MedicalResearch.com Interview with:
Professor Dr. Bernd Weber
Heisenberg Professor
Department of Epileptology
Head - NeuroCognition | Imaging
Life&Brain Center Board of Directors
Center for Economics and Neuroscience Bonn
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MedicalResearch.com Interview with:
Michael J. Orlich, MD, PhD
Program Director, Preventive Medicine Residency
Loma Linda University
Co-Investigator, Adventist Health Studies
Medical Research: What is the background for this study? What are the main findings?
Dr. Orlich: Colorectal cancer is the second leading cause of death from cancer in the United States. Screening efforts such as colonoscopies have helped save many lives by detecting pre-cancerous polyps and removing them. However, it is even better to prevent cancers from forming in the first place. We call this primary prevention. Diet is a potentially important approach to reduce the risk of developing colorectal cancer. In this analysis, we compared those eating different categories of vegetarian dietary patterns to those eating a non-vegetarian diet. About half of our study population was classified as non-vegetarian, which we defined as eating meat at least weekly. The other half of our population we called vegetarian and further divided them into four different vegetarian groups: semi-vegetarians ate meat but less than once per week; pesco-vegetarians ate fish but avoided other meats; lacto-ovo-vegetarians avoided meat but ate eggs and/or dairy products; and vegans avoided all meats, eggs, and dairy. All vegetarians together had on average a 22% relative reduction in the risk of developing colorectal cancer, compared to non-vegetarians, after carefully adjusting for many other factors. Pesco-vegetarians in particular had a much lower risk compared to non-vegetarians. (more…)
MedicalResearch.com Interview with:
Benoit Chassaing, Ph.D.
Post-Doctoral Fellow Dr. Gewirtz's lab.
Institute for Biomedical Sciences
Center for Inflammation, Immunity, & Infection
Georgia State University Atlanta GA 30303
Medical Research: What is the background for this study? What are the main findings?
Dr. Chassaing: A key feature of inflammatory bowel diseases and metabolic syndrome is alteration of the gut microbiota in a manner that promotes inflammation. Importantly, incidence of IBD and metabolic syndrome has been markedly increasing since about the mid-20th century, and this dramatic increase has occurred amidst constant human genetics, suggesting a pivotal role for an environmental factor. We considered that any modern additions to the food supply might play an important role, and addition of emulsifiers to food seems to fit the time frame of increased incidence in these diseases. We found that emulsifiers, which are added to most processed foods to aid texture and extend shelf life, can alter the gut microbiota composition and localization to induce intestinal inflammation that promotes development of inflammatory bowel disease and metabolic syndrome.
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MedicalResearch.com Interview with:
Dr. Sandra L. Jackson, Ph.D., M.P.H
Epidemic intelligence service fellow
Centers for Disease Control and Prevention, Chamblee, GA
Medical Research: What is the background for this study? What are the main findings?
Dr. Jackson: With more than 90 percent of U.S. adults exceeding recommended sodium intake levels, healthcare providers can play a key role in counseling patients on the importance of limiting salt in the diet.
To assess the impact of medical advice on an individual’s efforts to reduce sodium intake, CDC researchers examined self-reported telephone survey information from nearly 174,000 U.S. adults. Overall, more than half of the respondents reported watching or reducing their sodium intake in 2013 – but less than one quarter (23 percent) said they received advice from a doctor or healthcare professional about sodium reduction. Of those that received the medical advice, 82 percent reported taking action to limit their sodium intake. In comparison, only 44 percent of respondents who reported not receiving medical advice said they took steps to reduce sodium.
The substantial proportion of patients who are not receiving medical advice (77%), according to these findings, reveals a missed opportunity to reduce sodium intake, particularly among groups that have a higher risk of developing cardiovascular disease. This includes African Americans, and those with high blood pressure, diabetes or chronic kidney disease.
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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…)
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.
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MedicalResearch.com Interview with:
Luc Djousse, MD, ScD, FAHA
Associate Professor of Medicine, Harvard Medical School
Editor-in-Chief, Current Nutrition Reports
Director of Research, Division of Aging
Brigham and Women's Hospital Boston, MA 02120
MedicalResearch: What is the background for this study? What are the main findings?
