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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Hormones in Breast Milk Shape Infant’s Microbiome

MedicalResearch.com Interview with:

Jacob (Jed) E. Friedman, Professor, Ph.D. Department of Pediatrics, Biochemistry & Molecular Genetics Director, NIH Center for Human Nutrition Research Metabolism Core Laboratory University of Colorado Anschutz

Dr. Jed Friedman

Jacob (Jed) E. Friedman, Professor, Ph.D.
Department of Pediatrics, Biochemistry & Molecular Genetics
Director, NIH Center for Human Nutrition Research Metabolism Core Laboratory
University of Colorado Anschutz

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

Response: Scientists have long established that children who are breastfed are less likely to be obese as adults, though they have yet to identify precisely how breastfeeding protects children against obesity. One likely reason is that children who are breastfed have different bacteria in their intestines than those who are formula fed.
The study, published Monday in the American Journal of Clinical Nutrition examines the role of human milk hormones in the development of infants’ microbiome, a bacterial ecosystem in the digestive system that contributes to multiple facets of health.

“This is the first study of its kind to suggest that hormones in human milk may play an important role in shaping a healthy infant microbiome,” said Bridget Young, co-first author and assistant professor of pediatric nutrition at CU Anschutz. “We’ve known for a long time that breast milk contributes to infant intestinal maturation and healthy growth. This study suggests that hormones in milk may be partly responsible for this positive impact through interactions with the infant’s developing microbiome.”

Researchers found that levels of insulin and leptin in the breastmilk were positively associated with greater microbial diversity and families of bacteria in the infants’ stool. Insulin and leptin were associated with bacterial functions that help the intestine develop as a barrier against harmful toxins, which help prevent intestinal inflammation. By promoting a stronger intestinal barrier early in life, these hormones also may protect children from chronic low-grade inflammation, which can lead to a host of additional digestive problems and diseases.

In addition, researchers found significant differences in the intestinal microbiome of breastfed infants who are born to mothers with obesity compared to those born to mothers of normal weight. Infants born to mothers with obesity showed a significant reduction in gammaproteobacteria, a pioneer species that aids in normal intestinal development and microbiome maturation.

Gammaproteobacteria have been shown in mice and newborn infants to cause a healthy amount inflammation in their intestines, protecting them from inflammatory and autoimmune disorders later in life. The 2-week-old infants born to obese mothers in this study had a reduced number of gammaproteobacteria in the infant gut microbiome.

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Zinc Levels Can Be Improved In Nursing Home Patients with Supplementation

MedicalResearch.com Interview with:

Simin Nikbin Meydani, D.V.M., Ph.D. Director, JM USDA-HNRCA at Tufts University Professor of Nutrition and Immunology Friedman School of Nutrition Science and Policy and Sackler Graduate School at Tufts University Boston, MA 02111

Dr. Simin Meydani

Simin Nikbin Meydani, D.V.M., Ph.D.
Director, JM USDA-HNRCA at Tufts University
Professor of Nutrition and Immunology
Friedman School of Nutrition Science and Policy
and Sackler Graduate School at Tufts University
Boston, MA 02111

Medical Research: What is the background for this study?

Dr. Meydani: A significant number of older people are zinc deficient which can result in a compromised immune system which weakens as the body ages, making older adults more susceptible to infections and higher incidence and morbidity from pneumonia. Older adults with impaired immune response, particularly T cell-mediated function, have a higher susceptibility to infections and cancer. Our research team from the Jean Mayer USDA Human Nutrition Research Center on Aging created a small double-blind, placebo-controlled trial involved adults age 65 or older from three Boston-area nursing homes to determine the feasibility of increasing serum zinc concentrations in older adults. The full findings are published in The American Journal of Clinical Nutrition.

These results have a significant public health implication for the older adults because it shows directly that correction of a nutrient deficiency can improve immune response in older adult (a biological function which consistently has been shown to be impaired with aging).

