TalkingNutrition was conceived to provide a perspective on emerging science. It has been an exciting year in many respects. Most importantly, Julia Bird and I welcomed Eric Ciappio and Rachel Murphy to the writing team. Rachel and Eric bring unique expertise/insights and add diversity to our content. We celebrated TalkingNutrition 4th anniversary in July and 1,000 blog posting in September.
Archive for '2014'
Children have the greatest risk of malnutrition because of the demand for growth and development. In addition to macronutrients (fats, carbohydrates and proteins), essential nutrients (vitamins, minerals, and omega-3 fatty acids) are needed to support healthy growth, development and well-being. The question is: are children getting enough nutrients in their diet?
Google recently released their analysis of the top searches for 2014, and the most searched for diet of the year is the Paleo Diet. Others in the top 10 include the “Super Shred Diet” and “The Doctor’s Diet”. Nutrition trends like diets with fancy names or clever back stories come and go, and often when you boil them down the logic tends to fall apart. In the case of the “Paleo Diet” – which advocates a diet heavy in fruits, vegetables, and meats and avoiding anything processed (a la what a caveman would eat, hence the name) - may in fact have “no historical basis”. Evidently, the actual diet of early hominids was revealed to be quite diverse, and ultimately there’s no evidence that their diets were any healthier.
Often in science, different people look at the same data and walk away with different conclusions and interpretations, and the subsequent debate is what often leads to discovery and insight. Two publications released in the Journal of the National Cancer Institute on the relationship between selenium and prostate cancer are examples of this continued debate. What can we learn from these reports?
Could the chocolate in your advent calendar have health benefits including improving cognition and metabolic measures? Flavanols which are found in green tea, red wine, cocoa, and yes, chocolate have previously been reported to be associated with cardiovascular and metabolic health. The results of study published this week, suggest beneficial effects of flavanol consumption from cocoa in older adults.
New study finds 24h dietary recall overestimate sodium and potassium intake. Using objective measures of nutritional status, in this case 24 hour urinary collection, Mercado and colleagues suggest that the discrepancy may partially reflect inaccurate food databases. In other words, foods may contain less than expected amounts of sodium.
Food fortification has been an extremely powerful public health tool, improving the nutrient intakes of the public and preventing nutritional deficiencies. Much of the data we refer to in TalkingNutrition is based on information in the United States, however today we have new data from Ireland showing a similar beneficial impact of fortification.
With over one-third of American children being classified as overweight or obese, we are becoming increasingly aware of the consequences of the childhood obesity epidemic. Non-alcoholic fatty liver disease (NAFLD) is one such consequence in which fat accumulates in the liver, resulting in inflammation and disruptions in liver function, with the potential to result in liver failure. Right now, the primary treatment for this condition involve lifestyle modifications such as weight loss, but an emerging option is that of vitamin E supplementation.
Low maternal vitamin D status during pregnancy has been associated with offspring language impairment. A new study finds maternal vitamin D deficiency (measured at week 18 of pregnancy) is associated with impaired lung development in the child at 6y of age, neurocognitive difficulties at 10y of age, increased risk of eating disorders in adolescence, and lower peak bone mass at 20 years.
Dietary Reference Intakes (DRIs) are based upon an Estimated Average Requirement (EAR) – the average daily nutrient intake to meet the requirements of half the individuals. Adjustments are made for life stage (age, pregnancy, lactation)because they influence requirements. Because gender affects nutrient requirements, DRIs are established separately for males and females. As genetic insights grow, expect current male and female DRIs to be delineated into appropriate subgroups.
Even though vitamin D can be made in skin exposed to sunshine, vitamin D insufficiency is a global health concern. Normal serum 25(OH)D3 concentrations can usually be achieved by exposing arms and face to sunshine for 15-20 minutes daily. Clothing, use of sunscreens, skin color, geographical location (near the equator or the poles of the earth) and time of day also affect vitamin D synthesis.
Mazahery and colleagues examined serum 25(OH)D3 status of Middle Eastern women living in New Zealand.
The FDA finalized new pregnancy and lactation labeling requirements on prescription drugs and biological products. The ruling involves a subsection, Females and Males of Reproductive Potential, that will encompass information about potential effects on fertility. I wish there was more emphasis on nutrition recommendations, especially vitamin E, with respect to fertility, full-term pregnancies and baby development.