Dr. Djousse: While some studies have reported a higher risk of coronary heart disease, diabetes, or high blood pressure with frequent consumption of fried foods, other investigators did not confirm those results. To date, only few studies have evaluated whether frequent consumption of fried foods can raise the risk of developing heart failure. Frying foods not only increases the energy density of foods, but also increase the amount of trans fats. Trans fats can lead to development of heart disease and diabetes and consumption of energy-dense foods in large quantity can lead to weight gain and resulting cardiovascular consequences.
We followed about 15000 US male physicians who were free of heart failure for an average of 10 years and found that frequent consumption of fried foods was related to a higher risk of developing heart failure. For example, people that consumed fried foods daily or more were twice more likely to develop heart failure than individuals who consumed fried foods less than once per week.
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MedicalResearch.com Interview with:
Anestis Dougkas, MSc, PhD
Food for Health Science Centre
Lund University Lund, Sweden
MedicalResearch: What is the background for this study?
Dr. Dougkas: There has been an increased interest in the macronutrient profile of diets and meals as a factor that influences appetite. Dietary protein is considered as the most satiating macronutrient, yet there is little evidence on whether the effects observed are attributed to the protein or to the concomitant manipulation of carbohydrates and fat. The aim was to examine the effect of consumption of beverages varying in macronutrient content on appetite ratings, energy intake and appetite-regulating hormones.
MedicalResearch: What are the main findings?
Dr. Dougkas: Increased protein content suppressed more average appetite than carbohydrate and fat with a more pronounced effect of protein intake on subjective ratings of prospective consumption. Protein was also the most influential macronutrient for postprandial glucagon like peptide-1 (GLP-1, an appetite- suppressing hormone) response. This appetite-suppressing effect of protein was independent of the changes in fat and carbohydrates.
(more…)MedicalResearch.com Interview with: Dr. Alex Johnstone PhD Rowett Institute of Nutrition and Health Aberdeen Medical Research: What is the background for this study? Response: Previous...
MedicalResearch.com Interview with:
Xiao-ou Shu M.D., MPH, Ph.D
Associate Director of Global Health
Co-Leader, Cancer Epidemiology Research Program
Ingram Professor of Cancer Research
Professor of Medicine (Epidemiology)
Cancer Epidemiologist
MedicalResearch: What is the background for this study? What are the main findings?
Dr. Shu: Nuts are rich in nutrients, such as unsaturated fatty acids, fiber, vitamins, phenolic antioxidants, arginine, and other phytochemicals. These are all known to be beneficial to cardiovascular health, probably through their anti-oxidative, anti-inflammatory, and endothelial function maintenance properties. Previous studies, primarily conducted in white and affluent populations, have shown that nut consumption may be related to cardiovascular health. Much of the nut consumption in those populations would be tree nuts. In our study, we found that peanut consumption was associated with reduced total mortality and CVD mortality in a predominantly low-income black and white population in the US, and among Chinese men and women living in Shanghai. Because peanuts are much less expensive than tree nuts, as well as more widely available to people of all races and all socioeconomic backgrounds, increasing peanut consumption may provide a potentially cost-efficient approach to improving cardiovascular health.
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MedicalResearch.com Interview with:
Colette Nicole Miller FDN
Department of Foods and Nutrition
Edgar L. Rhodes Center for Animal and Dairy Science
University of Georgia, Athens, Georgia
Medical Research: What is the background for this study?
Response: Our laboratory has been interested for quite some time in the relationship that natural, plant-derived compounds have on various tissues in the body. Both bone and adipocytes are derived from the same progenitor cell, mesenchymal stem cells. Thus, if a drug or compound affects one type of cell, it may affect both. When women transition through menopause, and see a reduction in their female sex hormones like estrogen, they can see adverse changes in both how much fat they store and their bone density. Thus our lab is interested in compounds that can be used to prevent the bone loss and visceral adipogenesis that menopausal women often experience. Previous work both in vivo and in vitro has shown that phytochemicals have synergistic effects and thus can ultimately work together to reduce the dosages needed to promote overall health. Through this work we have identified a combination of genistein, resveratrol, quercetin and Vitamin D that improve bone density in addition to promoting apoptosis of adipocytes. However, the health of the liver had never been addressed with our phytochemical blend. We know that supplements are sometimes toxic to the liver for many different reasons. Thus, it was very important for us to address the toxicity and potential risk of non-alcoholic fatty liver disease with our phytochemical blend in a menopausal rat model.
