MedicalResearch.com Interview with:
Dr. Mila Kingsbury PhD
Senior Research Associate at Department of Epidemiology and Community Medicine
University of Ottawa
Medical Research: What is the background for this study?
Dr. Kingsbury: Eating a healthy diet, including enough fruits and vegetables, is good for physical health, and some evidence suggests that it may be good for mental health, too. Specifically, intake of fruits and vegetables has been associated with lower risk of depression.
However, there are very few longitudinal studies on this topic. Most studies haven’t accounted for the effects of other related lifestyle factors such as smoking and exercise, nor for the fact that the links between lifestyle and mental health are bidirectional (i.e., depression can also hinder our ability to engage in healthy behaviours).
Medical Research: What are the main findings?
Dr. Kingsbury: While we found an association between fruit and vegetable consumption and psychological distress and depression two years later, depression and distress also predicted future fruit and vegetable consumption. Importantly, these associations became non-significant when we controlled for lifestyle factors like smoking and exercise.
MedicalResearch.com Interview with:
Dr Aseem Malhotra MBChB, MRCP
Honorary Consultant Cardiologist -
Frimley Park Hospital
Consultant Clinical Associate to the Academy of Medical Royal Colleges
Science Director- Action on Sugar
Saving Londoners Lives - External Advisory Board Member
Medical Research: What is the background for this study? What are the main findings?
Dr. Malhotra: It is a review of all the research up to date on what is the impact of diet on health. What type of diet has the most robust evidence for weight and health and how this can be translated into policy to rapidly reduce the burden of chronic disease.
Medical Research: What should clinicians and patients take away from your report?
Dr. Malhotra:
MedicalResearch.com Interview with:
Candida Rebello, PhD candidate
Louisiana State University
Pennington Biomedical Research Center
School of Nutrition and Food Sciences
Baton Rouge , Louisiana
MedicalResearch: What is the background for this study? What are the main findings?
Response: Oats contain a soluble fiber called beta-glucan. When mixed with liquids, this fiber induces viscosity or what is commonly called thickening. The degree of thickening depends on a number of factors such as the structure and concentration of the fiber, its molecular weight, and the ease with which the fiber will absorb water. These qualities of the fiber can be affected by various processing techniques used in the preparation of food products. Viscosity affects appetite by influencing the way foods interact with the mouth, as well as the stomach and intestines. Viscosity in the stomach can cause distension and promote a feeling of fullness. Viscosity in the intestinal tract delays digestion and absorption allowing nutrients to interact with cells and release hormones that reduce hunger and keep a person full for a prolonged period after eating a meal which is termed satiety. Viscosity in the mouth also affects appetite and all these effects often work in concert. In animal studies, oat beta-glucan has been shown to influence appetite regulating hormones, as well as reduce food intake and body weight.1,2 In human trials, several studies have shown that oat beta-glucan reduces appetite.3-10 In this study, we found that instant oatmeal eaten at breakfast reduced hunger, increased fullness, and reduced food intake at lunch, compared to an oat-based ready-to-eat cereal containing equal calories. Instant oatmeal had greater viscosity than the ready-to-eat cereal.
MedicalResearch.com Interview with:
Dimitry N. Krementsov PhD
Research Associate
University of Vermont
Burlington, VT 05405
Medical Research: What is the background for this study? What are the main findings?
Dr. Krementsov: Multiple sclerosis (MS) is the most common disabling neurologic disorder affecting young adults. The disease is initiated by the individual’s own immune system attacking the central nervous system (brain and spinal cord).Multiple sclerosis is complex and is controlled by the interplay between sex/gender, genetics, and environmental factors. How this happens is not well understood, but an intriguing clue is that MS incidence over the last 50-100 years has been increasing in women and not men, suggesting that a recent environmental change is affecting MS preferentially in females.
There are several well-documented risk factors for Multiple Scleroisis, including Epstein-Barr virus infection, low sunlight exposure, low vitamin D, and smoking. Recent studies have suggested the existence of a new risk factor – high intake of dietary salt. In our study, we sought to understand how this environmental factor may interact with genetics and sex.
We used an animal model of MS, called experimental autoimmune encephalomyelitis (EAE), in laboratory mice. The advantage of this approach is the ability to precisely control both the genetics and the environment, something that cannot be done in epidemiological studies in humans. Just as in previous studies, we found that when mice were fed a high salt diet, their MS-like disease got worse.
