (3.0±3.5 vs. 8.4±7.4) (p=0.018). MDA levels of patients receiving placebo water increased significantly compared to MDA levels of patients receiving healing water (p=0.049). CONCLUSION: The effectiveness of dithranol resides in the formation of reactive oxygen species. No increased oxidative stress was found in the patients treated with healing water, thus healing water seems to be protective against oxidative stress. However, further research is needed to confirm these preliminary results.

A New and Validated, Randomised, Controlled Placebo Water Development Trial for Medicinal Water-based Research.

BACKGROUND/AIM: To develop and validate an easy-to-use and cheap method capable of producing placebo from tap water for medicinal water efficacy trials. PATIENTS AND METHODS: Patients were divided into two groups, medicinal water and tap water group. A single 20-minute-long treatment was performed in bathtubs. Patients were asked four times during the bath to tell if they were treated with medicinal water, tap water, or could not decide. Patients were scored, one point was given for each correct answer. RESULTS: A total of 174 patients were enrolled. No significant differences were found either between the average scores or the answers of the two groups. Being familiar with the Harkány medicinal water did not influence the rate of correct answers either. There was no statistically significant difference in the number of changes of opinions between the two groups. CONCLUSION: The used method is appropriate for producing a validated placebo from tap water.

Effects of medicinal waters on the UV-sensitivity of human keratinocytes - a comparative pilot study.

Balneotherapy has been used to treat several diseases including locomotor, neurological and dermatological conditions. The basis of the "organic hypothesis" of medical balneology is that medicinal waters, especially thermal spa and hot spring waters, contain a high variability of organic components with possible biological effects, including UV photo-protection. The recent study aims to clarify this effect in a human keratinocyte cell line model. Results confirm that organic-rich extract of selected medicinal waters might protect skin-derived cells from DNA damage. These results give a clinical relevance to medicinal waters or pharmaceutical products prepared from them in preventing the adverse effects of solar or artificial UV radiation on the human skin.

Evidence for the therapeutic effect of the organic content in Szigetvár thermal water on osteoarthritis: a double-blind, randomized, controlled clinical trial.

The therapeutic effects of mineral waters have been attributed to the inorganic components alone; however, biologically active organic components are also present. We aimed to investigate whether the healing effect of Szigetvár thermal mineral water could relate to the organic matter in patients suffering from osteoarthritis of the hips and the knees. XAD macroreticular resins were used to prepare the organic fraction. Patients received a 30-min thermal water (34 °C) treatment in a bath tub, five times a week for 3 weeks. After randomization, patients were divided into three groups: tap water, mineral water, and organic fraction group. Primary outcomes were range of movement (ROM), Western Ontario and McMaster University Osteoarthritis Index (WOMAC), and visual analog scale (VAS) for pain severity, and the Short Form 36 (SF-36) questionnaire was used. These scores and indices were measured at baseline, after the last treatment, and at the end of the 3-month follow-up period. Seventy-four patients (age 67.3 ± 4.48 years) were enrolled: tap water n = 24, mineral water n = 26, and organic fraction n = 24. Treatment with the redissolved organic fraction significantly improved ROM, WOMAC, and SF-36 scores compared to the tap water. Our clinical trial provided evidence for the beneficial health effects of the organic fraction of Szigetvár medicinal water.

Clinical improvement of patients with osteoarthritis using thermal mineral water at Szigetvár Spa-results of a randomised double-blind controlled study.

Since 1966, Szigetvár in Hungary is well recognised as a thermal spa. Many patients suffering from rheumatic diseases are treated with its thermal mineral water. Our objective was to investigate the effects of a 3-week-long outpatient balneotherapy-based rehabilitation program on patients suffering from osteoarthritis of the hips and the knees. During the treatment period, patients received a 30-min underwater jet massage in a bath tub, five times a week. One patient group received jet massage in a bath tub containing mineral water; the other group received the same treatment in tap water. Primary outcomes were measured by range of movement of the involved joints and Western Ontario and McMaster University Osteoarthritis Index (WOMAC). Visual analogue scale (VAS) was applied to measure current severity of pain. Furthermore, quality of life was assessed using the Short Form 36 questionnaire (SF-36). Range of movement (ROM) score, Western Ontario and McMaster University Osteoarthritis Index and visual analogue scale were determined before the first treatment, after the last treatment and 3 months after the last treatment. SF-36 questionnaire was filled in before the first and after the last treatment. Fifty patients (17 male, 33 female mean age 66.7 ± 4.79 years) were enrolled. After randomisation, patients were divided into two groups: tap water n = 24 and mineral water n = 26. Treatment with the thermal mineral water of Szigetvár significantly improved ROM, WOMAC scores, and SF-36-scored quality of life of the patients. Our double-blind study provided evidence for the beneficial health effects of another Hungarian thermal mineral water masking the colour, odour and pH of the tap water and mineral water.

