Calorie Restriction Extends Life Through Protein Regulation

MedicalResearch.com Interview with:

John C. Price, Ph.D Asst. Professor Chemistry and Biochemistry Brigham Young University Provo, Utah

Dr. John Price

John C. Price, Ph.D
Asst. Professor Chemistry and Biochemistry
Brigham Young University
Provo, Utah

MedicalResearch.com: What is the background for this study?

Response: Since 1930 it has been known that the rate of biological aging could be modified by the diet.  In mice for example if you let them eat as much as they want they will live almost 3 years.  Providing essentially the same diet but controlling the number of total calories, there is an almost linear increase in lifespan as you restrict calories.  The studies in mice and rats have been repeated hundreds of times since that time.  There have been a lot of somewhat conflictive observations, like increased formation of new mitochondria, and increased autophagy which targets organelles for degradation, during stable reduced calorie intake. This expectation, that a restricted diet with fewer calories available to the animal could support increased protein synthesis and degradation and result in increased lifespan, is what got us interested in studying Calorie Restriction.  So we measured the relative synthesis rates for several hundred proteins in 18 month old calorie restricted mice which were experiencing the benefits of improved health and lifespan.  We found overwhelmingly that the calorie restricted mice had reduced synthesis rates down to as low as 25% of the age matched control group.  This observation has now been independently confirmed by multiple groups.

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Link Between Soy Consumption and Breast Cancer Remains Complicated

MedicalResearch.com Interview with:
Xiyuan Zhang PhD
and Leena Hilakivi-Clarke, PhD
Professor of Oncology
Georgetown University
Research Building, Room E407
Washington, DC 20057

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: Breast cancer is the most common cancer type in women and it also is the second leading cause of death by cancer in the United States. Every year, over 200,000 new cases of breast cancer are diagnosed in the US and this number reached over 1.5 million worldwide in 2012.

Asian women exhibit much lower risk of breast cancer than Caucasian women, accounting for about one fifth of the breast cancer incidence in Western women. Therefore, researchers have been intensively studying and aiming to decipher the difference between these two populations. Results of previous research from our laboratory and by others, in animal models and humans, indicate that higher intake of soy foods or soy isoflavone genistein during childhood is associated with reduced breast cancer risk. However, findings done using human breast cancer cells indicate that soy isoflavones stimulate growth of breast cancer cells. Thus, there is an apparent controversy regarding soy isoflavones and breast cancer.

70% of all breast cancer cases are estrogen receptor positive (ER+) and are therefore treated with endocrine therapy, including with tamoxifen. Although these treatments effectively prevent recurrence in half of the ER+ breast cancer patients, the other half are resistant or develop resistance to the endocrine therapy and recur. Intriguingly, several studies done using human breast cancer cells in culture or in mice found that soy isoflavone genistein negates tamoxifen’s effects. However, observational studies in women suggest that those patients who consume most soy foods have the lowest risk of breast cancer recurrence. The present study was designed to address these conflicting findings using a preclinical animal model and to determine if lifetime isoflavone intake has different effect on tamoxifen’s ability to treat breast cancer than intake that starts when cancer is detected.

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How Many Calories Do You Add To Your Coffee or Tea?

MedicalResearch.com Interview with:

Ruopeng An, PhD Assistant Professor Department of Kinesiology and Community Health College of Applied Health Sciences University of Illinois at Urbana-Champaign Champaign, IL 61820

Dr. Ruopeng An

Ruopeng An, PhD
Assistant Professor
Department of Kinesiology and Community Health
College of Applied Health Sciences
University of Illinois at Urbana-Champaign
Champaign, IL 61820

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: Coffee and tea are among the most widely consumed beverages in U.S. adults.1,2 Unlike other popular beverages including alcohol and sugar-sweetened beverages that are typically consumed in isolation, many people prefer drinking coffee and tea with add-ins like sugar or cream. These add-in items are often dense in energy and fat but low in nutritional value. Drinking coffee and tea with add-ins on a regular basis might impact an individual’s daily energy/nutrient intake and diet quality.3 The 2015-2020 Dietary Guidelines for Americans suggests that “coffee, tea, and flavored waters also can be selected, but calories from cream, added sugars, and other additions should be accounted for within the eating pattern.”4