Importantly, we found that this was dependent on genetics and sex; when we varied the genetic background of the mice, we saw three different outcomes:
1) an effect of salt in both males and females,
2) an effect only in females, and
3) no effect in either sex.
MedicalResearch.com Interview with:
Dr. Karen Hardy
ICREA, Catalan Institution for Research and Advanced Studies
Departament de Prehistòria
Facultat de Filosofia i Lletres
Universitat Autònoma de Barcelona
Barcelona, Spain
MedicalResearch: What is the background for this study? What are the main findings?
Dr. Hardy: There continues to be little clear agreement on what quantitatively constitutes a healthy diet. The global increase in the incidence of obesity and diet-related metabolic diseases have intensified interest in ancestral or “Palaeolithic” diets as it is clear that to a first order of approximation our physiology should be optimized to the diet that we have experienced during our evolutionary past. However, reconstructing ancestral diets is very challenging, and exactly what was eaten during the Palaeolithic remains largely unknown.
Until now, there has been a heavy focus on the role of animal fats and protein in the development of the human brain and there is little doubt that increases in meat consumption from around 3.4 million years ago, was a major driver. However, the role of carbohydrates, particularly in the form of starch-rich plant foods, has largely been overlooked. But the human brain today uses up to 25 % of the body’s energy budget and up to 60 % of blood glucose as a general rule, while pregnancy and lactation in particular, place additional demands on the body’s glucose budget. In this study we integrated multiple lines of evidence from human genetics, archaeology, anthropology, physiology, and nutrition, to hypothesise that cooked carbohydrates played an important part in the evolution of the body, and particularly the brain, over the last 800,000 years.
Our results suggest that while meat was important, brain growth is less likely to have happened without the energy obtained from carbohydrates. While cooking has also been proposed as contributing to early brain development, it has a particularly profound effect on the digestibility of starch. Furthermore, humans are unusual among primates in that they have many copies of the salivary amylase gene (average of around six salivary amylase genes, other primates have only two) leading to more efficient starch digestion. This suggests that cooking starch-rich plants and having more amylase coevolved. We don’t know exactly when the number of amylase gene copies multiplied, but genetic data suggest it was in the last million years; a timeframe that brackets archaeological evidence for cooking and when our brain size increase accelerated (around 800,000 years ago). Salivary amylases are largely ineffective on raw crystalline starch, but cooking substantially increases both their energy-yielding potential and glycemia.
MedicalResearch.com Interview with:
James M. Shikany, DrPH
Professor of Medicine
Division of Preventive Medicine
University of Alabama at Birmingham
Birmingham, AL
Medical Research: What is the background for this study? What are the main findings?
Dr. Shikany: There is a growing interest in the field of nutritional epidemiology in relating overall dietary practices to various disease endpoints. For example, the assessment of dietary patterns in a population may be more meaningful than concentrating on isolated nutrients or foods because they more closely reflect how people eat in the real world. Previously, we looked at how the degree to which one adhered to 5 dietary patterns identified in the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study was associated with the risk of stroke. In the current study, we investigated how the degree to which one adhered to these dietary patterns was related to the risk of incident acute coronary heart disease.
The main finding was that a Southern dietary pattern (characterized by added fats, fried foods, eggs and egg dishes, organ meats, processed meats, and sugar-sweetened beverages) was associated with a significantly greater hazard of incident acute coronary heart disease in REGARDS participants. The association persisted following adjustment for sociodemographics, lifestyle factors, and energy intake. Specifically, following multivariable adjustment, participants in the highest quartile of consumption of the Southern pattern experienced a 56% greater hazard of incident coronary heart disease compared with those in the lowest quartile of consumption of this pattern. Another pattern we observed – the Plant-based pattern – characterized by vegetables, fruits, beans, yogurt, poultry, and fish was not associated with an increased risk of coronary heart disease.
MedicalResearch.com Interview with:
Prof. Kate Jolly
Professor of Public Health and Primary Care
Public Health Building
School of Health & Population Sciences
University of Birmingham
Edgbaston Birmingham
Medical Research: What is the background for this study?