What is a reasonable risk reduction goal to use in evaluating randomized, controlled trials (RCTs)? MedPage Today is negating benefits of vitamin D supplementation based on a meta-analysis which applied a 15% risk reduction target. Isn’t any nutritionally-attributable reduction in risk of fracture, cardiovascular disease (CVD) and cancer beneficial? If pharmaceutical treatments fail to achieve a 15% risk reduction, are they dismissed?
The American Society for Nutrition held its Advances & Controversies in Clinical Nutrition conference. It began with an exciting discussion around the benefits of dietary supplementation. If you are interested in another summary, see ASN student blog by Sheela Sinharoy.
Dr Johanna Dwyer, Tufts University and NIH Office of Dietary Supplements, reviewed data NHANES dietary intake data. She emphasized that nationally representative data, NHANES, finds many Americans not consuming recommended micronutrient intakes from the foods we eat (see Keast et al, 2013 and Fulgoni et al, 2011).
Maintaining or improving healthy eating habits is on the mind of many people as we enter the holiday season. But what to eat can be confusing because of mixed messages. Nutritional epidemiology is often used as a starting place to test relationships between nutrients, foods or a variety of foods (diet patterns) and health outcomes. The caveat to epidemiological studies is that unlike an intervention, nutrients or foods are not controlled and individuals often have very different characteristics. As Nicklas and colleagues point out in a recent publication, this can result in inconsistent findings if the statistical approach, covariates used and assumptions are not appropriate for the study.
Most people associate omega-3 fatty acids with cardiovascular. Because research shows that consumption of eicosapentaenoic acid (EPA) and docosashexaenoic acid (DHA) may reduce the risk of coronary heart disease, regulatory agencies in the United States and Europe have approved health claims.
Healthy levels of omega-3 are important for more than the heart. DHA is also structurally essential for the brain. Observational studies have found children with Attention-Deficit Hyperactivity Disorder
With over 90% of Americans not getting enough vitamin D in their diet, vitamin D deficiency is one of the biggest issues in nutrition today. With this in mind, the US Preventive Services Task Force (USPSTF), recently released a recommendation on screening for vitamin D deficiency, stating that there is insufficient evidence to make a conclusion. What should we take away from this report?
For decades, a cluster of outcomes – hypertension, hyperglycemia, hypertriglyceridemia and gout – have been associated with being overweight/obese and risk on non-communicable diseases. Over time, the term metabolic syndrome has been used to describe this constellation of risk factors.
Liu and colleagues report serum carotenoid concentrations and metabolic syndrome prevalence from a cross-sectional study of 2,148 adults
It is difficult to adhere to goals during this season of indulgences and special events. Self-monitoring has been shown to influence behavior even though self-reported data may be woefully inaccurate for scientific purposes.
Inflammatory responses affect health, immunity and cancer risk. Metabolism generates reactive oxygen (and nitrogen) species which damage cells, mutate DNA and contribute to oxidative stress.
We’re officially less than 24 hours away from Thanksgiving and people are clearly excited by the thought of going into tryptophan-induced turkey comas*. Another nutrient found in turkey that is involved in tryptophan metabolism is vitamin B6. And did you know that, according to the CDC, vitamin B6 deficiency is the most common nutrient deficiency in the United States?
It seems like the only nutrition-related topic in the news this week is Thanksgiving, and rightfully so! We’ve all heard the story about how the tryptophan in turkey makes us sleepy because it supports the production of the neurotransmitter serotonin, which is involved in the brain’s regulation of sleep. But did you know that tryptophan can actually be used to produce the B-vitamin niacin in the body?
Dietary guidance encourages the consumption of fruits, vegetables, whole grains, fat-free and low-fat dairy products, and seafood. Why? Because far too many people are not consuming recommended amounts of dietary fiber, calcium, magnesium, vitamin D and vitamin E. As discussed yesterday, most people need to increase their consumption of omega-3 fatty acids to balance n-3:n-6 fatty acid levels in the body. These food groups provide these nutrients.
The membranes of cells in our bodies require long-chain polyunsaturated fatty acids (LCPUFA) to function normally. Based on typical dietary patterns, recommendations are to increase intake of LCPUFA and limit saturated and trans fatty acids.
With the exception of coconut and palm kernel oil, vegetable fats tend to be richer sources of LCPUFA then saturated fatty acids. There are two families of LCPUFA : the omega-3s and omega-6s.