Balneotherapy in Psoriasis Rehabilitation.

BACKGROUND/AIM: This study aimed to report a balneotherapy-based psoriasis rehabilitation protocol and assess its effectivity. PATIENTS AND METHODS: Eighty psoriatic patients who underwent a 3-week-long inward balneotherapy-based rehabilitation were enrolled. Psoriasis Area and Severity Index (PASI) score and high sensitivity C-reactive protein (CRP) were determined on admission and before discharge. RESULTS: The mean PASI score and CRP level -determined on admission and before discharge-decreased significantly after the 3-week-long rehabilitation 7.15±7.3 vs. 2.62±3.05 (p<0.001) and 4.1±3.8 vs. 3.5±3.1 (p=0.026). A negative correlation was found between PASI delta and the number of spa therapies received (r=-0.228). CONCLUSION: After completing the 3-week-long spa therapy based rehabilitation, both PASI score and CRP levels showed improvement of psoriasis. The complex spa therapy used during the rehabilitation is an effective tool to reduce the symptoms of psoriasis and improve the patient's well-being.

Multi-endpoint biological monitoring in combined, carcinogenic occupational exposures.

We aimed to develop a relevant multi-endpoint biomonitoring system by studying different genotoxicity biomarkers in complex carcinogenic exposures under occupational situations. Altogether 109 workers were followed in five different workplaces. The combined carcinogenic exposures were monitored in the urine and peripheral blood samples using Ames mutagenicity test and cytogenetic analyzes. The different genotoxicity endpoints studied showed different results in the same carcinogenic exposure situations. The urinary mutagenicity tests provided more information and proved to be more sensitive compared to the cytogenetic tests in the majority of cases. In complex exposures multistep biomonitoring panel should be applied, because the exact mechanisms of the combination of single exposing agents are not known. Such a panel should involve monitoring different endpoints, e.g. point mutations, chromosomal mutations. A relatively affordable and rapid testing panel was developed using validated tests as Ames and cytogenetic assays, but its practical use should be confirmed by further investigations.

In Vivo Induction of Primary DNA Lesions upon Subchronic Oral Exposure to Multi-walled Carbon Nanotubes.

Comet assay was used for testing the potential genotoxicity of multi-walled carbon nanotubes after ingestion. Three rat strains were treated through oral gavage with 50 mg/kg/weekly nanoparticles for 90 days. Induced DNA lesions were studied in lymphocytes at 24 and 48 h following the first treatment. This was repeated at the end of the subchronic treatment in lymphocytes as well as peritoneal macrophages. A significant increase in the level of DNA lesions was measured in lymphocytes of Fischer-344 and Long-Evans rats in the first 24 h. Similar results were observed in their macrophages after 90 days. More significant differences were detected in the sensitivities of the strains. Fisher-344 rats proved the most sensitive and Wistar rats the most tolerant to the genotoxic effects of nanotubes. This may also have human relevance as populations with diverse genetic characteristics might present higher or lower susceptibility to the effects of exposure to ingested nanoparticles.

Natural UV-protective organic matter in thermal water.

Medical significance of the organic fractions of natural waters is still poorly understood. Nevertheless, there are putative biologically active organic compounds found in natural medical waters and related clay or mud samples. Organic fractions of five thermal (spa) water samples of different geochemical origin were tested for photo-biological effects. To study possible effects on the UV sensitivity of Salmonella typhimurium TA strains, the organic isolates were applied in the "plate incorporation" Ames test combined with UV-irradiation. Four samples showed measurable survival of TA100 his+ revertants following exposure to a normally lethal UV dose. Metabolic activation with a mammalian microsomal fraction (S9) elevated the effect detected (up to 61% survival). This is the first study to demonstrate the UV-protective property of organic matter in natural thermal water samples used in balneotherapy.

Can the use of medical muds cause genotoxicity in eukaryotic cells? A trial using comet assay.

Despite the lack of knowledge of their exact effects, peloids (natural muds) are widely applied in clinical treatment and prevention of different diseases, especially in rheumatic and gynecological disorders or skin diseases. Primarily we have information on their inorganic components, but only limited data are available on the organic components and nothing on their mechanism of chemical action. The objective of the present study was to detect the DNA-damaging effects (possible genotoxic effect) of peloid samples using the single-cell comet assay on Long Evans rat lymphocytes, human lymphocytes, and Eisenia fetida coelomocytes. Rat and human lymphocytes were exposed to the in toto peloid samples, in vitro. The Eisenia cells were extracted from the coelom of animals kept in the intact peloid sample. An indicator derived from the DNA fluorescence intensity was used in the statistical evaluation. The predominantly organic (Hévíz) sample showed a significant alteration from the negative control in several cases, while the inorganic (Kolop) applied did not. A higher quantity of organic compounds may have an important role in the emergence of DNA damage. The results revealed that medical muds have not only positive health effects but can also contain substances with potential human toxicity risk. Our research provides essential steps towards the creation of a toxicity profile and the possible safe use of peloids as medicinal therapy.