Response: The UK is amongst 32 countries worldwide with evidence of iodine deficiency. Severe iodine deficiency during pregnancy is associated with a lower intelligence quotient (IQ) and developmental abnormalities in the children; these are reversible by iodine supplementation during pregnancy. However, the effects of mild or moderate iodine deficiency during pregnancy are less clear as there are no high quality trials of supplementation that have reported the outcome of child IQ. However, in two studies in the UK and Australia, nine year old children of women who had a urinary iodine concentration suggestive of mild iodine deficiency during their pregnancy exhibited reduced educational outcomes and decreased IQ scores compared to children of iodine replete mothers.
Recent research from the UK suggests that the country has become mildly iodine deficient. Many countries address their iodine deficiency by programmes of adding iodine to salt and some recommend that pregnant women take iodine supplements. Neither of these occur in the UK, although some commonly used pregnancy supplements already include iodine.
Controversy about the need for supplementation in pregnancy, the ethics of undertaking a trial in which women would be randomly allocated to have iodine supplements, or not, and the high cost of following-up and assessing large numbers of children makes a trial unlikely.
MedicalResearch.com Interview with: Lu Qi, MD, PhD, FAHA Associate Professor of Medicine Harvard Medical School Associate Professor of Nutrition and Epidemiology Harvard T.H. Chan School of Public Health Medical Research: What is the background for this study? What are the main findings? Dr. Lu Qi: There are accumulating evidence from mostly experimental research to show the benefit...
MedicalResearch.com Interview with:
Auriel A. Willette, M.S., Ph.D.
Food Science and Human Nutrition
Neuroscience Interdepartmental Graduate Program
Gerontology Interdepartmental Graduate Program
Iowa State University, Ames
Medical Research: What is the background for this study? What are the main findings?
Response: Obesity is a major health concern around the world. Obesity causes insulin resistance, defined in this case as the inability of insulin to bind to its receptor and mediate glucose metabolism. Other researchers and I have recently found that higher insulin resistance is associated with less glucose metabolism in the brains of patients with Alzheimer's disease. This relationship is found primarily in medial temporal lobe, an area necessary for generating new memories of facts and events. This is important because Alzheimer's disease is characterized by progressive decreases in glucose metabolism over time, and partly drives worse memory performance. Insulin resistance in midlife also increases the risk of developing Alzheimer's disease.
We wanted to determine if insulin resistance is linked to similar effects in cognitively normal, late middle-aged participants decades before Alzheimer's disease typically occurs. If so, insulin resistance might be an important biological marker to track from middle-age onwards. Thus, we examined the association between insulin resistance, regional glucose metabolism using FDG-PET, and memory function in 150 middle-aged participants, many of whom had a mother or father with Alzheimer's disease.
We found that higher insulin resistance was strongly associated with less glucose metabolism throughout many brain regions, predominantly in areas that are affected by Alzheimer's disease. The strongest statistical effects were found in left medial temporal lobe, which again is important for generating new memories. This relationship, in turn, predicted worse memory performance, both immediately after learning a list of words and a 20-minute delay thereafter.
The take-home message is that insulin resistance has an Alzheimer's-like association with glucose metabolism in middle-aged, cognitively normal people at risk for Alzheimer's, an association which is related to worse memory.
Editor's note: Metabolic dysfunction may also manifest externally through dermatological signs such as insulin resistance on neck regions like acanthosis nigricans.
MedicalResearch.com Interview with:
Tomonori Sugiura, MD, PhD
Department of Cardio‐Renal Medicine and Hypertension
Nagoya City University Graduate School of Medical Sciences
Nagoya Japan
Medical Research: What is the background for this study? What are the main findings?
Dr. Sugiura: Although there is a close relationship between dietary sodium and hypertension, the concept that individuals with relatively high dietary sodium are at increased risk of developing hypertension compared to those with relatively low dietary sodium, has not been intensively studied in a cohort. Therefore, the present observational study was designed to investigate whether individual levels of dietary sodium critically affect future increases in blood pressure in the general population.
The main findings of this study were that a relatively high level of dietary sodium intake and also a gradual increase in dietary sodium, estimated by urinary sodium excretion, are associated with a future increase in blood pressure and the incidence of hypertension in the general population.
MedicalResearch.com Interview with:
Junfeng Jiao, PhD
Assistant Professor, The University of Texas at Austin School of Architecture
Director, Urban Information Lab
Austin, Texas
Medical Research: What is the background for this study?
