Another year has passed! Amazing! You may wonder, what compels us to write more than 245 TalkingNutrition blogs? The answer is simple. A single newly published study does not change everything known about nutrition. While new research studies add to the body of scientific evidence, they need to be put into context. With TalkingNutrition, we try to put nutrition research into perspective. And there was a lot that went on in 2015.
Archive for '2015'
Nutrition research is important. We can only advance understanding of the roles of micronutrients if we study them in detail. But what is the most important focus at the moment? As we have done in previous years, TalkingNutrition will be reporting on the most researched vitamin of the year, but with a twist. To reflect the greater emphasis that DSM is placing on preventing all micronutrient deficiencies, we have expanded our scope to include research into minerals and a range of fatty acids. Read on to find out what vitamin, mineral and fatty acid was the most researched this year…
The end of the year is almost here, and I thought it would be interesting to look back at 2015 and see which nutrition research had the most impact over the past year. There is no definitive way to do this, so I will be experimenting a little with some tools to give the best overview of what has been going on.
Today is the shortest day of the year in the Northern Hemisphere. A lack of sun exposure can lead to seasonal affective disorder. A new study from Japan finds low blood levels of omega-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are associated with depressive symptoms.
In a cross-sectional study conducted in 1,050 men and 1,073 women (≥40 years of age) living in Japan, adults with the highest concentrations of EPA+DHA in the blood were the least likely to experience depression symptoms.
DSM extends its partnership with the World Food Programme for another 3 years. Having already helped 25 million people annually, the public-private partnership that began in 2007 will continue providing essential vitamins, nutrients and fortified rice to pregnant and nursing women and young children.
Good nutrition in the 1,000 days between a woman’s pregnancy and her child’s second birthday sets the foundation for all days that follow. Undernutrition is responsible for almost half (45%) of all child deaths under five years of life.
Babies are wonderful, aren’t they? Each is a unique bundle of life, so different and yet so similar with fingers, toes, ears, eyes, wiggles, cries, and other less-appealing bodily functions! Because the world population exceeds 7.3 billion people, we seem to have evolved to successfully transition newborns to healthy adolescents.
In reality, the nutritional value of human milk isn’t constant. Millk composition changes within a feeding, over the entirety of a lactation, and between mothers.
Micronutrient deficiencies co-exist with overweight and obesity in many parts of the world. Hidden Hunger is a term describing the invisible nature of symptoms associated with inadequate micronutrient intake and suboptimal vitamin and mineral status.
A new report finds that the prevalence of hidden hunger (measured by a higher Hidden Hunger Index) continues to worsen in Africa. Improvements in other regions of the world are primarily attributable to reductions in the prevalence of zinc and vitamin A deficiencies. Chile continues to have the lowest score of 138 countries.
Good advice about healthy behaviors is everywhere. Even if we don’t want to look for it on our own, public service announcements sent out on the radio and on the television try to get us off the sofa, well-meaning Facebook friends chronicle their weight-loss and can’t help but try to convince others to follow the same path, and even packets of food extol the virtues of a balanced diet and regular physical activity. Starting from now, we can all make changes that will have a positive impact on our health and quality of life. But sometimes we need a major trigger, a lightning bolt, to illuminate a better way forward. Does a heart attack trigger a simple lifestyle change?
Remember when 3 commercial broadcast networks provided news, typically at 6 and 11pm? With 24-hour news networks, there is a continuous stream of updates. No longer do we have Walter Cronkite, the “most trusted man in America”, ending the day with “And that’s the way it is”.
You may have heard that there is insufficient evidence (two studies) to conclude that omega-3s alone, or combined with anti-depressant therapy, affect depression. Only 2 studies involving omega-3 fatty acids were included in the Agency for Healthcare Research and Quality (AHRQ) report (Table 16).
Increasingly, studies link air pollution, exposure to fine particulate matter in the air which causes haze, with lung cancer. Fine particulate matter from motor vehicles and power generation stations, the main sources of urban pollution, cause oxidative injury and inflammation in the bronchiole and lung tissues and are linked to increased risk of asthma.
