Author Interviews, Endocrinology, Weight Research / 11.03.2015

Elizabeth A. Lawson, M.D., M.M.Sc. Assistant Professor of Medicine Harvard Medical School Director, Interdisciplinary Oxytocin Research Program Neuroendocrine Unit Massachusetts General Hospital Boston, MA 02114 MedicalResearch.com Interview with: Elizabeth A. Lawson, M.D., M.M.Sc. Assistant Professor of Medicine Harvard Medical School Director, Interdisciplinary Oxytocin Research Program Neuroendocrine Unit Massachusetts General Hospital Boston, MA 02114 Medical Research: What is the background for this study? What are the main findings? Response: Oxytocin is a hormone produced in the brain that has been shown to reduce food intake in animal studies. The role of oxytocin on appetite and food consumption in humans is not well understood. We therefore performed a randomized, placebo controlled cross-over study of single dose administration of intranasal oxytocin (Syntocinon, Novartis) in healthy men. Subjects presented fasting in the early morning and were randomized to receive 24 IU intranasal oxytocin or placebo. They selected breakfast from a menu and were offered double portions. The caloric content of the food they ate was calculated. They returned for a second visit, which was the same except for this time, they received the other treatment (placebo or oxytocin). There was no difference in how much food the men reported eating in the three days leading up to each of the study visits. On average, the men ate 122 fewer calories and about 9 grams less fat after receiving oxytocin compared to placebo. There was also evidence that oxytocin resulted in greater use of fat as a fuel for the body, and improved insulin sensitivity. (more…)
Author Interviews, OBGYNE, Toxin Research, University of Pittsburgh / 07.03.2015

Dr. Jennifer Adibi, MPH ScD University of Pittsburgh, Public Health Assistant Professor, Epidemiology Assistant Professor, Department of Obstetrics/Gynecology and Reproductive Sciences Affiliate, Department of Obstetrics/Gynecology and Reproductive Sciences University of California, San Francisco MedicalResearch.com Interview with: Dr. Jennifer Adibi, MPH ScD University of Pittsburgh, Public Health Assistant Professor, Epidemiology Assistant Professor, Department of Obstetrics/Gynecology and Reproductive Sciences Affiliate, Dept. of ObGYN and Reproductive Sciences University of California, San Francisco Medical Research: What is the background for this study? Dr. Adibi: Prenatal exposure to phthalates in rodents can cause defects in male sexual development including a shorter distance between the anus and the genitalia (anogenital distance or AGD). Human studies have shown a correlation between higher prenatal phthalate urinary concentrations in the mother and shorter AGD in males. AGD in males is related to fertility and reproductive health over the lifetime. In females, AGD was associated with numbers of ovarian follicles. The role of the placenta has not been considered in these studies. A placental hormone called human chorionic gonadotropin (hCG) is essential for normal male development. Our previous research has shown that hCG expression by human placental cells is disrupted by phthalate concentrations equal to what we measured in maternal urine. The placenta secretes molecules early in pregnancy that might provide an opportunity to detect these effects in humans. Medical Research: What are the main findings? Dr. Adibi: In 350 pregnancies, we measured a significant association of maternal urinary concentrations of mono-n-butyl phthalate (MnBP) and monobenzyl phthalate (MBzP) with hCG in maternal blood in the first trimester. Higher phthalate concentrations were associated with higher hCG if the mother was carrying a female fetus, and lower concentrations if she was carrying a male fetus. In a high/low MnBP comparison, hCG was 15-fold higher in the higher exposed female fetuses. We also observed a relationship between maternal levels of hCG in the first trimester and anogenital distance in the newborns. The correlation was positive in female newborns, and inverse in male newborns. Similar to the parent study, we observed associations of higher first trimester MnBP and mono-2-ethyl hexyl phthalate (MEHP) with lower male anogenital distance. If we combined these findings into a mediation analysis, we estimated that approximately 20-30% of the phthalate-induced effect on anogenital distance was due to the phthalate disruption of hCG. (more…)
Author Interviews, Nutrition, Weight Research / 06.03.2015