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MedicalResearch.com Interview with:
William Mair, Ph.D Assistant Professor
Department of Genetics and Complex Diseases
Harvard T. H Chan School of Public Health
Boston, MA 02115
MedicalResearch: What is the background for this study? What are the main findings?
Dr. Mair: Dietary restriction, the reduction of food intake without malnutrition has been known for 80 years to prolong lifespan in organisms ranging from single celled yeast to non human primates, and early signs suggest improvement of metabolic parameters in patients undergoing clinical trials. However, negative side effects associated with low calorie intake remain, and compliance and lifestyle factors make it an unappealing therapeutic. Since calorie restriction (CR) can have remarkable protective effects against multiple age onset diseases in mouse models - ranging from cancer to neurodegeneration to metabolic disease - finding molecular mechanisms though which calorie restriction functions might provide novel therapeutic targets that promote healthy aging. Using a model system, the nematode worm C. elegans, we show that perception of energy intake in the nervous system may be as critical for the effects of low energy on aging as actual calorie intake itself. Animals expressing an active form of a protein called AMPK, which is a cellular energy sensor, were long lived despite eating normally but this longevity could be turned off or on by changes to a neurotransmitter in just a few neurons. This suggests that therapeutic targets that modulate the perception of energy status in the nervous system might provide novel ways to gain the benefit of calorie restriction and promote healthy aging.
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MedicalResearch.com Interview with:
Professor Daniela Jakubowicz MD
Diabetes Unit. E. Wolfson Medical Center
Sackler Faculty of Medicine,
Tel Aviv University and Tel Aviv Medical Center
Israel
MedicalResearch: What is the background for this study? What are the main findings?
Professor Jakubowicz: Obesity epidemic have lead to alarming rise of type 2 diabetes. It is estimated that more than 382 million worldwide have diabetes, predominately type 2 diabetes.
In these persons the cardiovascular disease is the leading complication, carrying 10 to 20-fold increase in the risk compared with persons without diabetes.
It has been shown that large glucose peaks after meals along the day, are strongly associated with increased a risk for cardiovascular complications.
Therefore the mitigation of glucose excursions after meals becomes a major target in the treatment of type 2 diabetes in order to improve glucose balance and prevent complications.
Accordingly, dietary modification focused on reduction post meal glucose peaks is needed. Even though still there is no consensus on which of the dietary strategies (i.e. low-fat diet, Mediterranean and low-carbohydrate, higher fiber, low GI glycemic index meals, etc.) is more suitable in improving post-meal glycemic responses along the day.
However in none of these interventions has been considered that modifying the meal timing pattern or daily caloric distribution, may lead to improved post-meal glycemic responses in type 2 diabetic patients.
The circadian clock genes existing in the pancreatic β-cells, gut, liver and in skeletal muscle, regulate the diurnal (circadian) oscillation of post-meal glucose responses. In fact, post-meal glycemia displays a clear diurnal variation: it is higher and more prolonged in the evening than in the morning. Meal timing schedule, on the other hand, exerts strong controlling influence on circadian clock regulation, thereby influencing the variation and degree of the post meal glycemic elevations. Indeed meal timing non-aligned with the clock gene circadian rhythms, such as breakfast skipping or high-energy intake at dinner, is associated with obesity, higher HbA1C and poor glycaemic control in type 2 diabetes.
To clarify the impact of meal timing and composition on overall post-meal glucose responses, we tested the effect of 2 isocaloric diets with different meal timing one with high energy breakfast (704 kcal), mid-sized lunch (600 kcal) and reduced dinner (200 kcal) and other with similar lunch but reduced breakfast (704 kcal) and high energy dinner(704 kcal).