The health consequences of air pollution are particularly felt in Beijing with more than 200 days being labeled as ‘unhealthy’ and smog being so severe last week that a ‘red alert’ was issued. China’s smog may make headlines but it can be much worse, eg. India.
Air pollution can be highly localized and has the potential to affect us all. It is produced both indoors by the use of open fires and from various emissions from items in the home, and outdoors with vehicles and emissions from industry. Surprisingly, there is a link between diet and the health effects of air pollution, primarily through nutrients' effects on the immune response. Péter and co-workers summarize the research.
Two newly published studies demonstrate the importance of measuring blood concentrations of nutrients. Neither of these reports rely upon self-reported dietary intake data combined with food composition databases. Both studies directly examine the relationship between plasma concentrations and performance.
As noted yesterday, low plasma omega-3 concentrations (eicosapentaenoic acid, EPA, and docosahexaneoic acid, DHA) are associated with increased risk of coronary heart disease. Using data from the Singapore Chinese Health Study (participants were 47-83y old), Sun and colleagues compared plasma omega-3 concentrations
Low intakes of dietary omega-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), found in fish, fish oils and algal oils are reflected in low blood concentratiosn. The omega-3 index is a measure of DHA+EPA concentrations in blood. Harris proposed that an omega-3 index of <4% was a high risk indicator for coronary heart disease.
Using the most recently published national data on blood omega-3 fatty acid concentrations, a new study finds ~96% of American adults have an omega-3 index below levels associated with cardiovascular protection (~4%).
The American Society of Nutrition held its 5th Advances and Controversies in Clinical Nutrition Conference Dec 4-6 in Long Beach, CA. Dr Marian Neuhouser, a member of the 2015 Dietary Guidelines Advisory Committee, presented highlights from the 2015 DGAC.
Today’s accompanying image shows results for the consumption of whole grains, vegetables and fruit. Briefly, nobody in the United States is consuming the recommended number of whole grain servings daily.
The Institute of Medicine (IOM) updated Dietary Reference Intakes (DRIs) for vitamin D and calcium in 2010. At the time, the vitamin D Recommended Dietary Allowances (RDAs) were increased to 600 IU daily for all age groups except those over 70y which were set to 800 IU. Estimated Average Intakes (EARs) and RDAs were based on serum 25(OH)D concentrations of 40 and 50 nmol/L, respectively. The Upper Tolerable Limit (UL) for adults was set at 4,000IU.
In a new study, Veugelers and associates aggregated data from 36 studies with 108 study dose estimates and 13,987 observations (participants).
The FAO’s 2012 report on food insecurity states that “progress in reducing hunger has been more pronounced than previously believed”. Even so, almost 1 billion people suffer from chronic undernutrition. Eating the right amounts of all vitamins and essential minerals, as well as protein, fats and carbohydrates, is important for people to be healthy and productive. Food fortification is one means to improve the micronutrient intake of populations. Is it a silver bullet approach to reducing hidden hunger?
Hoping to have a baby? Low blood vitamin E concentrations have been associated with infertility and increased risk of miscarriage. Not a trivial association with ~90% of Americans not consuming recommended intakes of vitamin and 93% and 81% of 20-30 year olds and 31-50 year olds, respectively, having suboptimal vitamin E status. A new study finds vitamin D status is also very important.
To understand if vitamin D concentrations affect fertility, Pagliardini and colleagues measured 25(OH)D3 concentrations in 1,072 women visiting an infertility center.
How much vitamin C is in 100g (about two thirds of a cup) of blueberries? Well, that depends. My trusty kitchen companion “The Food Guide” reckons 13mg, my nutrition textbook “Understanding Nutrition” counts 7mg, and the USDA food database has measured 9.7mg in their release 28. What the online USDA food list does not mention is that this value was based on 4 data points, the minimum amount measured was 7.4mg and the maximum was 11.5mg (based on the Access database for release 28). There is a lot of variation in the vitamin content of blueberries, it seems.
If you live in the US and have just celebrated Thanksgiving, it is quite possible your waistband feels a tad tighter this Monday. You should also know that increased visceral fat may increase your need for vitamin D supplementation. And shortening daylength in the northern hemisphere isn’t any help.