Dr. Jiao: The increase in obesity rates has been explained by dietary changes including the consumption of high-energy, low-nutrient foods. Over the past thirty years, trends reveal increases of eating away from home. Public Health professionals have hypothesized that the heightened exposure to the ubiquitous fast food establishments may be an avenue through which health and diets are impacted.
Medical Research: What are the main findings?
Dr. Jiao: This study examined whether the reported health impacts of eating at a fast food or quick service establishment on a frequent basis were associated with having such a restaurant near home. Results indicated that eating at a fast food or quick service restaurant two times or more per week was related with perceived poor health status, overweight, and obese. Simply living close to such establishments was not related to negative health outcomes such as being overweight or obese, having cardiovascular disease (CVD) or diabetes.
MedicalResearch.com Interview with:
Mara Meyer Epstein, ScD
Assistant Professor
Meyers Primary Care Institute
University of Massachusetts Medical School
MedicalResearch: What is the background for this study? What are the main findings?
Dr. Epstein: Hodgkin lymphoma is a relatively rare cancer, with about 9,000 new cases diagnosed in the US each year. Hodgkin lymphoma is most commonly diagnosed in earlier (aged 15-34 years) or later adulthood (aged ≥50 years). The causes of the disease are not well understood, and most identified risk factors are not modifiable (for example, age, sex, family history, and infection with Epstein-Barr virus [EBV]). Previous studies have suggested that chronic inflammation may play a role in the development of Hodgkin lymphoma. Therefore, it is possible that a factor that can influence inflammation, such as diet, may be associated with risk of Hodgkin lymphoma. Discovering modifiable risk factors for Hodgkin lymphoma could offer a means for preventing this disease. The few existing studies of diet and Hodgkin lymphoma risk have focused on individual nutrients or foods; this is the first study to examine dietary pattern and risk of Hodgkin lymphoma. By examining dietary patterns instead of individual foods, we sought to assess Hodgkin lymphoma risk from the food combinations that may more closely reflect typical dietary habits.
The current study includes 435 cases of Hodgkin lymphoma and 563 controls with no history of cancer from Massachusetts and Connecticut who were enrolled in the study between 1997 and 2000. Cases and controls provided information about their average intake of 61 food and beverage items over the year prior to the study. By evaluating foods commonly consumed by the study participants, we identified four major dietary patterns; high vegetable intake, high meat intake, high intake of fruit and low-fat dairy, and high intake of desserts and sweets. We looked for associations between each dietary pattern and risk of Hodgkin lymphoma overall, and also separately by age group (<50 years or ≥50 years old), tumor EBV status (positive or negative), and by tumor cell pattern (nodular sclerosis or mixed cellularity). The dietary pattern characterized by high intake of desserts and sweets was associated with a statistically significant increased risk of Hodgkin lymphoma among younger adults, and in particular, a 2-fold increased risk among younger adults with EBV-negative tumors. The dietary pattern featuring high meat intake was associated with a 3-fold increased risk of Hodgkin lymphoma among older adults, and again, we saw a stronger association among older adults with EBV-negative tumors, although the number of such cases in this group was small. We did not observe a clear association between the high vegetable dietary pattern, or the dietary pattern high in fruit and low-fat dairy intake, with Hodgkin lymphoma risk, and we also did not find any clear associations with EBV-positive tumors, which were relatively infrequent in the study population. The findings described above were obtained from statistical calculations that also took into account known Hodgkin lymphoma risk factors, other lifestyle factors, total caloric intake, and body mass index.
MedicalResearch.com Interview with:
Benjamin D. Horne, PhD, MPH, FAHA, FACC
Director, Cardiovascular and Genetic Epidemiology, Intermountain Heart Institute
Adjunct Assistant Professor, Genetic Epidemiology Division, Department of Medicine,
University of Utah
Medical Research: What is the background for this study? What are the main findings?
Dr. Horne: A rapidly expanding set of results from animal studies exists regarding the effects of intermittent fasting among animals. Many pilot studies of intermittent fasting have been performed now, too, but the body of literature regarding the human response to fasting is incomplete. This study sought to determine how preliminary and incomplete the evidence is in humans regarding the health benefits and the harmful side-effects of intermittent fasting. The purpose was to determine how reliable the evidence is that people should be engaging in fasting to improve their health. In particular, one major concern is that diet gurus and even some scientists are marketing intermittent fasting to the public through diet books and other methods that produce additional income for them, but it is unclear whether their claims can be supported.
