Author Interviews, Brigham & Women's - Harvard, Diabetes, Nutrition, PLoS / 15.06.2016
Plant-Based Diet Linked To Lower Risk of Diabetes
MedicalResearch.com Interview with:
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Ambika Satija[/caption]
Ambika Satija
Departments of Nutrition & Epidemiology
Harvard T. H. Chan School of Public Health
Boston, MA
MedicalResearch.com: What is the background for this study?
Response: In this study, we followed more than 200,000 male and female health professionals across the U.S. for more than 20 years who had regularly filled out questionnaires on their diet, lifestyle, medical history, and new disease diagnoses as part of three large long-term studies.
Ambika Satija[/caption]
Ambika Satija
Departments of Nutrition & Epidemiology
Harvard T. H. Chan School of Public Health
Boston, MA
MedicalResearch.com: What is the background for this study?
Response: In this study, we followed more than 200,000 male and female health professionals across the U.S. for more than 20 years who had regularly filled out questionnaires on their diet, lifestyle, medical history, and new disease diagnoses as part of three large long-term studies.
Dr. Geng Zong[/caption]
Geng Zong, Ph.D.
Research fellow at Harvard T.H. Chan School of Public Health
Boston, Massachusetts.
MedicalResearch.com: What is the background for this study? What are the main findings?
Response: The refining process of grains removes most of fiber, minerals, vitamins, polyphenols and alkyl resorcinols that mainly exist in the outer layer of a kernel, thus enriches grains with carbohydrate and energy. Whole grains, on the other hand, are cereal grains or processed cereal grains that contains bran and germ, in addition to the inner most endosperm, as their natural proportions in the kernel. Observational studies have repeatedly linked whole grain intake with major chronic diseases, including obesity, diabetes, cardiovascular diseases, and cancer, but findings regarding mortality are inconsistent and have not been quantitatively summarized. By meta-analyzing 14 existing or unpublished prospective cohort studies, our investigation found that whole grain intake is inversely associated with mortality risk from all-causes, CVD, and cancer. Among people with whole grain consumption, estimated all-cause mortality risk was 7% (for 10 grams/day), 16% (for 30 grams/day), 20% (for 50 grams/day), and 22% (for 70 grams/day) lower than people with no whole grain consumption. Similar dose-response relationship was observed for CVD and cancer mortality.
Susanne Cutshall[/caption]
SUSANNE M. CUTSHALL, APRN, CNS, D.N.P.
Division of General Internal Medicine
Mayo Clinic, Rochester, MN
MedicalResearch.com: What is the background for this study? What are the main findings?
Response: Several years ago a group of practitioners from the Mayo Clinic, including Sue Cutshall and Larry Bergstrom took my functional medicine training program that I teach through The Kalish Institute. They were interested in researching the effectiveness of the functional medicine techniques I’ve developed over the last twenty years, so we embarked on this study together. The study showed women on the program experienced increased energy, were better able to handle stress and had less physical pain. Additional information gathered from follow-up testing, but not reported in the formal study, showed a significant improvement in digestive health as well.
Dr. Ramon Estruch[/caption]
Dr Ramon Estruch, MD PhD
Senior Consultant in the Internal Medicine Department of the Hospital Clinic
Barcelona
MedicalResearch.com: What is the background for this study? What are the main findings?
Dr. Estruch: Although weight stability requires a balance between calories consumed and calories expended, it seems that calories from vegetable fats have different effects that calories from animals on adiposity. Thus, an increase of dietary fat intake (mainly extra virgin olive oil or nuts) achieved naturally in the setting of Mediterranean diet does not promote weight gain or increase in adiposity parameters such as waist circumference.
Dr. Jennifer Lemon[/caption]
Jennifer Lemon, PhD
Research Associate
Medical Radiation Sciences
McMaster University
MedicalResearch.com: What is the background for this study?
