Vitamin E supplementation to reduce prostate cancer risk has been controversial, especially among smokers. New research published in the Journal of Nutrition adds another layer of complexity – the effect of genetics on oxidative stress and cancer risk. Four antioxidant enzymes are known to affect oxidative stress. Neuhouser and colleagues studied the interaction of polymorphisms in 4 enzymes, including myeloperoxidase (MPO), with serum α- and γ-tocopherol levels and prostate cancer risk in 18,314 heavy smokers and asbestos-exposed workers. They found:
Archive for 'July 2011'
Every year 80 million unintended pregnancies occur. According to research published by Monea and Thomas in May 2011, almost half of all pregnancies in the United States are unintended. In 29 states, more than half of all pregnancies were unintended. Given these facts, women of child-bearing age should be taking a daily multivitamin. Catov and colleagues examined the timing and frequency of periconceptual multivitamin use. Yesterday, they reported in the American Journal of Clinical Nutrition that
Skin health depends upon vitamin D status. Makes sense. Vitamin D can be synthesized by skin when exposed to sunlight. Then vitamin D circulates through the body to protect bones and help reduce the risk of diseases like diabetes and cancer. However, working inside, use of sunscreens, living nearer the poles of the earth, shorter days during winter months, and dark skin pigmentation all reduce vitamin D production in the skin. So it is not surprising that 3 new studies report benefits of having adequate vitamin D status. Touma and colleagues studied 302 patients with psorias living at different latitudes
Fast food has long been considered to be a nutritional foe for many, being high in calories and low in nutrients. With US obesity rates remaining high in the most recent surveys, and two thirds of Americans eating out of the home at least once a week, more healthful options would be a boon for consumers. In particular, fruit and vegetable consumption remains low, and there is a high prevalence of vitamin D deficiency.
Vitamin A is a crucial micronutrient, especially for infant and child development. It has multiple roles in the body, particularly in eye health and establishing the immune system. In fact, it is the breakdown of a pre-formed vitamin A metabolite, retinal, in the presence of light that triggers the signal to the optical nerve that we interpret as vision. Vitamin A also is needed for cellular differentiation, the process by which cells change from a less to more specialized cell type. This is particularly important in epithelial cells, which line the body and are the main line of defense against pathogens. Vitamin A is obtained in the diet from animal products, particularly liver, dairy, and is also converted from beta-carotene, which is found in significant quantities in orange and dark green leafy vegetables. Additionally, foods such as milk and margarine are often fortified with vitamin A.
Everyone eats. You have to eat to get essential nutrients like vitamins and minerals to stay healthy. The questions are: how much nutrient X does a person need to consume? Dietary Guidelines are partially based on survey programs like NHANES which primarily try to measure food intake. NIH announces new program to identify nutritional biomarkers, beginning with folic acid, vitamin A, vitamin B12, iron, iodine, and zinc. The Biomarkers of Nutrition for Development (BOND) program will bring together experts to provide advice on biomarkers which will guide nutrition policy and identify questions for future research.
Do you ever pause to remember someone’s name in a conversation? Is this happening more now than 10 years ago? Daily antioxidant supplementation may help preserve verbal memory according to a July 20 study by Kesse-Guyot and colleagues in the American Journal of Clinical Nutrition. The French study with 4,447 volunteers (ages 45-60y) found those who took a daily antioxidant supplement for 8 years containing 120 mg vitamin C, 6 mg beta-carotene, 30 mg vitamin E, 100 ug selenium and 20 mg zinc performed better in memory tests than those receiving placebo IF they had low serum vitamin C concentrations at baseline or were nonsmokers. In other words, supplementation wasn’t a panacea to people who had adequate antioxidant status from the beginning. And for smokers, well better nutrition doesn’t overcome an unhealthy addiction.
More than half of Australian children are not consuming the Adequate Intake (AI) of long-chain omega-3 fatty acids (LC n-3 PUFA) for optimal health according to a new study in press at Nutrition. Meyer & Kolanu studied data obtained from 4,486 children (2-16y) as part of the 2007 Australian National Children’s Nutrition and Physical Activity Survey (ANCNPAS). Five percent of children were underweight, 18% were overweight and 6% were obese.
An innovative ad is linking vitamins with energy at bus stops in Boston, New York, Chicago, and Los Angeles by having a USB port in the image of the water bottle to charge mobile devices. This ad shows the regenerative power of antioxidant vitamins. Antioxidants, like vitamin C, vitamin E, beta-carotene, lycopene, lutein, and zeaxanthin, counteract oxidative damage by reactive oxygen and nitrogen compounds to molecules and cells. They also help regenerate reduced moieties. A new study published in the Journal of Neuroscience reports that vitamin C is needed to maintain normal brain and eye cell function.