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One Serving of Tree Nuts Daily Linked To Lower Lipid Profile

Liana Del Gobbo PhD Friedman School of Nutrition Science and Policy, Tufts University, Boston, MA; and Life Sciences Research Organization, Bethesda, MD

Dr. Del Gobbo

MedicalResearch.com Interview with:
Liana Del Gobbo PhD
Friedman School of Nutrition Science and Policy, Tufts University, Boston, MA; and
Life Sciences Research Organization, Bethesda, MD

Medical Research: What is the background for this study? What are the main findings?

Dr. Del Gobbo: Accumulating evidence suggests that nut intake lowers risk of cardiovascular disease. But the specific mechanisms by which nuts may exert beneficial effects (eg. through lowering blood cholesterol, blood pressure, inflammation, etc.) were not clear. Two prior reviews on this topic only evaluated one type of nuts, and only a few cardiovascular risk factors.

To address these knowledge gaps, we performed a systematic review and meta-analysis of controlled trials to examine the effects of eating tree nuts (walnuts, pistachios, macadamia nuts, pecans, cashews, almonds, hazelnuts, Brazil nuts) on major cardiovascular risk factors including blood lipids (total cholesterol, LDL, HDL, triglycerides [TG]), lipoproteins (ApoA1, ApoB, ApoB100), blood pressure (systolic, SBP; diastolic, DBP), and inflammation (C-reactive protein, CRP) in adults 18 years or older without cardiovascular disease.

A daily serving of nuts (1oz serving, or 28g per day) significantly lowered total cholesterol, LDL, ApoB, and triglycerides, with no significant effects on other risk factors, such as HDL cholesterol, blood pressure or inflammation. To give you an idea of a 1oz serving size of nuts, it is about 23 almonds, 18 cashews, 21 hazelnuts, 6 Brazil nuts, 12 macadamia nuts, 14 walnut halves, 20 pecan halves, 49 pistachios.

We did not see any differences in cholesterol-lowering effects by nut type.

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No evidence dietary acid load has detrimental effect on childhood bone health

Audry H. Garcia PhD Scientist Department of Epidemiology Erasmus MC, University Medical Center Rotterdam Rotterdam, The Netherlands

Dr. Garcia

MedicalResearch.com Interview with:
Audry H. Garcia PhD
Scientist Department of Epidemiology
Erasmus MC, University Medical Center Rotterdam
Rotterdam, The Netherlands

Medical Research: What is the background for this study? What are the main findings?

Dr. Garcia: Mild and chronic metabolic acidosis as a result of a diet rich in acid-forming nutrients, such as cheese, fish, meat and grain products, may interfere with optimal bone mineralization and indirectly increase the risk of osteoporosis later in life. Previous observational studies in adults have reported inverse associations between dietary acid load and bone mass. However, the evidence in younger populations is scarce; only a few studies have been performed in healthy children and adolescents with inconsistent results, and not much is known on the effects of dietary acid load on bone mass in younger children or in children with a non-European background.

In a prospective multiethnic population-based cohort study of 2,850 children from the city of Rotterdam, the Netherlands, we found that dietary acid load estimated as dietary potential renal acid load (dPRAL), and as protein intake to potassium intake ratio (Pro:K) at 1 year of age, was not consistently associated with childhood bone health. Furthermore, associations did not differ by sex, ethnicity, weight status, or vitamin D supplementation.

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High Pregnancy Weight Gain Linked To Long Term Increased Maternal Body Fat

Elizabeth M. Widen, PhD, RD Postdoctoral Fellow in the Department of Medicine, Institute of Human Nutrition & Department of Epidemiology Columbia University Mailman School of Public Health New York, NY 10032MedicalResearch.com Interview with:
Elizabeth M. Widen, PhD, RD
Postdoctoral Fellow in the Department of Medicine, Institute of Human Nutrition & Department of Epidemiology
Columbia University
Mailman School of Public Health
New York, NY 10032

Medical Research: What is the background for this study? What are the main findings?