The main findings of the study are that only three controlled clinical trials of intermittent fasting in humans have been published that were designed rigorously and included a control group in addition to the fasting intervention arm of the study. One of the three had a pre-specified primary outcome (weight loss) and another used the Bonferroni correction to account for inflated false positive results due to multiple hypothesis tests (the third study unfortunately did neither, which is the common approach in human studies of intermittent fasting). These three controlled trials only used surrogate or intermediate endpoints, though, such as weight, cholesterol, or other risk factors for disease. The three trials also have substantial limitations, including small sample sizes (~30 people total), a fasting regimen that was studied for less than three months, and no evaluation of clinical safety outcomes. Only one of the three trials was registered on ClinicalTrials.gov, a site instituted as part of the FDA Modernization Act and a pre-requisite for trials that are published in scientifically sound medical journals and are to be reviewed by the FDA.
Two observational studies of the association of intermittent fasting with clinical events (i.e., coronary artery disease diagnosis and diabetes diagnosis) also have been published. These two studies included 200 patients and 445 patients. They were performed in patients drawn from a general population in which a large proportion of people engage in fasting intermittently over a period of decades. These observational studies provide the only evidence that fasting is associated with a lower risk of disease outcomes. Such studies are limited, though, by adjustment for only known or measured confounders, making it possible that some important factors may be unobserved in the studies that would account for the fasting benefit that was observed. No randomized controlled clinical trial of fasting for clinical events or disease outcomes has been performed, though, thus these five studies are the whole body of reliable evidence that intermittent fasting is beneficial to humans.
MedicalResearch.com Interview with:
Lu Qi, MD, PhD, FAHA
Associate Professor of Medicine
Harvard Medical School
Assistant Professor of Nutrition
HarvardSchool of Public Health
Medical Research: What is the background for this study? What are the main findings?
Dr. Lu Qi: Most previous studies focus on the effects of either lifestyle or prenatal malnutrition on diabetes risk; no study has assess these two types of risk factors in combination.
MedicalResearch.com Interview with:
Maria L Marco, PhD
Associate Professor
Department of Food Science & Technology
Davis, CA 95616
Medical Research: What is the background for this study? What are the main findings?
Dr. Marco: Probiotics encompass certain strains of bacteria and yeast that when administered alive and in sufficient amounts can confer specific health benefits. Probiotics are increasingly added to foods, beverages, and intestinal supplements for delivery to the digestive tract. (Fermented) dairy products are currently the most popular food carriers for probiotic strains in clinical studies and commercial products. Although microorganisms generally respond quickly and adapt to their surrounding environments (e.g. in foods), the importance of the carrier format on probiotic function in vivo has yet to be systematically and mechanistically investigated. To address this need, we performed a couple studies in rodents to (i) examine whether probiotic Lactobacillus casei produces different proteins during low temperature (refrigeration) incubation in milk and (ii) measure whether incubation in milk is required for L. casei protection against inflammation. We found by shot-gun proteomics that L. casei does adapt for growth and survival in milk by producing a variety of (extra)cellular proteins, even at low-temperatures used to store dairy products prior to consumption. Such exposure of L. casei to milk was also essential for reducing the severity of disease in a mouse model of Ulcerative Colitis (UC), an inflammatory bowel disease characterized by continuous inflammation in the large intestine. Consuming milk alone also provided some protection against weight loss and intestinal inflammation in the Ulcerative Colitis mouse model but was not as effective as L. casei and milk in combination. Lastly, the importance of dairy for L. casei in preventing Ulcerative Colitis was confirmed by our findings that L. casei mutants lacking the capacity to synthesize proteins which are selectively produced during low-temperature incubation in milk were also impaired in preventing inflammatory responses in the intestine.
MedicalResearch.com Interview with: Dr. Fumiaki Imamura Ph.D.
MRC Epidemiology Unit
University of Cambridge
Medical Research: What is the background for this study? What are the main findings?
Dr. Imamura: Soft drink consumption is associated with risk of diabetes, but whether or not the association persists after controlling for obesity status is not known. Diet drinks and fruit juice may be good alternatives to soft drinks. However, while obese individuals may consume diet drinks or fruit juice instead of sugar-sweetened soft drinks, evidence was weak to determine whether or not consuming these beverages is associated with risk of diabetes.