The study clearly demonstrated that in type 2 diabetic patients, a diet consisting on high energy breakfast, and reduced dinner, resulted in significantly reduced glucose response after meals and lower overall plasma glucose levels along the entire day, when compared to a diet with the same caloric content but inverse distribution: breakfast (200 kcal) , lunch (600 kcal) and high energy dinner(704 kcal).
Moreover, when we compared the glucose response after high energy meal consumed at breakfast (700 kcal) versus in the dinner (700 kcal), it comes out that the glucose response was significantly higher after dinner than after breakfast. It shows that just by changing the time of the high energy meal we may achieve significant reduction in the glucose response.
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MedicalResearch.com Interview with:
Brian Elbel, PhD, MPH
Associate Professor, Department of Population Health;
Associate Professor, Department of Medicine
Population Health NYU School of Medicine
Medical Research: What is the background for this study? What are the main findings?
Dr. Elbel: This study tried to determine whether a new supermarket that received tax and zoning credits from New York City, locating in a high need area, impacted healthy eating for children. No previous controlled study has looked at children, and supermarkets are tool being increasingly used to improve healthy eating. We did not find, at least one year after the store opened, any appreciable change in shopping or eating.
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MedicalResearch.com Interview with:
Ekaterina Maslova PhD
Doctor of Science in Nutrition and Epidemiology
Center for Fetal Programming
Copenhagen, Denmark
Medical Research: What is the background for this study? What are the main findings?
Response: From prior studies we know that excessive gestational weight gain (GWG) in pregnancy is associated with complications for both the mother and the child, including gestational diabetes, hypertension, and high birth weight. Understanding the factors that determine gestational weight gain would allow for interventions early on to improve pregnancy outcomes. Dietary intake has been found to influence gestational weight gain in other studies, but evidence is conflicting and still quite limited. In non-pregnant populations a high-protein diet was shown to decrease weight and improve weight maintenance. We therefore hypothesized that a similar relation may exist for gestational weight gain in pregnant women.
In this study we had data on dietary intake of more than 45,000 Danish women who were pregnant between 1996 and 2002. We examined the relation between their intake of protein and carbohydrates and the rate of gestational weight gain (in grams per week). We found that women who consumed a high protein-to-carbohydrate (PC) ratio gained less gestational weight gain compared to women with a lower PC ratio in their diet. The results was stronger in women who started their pregnancy already overweight compared to normal weight women.
Since a high PC ratio may result from either a high protein intake or low carbohydrate intake, we decided to focus on a component of carbohydrates that may increase gestational weight gain: added sugar. We found that pregnant women with higher intake of sugar gained more weight in pregnancy compared to those who consumed less added sugar. This averaged out to about 1.4 kg (or 7%) higher weight gain across the entire pregnancy.
(more…)MedicalResearch.com Interview with: Sheena M. Patel, MPH, ORISE, Fellow Division for Heart Disease and Stroke Prevention CDC MedicalResearch: What is the background for this...
MedicalResearch.com Interview with:
James J. DiNicolantonio, PharmD
Associate Editor BMJ Open Heart
Cardiovascular Research Scientist
Saint Luke's Mid America Heart Institute
Medical Research: What is the background for this study? What are the main findings
Response: There were 6 randomized controlled dietary trials performed before the government dietary fat recommendations were released. When we performed a systematic review and meta-analysis of the available trials at this time, there was no significant difference in all-cause mortality or cardiovascular heart disease mortality. In essence, there was no support from randomized controlled trials at the time to support a reduction in fat and saturated fat (and there still isn't from recent meta-analysis including newer trials).
The reductions in mean serum cholesterol levels were significantly higher in the intervention groups but this did not result in significant differences in cardiovascular heart disease or all-cause mortality. (more…)
MedicalResearch.com Interview with:
Ashok K. Shetty, Ph.D.
Professor and Director of Neurosciences
Institute for Regenerative Medicine and Department of Molecular and Cellular Medicine
Texas A&M Health Science Center College of Medicine, Temple, TX
Research Career Scientist, Central Texas Veterans Health Care System (CTVHCS), Temple, TX
Medical Research: What is the background for this study?