Dr. Lemon: Research with the supplement began in 2000, as part of my doctoral degree; we developed the supplement to try to offset the severe cognitive deterioration and accelerated aging in a mouse model we were working with in the lab. Based on aging research, five mechanisms appeared to be key contributors to the process of aging; those include oxidative stress, inflammation, mitochondrial deterioration, membrane dysfunction and impaired glucose metabolism. The criteria we used for including components in the supplement were as follows: each one of the 30 components had scientific evidence to show they acted on one or more of the above mechanisms were able to be taken orally, and were available to humans over-the-counter. Even then the hope was that if the formulation was successful, this would make it more available to the general public.
Ettje Tigchelaar[/caption]
Ettje Tigchelaar MSc
PhD student from department of Genetics
University of Groningen, Groningen
MedicalResearch.com: What is the background for this study? What are the main findings?
Response: A gluten-free diet is used by celiac disease patients to alleviate their symptoms. Previous research in these patients has shown differences in gut microbiota composition when on habitual gluten containing diet (HD) compared to a gluten-free diet (GFD). Recently more and more individuals without celiac disease also started to adopt a gluten-free diet to improve their health and/or control weight. We studied changes in gut microbiota composition in these healthy individuals on a gluten-free diet.
We observed changes in the abundance of specific bacteria, for example the abundance of the bacterium family Veillonellaceae was much lower on a gluten-free diet versus HD, whereas it was higher for the family Clostridiaceae. We also looked at the function of the bacteria in the gut and found that many of those bacteria that changed because of the gluten-free diet played a role in metabolism of starch. This makes sense since starch is like gluten highly present in wheat containing products, thus when eliminating gluten from the diet, the intake of starch also changes and the gut bacteria processing this dietary starch change accordingly.
Dr. Jennifer Kuk[/caption]
Jennifer L. Kuk, PhD
Associate Professor
York University
School of Kinesiology and Health Science
Toronto, Ontario
MedicalResearch.com: What is the background for this study? What are the main findings?
Dr. Kuk: Artificial sweeteners are used to help individuals manage their weight, however, individuals who consume aspartame (a type of artificial sweeteners) have worse glucose metabolism than individuals with the same body weight but do not consume aspartame. This observation was only true for adults with obesity. Further, saccharin and natural sugars were not associated with differences in health after considering differences in obesity.
Dr. Jiang He[/caption]
Jiang He, M.D., Ph.D.
Joseph S. Copes Chair and Professor
Department of Epidemiology
School of Public Health and Tropical Medicine
Tulane University, New Orleans
MedicalResearch: What is the background for this study?
Dr. Jiang He: Chronic kidney disease is associated with increased risk of end-stage renal disease, cardiovascular disease, and all-cause mortality. A positive association between sodium intake and blood pressure is well established in observational studies and clinical trials. However, the association between sodium intake and clinical cardiovascular disease remains less clear. Positive monotonic, J-shaped, and U-shaped associations have been reported. Methodologic limitations, including inconsistencies in dietary sodium measurement methods, could be contributing to these conflicting findings. Furthermore, no previous studies have examined the association between sodium intake and incident cardiovascular disease among patients with chronic kidney disease.
Dr. Brian Stansfield[/caption]
Dr. Brian Stansfield MD
Neonatologist
Children's Hospital of Georgia and the Medical College of Georgia
Augusta University
MedicalResearch.com: What is the background for this study?
Dr. Stansfield: Since the mid-20th century, we have experimental evidence in animal models and human data demonstrating the influence of maternal nutrition on the offspring - both in the short term and long term. Low birth weight has been connected with higher incidence of cardiometabolic diseases including insulin resistance, coronary artery disease, and hypertension. Interestingly, low birth weight infants grow up to be relatively thin adults compared to their normal or high birth weight counterparts. Conversely, high birth weight infants tend to become heavier adults and obesity is directly linked with the same adult outcomes. So the association of cardiac and metabolic diseases with low birth weight is not linked to adult obesity in general. Thus, speculation as to why extremes of birth weight lead to adult onset cardiometabolic disease suggests different mechanisms and modifying factors.
MedicalResearch.com: What are the main findings?
