Association between adherence to a dietary approach to stop hypertension and the Mediterranean diets and risk of colorectal cancer: A matched case-control study.

BACKGROUND: Colorectal cancer (CRC) is one of the most common cancers and is currently the third leading cause of cancer-related deaths worldwide. This study aimed to evaluate whether the dietary approach to stop hypertension (DASH) and Mediterranean (MED) diets are associated with CRC in Iranian adults. METHODS: This hospital-based case-control study was conducted on 71 cases and 142 controls (40-75 years old) in three general hospitals in Tehran, Iran. The dietary intakes of individuals were collected through face-to-face interviews using a semi-quantitative food frequency questionnaire (FFQ) that included 125 food items. The DASH and MED diet scores were calculated according to food items based on guidelines. Two logistic regression models were applied to evaluate the association between DASH and MED score adherence. RESULTS: After adjusting for confounding factors, a negative association between DASH diet adherence and CRC risk was observed in the second and last tertile compared to the first tertile (T) (T2: odds ratio (OR) = 0.33; 95% confidence interval (CI): 0.14-0.77 - T3: OR = 0.09; 95% CI: 0.03-0.27). There was no significant association between the MED diet and the risk of CRC. CONCLUSIONS: In conclusion, the current study's findings presented that adherence to a DASH diet could reduce the odds of CRC.

The effects of vitamin C supplementation on glycemic control in patients with type 2 diabetes: A systematic review and meta-analysis.

BACKGROUND AND AIM: It has been suggested that taking vitamin C supplements may improve glycemic control in patients with type 2 diabetes mellitus (T2DM). However, there has not been a thorough evaluation of the actual impact or certainty of the findings. This systematic review and meta-analysis was conducted to determine the effect of vitamin C supplementation on glycemic profile in T2DM patients. METHODS: A systematic search was performed across online databases including Scopus, Web of Science, and PubMed/Medline to identify relevant randomized controlled trials (RCTs) published until July 2022. A random-effects model was applied for the meta-analysis. RESULTS: The present meta-analysis included a total of 22 RCTs with 1447 patients diagnosed with T2DM.A pooled analysis revealed a significant decrease in levels of serum hemoglobin A1c (HbA1c), fasting insulin, and fasting blood glucose (FBG) in vitamin C-treated T2DM patients compared with their untreated counterparts. The dose-response evaluation displayed a substantial linear association between the intervention duration and changes in serum HbA1c levels. However, the analysis did not demonstrate any significant effect of vitamin C on serum values of homeostasis model assessment of insulin resistance(HOMA-IR) in diabetic patients. Subgroup analyses indicated that high-dose vitamin C administration (≥1000 mg/d) considerably decreased serum HOMA-IR levels. CONCLUSION: These findings suggest that long-term (≥12 weeks) and high-dose vitamin C supplementation (≥1000 mg/d) may ameliorate glycemic profile in T2DM patients. However, additional high-quality RCTs are necessary to validate these results.

Ultra-Processed Food Intake and Risk of Colorectal Cancer: A Matched Case-Control Study.

Colorectal cancer (CRC) is the third most prevalent and the second fatal cancer in the world. Ultra-processed foods (UPFs) are suggested to be related to various non-communicable diseases including cancers. However, studies on the relationship between UPFs and CRC are scarce. The aim of this study was to determine the association between consumption of UPFs and CRC. In a case-control study conducted in four hospitals in Tehran, Iran, consumption of UPFs in 71 CRC patients and 142 controls (patients with non-neoplastic diseases) were compared. Using 125-item semi-quantitative food frequency questionnaire, dietary intakes were assessed. We used Multivariate logistic regression to estimate the association between UPFs intake and risk of CRC. Intake of nondairy beverages (P = 0.009), processed meat and fast food (P = 0.04) was significantly higher in those in the highest tertile of UPFs intake compared to the lowest tertile. In addition, intake of UPFs was associated with higher risk of CRC. The association remained constant after adjustment for BMI, income, smoking, type of job, educational level, and physical activity (OR, 3.32; 95% CI, 1.44-7.61; P = 0.003). Results of this study indicate that the intake of UPFs is associated with increased odds of CRC.

Long-term administration of metformin ameliorates age-dependent oxidative stress and cognitive function in rats.

BACKGROUND: Aging is an inevitable physiological process, associated with a decline in cognitive function. Recently, metformin, as the first-line treatment for type II diabetes, has been shown to increase the life expectancy of diabetic patients. Therefore, researchers are paying increasing attention to its anti-aging properties. Oxygen free radicals are responsible for oxidative stress, which is a prominent factor in age-associated diseases. This study aimed to evaluate the effects of long-term administration of metformin on age-dependent oxidative stress and cognitive function. METHODS: In this experimental study, 32 normal (nondiabetic) male Wistar rats were randomly assigned into control and metformin groups (n = 16 per group). The metformin group received 100 mg/kg of metformin in drinking water daily for six months. The shuttle box test was used for the passive avoidance task in 24-month-old rats. For the biochemical assay, the total antioxidant capacity (TAC) and malondialdehyde (MDA) level were measured. Nissl and TUNEL staining were also used for histopathological assessments. Data were analyzed using independent t-test. RESULTS: The present findings revealed that metformin significantly reduced the MDA level and increased the TAC in the hippocampus of the metformin group (p < 0.05). The survival of hippocampal CA1 neurons was significantly higher in the metformin group as compared to the control group, while the number of TUNEL-positive neurons decreased significantly (p < 0.05). On the other hand, metformin markedly improved the passive avoidance memory in the metformin group as compared to the control group (p < 0.05). CONCLUSION: It can be concluded that long-term metformin intake, by modulating the oxidant/antioxidant mechanisms, prevents the loss of hippocampal neurons caused by age-dependent oxidative stress and improves memory.