Prof. Shetty: Hippocampus is a region in the brain important for maintaining functions such as learning, memory and mood. However, this region is highly vulnerable to aging and brain insults. Previous research has shown that diminished function in the dentate gyrus region of the hippocampus is one of the key reasons for memory impairments seen in old age. Dentate gyrus is also one of the few regions in the brain where neural stem cells generate new neurons on a daily basis, also referred to as "adult neurogenesis". Studies have suggested that a significant fraction of newly born neurons mature, get incorporated into the existing hippocampus circuitry and contribute to learning, formation of new memories, and normal mood. However, with aging, the dentate gyrus shows decreased function with some conspicuous structural changes, which include reduced production of new neurons, diminished microvasculature implying reduced blood flow, and occurrence of hypertrophy of astrocytes and activated microglia, signs of chronic low-level inflammation. Because alterations such as reduced neurogenesis, decreased blood flow and brain inflammation can contribute to memory and mood impairments, the idea that drugs that are efficacious for mitigating these changes may preserve memory and mood function in old age has emerged. Such drugs may be prescribed to the aging population if they are efficacious for maintaining normal cognitive and mood function in old age with no or minimal side effects.
Medical Research: What is the rationale for choosing resveratrol for preventing age-related memory dysfunction in this study?
Prof. Shetty: Administration of resveratrol, a naturally occurring polyphenol found in the skin of red grapes, red wine, peanuts and some berries, appeared suitable for counteracting age-related detrimental changes in the hippocampus. This is because, previous studies have shown that resveratrol has ability to promote the formation of new capillaries (through pro-angiogenic effects) and to suppress oxidative stress and inflammation (via antioxidant and antiinflammatory effects) with no adverse side effects. Other studies have also reported that resveratrol can mediate extension of the life span and delayed onset of age related diseases. More importantly, a recent human study suggested that a reasonably lower dose of resveratrol intake for 26 weeks is good enough to improve memory performance as well as hippocampus functional connectivity in 23 healthy overweight older individuals (Witte et al., J. Neurosci., 34: 7862-7870, 2014).
(more…)James J. DiNicolantonio, PharmD
Associate Editor BMJ Open Heart
Cardiovascular Research Scientist
Saint Luke's Mid America Heart Institute
Medical Research: What is the background for this study? What are the main findings?
Dr. DiNicolantonio: We performed a comprehensive literature review comparing the isocaloric exchange of added sugars (sucrose, also known as table sugar, or high fructose corn syrup) versus other types of carbohydrates (such as lactose found in milk, glucose, starch, or dextrose). Our main findings were that "a calorie isn't a calorie," i.e., that added sugars are more harmful than other carbohydrates even when matched for calories for promoting pre-diabetes and diabetes and the related morbidity and mortality associated with these diseases
(more…)MedicalResearch.com Interview with: Karin B. Michels, MPH, PhD, ScD Department of Epidemiology, Harvard School of Public Health Channing Division of Network Medicine, Department...
MedicalResearch.com Interview with:
John Brannan PhD
Firestone Institute for Respiratory Health at St Joseph’s Healthcare & McMaster University, Hamilton, Ontario, Canada
Medical Research: What is the background for this study?
Response: The use of omega-3 acid supplements as treatments for allergic diseases including asthma is controversial. Studies by investigators from Indiana University in the USA have repeatedly demonstrated a beneficial effect of high dose omega-3 fatty acid supplements over 3 weeks in attenuating exercise-induced bronchoconstriction (EIB) similar or possibly better in potency to what may be expected with a regular inhaled corticosteroids. The study by Brannan et al. attempted to validate these findings by using inhaled mannitol, a bronchial provocation test that was derived from the understanding of exercise-induced bronchoconstriction and which has demonstrated experimentally to be a useful model for exercise-induced bronchoconstriction. All pharmacotherapies that modify exercise-induced bronchoconstriction can modify the airway sensitivity to inhaled mannitol in persons with asthma, thus it was of interest to see if an 'alternative' treatment that demonstrated efficacy in exercise-induced bronchoconstriction could too modify the airway response to mannitol.