MedicalResearch.com Interview with:
Dr. Vincent L. Cryns MD
Chief of the Division of Endocrinology, Diabetes and Metabolism
Department of Medicine
University of Wisconsin Carbone Cancer Center
University of Wisconsin School of Medicine and Public Health Madison, Wisconsin
Medical Research: What is the background for this study? What are the main findings?
Dr. Cryns: It’s been known for quite some time that many tumors are highly vulnerable to deficiencies in certain amino acids such as methionine, causing tumor cells to stop growing or die. What’s been missing is a molecular explanation for these effects that would allow us incorporate this approach into a rationally designed clinical trial. In our work, we have demonstrated that “starving” triple-negative breast cancer cells of methionine uncovers a “fatal flaw” by increasing the expression of a cell death receptor (TRAIL-R2) that we can activate with a therapeutic antibody to efficiently kill the tumor cells. What’s especially exciting is that we can use a specific diet to metabolically prime cancer cells to respond to a targeted cancer therapy.
MedicalResearch.com Interview with:
Dr. Alison Thorburn Ph.D.
Department of Immunology
Monash University
Victoria, Australia
Medical Research: What is the background for this study?
Dr. Thorburn: Asthma is a highly prevalent disease in the Western World. The prevailing explanation for this has been the hygiene hypothesis, which proposes that a decline in family size and improved hygiene has decreased exposure to infectious agents and therefore resulted in dysregulated immune responses that lead to asthma. However, recently there has been more attention on the role of diet and the gut microbiota in explaining the prevalence of inflammatory diseases in Western World. Indeed, many studies implicate obesity, as well as a high fat, low fruit and vegetable diet with higher prevalence of asthma. On the other hand, a Mediterranean diet, which is high in fruit and vegetables, is associated with lower prevelance of asthma. Interestingly, the consumption of dietary fiber is reduced in severe asthmatics. These and other data suggest that the diet (particularly dietary fibre) and the gut microbiota may play an important role in the development of asthma.
Medical Research: What are the main findings?
Dr. Thorburn: The main findings of this study are that:
- In mice: A high-fiber diet promotes a gut microbiota that produces high levels of anti-inflammatory short-chain fatty acids (SCFAs), particularly acetate. Acetate (alkaline form of vinegar) suppressed the development of allergic airways disease (AAD, a model for human asthma) in adult mice and the offspring of pregnant mice.
- In humans: High dietary fiber intake during late pregnancy is associated with higher acetate levels in the serum and a decrease in the percentage of infants showing predictors for asthma development in later life.
- The mechanism underlying these findings involves increasing T regulatory cell number and function through epigenetic mechanisms, which enhance immune regulation to prevent inflammation.
MedicalResearch.com Interview with: Todd Morgan, Ph.D. Chief Scientific Officer L-Nutra, Inc Culver City, CA 90232 Medical Research: What is the background for this study? Dr. Longo: Despite health benefits, even short periods of fasting are difficult to maintain for most people, as it can lead to electrolyte abnormalities and malnutrition in at-risk individuals, such as the...
MedicalResearch.com Interview with:
Professor Phyo Kyaw Myint MBBS MD FRCP(Edin) FRCP(Lond)
Clinical Chair in Medicine of Old Age
Epidemiology Group, Division of Applied Health Sciences
University of Aberdeen
Scotland
Medical Research: What is the background for this study? What are the main findings?
Response: The research was carried out by academics from the Universities of Aberdeen, Manchester, Cambridge and East Anglia, as well as the Lancashire Teaching Hospital, the Medical Research Council Epidemiology Unit, Cambridge and the Academic Medical Centre, Amsterdam. It has been published online in the journal Heart. The team base their findings on almost 21,000 adults taking part in the EPIC-Norfolk study, which is tracking the impact of diet on the long term health of 25,000 men and women in Norfolk, England, using food frequency and lifestyle questionnaires. The researchers also carried out a systematic review of the available international published evidence on the links between chocolate and cardiovascular disease, involving almost 158,000 people—including the EPIC study participants.