To our knowledge, no study has been conducted to assess consumption of coffee and tea with add-ins in relation to daily energy and nutrient intake at the population level. Bouchard et al. examined the association between coffee and tea consumption with add-ins and body weight status rather than energy/nutrient intake, and consumption was measured by a few frequency-related questions instead of a 24-hour dietary recall.5

The purpose of this study was to examine consumption of coffee and tea with add-ins (e.g., sugar, cream) in relation to energy, sugar, and fat intake among U.S. adults 18 years of age and above. Data came from 2001-2012 National Health and Nutrition Examination Survey (NHANES), comprising a nationally-representative (biennially) repeated cross-sectional sample of 13,185 and 6,215 adults who reported coffee and tea consumption in in-person 24-hour dietary recalls, respectively.

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Type of Sugar, Not Just Amount, Influences Metabolic Effects

MedicalResearch.com Interview with:
Dr. Marta Alegret

Department of Pharmacology, Toxicology and Therapeutic Chemistry
Pharmacology Section
School of Pharmacy and Food Sciences
University of Barcelona

MedicalResearch.com: What is the background for this study?

Response: In humans, an excessive intake of sugars has been linked to the development of metabolic disturbances, and therefore to an increase in the risk for cardiovascular diseases. Specifically, increased consumption of simple sugars in liquid form, as beverages sweetened with high fructose corn syrup or sucrose, has been linked to obesity, insulin resistance and type 2 diabetes. However, two questions remain unresolved: what is/are the underlying molecular mechanism(s) linking these metabolic alterations to cardiovascular diseases? Are the adverse cardiovascular and metabolic effects of sugar-sweetened beverages merely the consequence of the increase in caloric intake caused by their consumption?

To answer to these questions, we performed a study in female rats, which were randomly assigned to three groups: a control group, without any supplementary sugar; a fructose-supplemented group, which received a supplement of 20% weight/volume fructose in drinking water; and a glucose-supplemented group, supplemented with 20% weight/volume glucose in drinking water.

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Government Endorsed DASH Diet Voted Best Overall

MedicalResearch.com Interview with:

Janet M. de Jesus, M.S., R.D. Program Officer, Implementation Science Center for Translation Research and Implementation Science (CTRIS) National Heart, Lung, and Blood Institute

Janet de Jesus

Janet M. de Jesus, M.S., R.D.
Program Officer, Implementation Science
Center for Translation Research and Implementation Science (CTRIS)
National Heart, Lung, and Blood Institute

MedicalResearch.com: What is the background for the DASH diet? What are the main components?

Response: The DASH eating plan was created for a clinical trial funded by the National Heart, Lung, and Blood Institute (NHLBI). DASH stands for Dietary Approaches to Stop Hypertension. The goal of the original DASH trial was to test the eating plan compared to a typical American diet (at the time in the 1990s) on the effect of blood pressure.

The DASH eating plan is rich in fruits, vegetables, and whole grains. It includes low-fat dairy products, poultry, fish, legumes, vegetable oils, and nuts; and limits intake of sweets and sugar-sweetened beverages and high-fat meats. The eating plan is a good source of potassium, magnesium, and calcium. The DASH eating plan was shown to reduce blood pressure and improve lipid profiles.

A second DASH trial, “DASH-sodium,” showed that adding sodium reduction to the DASH eating plan reduced blood pressure even more.

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Endocannabinoids Link Overeating a Western Diet to Obesity

MedicalResearch.com Interview with:

Nicholas V. DiPatrizio, Ph.D. Assistant Professor of Biomedical Sciences University of California, Riverside School of Medicine Riverside, California, 92521

Dr. Nicholas DiPatrizio

Nicholas V. DiPatrizio, Ph.D.
Assistant Professor of Biomedical Sciences
University of California, Riverside School of Medicine
Riverside, California, 92521

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: Endocannabinoids are a group of lipid signaling molecules that serve many physiological roles, including the control of food intake, energy balance, and reward. Previous research by my group found that tasting specific dietary fats drives production of the endocannabinoids in the upper small intestine of rats, and inhibiting this signaling event blocked feeding of fats (DiPatrizio et al., Endocannabinoid signaling in the gut controls dietary fat intake, Proceedings of the National Academy of Sciences, 2011). Thus, gut-brain endocannabinoid signaling is thought to generate positive feedback to the brain that promotes the intake of foods containing high levels of fats.