Zhang and colleagues randomly selected 1,105 adults living in China. Visceral fat accumulation and serum vitamin D concentrations were measured. Men and pre-menopausal women carrying extra visceral fat were more likely to have serum 25(OH)D3 concentrations below 30 µg/L
Babak and co-workers published an analysis of neural tube defect prevalence in Europe over a twenty year period from 1991 to 2011. The data was obtained from the extensive EUROCAT birth defect registry, which collects data from 43 registries in 23 countries in Europe. It seems that in the past 20 years, the rate of neural tube defects has largely remained unchanged at around 9 pregnancies affected out of every 10,000. In contrast, rates of neural tube defects has fallen over the same period in the US. What is the difference?
Do you know your iodine status? I don’t. In fact, rarely do I even look for the iodine content of a food. For people living in regions where the iodine content of soils and ground water is low, consuming crops grown locally can lead to iodine deficiency. In fact, 26-70% of children living in the Great Lakes, Appalachians and Northwestern regions of the US were iodine deficient with clinically apparent goiters in the early 1900’s. Iodization of salt changed their lives and millions of others. However, salt iodization is only effective if people consume iodized salt.
Anaforoglu and colleagues studied 864 healthy pregnant women from an iodine deficient region of
Countries such as the USA and Canada legislated folic acid fortification of flour to help prevent neural tube defects during pregnancy. Mandatory legislation was important because a baby’s brain stem and spine closes during the first trimester of pregnancy – a time when many women do not yet realize they are pregnant. After the first few months of pregnancy, it is too late to begin supplementation to protect the infant.
According to the CDC, half of pregnancies in the US are unintended. Unintended pregnancies are those which are mistimed, unplanned or unwanted at time of conception.
As the winter solstice approaches in the northern hemisphere, people living north of the equator need to remember that vitamin D is a nutrient of concern. Without skin exposure to sunlight, people must rely upon dietary intake of vitamin D. Since very few foods are naturally rich in vitamin D and regulatory agencies restrict the categories of foods and beverages which can be fortified, most people will need to supplement.
What do you notice about a person? Is it their hair? Maybe their eyes? Their skin? For me, it is teeth. I notice smiles and especially notice if teeth when are well maintained. For this reason, today’s main citation caught my attention.
Eighty-six individuals (63 nonsmokers and 23 smokers) with chronic periodontitis were evaluated for healing and reduced probing depth (PD) at baseline and 8-16 weeks after scaling and root planing.
Yesterday, the US FDA announced the results of a widespread investigation into the safety of dietary supplements on the market. The sweep has led to civil injunctions and criminal actions against 117 manufacturers of distributors of dietary supplements. Information about hundreds of supplements that contain hidden or potentially harmful ingredients have been identified. In the most egregious case, the dishonestly named USPlabs, who have produced some widely popular weight loss and muscle building supplements, has received may charges related to falsification of documentation and knowingly placing unsafe products on the market. How can consumers protect themselves from unsafe dietary supplements?
Children need vitamins and minerals to grow. Calcium and vitamin D are required to build strong bones and teeth. Omega-3 fatty acids, docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), are needed for brain, eye and immune development and function. Lutein and zeaxanthin and vitamin A are needed for visual development and eyesight. B vitamins are needed to access the energy consumed from macronutrients – carbohydrate, protein and fat. What happens when children are undernourished?
In a 12 week double-blind randomized controlled trial (RCT), Tamman and colleagues tested the effect of vitamin-mineral and omega-3 supplementation (vs placebo) in 196 children
Achieving work-life balance is not easy. Among Millenials (18 to 34y), there is a scarcity of good, stable jobs. Millenials are 3 times more likely to be unemployed that older working-age people. Gen Xers (35-50y) are mid-career and being squeezed with increasing responsibilities at work and the frantic pace associated with school and social commitments of their children. Baby boomers (the youngest of whom is 51y) face age-related health changes and uncertain financial futures. Stress is too common occurrence.
Two new Advances in Nutrition reviews highlight the importance of nutrition for well-being.
