Author Interviews, BMJ, Diabetes, Lipids, Omega-3 Fatty Acids / 23.08.2019
Omega-3 Supplements Did Not Protect Agains Diabetes
MedicalResearch.com Interview with:
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Dr. Hooper[/caption]
Lee Hooper PhD, RD
Reader in Research Synthesis, Nutrition & Hydration
Norwich Medical School
University of East Anglia
England, UK
MedicalResearch.com: What is the background for this study?
Response: The World Health Organization asked us to carry out a set of studies (systematic reviews of randomised controlled trials) assessing health effects of omega-3 and omega-6, which are polyunsaturated fats. This is because the WHO are planning to update their dietary guidance on fats in the near future.
Worries about effects of long chain omega-3 on control of diabetes have long existed, and some experimental studies have suggested that omega-3 supplementation and diets high in PUFA and omega-3 raise fasting glucose. Pollutants such as methylmercury and polychlorinated biphenyl levels exceeding recommended thresholds are rarer now, but have been reported in seafoods and fish oil supplements; elevated mercury levels interrupt insulin signalling, raising fasting glucose, in mouse models. Body concentrations of organic pollutants are correlated with prevalence of diabetes in the US, but other cross sectional studies have suggested either no association with or benefits of eating fish on glycaemic control. Systematic reviews of observational studies have suggested both positive and negative associations with glucose metabolism, but strong evidence shows that omega-3 supplements reduce raised triglycerides and have little or no effect on body weight. Theories suggest that omega-3 and omega-6 fats compete in some metabolic pathways so that the omega-3/omega-6 ratio is more important than absolute intakes of either.
Dr. Hooper[/caption]
Lee Hooper PhD, RD
Reader in Research Synthesis, Nutrition & Hydration
Norwich Medical School
University of East Anglia
England, UK
MedicalResearch.com: What is the background for this study?
Response: The World Health Organization asked us to carry out a set of studies (systematic reviews of randomised controlled trials) assessing health effects of omega-3 and omega-6, which are polyunsaturated fats. This is because the WHO are planning to update their dietary guidance on fats in the near future.
Worries about effects of long chain omega-3 on control of diabetes have long existed, and some experimental studies have suggested that omega-3 supplementation and diets high in PUFA and omega-3 raise fasting glucose. Pollutants such as methylmercury and polychlorinated biphenyl levels exceeding recommended thresholds are rarer now, but have been reported in seafoods and fish oil supplements; elevated mercury levels interrupt insulin signalling, raising fasting glucose, in mouse models. Body concentrations of organic pollutants are correlated with prevalence of diabetes in the US, but other cross sectional studies have suggested either no association with or benefits of eating fish on glycaemic control. Systematic reviews of observational studies have suggested both positive and negative associations with glucose metabolism, but strong evidence shows that omega-3 supplements reduce raised triglycerides and have little or no effect on body weight. Theories suggest that omega-3 and omega-6 fats compete in some metabolic pathways so that the omega-3/omega-6 ratio is more important than absolute intakes of either.
Dr. Mikkola[/caption]
Tomi Mikkola MD
Associate Professor
Helsinki University Hospital
Department of Obstetrics and Gynecology
Helsinki, Finland
MedicalResearch.com: What is the background for this study? What are the main findings?
Response: In Finland we have perhaps the most comprehensive and reliable medical registers in the world. Thus, with my research group I have conducted various large studies evaluating association of postmenopausal hormone therapy use and various major diseases (see e.g. the references in the B;MJ paper). There has been various smaller studies indicating that hormone therapy might be protective for all kinds of dementias, also Alzheimer’s disease.
However, we have quite recently shown that hormone therapy seems to lower the mortality risk of vascular dementia but not Alzheimer’s disease (Mikkola TS et al. J Clin Endocrinol Metab 2017;102:870-7). Now in this upcoming BMJ-paper we report in a very large case-control study (83 688 women with Alzheimer’s disease and same number of control women without the disease) that systemic hormone therapy was associated with a 9-17% increased risk of Alzheimer’s disease.
Furthermore, this risk increase is particularly in women using hormone therapy long, for more than 10 years. This was somewhat surprising finding, but it underlines the fact that mechanisms behind Alzheimer’s disease are likely quite different than in vascular dementia, where the risk factors are similar as in cardiovascular disease. We have also shown how hormone therapy protects against cardiovascular disease, particularly in women who initiate hormone therapy soon after menopause.
Dr Paul Gentil
Faculty of Physical Education and Dance
Federal University of Goias
Goiania, Brazil
MedicalResearch.com: What is the background for this study? What are the main findings?
Response: Although being overweight and/or obese are associated with numerous health risks, the prevalence of both are continuing to increase worldwide. The treatment would include anything that results in an increase in energy expenditure (exercise) or a decrease in energy intake (diet). However, our metabolism seems to adapt to variations in physical activity to maintain total energy expenditure. Although lower-than-expected weight loss is often attributed to incomplete adherence to prescribed interventions, there are other factors that might influence the results, such as, metabolic downregulation.
So, instead of making people spend more calories, maybe we have to think on how to promote metabolic changes in order to overcome these physiological adaptations above-mentioned. In this regard, high intensity training might be particularly interesting as a strategy to promote fat loss. Irrespective the amount of calories spent during training, higher intensity exercise seems to promote many physiological changes that might favor long-term weight loss. For example, previous studies have shown that interval training is able to promote upregulation of important enzymes associated with glycolysis and beta oxidation pathways, which occurs in a greater extent than with moderate intensity continuous exercise.
Our findings suggest that interval training might be an important tool to promote weigh loss. However, I t might be performed adequately and under direct supervision in order to get better results.
Dr. Kitchener[/caption]
Professor Henry Kitchener, MD FRCOG FRCS
University of Manchester, Manchester, UK
MedicalResearch.com: What is the background for this study?
Response: We now have reliable and affordable technologies to detect human papillomavirus (HPV), a virus which is universally accepted as the cause of cervical cancer. Various large trials confirmed that cervical screening could be improved by replacing the smear (cytology) test that has been in use for decades, with HPV testing. Many countries are now making the switch. In England, this is planned for the end of 2019. To test how to run HPV testing within the English National Health Service, a pilot was initiated in 2013 in six screening laboratories. We also wanted to determine whether the encouraging findings from the trials could be translated to everyday practice. This is important not only because we will be using different HPV tests, but also because women undergoing screening in trials are much more selected than those who are invited to population-based screening.