Dr. Widen: The Columbia Center for Children’s Environmental Health Mothers and Newborns Study was started in 1998 and is based in Northern Manhattan and the South Bronx. Pregnant African American and Dominican mothers were enrolled from 1998 to 2006, and mothers and their children have been followed since this time. Pregnancy weight gain and maternal size and body fat was measured at seven years postpartum, allowing us to examine the role of nutrition in pregnancy on long-term maternal health. We found that high pregnancy weight gain, above the Institute of Medicine 2009 guidelines, was associated with long-term weight retention and higher body fat at seven years postpartum among women who began pregnancy with underweight, normal weight and modest overweight body mass index (BMI). These findings suggest that prepregnancy BMI and high pregnancy weight gain have long-term implications for maternal weight-related health, especially among mothers who begin pregnancy with lower prepregnancy BMI values.

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Alcohol Linked To Increased Basal Cell Carcinoma Skin Cancer Risk

Shaowei Wu, MD, PhD Department of Dermatology, Warren Alpert Medical School Brown University, Providence, Rhode Island Department of Dermatology Brigham and Women’s Hospital and Harvard Medical School Boston, Massachusetts

Dr. Shaowei Wu

MedicalResearch.com Interview with:
Shaowei WuMDPhD
Department of Dermatology, Warren Alpert Medical School
Brown University, Providence, Rhode Island
Department of Dermatology
Brigham and Women’s Hospital and Harvard Medical School
Boston, Massachusetts

Medical Research: What is the background for this study? What are the main findings?

Response: Basal cell carcinoma (BCC) of the skin is the most prevalent cancer in the US, and is responsible for substantial morbidity and billions of dollars of health care expenditures. Knowledge on the modifiable risk factors of BCC is required for targeted prevention of cancer incidence. Alcohol consumption is a well-known risk factor for human cancer and has been linked to a number of cancers, including breast, prostate, pancreatic, and colon cancers. Interestingly, a large epidemiological study has reported a positive association between alcohol consumption and increased prevalence of severe sunburn, an established skin cancer risk factor. It is hypothesized that metabolites of alcohol (e.g., acetaldehyde) can serve as photosensitizers and promote skin carcinogenicity in the presence of UV radiation. However, epidemiological evidence for the association between alcohol consumption and BCC risk has been limited and a few previous studies on this topic have yielded conflicting results. Therefore we conducted a comprehensive prospective study to investigate this question using data from three large cohorts including the Nurses’ Health Study (1984-2010), Nurses’ Health Study II (1989-2011), and Health Professionals Follow-up Study (1986-2010).

We documented a total of 28,951 incident Basal cell carcinoma cases over the study follow-up. We found that increasing alcohol intake was associated with an increased Basal cell carcinoma risk in both women and men. In the combined analysis with all 3 cohorts, those who consumed 30 grams or more alcohol per day had a 22% higher risk of developing BCC when compared to nondrinkers. This increased risk was consistent in people with different levels of sun exposure. We also found that BCC risk was associated with alcohol intake levels more than a decade ago, suggesting that alcohol may have a lagged effect that can persist for a long-term period. Among the individual alcoholic beverages, white wine and liquor were positively associated with Basal cell carcinoma risk whereas red wine and beer were not associated with BCC risk. This difference may be due to some other chemicals accompanying alcohol in the specific beverages. For example, red wine contains higher amounts of phenolic compounds compared to white wine, and these compounds have antioxidant activities which may be beneficial for counteracting the potential carcinogenic properties of alcohol and its metabolites.

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Eggs Not Linked To Heart Attack or Stroke

Susanna C. Larsson | PhD, Associate Professor Associate professor, Nutritional Epidemiology Institute of Environmental Medicine Karolinska Institutet Stockholm, SwedenMedicalResearch.com Interview with:
Susanna C. Larsson  PhD, Associate Professor
Associate professor, Nutritional Epidemiology
Institute of Environmental Medicine
Karolinska Institutet
Stockholm, Sweden

Medical Research: What are the main findings?