Frances M. Sladek, Ph.D. Professor of Cell Biology and Toxicologist Associate Director, UCR Stem Cell Center Department of Cell Biology and Neuroscience University of California Riverside, CA 92521-0314 MedicalResearch.com Interview with: Frances M. Sladek, Ph.D. Professor of Cell Biology and Toxicologist Associate Director, UCR Stem Cell Center Department of Cell Biology and Neuroscience University of California Riverside, CA 92521-0314 Medical Research: What is the background for this study? What are the main findings? Dr. Sladek: In 2011 Blasbalg et al reported in the American Journal of Clinical Nutrition that the consumption of soybean oil was the component of the American diet that had changed the most since the early 1900s. It had in fact increased 1000-fold. Soybean oil is currently not only the main type of vegetable oil used in the U.S. but soybean meal is a major component of the diet of the animals such as cows and pigs, resulting in changes in the fatty acid composition of animal fat. Soybean oil is also increasingly being used worldwide: 40 million tons were produced in 2007 alone. In our previous study we found that a high fat diet containing comparable amounts of soybean oil to what Americans are currently consuming caused mice to become obese, diabetic and insulin resistant and to have large lipid droplets and hepatocyte ballooning in their livers. Others had found similar results and proposed that linoleic acid (an omega 6 polyunsaturated fat) that makes up >55% of the oil was responsible for the negative metabolic effects. DuPont recently generated a genetically modified soybean oil that had reduced levels of linoleic acid and hence less of a tendency to generate trans fats. This oil (called Plenish) came onto the market for the first time in 2014. The fatty acid composition of Plenish is similar to that of olive oil (low linoleic acid and high oleic acid), which is a major component of the healthy Mediterranean diet. The implication, therefore, is that Plenish is healthier than conventional soybean oil but that has not been formally proven. In the current study, we found that while a high fat diet containing Plenish also induced obesity, glucose intolerance and fatty liver, it did not induce insulin resistance as did the conventional soybean oil. It also induced somewhat less fat accumulation. Finally, we compared the diet enriched in soybean oil to an isocaloric diet that contained the same amount of total fat (40%kcal, Americans consume 34-37% fat) but with 90% of the fat from coconut oil. Those animals gained very little weight (13% versus 38% with the conventional soybean oil and 30% with the Plenish) and were not diabetic or insulin resistant. Their livers also had less fat than either of the two soybean oil diets and showed no signs of hepatocyte ballooning. Coconut oil has essentially no linoleic acid or other PUFAs. Our results, assuming humans respond in the same way as mice, suggest that people should avoid the consumption of too much soybean oil, either conventional or Plenish. They also show that coconut oil, which is made up of saturated fats (primarily medium chain triglycerides), is much healthier for you than soybean oil. Coconut oil has been noted previously for its beneficial health effects. (more…)
Author Interviews, Endocrinology, Metabolic Syndrome, Nutrition, Pediatrics, UT Southwestern / 06.03.2015

Dr. Roy Kim, MD Depts. Endocrinology and Pediatrics UT Southwestern Medical Center MedicalResearch.com Interview with: Dr. Roy Kim, MD Depts. Endocrinology and Pediatrics UT Southwestern Medical Center Medical Research: What was the problem you were focused on? Dr. Kim: We were focused on the problem of adolescent metabolic syndrome, a major public health problem. Our objective was to determine whether nut intake is linked with any difference in odds for metabolic syndrome in US adolescents. Medical Research: How is metabolic syndrome defined? Dr. Kim: In general it is diagnosed when there are 3 or more of the following things: increased belly fat, high blood pressure, high fasting glucose, elevated triglycerides, and low HDL cholesterol. Medical Research: How did you do your study? Dr. Kim: We used data from the National Health and Nutrition Examination Survey (NHANES), years 2003-2010, to examine health status and the diet history for 2,322 US adolescents age 12 to 19 years. Dr. Kim: Our first major finding was that adolescents who ate at least 12.9 grams of nuts per day - this is the equivalent of about 1 ounce of nuts 3 times per week – had a dramatically lower odds for metabolic syndrome compared to adolescents who ate less than that amount. The odds for nut-consumers was only about 43% of the odds for non-consumers. This remained true after controlling for age, gender, race, income, and dietary factors including sugar, fruit, and vegetable intake. Our second major finding was that average nut intake is very low among US adolescents – only about 5 grams per day - and more than 75% of US adolescents eat no nuts at all on a typical day. (more…)