We now asked the question of what role peripheral endocannabinoid signaling plays in promoting obesity caused by chronic consumption of a western diet (i.e., high levels of fats and sugar), as well as the role for endocannabinoids in overeating that is associated with western diet-induced obesity. When compared to mice fed a standard low-fat/sugar diet, mice fed a western diet for 60 days rapidly gained body weight and became obese, consumed significantly more calories, and consumed significantly larger meals at a much higher rate of intake (calories per minute). These hyperphagic responses to western diet were met with greatly elevated levels of endocannabinoids in the small intestine and circulation. Importantly, blocking elevated endocannabinoid signaling with pharmacological inhibitors of cannabinoid receptors in the periphery completely normalized food intake and meal patterns in western diet-induced obese mice to levels found in control lean mice fed standard chow. This work describes for the first time that overeating associated with chronic consumption of a Western Diet is driven by endocannabinoid signals generated in the periphery.

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Does Red Meat Really Increase Risk of Heart Disease?

MedicalResearch.com Interview with:

Wayne W. Campbell PhD Center on Aging and the Life Course Purdue University

Dr. Wayne Campbell

Wayne W. Campbell PhD
Center on Aging and the Life Course
Purdue University

MedicalResearch.com: What is the background for this study?

Response: Organizations that promote healthy eating often recommend consuming no more than 3.5-4.5 2-3 ounce servings of red meat per week. This recommendation is mainly based on data from epidemiological studies that observe a cohort of peoples’ eating habits over time and relate those habits to whether or not they experience a cardiovascular event, such as a heart attack or stroke, or cardiovascular-related death.

These studies show associations between dietary choices and health but are unable to determine if a dietary choice is actually causing the disease. Randomized controlled clinical trials are able to determine causality by isolating one dietary variable to see the effects of that variable on certain health risk factors. Therefore, our lab compiled data from randomized controlled trials assessing the consumption of ≤ vs >3.5 servings of total red meat per week on blood lipids and lipoproteins and blood pressures, since these are common measures taken by clinicians to determine the risk for developing cardiovascular disease.

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Resistant Starches in Diet May Help Reduce Body Weight

MedicalResearch.com Interview with:

Dr Stacey Lockyer BSc(hons) MSc PhD RNutr Nutrition Scientist British Nutrition Foundation Imperial House 6th Floor London

Dr Stacey Lockyer

Dr Stacey Lockyer BSc(hons) MSc PhD RNutr
Nutrition Scientist
British Nutrition Foundation
Imperial House 6th Floor
London

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: This in depth review examines the potential health benefits of resistant starch, a form of starch that is not digested in the small intestine and is therefore considered a type of dietary fibre. Some forms of resistant starch occur naturally in foods such as bananas, potatoes, grains, and pulses, and some are produced or modified commercially and incorporated into food products as a functional ingredient.

There has been increasing research interest in resistant starch, with a large number of human studies published over the last 10 years looking at a variety of different health outcomes such as postprandial glycaemia, satiety and gut health. The review summarises reported effects and explores the potential mechanisms of action that underpin them.

There is consistent evidence that consumption of resistant starch in place of digestible carbohydrates can aid blood glucose control and this has resulted in an approved health claim in the European Union. There is also some evidence that resistant starch can support gut health and enhance satiety, though much more research is needed in these areas.

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Byproduct of Sweet Potato Waste Offers Clue To Lipid Metabolism

MedicalResearch.com Interview with:
Dr. Koji Ishiguro

National Agriculture and Food Research Organization
Japan

MedicalResearch.com: What is the background for this study?

