Culture influences food choices and nutrient status at the population level. Even in countries that share cultural roots, there can be marked differences in the consumption of certain foods. New Zealand is a prime example, where recent shortages in supply of the Kiwis own beloved brand of yeast extract spread lead to a “crisis” situation. The consumption of yeast extract spread on bread or toast is not only a quaint undertaking by antipodeans, as the high levels of B-vitamins that are consumed with the spread can be of public health significance.
Archive for 'October 2013'
A new review by Fenton and colleagues states that increasing long chain omega 3 fatty acid (LCFA) intake of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) may have adverse health outcomes. Let’s discuss this statement. The conclusions were drawn from a summary of mouse studies where dietary EPA/DHA intakes were manipulated and immune responses to pathogens were assessed. As expected, manipulating the type of fat (saturated, monounsaturated, polyunsaturated) and amount (% of total energy intake) in the diet exerted physiological changes in membrane and red blood cell composition and cellular signaling pathways. In effect, mice (and people) are made of what they eat.
Chronic inflammation and oxidative stress contribute to age-related disease. Having adequate antioxidant status helps maintain normal cell function, especially important in people who don’t eat enough fruit and vegetables, are overweight, and/or live a sedentary lifestyle. As summarized by Stephen Daniells on Oct 22, a depletion in plasma levels of antioxidants (in this case vitamin E) may play a role in age-related, non-communicable diseases.
Lambrecht and colleagues assessed markers of oxidation and inflammation in 42 obese, premenopausal women before and after a 30 min walk.
A new report finds that older volunteers are in better physical health than younger peers. Purdue University sociologists, Kim and Ferraro, used regression to analyze the effects of volunteering, employment, attending meetings and caregiving on a biomarker of stress and inflammation, C-reactive protein, measured in the blood of 1,790 adults (57-85y) from the National Social Life, Health, and Aging Project. CRP levels were ~15% lower in those who volunteered several times per year (vs those who did not volunteer during the past year).
The Gerontologist paper provides insight into the complexity of conducting randomized controlled trials (RCTs) to test nutrient-disease relationships.
Today’s blog is on interpreting science. It is an important topic because of our increasing dependence upon our ‘science intelligence (IQ)’ . The creation of the internet and mobile devices have given access to information and transparency unlike that experienced by any other generation. With access we can bypass experts, i.e. gatekeepers, who filtered information for us - Travel agencies. Professionals who distilled and summarized scientific evidence via a few national evening news channels or weekly health columns in print media. These are not needed because we can search the internet for airfares, insurance vendors, and more. We can verify our physician’s treatment, including prescription choice, online.
The first thousand days of a child’s life, from pre-conception to their second birthday, are the most important. Adequate nutrition during this critical window of opportunity helps children have healthier futures. Malnutrition is a significant worldwide problem, however, and many organizations are working hard to develop effective solutions. A study published recently looks at how effective baseline diet and supplemental foods are in meeting the needs of 6 to 11 month old infants.
Omega-3 fatty acids are good for the brain and the heart. It is not surprising since long chain polyunsaturated fatty acid(LCPUFA) docosahexaenoic acid (DHA) makes up 97% of the LCPUFA present in the brain. DHA, along with its precursor eicosapentaenoic acid (EPA) are important for heart health. Triglycerides are found in the blood in a range of particle size. Supplementation with 4g EPA and 5g DHA daily for 12 wk has been shown to reduce serum triglycerides 26% (Oelrich and colleagues).
It seems like a no-brainer. Chocolate is energy dense and irresistible. Therefore it must contribute to excessive calorie intakes. The average chocolate bar contains around 250 kcal and is part of the food group most nutritionists refer to as “discretionary calories.” Even so, chocolate does contain some other bioactive compounds, and it is also possible that a responsible intake of chocolate does not cause obesity, as diet is more than simply the consumption of one type of food.
Despite low awareness, over 10% of a well-nourished population such as the US has both low intakes and deficient or marginal vitamin status of vitamin B6. This is important because low vitamin B6 levels have been associated with increased risk of cardiovascular disease.
Yesterday Chris van Tullekin advised readers that they were wasting their time, and potentially even harming themselves by taking vitamin supplements via BBC News Magazine. Chris started with an example of vitamin A toxicity from eating dog liver. It is true. Eating a bear liver can be toxic because it can contain 18,000 IU per gram (Rodahl & Moore, 1942). But I am digressing, as was Chris, into a discussion of nutrient toxicity from natural overdoses and away from the topic at hand – the wisdom of using dietary supplements to help meet nutrient requirements.
Pregnant women want to have a healthy pregnancy. One increasingly prevalent pregnancy complication is gestational diabetes, which affects 2% to 20% of all pregnancies depending on geographic region. Gestational diabetes is a type of diabetes that is first detected during pregnancy (normally during the end of the second trimester) and usually subsides after delivery. Women with gestational diabetes no longer respond effectively to the insulin that they produce after a meal and blood glucose levels increase too much. Vitamin D has been shown to improve insulin sensitivity. Can it help in gestational diabetes?
Today is World Food Day. The theme for 2013 is sustainable food systems for food security and nutrition. The objective is to increase awareness of hidden hunger and drive greater collaboration throughout the food chain.
As Andre Croppenstedt, FAO, writes, “While nutritional outcomes depend upon many factors, food systems are a fundamental part of the equation as they determine the quantity, quality, diversity and nutritional content of foods available.” With the world population rapidly approaching 9 billion people, most of whom are opting to live in urban environments,
Much is written, spoken, and tweeted about public-private partnerships. Experts from academics, government, non-government organizations, and industry published 12 principles for building partnerships to benefit food safety, nutrition and health research in Nutrition Reviews.