The Food and Agriculture Organization (FAO) is holding its Second International Conference on Nutrition this week in Rome. In their Declaration on Nutrition, the Ministers and Representatives reaffirm the right of everyone to adequate food and fundamental right of everyone to be free of hunger. Malnutrition, including undernutrition, micronutrient inadequacies, overweight and obesity, affect individual well-being. They limit human potential and reduce productivity of individuals.
Following the scientific literature on the relationship between plasma homocysteine and health has been something of a roller coaster ride over the last few years. The brief introduction is that elevated homocysteine levels have been associated with an increased risk of health conditions such as stroke, heart disease, and cognitive decline – yet randomized controlled trials (RCTs) have had mixed results. So what’s going on here?
Babies are beautiful. How amazing that a fertilized egg can transform over 9 months into a wiggling, sometimes screaming, little being! After birth, it seems like the parental challenges of feeding, comforting, and nurturing begin but maternal nutrition has already had a major developmental impact.
Increased folate levels in women during the first trimester of pregnancy is associated with reduced risk of birth defects. Maternal folate status may affect the risk of a preterm birth.
Phytate is a known as an ‘antinutrient’ because it binds with iron, zinc and calcium to limit absorption from the intestine. In some regions of the world where animal sources of protein are scarce, the most commonly consumed form of phosphorus is linked with phytate present in plant-foods.
People don’t eat enough dietary fiber. We just don’t and we aren’t changing our habits. The average intake of US adults still hovers around 15g daily. We should be eating twice that amount. Why?
There are good reasons. Let’s start from the back and work forward! Bacteria living in the large intestine have the enzymes that we lack to digest fiber. As gut bacteria break down dietary fibers anaerobically (called fermentation), they also use nitrogen sources
For decades, the advice has been to reduce consumption of saturated and trans fatty acids. As evidence accumulated, people were urged to replace solid fats with oils and increase their seafood consumption. The intent was to encourage dietary patterns rich in long-chain monounsaturated and polyunsaturated fatty acids (LCPUFA) and better balance omega-3 to omega-6 fatty acids. What about antioxidants protecting LCPUFA?
Life is a balancing act. Regularly we find ourselves weighing circumstances. An obvious example is work-life balance. A classic nutritional example is vitamin D status. When exposed to sunlight, skin can synthesize vitamin D3. However sun exposure, especially sunburns, increases the risk skin cancer. Skin cancer is the most common cancer in the US.
Guy Jr and colleagues report the incidence of skin cancer is increasing. Using data from the 2002-2011 Medical Expenditure Panel Survey,
Controversy grabs attention. It makes news cycles turn. Eyeballs become focused. People stop to listen. People converse about current events. All of these actions help make cash registers ring. Today’s nutrition story won’t do any of those. Unfortunately because the scientific insight is important. What is the message?
Multivitamin use is safe. Multivitamin use is not associated with long-term risk of cardiovascular (CVD) events: myocardial infarction (MI), stroke, or cardiac revascularization or CVD death. The story confirms previous findings.
What is good health? According to the World Health Organization, it is more than the absence of disease. The social well-being of people in a community must be considered when defining good health. The Samueli Institute writes of resilience – the ability of individuals and societies to respond to stressful challenges, including our ability to cope mentally and physically.
Dr Barberger-Gateau explores nutritional opportunities to support the brain during aging.
At the Council for Responsible Nutrition Day of Science, Dr Wayne Jonas (@waynejonas1) from the Samueli Institute highlighted the release of a special issue of Military Medicine entitled “Nutritional Armor: Omega-3 for the Warfighter”. The collection of peer-reviewed papers demonstrate the importance of maintaining n-3/n-6 balance to fulfill demanding mental and physical performance expectations of active military personnnel.
Women of childbearing age are encouraged to supplement with 400 mcg/day of folic acid to reduce the risk of neural tube defects in their children. The current Dietary Reference Intake for folate during pregnancy is 600 mcg/day, yet women who are considered at high risk for having children with neural tube defects are often advised to consume up to 5000 mcg/day. Recent data suggests that this practice may be harmful – so is it cause for alarm?
Researchers confirm the food system is primarily an economic enterprise. Food choices are affected by price, demand, cost, and trade regulations. Our food supply is complex with over 85,000 uniquely formulated food and beverage products which are often changing. New products enter the market, old ones leave, and others are reformulated.