With two adult sons, I hope to become a grandparent someday. Because our sons live further north (Canada), today’s research study has me reflecting upon vitamin D recommendations. Over 100 years ago, scientists knew the bones of rachitic children had abnormally low bone mineral density, administering calcium did not prevent the condition, and the disease occurred primarily in large cities (with pollution from burning coal) in northern latitudes.
Using a cross-sectional analysis from the healthy New Nordic Diet (OPUS) School Meal Study, Petersen and colleagues examined vitamin D status of 782 Danish children (8-11y).
The recommendation to consume adequate folic acid before conception and during early pregnancy to avoid neural tube defects is well known. Even fairly recently, large-scale clinical trials show that folic acid supplements are effective in preventing birth defects. However, there is less research that has looked into whether it is beneficial to continue supplementation after the first trimester. As folic acid is needed for proper neural development, the domain of cognition seems a logical one for further testing.
Whether to follow an omnivorous, vegan or vegetarian diet is one of those hot-button issues, with fierce proponents on both sides. Omnivores claim that their diet is better as it is less likely to lead to deficiencies in nutrients such as iron, calcium and vitamin B12, which can be of concern in vegan diets especially, while vegans point to the lower saturated fat and higher fiber and vitamin C intakes in their diets, and state that they are beneficial in preventing chronic disease and increasing life span. While the jury is still out on whether cutting out all animal products can help us live longer, a group of researchers lead by Schüpback recently compared the diets and nutritional status of 200 Swiss omnivores, ovo-lactovegetarians and vegans to see whether there are differences in intakes and rates of deficiency in a large number of micronutrients.
Newborns and breastfed infants are solely reliant on the nutrients that they receive via their mother. Nature attempts to provide good quality nutrition for most babies by making certain adaptations during pregnancy and lactation. Vitamin D concentrations in mothers is highly correlated with that of their neonates and represents a nutrient for which supplementation is likely to be effective. Perumal, Al Mahmud and Baqui describe a study in which they attempt to prevent newborn vitamin D deficiency by supplementing pregnant women during the third trimester of pregnancy.
Minimally invasive techniques to measure nutrient status could be far superior to self-reported dietary intake information. Why? Self-reported dietary intake doesn’t correlate very with nutritional biochemical markers. According to Lassale and colleagues, dietary intake data explains less than 14% of the variability in nutritional biomarkers. Probably because we are not very precise in recording food intake.
When using finger-prick sampling, the very small blood sample may limit the accuracy of assessing nutritional status by biochemical biomarkers. Hoeller and colleagues wanted to know if vitamin D status could be measured by applying a finger prick spot of blood to a filter paper.
A major pitfall of nutrition research is the difficulty in accurately recording food intakes. All methods have considerable limitations that affect the collection of data and have the potential to lead to under-, over, or misreporting of food consumed, and potentially influence the results and conclusions of nutrition research. A research paper by Archer, Hand and Blair recently stirred up controversy in this field when they found that estimations of food intake over the history of NHANES were not plausible for most participants, especially the obese. Two recent publications looked at this problem: one reports on factors that affect under-reporting of food intakes in children and adolescents (Murakami), and the other investigates the use of a micro-camera to record food intakes (Pettitt).
Some of the symptoms of the vitamin C deficiency disease, scurvy – sore limbs, bleeding gums, and poor wound healing – are related to one of the roles of vitamin C in the body, namely the production of collagen. Collagen is a structural protein in the body and forms the matrix upon which bone minerals are deposited. Finck and co-workers recently looked at whether vitamin C intake or serum levels in EPIC study participants are associated with measures of bone health in elderly people for this reason.
Who can say they live a life free of stress? Very few indeed. Pressures at work, tough physical workouts and less-than-optimal dietary choices can all contribute to oxidative stress. Researchers believe that oxidative stress may increase risk of prostate cancer.
When we fail to eat the recommended number of servings of green, yellow, and red vegetables, our dietary intake of antioxidants is low. Greater intake of antioxidants is associated with lower concentrations of biomarkers of stress in blood and urine.