The EPIC-Norfolk participants (9214 men and 11 737 women) were monitored for an average of almost 12 years, during which time 3013 (14%) people experienced either an episode of fatal or non-fatal coronary heart disease or stroke. Around one in five (20%) participants said they did not eat any chocolate, but among the others, daily consumption averaged 7 g, with some eating up to 100 g.
Higher levels of consumption were associated with younger age and lower weight (BMI), waist: hip ratio, systolic blood pressure, inflammatory proteins, diabetes and more regular physical activity —all of which add up to a favourable cardiovascular disease risk profile. Eating more chocolate was also associated with higher energy intake and a diet containing more fat and carbs and less protein and alcohol.
The calculations showed that compared with those who ate no chocolate higher intake was linked to an 11% lower risk of cardiovascular disease and a 25% lower risk of associated death. It was also associated with a 9% lower risk of hospital admission or death as a result of coronary heart disease, after taking account of dietary factors. And among the 16,000 people whose inflammatory protein (CRP) level had been measured, those eating the most chocolate seemed to have an 18% lower risk than those who ate the least. The highest chocolate intake was similarly associated with a 23% lower risk of stroke, even after taking account of other potential risk factors.
Of nine relevant studies included in the systematic review, five studies each assessed coronary heart disease and stroke outcome, and they found a significantly lower risk of both conditions associated with regular chocolate consumption. And it was linked to a 25% lower risk of any episode of cardiovascular disease and a 45% lower risk of associated death.
The study concluded that cumulative evidence suggests higher chocolate intake is associated with a lower risk of future cardiovascular events.
MedicalResearch.com Interview with:
Catarina Rendeiro Ph.D.
Post-doctoral Research Associate
Rhodes lab University of Illinois
Urbana, Illinois
Medical Research: What is the background for this study? What are the main findings?
Dr. Rendeiro: The motivation for this study emerges in the context of understanding the link between sugar intake, particularly fructose, and the rising obesity epidemic that we are currently facing. Overeating and lack of physical activity certainly play major roles in obesity, but the sources of calories are also important. Fructose, a simple monosaccharide found in fruit and vegetables, and composing half of sucrose (i.e., table sugar), has been on the increase in Western diets. In our rodent study, 18% of dietary calories were derived from sugar, either fructose or glucose. This level is similar to typical American diets. However, the fructose diet resulted in increased weight gain and fat deposition and reduced physical activity even though food intake was similar between the two groups. It is also important to note that our animals were consuming their regular amount of calories, not overeating. Only the source of sugar was different between experimental groups, and still calorie-for-calorie, fructose caused greater weight gain and less physical activity than glucose.
MedicalResearch.com Interview with:
Dagfinn Aune, PhD student
Norwegian University of Science and Technology and
Imperial College London
Medical Research: What is the background for this study? What are the main findings?
Response: There are more than 360 million people worldwide that are affected by diabetes, and this number is projected to increase to more than 550 million by 2030, with serious consequences for the health and economy of both developed and developing countries. While previous research has found an association between increased dietary fibre intake and a reduced risk of developing type 2 diabetes, most of these data come from the United States, and amounts and sources of fiber intake differ substantially between countries. In this article the we evaluated the associations between total fiber as well as fiber from cereal, fruit, and vegetable sources, and new-onset type 2 diabetes in a large European cohort across eight countries, in the EPIC-InterAct Study (and included 12403 type 2 diabetes cases and 16835 sub-cohort members). We also conducted a meta-analysis where we combined the data from this study with those from 18 other independent studies from across the globe.
We found that participants with the highest total fiber intake (more than 26 g/day) had an 18% lower risk of developing diabetes compared to those with the lowest total fiber intake (less than 19g/day), after adjusting for the effect of other lifestyle and dietary factors. When the results were adjusted for body mass index (BMI) as a marker of obesity, higher total fiber intake was found to be no longer associated with a lower risk of developing diabetes, suggesting that the beneficial association with fiber intake may be mediated at least in part by BMI. In other words, dietary fiber may help people maintain a healthy weight, which in turn reduces the chances of developing type 2 diabetes.
In a meta-analysis of the EPIC-InterAct study and 18 other independent studies (>41000 type 2 diabetes cases) we found that the risk was reduced by 9% for each 10 g/day increase in total fiber intake and 25% for each 10 g/day increase in cereal fiber intake. There was no statistically significant association between fruit or vegetable fiber intake and diabetes.