Response: -Sweet potato (Ipomoea batatas L.) roots are not only used for human consumption, they are used to make starch materials, processed foods, and distilled spirits in Japan. Starch use accounts for about 15% (131,500 tons) of total sweet potato production. Starch residues are discharged during starch production and are mainly used in animal feed and compost. Large amounts of the wastewater, which can cause serious environmental problems, are discarded after clarification. Investigation into the uses of the by-products of the sweet potato starch industry would benefit both the environment and industry.

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Handful of Nuts a Day Can Reduce Chronic Diseases

MedicalResearch.com Interview with:

Dr. Dagfinn Aune Department of Epidemiology and Biostatistics School of Public Health Imperial College London St. Mary's Campus London  UK

Dr. Dagfinn Aune

Dr. Dagfinn Aune
Department of Epidemiology and Biostatistics
School of Public Health
Imperial College London
St. Mary’s Campus London  UK

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: There is a growing body of evidence suggesting that intake of nuts may reduce the risk of coronary heart disease, but the relation between nut intake and other diseases like cancer and stroke, and the relation with mortality and less common causes of death is not clear. Also it is not clear how much nuts are needed to reduce the risk.

So our current meta-analysis reviewed the data from 20 studies (29 publications) on nut intake and different health outcomes. We found that a nut intake of approximately one serving per day (28 g/d or a handful) was associated with a reduced risk of coronary heart disease (by 30%), total cancer (15%), all-cause mortality (22%) and mortality from respiratory disease (50%), diabetes (40%), and infections (75%), although there were few studies in the latter three analyses. We found that most of the benefit was observed up to an intake of around 20 grams per day. Similar results were found for total nuts, tree nuts and peanuts (which are botanically defined as legumes), but peanuts were also associated with reduced risk of stroke, while only tree nuts were associated with reduced cancer risk. We also calculated the number of deaths that potentially could be avoided, under the assumption that the observed associations are causal, and arrived at 4.4 million deaths in North and South America, Europe, Southeast Asia and the Western Pacific (unfortunately we did not have data on nut intake from West Asia and Africa so we were not able to include those areas).

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Some Saturated Fatty Acids Linked To Risk of Coronary Artery Disease

MedicalResearch.com Interview with:

Dr. Qi Sun Sc.D, M.D., M.M.S. Assistant Professor in the Department of Nutrition Harvard T.H. Chan School of Public Heath Boston

Dr. Qi Sun

Dr. Qi Sun Sc.D, M.D., M.M.S.
Assistant Professor in the Department of Nutrition
Harvard T.H. Chan School of Public Heath
Boston

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: Interpretation of existing human study data regarding saturated fat intake in relation to heart disease risk is quite confusing and distorted in certain publications. It is a fact that, depending on data analysis strategies, the effects of saturated fats may depend on which macronutrients they replace. For example, substituting saturated fats for refined carbohydrates will not lead to an elevated risk of heart disease because both nutrients are harmful whereas replacing saturated fats with good polyunsaturated fats results in risk reduction. In our current analysis, we clearly demonstrated that when total saturated fatty acids were replaced by polyunsaturated fatty acids, monounsaturated fatty acids, whole grain carbohydrates, and plant-based proteins, the diabetes risk would decrease.

Furthermore, we showed that major individual saturated fatty acids were all associated with an elevated heart disease risk.

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Difficulty Smelling May Lead to Malnutrition In Chronic Kidney Disease Patients

MedicalResearch.com Interview with:

Dr. Teodor G. Paunescu PhD Assistant Professor of Medicine Harvard Medical School Boston

Dr. Teodor G. Paunescu

Dr. Teodor G. Paunescu PhD
Assistant Professor of Medicine
Harvard Medical School
Boston

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: Patients with kidney disease frequently report food aversion and poor dietary intake leading to malnutrition, a complication associated with high morbidity and mortality. However, there are no effective treatments currently available to address this complication, and the mechanisms underlying anorexia and food aversion in these patients remain unclear.
Because of the critical role of olfaction in flavor appreciation and dietary intake, we decided to quantify olfactory (smelling) deficits in advanced chronic kidney disease (CKD) and end-stage renal disease (ESRD) patients.

We found that patients with kidney disease have significant olfactory deficits that need objective assessments for accurate characterization. Our results also indicate that olfactory deficits likely attribute to nutritional impairment in patients with kidney disease.

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