Dietary glycemic index, glycemic load, insulin index, insulin load and risk of diabetes-related cancers: A systematic review of cohort studies

Background & aims: It is believed that diets high in glycemic index (GI), glycemic load (GL), Insulin index (II), and Insulin load (IL) are associated with the increased risks of certain cancers through increasing serum glucose or insulin levels. Methods: We conducted this systematic review of cohort studies to evaluate the possible relation between GI, GL, II, and IL with diabetes-related cancers, including colorectal, bladder, breast, endometrium, liver, pancreas, and prostate cancers. Two separate investigators conducted a literature search through PubMed/Medline, Scopus, and Web of Science databases up to February 2020, plus reference lists of relevant articles. Results: Fifty-three cohort studies with a total of 100 098 cancer cases were included in this systematic review. Fifteen out of eighteen studies among breast cancer cases reported no significant association between GI/GL and cancer risk. These numbers were 4 out of 13 for colorectal cancer, 7 out of 9 for endometrial cancer, 2 out of 3 for liver cancer, 8 out of 10 for pancreatic cancer, and 3 out of 3 for prostate cancer. Only one cohort investigated this association in terms of bladder cancer and reported a significant association. Also, five studies reported this relation in terms of II/IL, and only one cohort among endometrial cancer patients observed a significant positive association between the risk of cancer and IL. Conclusion: We concluded a weak association between dietary GI/GL and no association between II/IL with diabetes-related cancer risk. More cohort studies are required to be performed regarding II/IL and the risk of cancer. © 2021 European Society for Clinical Nutrition and Metabolis

Can vitamin E supplementation affect obesity indices? A systematic review and meta-analysis of twenty-four randomized controlled trials

Background: Several mechanisms have been proposed for the effect of vitamin E on weight loss. Yet various interventional studies with wide ranges of doses and durations have reported contradictory results. Methods: Cochrane Library, PubMed, Scopus, and Embase databases were searched up to December 2020. Meta-analysis was performed using random-effect method. Effect size was presented as weighted mean difference (WMD) and 95 confidence interval (CI). Heterogeneity was evaluated using the I2 index. In order to identification of potential sources of heterogeneity, predefined subgroup and meta regression analyses was conducted. Results: A total of 24 studies with 33 data sets were included. There was no significant effect of vitamin E on weight (WMD: 0.15, 95 CI: �1.35 to 1.65, P = 0.847), body mass index (BMI) (WMD = 0.04, 95 CI: �0.29 to 0.37, P = 0.815), and waist circumference (WC) (WMD = �0.19 kg, 95 CI: �2.06 to 1.68, P = 0.842), respectively. However, subgroup analysis revealed that vitamin E supplementation in studies conducted on participants with normal BMI (18.5�24.9) had increasing impact on BMI (P = 0.047). Conclusion: There was no significant effect of vitamin E supplementation on weight, BMI and WC. However, vitamin E supplementation might be associated with increasing BMI in people with normal BMI (18.5�24.9). © 2021 Elsevier Ltd and European Society for Clinical Nutrition and Metabolis

Effect of spirulina and chlorella alone and combined on the healing process of diabetic wounds: an experimental model of diabetic rats

Background: Using chemical agents to cure diabetes mellitus and its complications may be accompanied by complications. New natural agents, such as spirulina and chlorella, could be used as alternative choices in this case. Methods: 65 male Wistar rats were allocated to 5 groups: A (healthy control), B (diabetic rats with a normal diet), C (diabetic rats supplemented with 50 g/kg/day spirulina), D (diabetic rats supplemented with 50 g/kg/day chlorella) and E (diabetic rats supplemented with 25 g/kg/day chlorella and 25 g/kg/day spirulina). After 21 days, wounds were inflicted on the back of rats. Assessment of blood sugar (BS), high-sensitivity C-reactive protein (hs-CRP), vascular endothelial growth factor (VEGF), granulation tissue formation, vascularization, epithelialization, and percentage of wound healing were determined along with macroscopic examinations. Results: The microscopic changes at days 3, 7, 14, and 21 showed significant evidence of improved angiogenesis, epithelial proliferation, and granulation tissue formation in the spirulina and chlorella treated rats compared with the controls (p�0.05). Both spirulina and chlorella treatments of diabetic rats resulted in a significant reduction in BS and weight (p�0.05), but VEGF and hs-CRP levels did not significantly change (p > 0.05). Percentage of wound healing was 100 on day 21 in all groups, except the control group B (97.8 ± 1.15). Conclusions: The results of this study showed that supplementation with spirulina and chlorella alone and combined could improve wound healing indices in diabetic rats and could therefore be recommended for the management of diabetic ulcer. © 2021, Springer Nature Switzerland AG