The 12 principles are:
1. Have a clearly defined and achievable goal to improve the health of the public
Articulate a clear statement of work, rules, and partner roles, responsibilities, and accountability, to build in trust, transparency, and mutual respect as core operating principles
The days are getting shorter in the northern hemisphere. Streetlights turn on earlier. Headlights are essential to drive. Couple this darkness with rain, or heaven forbid snow, and night-time glare from oncoming headlights and reflections makes driving more difficult for many. The ‘perfect storm’ of events may bring to mind the old adage ‘carrots help you see in the dark’. (click here for an interesting perspective on the history of the phrase).
Carrots provide a rich source of beta-carotene, a source of vitamin A. As MedlinePlus, a service of the US National Library of Medicine and National Institutes of Health writes, “ Vitamin A promotes good vision, especially in low light.”
Osteoporosis, the result of accelerated bone loss, leads to brittle, weak bones which are susceptible to fracture. An estimated 8.2 million women over 55 years have osteoporosis in the US (Frost and Sullivan, 2013). According to the International Osteoporosis Foundation, osteoporosis causes more than 8.9 million fractures worldwide annually. The combined lifetime risk of hip, forearm and vertebral fractures is equivalent to the risk for cardiovascular disease. In the US, Frost and Sullivan estimate the total health care expenditure on managing and treating osteoporosis-attributed bone fractures among women over 55y at $14 billion per year.
The choice of using dietary supplements to meet nutrient requirements is contentious. Maybe not as emotional as politics, religion, and taxes but many personal belief systems prevail when it comes to advice on dietary habits. Most health professionals, and journalists, prefer food-based solutions. Makes sense but then one has to navigate the merits of natural foods, organic foods, processed foods, minimally-processed foods, and locally-sourced foods. All of this is confusing. Could a multi-vitamin supplement serve as an insurance policy? Research supports the concept that supplement users are seeking nutritional adequacy to support health.
You have to like Steven Salzberg’s tagline “I cover pseudoscience and bad medicine, and sometimes good medicine”. He is the author of “The Top Five Vitamins You Should Not Take” published in Forbes. As a reformed vitamin user, Steven recommends ditching the vitamins and eating more spinach and blueberries. Presumably, this is a metaphor for more vitamin (and mineral-rich) fruit and vegetable.
Vitamins and minerals are not magic bullets. Nutrients are not drugs. Nutrients in the form of foods or dietary supplements do not prevent, mitigate or treat diseases. However, nutrients are essential for health. We need adequate nutrition for optimal health not pharmacologic doses. Let’s examine the 5 vitamins in question:
Last night actor Tom Hanks revealed he was diagnosed with high blood pressure 20 years ago and has just been diagnosed with type 2 diabetes. He is not alone. Hypertension affects one third of adults in the United States with the highest prevalence in African Americans. The most recent statistics (2011 CDC) find that 25.6 million Americans, 11.3% of those over 20y, have diabetes.
Type 2 diabetes is a disease where blood glucose levels are above normal. It occurs because the pancreas cannot produce enough insulin to help move glucose from the bloodstream into cells. Risk factors include being older, being overweight or obese, a family history, prior history of gestational diabetes, impaired glucose tolerance, physical activity, and race/ethnicity.
With the US federal government shut down, it is probably not a good time to propose new governmental activities. However, Flock and colleagues recommend that a Dietary Reference Intake (DRI) be established for the omega-3 polyunsaturated fatty acids (n-3 PUFA) eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).
The authors review current recommendations for n-3 PUFA intakes:
Nutrition is complex, especially in the realm of bioavailability. For nutrients with known deficiency disease, such as iron, assessing the effect of an intervention is more complicated than a simple dose-response effect. This is why it is important to perform studies that work out what effects iron absorption, and by how much. Finkelstein and colleagues recently looked at iron absorption in infants aged under 6 months, an under-studied population that is vulnerable for iron deficiency anemia.
For those living in the northern hemisphere, the days are getting shorter and colder. Both factors contribute to less skin exposure to sunlight, leading to lower serum 25(OH)D concentrations unless we increase our intake of vitamin D rich foods or use dietary supplements.
Vitamin D deficiency is widespread in newborn. Streym and colleagues analyzed cord blood from 107 Caucasian women and their infants at birth, 4 and 9 months living in Denmark. Serum 25(OH)D levels < 25 mmol/L and between 25-50 nmol/L were defined as deficient and insufficient, respectively.
Resveratrol is a polyphenolic compound found in the skin of red grapes and red wines. Resveratrol may partially explain the French Paradox – low incidence of coronary heart disease (CHD) despite high intakes of saturated fat and cholesterol.
Sahebkar conducted a systematic review of randomized, controlled trials (RCTs) using resveratrol and measuring lipid profiles (total cholesterol, HDL-C, LDL-C, and triglycerides). In total, 122 articles were found and 15 met the criteria.
The American Society for Nutrition (ASN) published a list of nutrition research priorities this year. Among the tools needed to advance nutrition research, databases are listed (along with omics, bioinformatics, biomarkers, and cost effectiveness analysis). While food databases are important to monitor food and nutrition security (nutrient availability in the region), validated biomarkers reflect dietary exposure and current nutrient status. Because of our rapidly changing food supply, it is almost impossible to accurately monitor the nutrient content of all foods and beverages in the marketplace. Biomarkers are a means to assess individual health and the nutritional status of a population.