Dr. Stansfield: The findings of our study shed considerable light on the relationship between birth weight and risk factors for insulin resistance and visceral adiposity. Using magnetic resonance imaging (MRI) to achieve precise measurements of visceral adipose content and biomarkers for insulin resistance, we show that both low and high birth weight are associated with increased visceral adiposity and insulin resistance in a healthy population of adolescents aged 13-17 years. This association persists when we account for several recognized confounders including age, sex, race, activity level, and socioeconomic status. The most interesting finding of our study is that when you account for each adolescent’s current body mass index, a measure of obesity, the relationship between increased visceral fat and insulin resistance and low birth weight is strengthened suggesting that these adolescents had relatively high visceral adipose content despite obesity rates that were similar to their normal birth weight counterparts. On the other hand, correction for adolescent BMI (obesity) reduced the relationship between these metabolic markers and high birth weight infants. Thus, low birth weight infants may develop insulin resistance and increased visceral fat, both significant risk factors for cardiovascular disease and metabolic disease, despite having a relatively normal body shape in adolescents.
Dr. Sikarin Upala[/caption]
Sikarin Upala MD, MS, LLB
Internal Medicine, Bassett Medical Center and Columbia University College of Physicians and Surgeons, Cooperstown, New York
Preventive and Social Medicine
Mahidol University, Bangkok, Thailand
MedicalResearch.com: What is the background for this study? What are the main findings?
Dr. Upala: Chronic hepatitis C virus infection is the most common cause of chronic liver disease and cirrhosis as well as the most common cause of liver transplantation in the United States. As caffeine has been found to be related to decreased liver enzymes, chronic liver disease,cirrhosis, and risk of hepatocellular carcinoma in several liver disease pathologies. There is inconclusive findings on the effect of caffeine on hepatitis C infected patients. Thus, we conducted a systematic review and meta-analysis to summarize the effect of caffeine consumption in patients with chronic hepatitis C.
We found that caffeine consumers have a 61% reduced risk of developing advanced hepatic fibrosis, which is one of the consequence of chronic hepatitis C. Our meta-analysis result is in the same way with other studies who found that coffee consumption could prevent the development of hepatic fibrosis in patients with liver disease. However, we cannot conclude about the effect of caffeine on HCV viral load as there is not enough information.
Dr. Nicole Shen[/caption]
Dr. Nicole Shen
New York-Presbyterian/Weill Cornell Medical College
MedicalResearch.com: What is the background for this study?
Dr. Shen: Clostridium difficile infection (CDI) is a persistent, healthcare associated infection with significant morbidity and mortality that costs the US billions of dollars annually. Prevention is imperative, particularly for patients at high risk for infection – hospitalized adults taking antibiotics. Trials have suggested probiotics may be useful in preventing CDI. We conducted a systematic review with meta-analysis in this high-risk population, hospitalized adults receiving antibiotics, to evaluate the current evidence for probiotic use for prevention of CDI.
MedicalResearch.com Interview with:
Prof Andrew Mente PhD
Clinical Epidemiology and Biostatistics, McMaster University
Hamilton, Canada
MedicalResearch.com Editor's Note: Dr. Mente discusses his Lancet publication regarding salt intake below. Dr. Mente's findings are disputed by the American Heart Association (AHA). A statement from the AHA follows Dr. Mente's comments.
MedicalResearch.com: What is the background for this study? What are the main findings?
Prof. Mente: Several prospective cohort studies have recently reported that both too little and too much sodium intake is associated with cardiovascular disease or mortality. Whether these associations vary between those individuals with and without high blood pressure (hypertension) is unknown.
We found that low sodium intake (below 3 g/day), compared to average intake (3 to 6 g/day), is associated with more cardiovascular events and mortality, both in those with high blood pressure and in those without high blood pressure. So following the guidelines would put you at increased risk, compared to consuming an sodium at the population average level, regardless of whether you have high blood pressure or normal blood pressure.
High sodium intake (above 6 g/day) compared to average intake, was associated with harm, but only in people with high blood pressure (no association in people without high blood pressure).
Dr. Meghan Azad[/caption]
Meghan Azad PhD
Assistant Professor, Department of Pediatrics & Child Health and Community Health Sciences
University of Manitoba
Associate Investigator, Canadian Healthy Infant Longitudinal Development (CHILD) Study
MedicalResearch.com: What is the background for this study?