Miller and colleagues examined the US food supply in relation to the Healthy Eating Index (HEI) 2010
A human hearts beat 100,000 times per day, 35 million times per year, and more than 2.5 billion times during the average lifetime. It pushes about 5.6 liters (6 quarts) of blood around the body three times every minute. An amazing amount of work. Most people understand that omega-3 long-chain polyunsaturated fatty acids (LCPFUFA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), have heart health benefits. The mechanism of action is presumed to be related to LCPUFA effects on blood lipid concentrations. There may be more to the EPA and DHA story than changes in lipid fractions.
In the US, a supplement is taken orally and intended to “supplement the diet” with ingredients such as vitamins, minerals, herbs or other botanical products, amino acids and substances such as metabolites. The Council for Responsible Nutrition reports that 68% of US adults report taking dietary supplements (50% report being regular users). The majority (>95%) use multivitamin-mineral supplements. An overwhelming majority (83%) express confidence in the safety, quality and effectiveness of dietary supplements.
Nutrition science developed from a desire to understand the components of a healthy diet. The goal of nutrition guidance (nutrition policy) is to guide human behavior, including food choices, to favor health and longevity. By helping people understand the 5 food groups in the context of a healthy plate, government agencies hope to influence nutritional value of our diet and ultimately, human health.
There are approximately 56 million Americans living with disabilities, and living with a disability is associated with a higher likelihood of having health issues such as obesity, hypertension, and many others. People with disabilities need to pay attention to their diet and lifestyle to help support their health just like anyone else, but relatively little is known about what these individuals are consuming.
You may already be aware that the FDA has proposed numerous revisions to the ever present “Nutrition Facts” panel present on the side of nearly all foods you buy. In the Personal Health section of Sunday’s New York Times, author Jane Brody wrote about these revisions – praising some changes yet also pointing out areas which she felt that the proposal left things to be desired. Relying on a quote from former FDA commissioner Dr. David Kessler, Ms. Brody was specifically critical of what she felt was a lack of promotion of “real foods” in the new Nutrition Facts panel, saying that “Instead, the new label, like the current one, would focus on specific nutrients and give ‘food companies an incentive to fortify their products so they can make claims such as added fiber’… ”. Given that the average daily intake of dietary fiber is roughly half of the recommendation in certain age/gender groups – why is fortification being painted as a bad thing?
The fatty acids found in the membranes of erythrocytes, also known as red blood cells (RBC), reflect the type of fats (animal, plant, seafood) being consumed and their fatty acid composition (saturated, monosaturated, polyunsaturated). The omega-3 index, the percentage of total fatty acids which are eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), found in RBC membranes may be a biomarker of cardiovascular risk, especially cardiac death.
The World Health Organisation considers Ready-to-Use Therapeutic Food (RUTF) to have “revolutionized” the treatment of severe malnutrition in children. RUTF saves the lives of hundreds of thousands of children every year. RUTF are shelf-stable pastes that can be used at home, and contain a nutritionally-balanced mix of ingredients that provide children with the energy, protein, fat, vitamins and minerals for them to put on weight and treat deficiency. But how can it be developed from local ingredients, and within the demanding nutritional and price-related constraints?
Vitamin D is an essential nutrient that supports healthy bones, muscles and more, yet more than 90% of Americans don’t get enough in their diets. This is partly due to the fact that naturally occurring vitamin D is not found in high amounts in many foods, save for fish – a food which Americans certainly do not to eat enough of (see: every article ever posted on Talking Nutrition about Omega-3’s). As a result, vitamin D intakes in the United States are largely driven by fortified foods and dietary supplements, with the main fortification target being milk and dairy foods. Alternative milk sources such as soy and almond milk are becoming increasingly popular, and yet these aren’t always fortified with vitamin D. So that begs the question – what happens to the vitamin D status of regular drinkers of alternative (that is, non-cow) milks?
Twenty years ago, Congress passed the Dietary Supplement Health and Education Act (DSHEA), recognizing the role of dietary supplements in health promotion and prevention of chronic diseases. The law established a new regulatory framework and mechanisms to deal with safety issues, labeling, and health claims. It provided guidance on good manufacturing practices. Unfortunately, Congress didn’t guarantee funding for enforcement of DSHEA.