Medical Research: What are the main findings?
Response: The main findings were, to our surprise, there was no benefit of high dose omega-3 fatty acid supplements on bronchial hyperresponsiveness to mannitol over 3 weeks. This was associated with no changes in airway inflammation (sputum eosinophils), lung function or asthma symptom control. We also found no benefit on resting urinary mast cell metabolites, in contrast to the findings in studies showing a benefit of omega-3 fatty acids on EIB. Our findings suggest that omega-3 supplements in tissues may not be able to penetrate tissue and/or modify the substrate flow of eicosanoids in tissue such as the airways of the asthmatic. We did observed the expected reductions in blood triglycerides which suggests that these doses of omega-3s can modify metabolism in the blood or to some extent tissues that are highly perfused.
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MedicalResearch.com Interview with:
Charles Bourque PhD
James McGill Professor
Centre for Research in Neuroscience
Montreal General Hospital Montreal QC, Canada
Medical Research: What is the background for this study? What are the main findings?
Dr. Bourque: Previous work has established that there is a link between a high level of dietary salt intake and the development of hypertension. In particular, so-called “salt-sensitive” individuals display increases in blood pressure that correlate with significantly increased levels of serum sodium concentration. Increased sodium levels are known to cause an excitation of vasopressin (VP)-releasing neurons of the hypothalamus. We therefore tested the hypothesis that this increase can contribute to the increase in blood pressure associated with high sodium intake in rats.
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MedicalResearch.com Interview with:
Andreas Kalogeropoulos, MD MPH PhD
Assistant Professor of Medicine (Cardiology)
Emory University School of Medicine Emory Clinical Cardiovascular Research Institute
Atlanta GA 30322
Medical Research: What is the background for this study? What are the main findings?
Dr. Kalogeropoulos: There is ongoing debate on how low should we go when it comes to dietary sodium (salt) restriction recommendations. In this study, we examined the association between self-reported dietary sodium intake and 10-year risk for death, cardiovascular disease, and heart failure in approximately 2,600 adults 71-80 years old. The subjects (women: 51.2%; white: 61.7%; black: 38.3%) were participants of the community-based Health, Aging, and Body Composition Study, which is sponsored by NIH and focuses on aging processes, i.e. was not specifically designed to address the issue of dietary salt intake. Also, it is important to note that salt intake was self-reported (not objectively measured) using a food frequency questionnaire, which underestimates salt intake. Keeping these limitations in mind, we did not observe a significant association between self-reported sodium intake and 10-year mortality, cardiovascular disease, and heart failure. Ten-year mortality was lower in the group reporting 1500–2300 mg daily sodium intake (30.7%) compared to those reporting daily intake less than 1500 mg (33.8%) or over 2300 mg (35.2%); however, this difference was not statistically significant. The 10-year event rates for cardiovascular disease (28.5%, 28.2%, and 29.7%) and heart failure (15.7%, 14.3%, and 15.5%) were also comparable across the <1500-mg, 1500-2300-mg, and >2300-mg dietary sodium intake groups.
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MedicalResearch.com Interview with:
Jinnie J. Rhee MSc, ScD
Department of Medicine, Stanford University School of Medicine Palo Alto, CA
Medical Research: What is the background for this study? What are the main findings?
Response: The goal of this study was to see if the dietary determinants of type 2 diabetes observed in predominantly white populations were similar to those in other racial and ethnic groups. We created a dietary diabetes risk reduction score using eight different dietary factors found to be associated with risk of type 2 diabetes, where a higher score indicates a healthier overall diet (A higher score included low intakes trans fat, sugar-sweetened beverages, and red and processed meats; lower glycemic index; and higher intakes of cereal fiber, nuts, and coffee; and higher polyunsaturated to saturated fat ratio). We found a protective association of similar magnitude between a healthy overall diet and type 2 diabetes risk in all racial and ethnic groups. However, in terms of the actual number of preventable cases, a healthier diet conferred even greater benefit for minority women because they were initially at higher risk than white women.