Dr. Azad: It is well known that maternal nutrition plays a key role in “programming” fetal development and infant weight gain, but the impact of artificial sweetener consumption during this critical period has not been extensively studied. Some animal research suggests that consuming artificial sweeteners during pregnancy can predispose offspring to develop obesity, but this has never been studied in humans, until now.
Dr. Maryam Farvid[/caption]
MedicalResearch.com Interview with:
Maryam Farvid, Ph.D.
Visiting Scientist
Department of Global Health and Population
Harvard T.H. Chan School of Public Health
MedicalResearch: What is the background for this study? What are the main findings?
Dr. Farvid: Breast cancer is one of the most frequently diagnosed cancers and is the second leading cause of cancer deaths among women in the United States. While we know many breast cancer risk factors, few of them are easily modified. Further, evidence suggests that exposure to carcinogens and anti-carcinogens in early life may play an important role. According to this study, what women eat as teens or young adults could affect their breast cancer risk in the future. Teenage girls who eat a lot of fruits may have a lower risk of breast cancer later in life. The risk of breast cancer among women who reported the highest amount of 
Danielle Schoffman[/caption]
Danielle E. Schoffman
PhD Candidate
Department of Health Promotion, Education, and Behavior
Arnold School of Public Health
University of South Carolina
Columbia, SC 29208
MedicalResearch.com: What is the background for this study? What are the main findings?
Response: In recent years, there has been large growth in the fast casual (e.g., Panera, Chipotle) restaurant sector, and there is a general perception among consumers that these restaurants are a healthier and fresher alternative to fast food. When we encourage participants in our research studies to reduce their fast food intake, they often ask if these fast casual restaurants also count. We were interested in looking at the calorie data for entrees at both restaurant types to see if they lined up with these assumptions.
We analyzed the calorie content of entrées at 34 fast food and 28 fast casual restaurants, and found that fast food entrées had an average of 760 calories per entrée compared to 561 for fast food entrées . Also, a greater proportion of fast casual restaurant entrées exceeded the median of 640 calories per entrée.
Dr. T. Dianne Langford[/caption]
Dr. T. Dianne Langford PhD
Associate Professor, Neuroscience and Neurovirology
Lewis Katz School of Medicine
Temple University
MedicalResearch.com: What is the background for this study?
Dr. Langford: The ocular-motor system has been shown to reflect neural damage, and one of ocular-motor functions, near point of convergence (NPC), was reported to worsen after a sport-related concussion (Mucha et al. Am J Sport Med). But the effects of subconcussive head impact, a milder form of head injury in the absence of outward symptoms remains unknown. Prior to this study, we found that in a controlled soccer heading experimental paradigm decreased NPC function, and even 24h after the headings, NPC was not normalized back to baseline (Kawata et al. 2016 Int J Sport Med). To extend our findings from the human laboratory study, we launched longitudinal clinical studies in collaboration with the Temple football team, to see if repetitive exposure to subconcussive head impacts negatively affects NPC.
Dr. Jed Friedman[/caption]
Jacob (Jed) E. Friedman, Professor, Ph.D.
Department of Pediatrics, Biochemistry & Molecular Genetics
Director, NIH Center for Human Nutrition Research Metabolism Core Laboratory
University of Colorado Anschutz
MedicalResearch.com: What is the background for this study? What are the main findings?
Response: Scientists have long established that children who are breastfed are less likely to be obese as adults, though they have yet to identify precisely how breastfeeding protects children against obesity. One likely reason is that children who are breastfed have different bacteria in their intestines than those who are formula fed.
The study, published Monday in the American Journal of Clinical Nutrition examines the role of human milk hormones in the development of infants’ microbiome, a bacterial ecosystem in the digestive system that contributes to multiple facets of health.
“This is the first study of its kind to suggest that hormones in human milk may play an important role in shaping a healthy infant microbiome,” said Bridget Young, co-first author and assistant professor of pediatric nutrition at CU Anschutz. “We’ve known for a long time that breast milk contributes to infant intestinal maturation and healthy growth. This study suggests that hormones in milk may be partly responsible for this positive impact through interactions with the infant’s developing microbiome.”