Not everyone is intrigued by science. I get that. However, science (and scientists) is interesting. Three reasons to follow science blogs: 1) By nature, scientists test hypotheses. When considering questions from different perspectives, they challenge the status quo. 2) Scientists have a profound ability to distill a problem into the obvious. And 3), being a scientist can be fun. We may even have friends.
Two new reviews were published this week. Barnes and colleagues review nutrients with a role in maintaining cognitive function. Whitehead and colleagues conducted a meta-analysis of randomized, placebo-controlled studies (RCTs) using ≥ 3 g oat beta glucan daily.
Both reviews focus on nutrient intakes required to optimize health.
Experts from the European Food Safety Authority (EFSA) published a scientific opinion that a cause and effect relationship has been established between the consumption of docosahexaenoic acid (DHA) and contribution to normal brain development. The Panel noted the well-established role of DHA in normal brain function across all ages, including brain development in infants and children.
Based on the scientific evidence, the Panel approved the following statement:
Iodine deficiency is one of the top three micronutrient deficiencies that are targeted by the World Health Organization. Shocking statistics estimate that 18 million infants are mentally impaired each year due to frank iodine deficiency. Another report shows that iodine deficiency is relatively common even in well-nourished populations. Why aren't we doing more to solve this problem?
Humans can synthesize vitamin D when skin is exposed to strong sunlight. Obviously, babies are dependent upon their mother for vitamin D until birth (in utero). Even after birth, depending upon seasonal temperatures, a baby may be bundled in wraps and kept inside. Thus, the vitamin D status of an infant is totally dependent upon his/her mother.
Zhang and colleagues examined the nutritional requirements for vitamin D in 30 women during pregnancy.
It seems like the only health-related news these days deals with the recent cases of Ebola that have appeared in Texas. In many ways, the Ebola situation in Africa draws parallels to the malnutrition crisis observed in developing nations, where millions are affected by deficiencies of essential nutrients such as vitamin A, iron, and iodine. But if we in the Western world are hardly impacted to the same degree by either Ebola or malnutrition, why should we feel compelled to help?
Experts from the European Food Safety Authority (EFSA) published a scientific opinion that supplemental DHA and EPA from algal oil sources (Schizochytrium species) can be safely increased from 3 grams daily to 5 grams daily as there is no safety concerns for adults.
Zhao and colleagues assessed dietary adequacy and plasma vitamin E (α-tocopherol and ϒ-tocopherol) concentrations in the plasma of Irish adults. Food sources were not sufficient. Two-thirds of women were not consuming recommended amounts of vitamin E. Supplementation was important, contributing 29% of their vitamin E. People who didn’t supplement with vitamin E had much lower plasma α-tocopherol concentrations.
It is a slow day today for nutrition science, but it seems that there is an article in the mass media every day about processed foods and how they can and should be avoided. These articles can be a little confusing to me as a nutrition scientist. The confusion stems from the use of the word “processed”. Isn't there a better way to say what we mean?
What does $2.5 million dollars get a scientist in 2014? The answer is a 10 year, double-blind randomized controlled trial (RCT) to determine whether prenatal supplementation with omega-3 long-chain polyunsaturated fatty acids (LCPUFA), especially docosahexaenoic acid (DHA) benefits children’s intelligence and school readiness.
This is important research. Higher levels of DHA in the blood of children have been correlated with better sleep and improved reading and behavior in healthy but underperforming children.
Nutrition experts recommend getting essential vitamins and minerals from a balanced diet – one with plenty of fruits, vegetables, whole grains, and dairy products. The challenge is that we don’t always make good choices. Reasons include: time costs, sensory and physical aspects, access, and perceived value. People with lower incomes eat fewer servings of vegetables and fruits. Food preferences. Even Presidents can shun nutrient-rich foods such as Brussels sprouts, liver and tomatoes. ‘Trigger’ foods can subvert choices. Consequently, millions of Americans are deficient in vitamins A, B6, B12, C, E, folate, or iron.
Did you read that a genetic study casts doubt that vitamin D prevents the development of type 2 diabetes? Well, don’t believe everything you read. The authors are quoted, “Our findings suggest that interventions to reduce the risk of type 2 diabetes by increasing concentrations of vitamin D are not currently justified.” That is one opinion. Here is a different perspective.
Ye and colleagues combined data from 22 observational studies with almost 100,000 participants to examine genetic markers, serum 25(OH)D3 concentrations and risk of developing type 2 diabetes.