Iron absorption is notoriously difficult to estimate. In what is sure to be an influential article, Armah, Carriquiry and Reddy estimate total population iron absorption and compare it to a value widely used to reflect iron absorption when creating Dietary Reference Intakes (DRIs). Can their results explain the widespread iron deficiency anemia that is found in well-nourished populations?
Inadequate vitamin and mineral intake can lead to suboptimal vitamin and mineral concentrations that affect metabolic processes in the brain, and therefore mood. In a meta-analysis of 8 RCTs, Long and Benton reported a beneficial effect of multivitamin-mineral supplementation. In particular, high doses of B vitamins may be affective. In 2013, Davison and Kaplan wrote “Nutrient intakes warrant further consideration in the treatment of people with mood disorders.”
In a new study, White and colleagues report on the effect of 4 week trial in 58 healthy, young adults with a multivitamin-mineral supplement
Short and sweet. Accurate nutritional assessment requires blood sampling (until other less-invasive measures are developed). Self-reported dietary intake instruments are poorly, in statistical terms the term would be ‘weakly’, correlated with blood biomarkers.
Lassale and colleagues asked 198 adult volunteers complete dietary records on 3 non-consecutive days. Two blood samples were taken 3 weeks apart to measure plasma concentrations of vitamin C, β-carotene, and omega-3 fatty acids – eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA) and eicosapentaenoic acid (EPA).
With all the debates about fat, sugar and gluten, it is easy to forget about the other macronutrient: protein. Protein is necessary for all of us, but it is perhaps most important for older people. As people age, they tend to lose muscle mass from their bodies. Even if body weight stays the same, there is a strong tendency for muscle to turn into fat over a period of decades. Loss in muscle results in frailty and reduced ability to carry out normal, everyday activities. Helping people maintain muscle strength and function in old age is key to healthy aging. What role does protein play in muscle building in the elderly?
Vitamin E is an antioxidant known to protect polyunsaturated fatty acids and other sensitive moieties within cell membranes, tissues (brain, eyes, muscles, etc) and sperm from oxidative damage. Shi and colleagues report that low vitamin E status may jeopardize bone health.
Collecting data from 3,203 adults (1,178 women and 1,025 men), 40-75y, living in China, dietary vitamin E intake and serum α-tocopherol concentrations were positively associated with bone mineral density (BMD).
In a recent narrative review, Dr Spence brings attention to the contributory role that vitamin B12 deficiency plays in dementia and stroke risk. Older people are much more likely to be affected by vitamin B12 deficiency. For example, while overall less than 3% of the US population has low vitamin B12 levels, incidence of low vitamin B12 concentrations in people aged over 60 is 5%. But how is B12 deficiency linked to stroke and dementia?
According to Wikipedia, the United States is the world’s largest national economy, representing 22% of nominal global GDP. Since the economic crash in 2008, U.S. GDP growth has exceeded 3.5% annually every year except 2009. Nevertheless, the American Academy of Pediatrics reports that 15 million children live in households struggling with hunger, a contributor to immediate and potentially lifelong health effects.
Many people do not realize that salt is an essential nutrient. The sodium in table salt regulates fluid in the body and is needed for the proper functioning of nerves and muscles. As with everything, we can have too much of a good thing. High consumption of salt can cause hypertension and contributes to cardiovascular disease risk. Salt reduction has long been touted as a means to reduce the burden of disease caused by too much salt. But is reducing salt in a single type of food, soup, likely to have a measurable effect on public health?
In 1912, Dr Casimir Funk discovered the first B vitamin. He was the first to isolate vitamin B3 (niacin). After a strange series of events, and discussion of a cast of scientific experts, the first Nobel Prize for vitamin research was jointly awarded to Eijkman and Hopkins in 1929.
Over 100 years later, Valente and colleagues report lower serum folate in men and women with celiac disease vs healthy controls. Men and women with celiac disease had significantly lower serum folate concentrations than controls, 5.7 vs 11.7 ng/mL and 8.8 vs 13.4 ng/mL, respectively
A recent study by Htet and co-workers reported on the micronutrient status of adolescent girls in Myanmar. There was good and bad news. On the one hand, less than 1% of the 391 anemic girls had vitamin B12 deficiency. On the other hand, over half the girls had folate deficiency, and most girls had a deficient intake of vitamins A, B6, C, folate, iron and calcium. What role could rice fortification play in reducing rates of folate deficiency?