Researchers found that levels of insulin and leptin in the breastmilk were positively associated with greater microbial diversity and families of bacteria in the infants’ stool. Insulin and leptin were associated with bacterial functions that help the intestine develop as a barrier against harmful toxins, which help prevent intestinal inflammation. By promoting a stronger intestinal barrier early in life, these hormones also may protect children from chronic low-grade inflammation, which can lead to a host of additional digestive problems and diseases.
In addition, researchers found significant differences in the intestinal microbiome of breastfed infants who are born to mothers with obesity compared to those born to mothers of normal weight. Infants born to mothers with obesity showed a significant reduction in gammaproteobacteria, a pioneer species that aids in normal intestinal development and microbiome maturation.
Gammaproteobacteria have been shown in mice and newborn infants to cause a healthy amount inflammation in their intestines, protecting them from inflammatory and autoimmune disorders later in life. The 2-week-old infants born to obese mothers in this study had a reduced number of gammaproteobacteria in the infant gut microbiome.
Dr. Stephen Freedman[/caption]
Stephen B. Freedman MDCM, MSc,
Associate Professor
Department of Paediatrics, Sections of Emergency Medicine and Gastroenterology;
ACHRI Healthy Outcomes Theme Group Leader
Alberta Children’s Hospital, and Alberta Children’s Hospital Research Institute
University of Calgary,
Calgary, Canada
MedicalResearch.com: What is the background for this study?
Dr. Freedman: As a pediatric emergency medicine physician I continue to see large numbers of children who are brought for emergency care because of vomiting and diarrhea. In speaking with their caregivers it is clear that many of them try to administer electrolyte maintenance solutions at home but the children either refuse to drink them or they continue to vomit. As a researcher I have noticed that many children continue to receive intravenous rehydration despite not being significantly dehydrated and it appeared that this was often a physician’s response to a failed oral rehydration challenge in the emergency department, either due to refusal to consume the electrolyte maintenance solution supplied or because the children became more nauseous due to the poor palatability of the solution. It appeared that perhaps a less dogmatic approach aimed at providing fluids that children actually like, might overcome these problems leading to improved outcomes.
MedicalResearch.com: What are the main findings?
Dr. Freedman: Children with mild gastroenteritis and minimal dehydration experienced fewer treatment failures when offered dilute apple juice followed by their preferred fluid choice compared with those instructed to drink electrolyte maintenance solution to replace fluid losses. We found the benefit was greatest in those 24 to 60 months of age. The group provided and instructed to take their preferred fluids were administered intravenous rehydration less frequently.
Evelyn Parr[/caption]
Evelyn Parr
Research Officer / PhD Candidate | Centre for Exercise and Nutrition
Mary MacKillop Institute for Health Research
Australian Catholic University
MedicalResearch.com: What is the background for this study? What are the main findings?
Response: Results from previous investigations suggest that compared to a healthy 'control' diet, increased consumption of dairy foods in an energy restricted diet lead to improved body composition (i.e., a loss of fat mass and the maintenance of lean mass).
We investigated the effects of manipulating the type of dairy foods (i.e., low- or high fat) within high protein, energy restricted diets on body composition and selected health parameters. Eighty-nine middle-aged (35-59 y), male and females who were overweight or obese completed a 16 week intervention comprising 3 d/wk supervised resistance training and 4 d/wk unsupervised aerobic -based exercise (i.e. walking). During this time they consumed a diet that was energy restricted by 250 kcal/d comprising either
1) high protein, moderate carbohydrate (4-5 normal fat dairy product servings),
2) high protein, high carbohydrate (4-5 low-fat, carbohydrate sweetened dairy product servings or
3) a control diet of moderate protein, high carbohydrate diet (1-2 dairy servings).
We found that in the face of energy restriction, when protein intakes were above the recommended daily intakes (>0.8 g/kg body mass) and regular exercise was completed, there was no difference in the loss of fat mass (~8 kg) when participants consumed 4-5 serves of dairy products in either low- or high-fat. Furthermore, participants maintained lean (muscle) mass throughout the energy restricted period.