This study is significant because diabetes is a rapidly growing epidemic in most parts of the world, but most previous studies of diet and diabetes have been conducted in populations of European origin. This analysis was very powerful because it combined two large populations with a total of 156,030 women who were followed for up to 28 years with many repeated assessments of diet. This allowed us to conduct detailed analyses within specific racial and ethnic groups.
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MedicalResearch.com Interview with:
Cecilia Cesa Schiavon
Department of Nutrition, Federal University of Santa Catarina
Florianópolis, Santa Catarina, Brazil
Medical Research: What is the background for this study? What are the main findings?
Response: The study was based on a nutritional intervention for patients undergoing treatment for breast cancer. The intervention took place right after the surgical procedure and lasted about a year, until the end of chemotherapy. The patients were submitted to a special methodology of intervention, aimed at increasing fruit and vegetable intake and reducing red and processed meat, following the World Cancer Research Fund and the American Institute for Cancer Research in the document entitled Food, Nutrition, Physical Activity and the prevention of Cancer: A Global Perspective”.
The main findings show that women undergoing breast cancer treatment may benefit from immediate, individualized, and detailed nutrition monitoring through appropriate nutrition education.
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MedicalResearch.com Interview with:
Jennifer Williams MSN, MPH, FNP-BC
National Center on Birth Defects and Developmental Disabilities
CDC, Atlanta, Georgia
Medical Research: What is the background for this study? What are the main findings?
Response: Neural tube defects are serious birth defects of the brain and spine that can cause significant disability and death. Studies have shown that taking 400 mcg of folic acid daily before and during pregnancy can reduce the prevalence of neural tube defects. Therefore, in 1992, the US Public Health Service (USPHS) recommended that all women of childbearing age in the United States who are capable of becoming pregnant consume 400mcg of folic acid per day to reduce the risk of neural tube defects. To help women meet this requirement, in 1998 the US Food and Drug Administration (FDA) mandated that folic acid be added to enriched grain products for the prevention of neural tube defects.
This study looks at how many neural tube defects have been prevented annually since folic acid fortification. Using data from birth defects tracking systems, researchers found that since folic acid fortification, the birth prevalence of neural tube defects has decreased by 35% in the United States, which translates to about 1,300 babies that are born each year without a neural tube defect who might otherwise have been affected. This study also reports that the number of babies born with a neural tube defect annually differs by the mother’s race/ethnicity. Hispanic mothers continue to be at the highest risk for having a baby with a neural tube defect.
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MedicalResearch.com Interview with:
Zvonko Rumboldt, MD, PhD Professor emeritus
Split University School of Medicine;
Split, Croatia
Medical Research: What is the background for this study? What are the main findings?
Dr. Rumboldt: Arterial hypertension is the major common denominator of a number of cardiovascular diseases and untoward outcomes including stroke, myocardial infarction, terminal renal insufficiency, heart failure and death. Excessive salt intake is the leading causative factor of blood pressure elevation across the world. It has been shown beyond any reasonable doubt that reduction in salt consumption decreases the prevalence of arterial hypertension and eases its management. Therefore many endeavors and campaigns aimed at moderation in salt ingestion have been launched with fair but less than expected results. The main source of ingested salt in developed countries is processed food, while in transitional and developing countries it is addition during food preparation (cooking), serving and salting at the table.
This study, executed in Mostar, Bosnia and Herzegovina, and Split, Croatia, was designed to evaluate the effects of emphasized warning, consisting in self-adhesive stickers with clear, short message, put on household salt containers. Analyzed were 150 treated hypertensives, randomized in two groups, both receiving oral information and written leaflet concerning salt-hypertension relationship; the intervention group received in addition warning labels to be put on salt containers. In both groups measured were 24-hour urinary sodium excretion (natriuria), blood pressure, and several other parameters at inception of the trial, and one and two months later. In the intervention group observed was a marked decrease in sodium excretion (e.g. from 211 mmol/l at the beginning to 176 mmol/l at two months), much less (from some 207 to 200 mmol/l) in the control group. At the same time, the mean blood pressure (already fairly well controlled) was reduced by additional 4 mm Hg in the intervention group (from 104 to 100 mm Hg), which was not the case in the control group (from 104 to 103 mm Hg).
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