Dr. Larsson: A high dietary cholesterol intake has been postulated to increase the risk of cardiovascular disease. Egg is a rich source of dietary cholesterol and has been positively associated with risk of heart failure in previous prospective studies. High consumption of eggs has also been associated with a higher risk of myocardial infarction in diabetic patients.

Medical Research: What is the background for this study?

Dr. Larsson:  We investigated the association between egg consumption and risk of cardiovascular diseases in two population-based prospective cohort studies of approximately 38,000 Swedish men and 33,000 Swedish women. Findings from our study indicate that egg consumption does not increase the risk of myocardial infarction, ischemic stroke, or hemorrhagic stroke. High egg consumption (one or more times per day) was associated with an elevated risk of heart failure in men but not in women. Egg consumption was not associated with an increased risk of heart failure, myocardial infarction, or stroke in individuals with diabetes.

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Folic Acid and B12 May Improve Assisted Reproductive Technology Results

Audrey J. Gaskins, Sc.D. Postdoctoral Fellow Department of Nutrition Harvard T.H. Chan School of Public Health Boston, MA 02115
MedicalResearch.com Interview with:
Audrey J. Gaskins, Sc.D.  Postdoctoral Fellow
Department  of Nutrition
Harvard T.H. Chan School of Public Health
Boston, MA 02115

 

 

Medical Research: What is the background for this study? What are the main findings?

Dr. Gaskins: Infertility, defined as the inability to conceive after 12 months of unprotected intercourse, is a common reproductive disorder affecting ~15% of couples who attempt to become pregnant. Assisted reproductive technologies (ART), which include in vitro fertilization (IVF) and intra-cytoplasmic sperm injection (ICSI), have become the main treatment modalities for couples facing infertility. Pre-conceptional folate and vitamin B12 have been linked to many beneficial early pregnancy outcomes among couples undergoing assisted reproductive technologies treatment in Europe but mixed results have been found in regards to clinical pregnancy and live birth rates. Therefore, we sought to investigate whether higher levels of serum folate and vitamin B12 could increase reproductive success in a cohort of women undergoing assisted reproductive technologies at an academic medial center in the United States.

We found that high concentrations of folate and vitamin B12 in serum are associated with increased chance of live birth following assisted reproduction. Moreover, women with higher concentrations of both serum folate and vitamin B12 had the greatest likelihood of reproductive success. Analysis of intermediate endpoints suggests that folate and vitamin B12 may exert their favorable effects on pregnancy maintenance following implantation.

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High Fiber Diets Linked To Lower Risk of Colon Polyps and Cancer

MedicalResearch.com Interview with:
Dr Andrew Kunzmann & Dr Helen Coleman
Joint first authorsCentre for Public Health
Queen’s University Belfast
Northern Ireland

Medical Research: What is the background for this study?

Response: There is now a large amount of evidence to suggest that individuals who consume diets high in fiber tend to be at a lower risk of bowel (colorectal) cancer. However, it is not known whether this association begins at the early stages of bowel cancer development or at later stages, in individuals with polyps (adenomas) that can lead to bowel cancer if left untreated. The best source of dietary fiber (cereals, fruit or vegetables) for bowel adenoma and cancer prevention is also debatable.

We analysed data from individuals taking part in a large U.S trial assessing bowel screening, who completed a dietary questionnaire and received sigmoidoscopy screening at the start of the trial and received further screening 3 to 5 years later. This allowed us to investigate whether individuals with higher fiber diets had a lower risk of developing their first left-sided adenoma, but also for having adenomas recur at a later time, or indeed risk of bowel cancer, than individuals with diets low in fiber. By analysing only the screened participants, everyone had an equal opportunity to have their recurrent adenomas diagnosed – something that previous studies of dietary fiber have been unable to address.

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