Recommendations for omega-3 consumption vary greatly. Healthy adults are advised to consume anywhere from 90 to 500 mg of long chain omega-3 PUFAs, but the recommendation of 250 mg per day seems to be most common. When the guidelines don’t directly mention long chain omega-3’s, they state that we should eat fish (especially fatty fish) at least twice a week, or otherwise increase consumption of foods containing omega-3. Unfortunately, it seems that it is difficult to reach these levels. Around the world, less than 20% of the population more consume than 250 mg per day omega-3. Why is this?
The value of dietary intake questionnaires to estimate food intake is under debate. A systematic review of 45 dietary intake studies conducted with children aged 6 to 12y finds timing of the interview to be important. As the interval between food consumption and the dietary intake survey increased, accuracy of recall diminished. Children’s age, body mass index, social desirability, food preferences, and cognitive ability were also related to accuracy.
When conducting randomized controlled studies (RCTs), a BIG challenge is that study participants often conceal information. Participants will lie to get into clinical trials. People are known to conceal health problems, deny use of prescription medications, and exaggerate symptoms to qualify for a study. This is a problem.
Nutrition RCTs are particularly difficult because a true placebo treatment does not exist. Everybody eats. Everybody has some level of nutritional status ranging across the spectrum of deficient, insufficient, and adequate.
Hospitals collect data on emergency visits for all types of injuries, including adverse drug events (ADEs). When someone goes to the emergency room for an ADE, they are asked to identify the drugs, vaccines, and dietary supplements they have taken. This information helps the medical team determine treatment strategies. A case report is generated listing the name, dose, route, frequency and duration of every item named by the patient, regardless of whether it contributed to the ADE or not.
By now you may have seen headlines that “Supplements Send Thousands of Americans to Emergency Room Every Year, Study Finds”.
A provocative viewpoint discusses obstacles to the development of cost-lowering health technologies. Basically, the authors suggest that venture capital focus on investment returns is hampering innovation. To make their case, Kellerman and Desai discuss a one-a-day miracle pill. They could have used a more realistic possibility – nutrition assessment.
This Friday, October 16, will be World Food Day. The 2014 theme is Family Farming, Feeding the World, Caring for the Earth. Being born on a farm, and having family who continue to farm and innovate to increase sustainability, makes this day especially important to me.
Without a sustainable agri-food system, food security cannot be achieved. Because of the prevalence of overweight and obesity, many believe everyone is eating too much. In reality, overweight/obesity often co-exist with inadequate vitamin and mineral intakes.
Because self-reported dietary intakes are fraught with errors (under- and over-reporting of food groups with healthy perceptions, difficulties in calculating nutrient intakes from a restrictive food list, etc), biological measures of nutrient status are preferred.
Dawczyniski and colleagues evaluated the associations of circulating fatty acids on cardiovascular outcomes, taking issue with the conclusions of Chowdhury and colleagues on the health benefits of saturated fatty acids found in dairy products.
Randomized, double-blind, controlled clinical trials are seen as the gold standard for biomedical research for proving that a given intervention causes a certain result. However, there are a few issues with testing interventions for chronic diseases that begin to develop decades before the clinical disease. One example of this is age-related macular degeneration (AMD). How can we adequately test the relationship?
Two very different vitamin D research studies demonstrate the complexities of nutrition. After identifying 20 eligible studies involving 9,209 participants, Zhang and colleagues report vitamin D deficiency is associated with increased risk of gestational diabetes mellitus (GDM). Qi and colleagues report that carrying a specific vitamin D polymorphism, the T allele of DHCR7 rs 12785878, may benefit individuals with greater improvements in insulin resistance (vs non-carriers) when following a high-protein weight-loss diet.
One of our most popular posts looks at whether supplemental folic acid is worthwhile in the second and third trimesters of pregnancy. A group of researchers lead by Wang have now conducted a study that looks at supplemental folic acid use during pregnancy and risk of pre-eclampsia that provides more evidence in favor of continuing supplementation during pregnancy.