MedicalResearch.com Interview with:
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Dr. David Hughes[/caption]
Dr. David Hughes
Honorary Lecturer, Centre for Systems Medicine
RCSI Physiology & Medical Physics Dept
Royal College of Surgeons in Ireland
Ireland
MedicalResearch.com: What is the background for this study? What are the main findings?
Response: Liver cancer is the second most common cause of death from cancer worldwide, and the seventh most common cause of death from cancer in Europe (1).
“The incidence of liver cancers is increasing in developed countries, likely due to Western lifestyle and dietary habits. Liver cancers are often diagnosed at late stages and have limited treatment options,” says IARC scientist Dr Mazda Jenab, one of the study’s authors. “Further research is needed into the modifiable determinants of these cancers and effective prevention strategies.”
A growing body of evidence suggests that suboptimal intakes of the micronutrient selenium contribute to the development of several cancers (2). Selenium is a trace mineral micronutrient that is found in foods like shellfish, salmon, Brazil nuts, meat, eggs, grains, and onions. However, selenium levels in foods depend largely on the levels of selenium in the soil where the food is grown and animals graze. Soil levels tend to be low in many regions in Europe, contributing to lower body levels of selenium in those populations compared with people living in regions with higher soil selenium concentrations, such as North America. In humans, selenium is essential, particularly for the effective functioning of the immune system and in controlling oxidative processes linked to cancer development.
This new study shows that the highest levels of blood selenium or of selenoprotein P, the protein that distributes selenium from the liver around the body, are associated with a decreased risk of developing liver cancer (particularly hepatocellular carcinoma), even when all other major liver cancer risk factors are taken into account. The study also shows that selenium level is not associated with the development of gall bladder or biliary tract tumours (3).
The study was based on the European Prospective Investigation of Cancer and Nutrition (EPIC) cohort, headed by the International Agency for Research on Cancer (IARC) in Lyon, France, and composed of more than half a million participants across 10 European countries. We used a case–control design of 121 liver cancers and 140 gall bladder and biliary tract cancers matched to equal numbers of individuals free of cancer within the cohort.
Dr. Armin Alaedini[/caption]
Armin Alaedini, PhD
Assistant Professor
Department of Medicine & Institute of Human Nutrition
Columbia University Medical Center
New York, NY 10032
MedicalResearch.com: What is the background for this study?
Response: It has been a mystery why some people experience a range of symptoms in response to the ingestion of wheat and related cereals, even though they do not have celiac disease (an autoimmune disorder) or wheat allergy. Both gastrointestinal (GI) symptoms, most commonly abdominal pain, diarrhea, and bloating, as well as extra-intestinal symptoms, such as fatigue, anxiety, depressed mood, and cognitive difficulties are reported by patients. The identity of the component(s) of wheat responsible for triggering the symptoms remains uncertain and it is not clear if gluten or non-gluten molecules are involved. There is evidence to indicate that wheat sensitivity also affects a subset of patients with irritable bowel syndrome (IBS), a common disorder. Despite the interest from the medical community and the general public, the causes and mechanism of the associated symptoms have remained unknown and no biomarkers are available to aid in the diagnosis of patients.
Lindsay Kohler[/caption]
Lindsay Kohler MPH
Mel and Enid Zuckerman College of Public Health
Tucson, Arizona
MedicalResearch.com: What is the background for this study? What are the main findings?
Response: Several studies have reported that following health promotion guidelines for diet, physical activity, and maintenance of a healthy body weight may reduce the risk of getting cancer or dying from cancer. We performed a systematic review to examine the associations between established cancer prevention guidelines for diet and physical activity and cancer outcomes. We found that adhering to cancer prevention guidelines set forth by the American Cancer Society or the World Cancer Research Fund/American Institute for Cancer Research consistently reduced the risk of overall cancer incidence and mortality (10-61%) in the studies included in this review. In addition, higher adherence to the guidelines consistently reduced the risk of breast, colorectal, and endometrial cancers. Adherence to a pattern of healthy behaviors may significantly reduce cancer incidence and mortality.
Dr. Ying Bao[/caption]
Dr. Ying Bao Sc.D., M.D
Assistant Professor of Medicine
Channing Division of Network Medicine
Department of Medicine
Brigham and Women's Hospital
Harvard Medical School,
Boston, MA
MedicalResearch.com: What is the background for this study? What are the main findings?
Response: Nuts are rich in bioactive macronutrients, micronutrients, tocopherols and phytochemicals. Current epidemiological evidence has consistently linked increased nut consumption to reduced risk of several chronic conditions including cardiovascular diseases, type 2 diabetes, and inflammation. In contrast, evidence on nut consumption and cancer risk has been insufficient and equivocal.
Prostate cancer is the leading cancer among U.S. men, with approximately 220,800 new cases diagnosed in 2015. However, very few studies have investigated the association between nut intake and prostate cancer. Thus, in the current study, we followed 47,299 US men from 1986-2012, and examined
(1) whether consuming more nuts prevents getting prostate cancer, and
(2) whether consuming more nuts reduces death rates among non-metastatic prostate cancer patients.
During 26 years of follow-up, 6,810 men were diagnosed with prostate cancer, and 4,346 of these patients were without metastasis at diagnosis. We found no association between nut intake and being diagnosed with prostate cancer. However, among non-metastatic prostate cancer patients, those who consumed nuts 5 or more times per week after diagnosis had a significant 34% lower rate of overall mortality than those who consumed nuts less than once per month.
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.