Carbon nanotubes induce granulomas but not mesotheliomas.

BACKGROUND: Different types of carbon nanotubes may represent toxic hazards due to their size distribution and massive surface area. They may adsorb other toxic agents that can consequently be transported into the body. Hence the aim of this study was to confirm or reject the hypothesis of carcinogenicity of two types of carbon nanotubes. MATERIALS AND METHODS: Well-defined single-walled and multi-walled carbon nanotubes were studied in a specific animal model for mesothelioma induction. RESULTS: Short-term pilot studies were published on the asbestos fibre-like mesothelioma-inducing effects of carbon nanotubes based on the proposed mechanistic correlation on health effects of fibres of the same size. Our results with a simple in vivo, peritoneal exposure model refute such an interpretation. The present studies with rats indicate that early granuloma formation does not lead to the development of mesotheliomas during chronic exposure of peritoneal mesothelium to either single- or multi-walled carbon nanotubes of varied size. CONCLUSION: Due to the limited toxicity data on carbon nanotubes, these results may be particularly important for risk assessment purposes.

Mesothelioma and environmental exposure.

A novel animal model was developed to study the direct exposure of mesothelial cells to crocidolite and chrysotile asbestos fibers. Chemically pure and pretreated Union Internationale Centre le Cancer (UICC) samples were implanted into a peritoneal envelope (Kertai's fold) of Wistar rats. Following the 12-month exposure, lack of mesothelioma induction was detected in all groups. Results suggest that the mechanism of mesothelioma formation is not a consequence of peritoneal physical exposure to the fibers.

Lack of genotoxicity of carbon nanotubes in a pilot study.

BACKGROUND: Different types of carbon nanotubes may represent toxic hazards due to their size distribution and massive surface area. They may adsorb other toxic agents that can consequently be transported into the body. The aim of the present study was to determine the possible genotoxicity of carbon nanotubes. MATERIALS AND METHODS: In vivo bacterial mutagenicity and in vitro cytogenetic studies were performed on single-walled and multi-walled carbon nanotubes. RESULTS: Oral exposure to nanotubes did not increase urinary mutagenicity in rats as studied using Ames test. No genotoxic effect was found in the in vitro micronucleus and sister chromatid exchange assays, either. Mitotic inhibition, a possible cytotoxic effect, however, was observed in the human lymphocyte cultures upon treatment with single-walled tubes. CONCLUSION: Due to the limited toxicity data on carbon nanotubes, these results may be particularly important for risk assessment purposes.

An in vivo model for testing genotoxicity of environmental fibre-associated nitroarenes.

The environmental carcinogens nitroarenes are frequently adsorbed by asbestos fibres. An effective dose of 1-nitropyrene was studied in vivo. The mutagenic pattern of excreted urine of orally and intraperitoneally exposed rats was tested by the Ames mutagenicity assay. The characteristics of detected mutagenicity proved to be different in the two routes of exposure. TA 100 mutagenicity was only detected following i.p. exposure, while TA 98 revertant frequencies were increased significantly only after deconjugation, in both groups. Since environmental asbestos exposure involves carcinogenic effects of adsorbed polycyclic aromatic hydrocarbons, this animal model provides a useful tool for testing fibre-associated nitroarenes, in both mechanistic and risk assessment studies.

[In vivo mutagenicity of the carcinogenic 1-nitropyrene. A model of a potential asbestos exposure]. / A karcinogén 1-nitropirén in vivo mutagenitása, egy potenciális azbesztexpozíció modellje.

The environmental carcinogen 1-nitropyrene was orally and intraperitoneally administered to rats in a single dose of 30 mmol/kg. Mutagenicity of excreted urine was tested in Salmonella typhimurium TA 98 and 100 strains. The mutagenic pattern of urine in case of oral exposure proved to be completely different as compared to the intraperitoneal administration. Frame-shift mutagen(s) was/were detected only after enzymatic deconjugation of sulphate or glucuronide metabolites within the first 24 h. Base-pair substitution-type mutagenicity was only detected in the urine samples collected after intraperitoneal treatment. Since environmental asbestos exposure involves carcinogenic effects of adsorbed polycyclic aromatic hydrocarbons, this animal model provides a useful tool for testing fiber-associated nitroarenes, in both mechanistic and risk assessment studies.