How much is enough vitamin D? Depends who you ask. Because “until skin is burned by the sun” is not the right answer, keep reading. The Institute of Medicine Committee to Review Dietary Reference Intakes for Vitamin D and Calcium summarized, “practically all persons are sufficient at serum 25(OH)D levels of at least 50 nmol/L (20 ng/mL)”. A new study published in the British Journal of Nutrition found 29% of Caucasians in the study had serum 25(OH)D levels under 50 nmol/L. The authors examined associations between hypovitaminosis D with diabetes, hypertension, and coronary heart disease (CHD)
A review and call to action published recently by Fleishman and Oinuma in the American Journal of Public Health discusses the potential role that fortifying corn masa flour could have on reducing neural tube defects (NTDs) in the Latino population in the USA. Current recommendations for women of childbearing age are 400 μg folate per day. The percentage of Hispanic women meeting folic acid recommendations is half that of non-Hispanic white women in recent nutrition surveys.
Got your omega fatty acid intakes right? Better try according to 3 papers just published in the British Journal of Nutrition. Barros and colleagues conducted a cross-sectional study with 174 asthmatics (average age 40 ± 15 years where they measured forced expiratory volume, exhaled NO, and responses to an Asthma Control Questionnaire. Higher intakes of n-3 PUFA were associated with better asthma control. α-linolenic acid had a protective effect independent of higher n-6:n-3 ratios. Studying 198 subjects at high cardiovascular risk living in Spain consuming an average of 0.9g DHA+EPA daily, Sala-Vila and associates found
Age-related macular degeneration (AMD) is increasingly prevalent as people age. An Arch Opthalmol study states that increased intakes of beta-carotene, lutein/zeaxanthin, and EPA/DHA intakes are associated with decreased risk of early AMD in those at high genetic risk. Eating diets rich in antioxidants helps prevent damage from reactive oxygen species which seems to lower risk of AMD. The Age-Related Eye Disease Study (AREDS) found using antioxidant supplements containing 500mg vitamin C, 400 IU vitamin E, 15mg beta-carotene, 80mg zinc, and 2 mg copper reduced risk of AMD.
Isn’t football played outdoors? Well, maybe it is, even on Friday nights, but it takes sunshine not stadium lights, for our bodies to make vitamin D. Otherwise, we must consume foods rich in vitamin D (or take a dietary supplement). 80% of football players had vitamin D insufficiency according to a study presented at the American Orthopaedic Society for Sports Medicine’s annual meeting. 16 of the 89 players had serum 25(OH)D3 levels under 20 ng/mL and they had experienced muscle injury. A February 2011 study reported that college athletes had low vitamin D levels in the fall and winter with the results being worse in indoor athletes.
Flour fortification is a widely used means to improve the nutritional value of the diet around the world. Flour is commonly fortified with minerals such as zinc and iron, and vitamins folic acid, riboflavin, thiamin and niacin. Initially, food fortification was introduced to avoid classic deficiency diseases such as pellagra and beriberi, which arise from insufficient thiamine and niacin. Other nutrients are now commonly used to prevent iron deficiency and recently, neural tube defects (NTDs). A recent report by Abdollahi and co-workers in the Annals of Nutrition and Metabolism studies the effects of folic acid fortification in flour in Iran. Combining the results of a longitudinal study of 13,361 postpartum women, and two cross-sectional studies conducted before and after fortification, the authors found improvements in folate consumption, folate levels in the blood, and a reduction in NTDs.
Health care costs are threatening national budgets. Good nutrition can prevent many non-communicable diseases (NCD). Folic acid is an essential vitamin. Spinach is a good source of folic acid but it isn’t a top food choice. To reduce the risk of NCD associated with folic acid inadequacy, several governments have established laws requiring fortification of certain foods. The US did this for grains in 1997. Using data collected from 99,253 persons enrolled in a cancer prevention study, Stevens and colleagues found high intakes of folate reduced the risk of colorectal cancer. They concluded that “there is no evidence that dietary fortification or supplementation with this vitamin increases colorectal cancer risk”.
Everyone eats. Everyone knows their favorite foods and flavors. You have experience in food and nutrition. However, only the chosen sit on committees responsible for making nutrition recommendations. In 1938, the first dietary standards were issued in Canada, then the U.S. followed in 1942 with Recommended Dietary Allowances (RDAs). By 1945, differences were realized in the approach taken by experts from both countries. In essence, an argument broke out between national nutrition expert committees. In her Nature article ‘The vitamin D-lemma’, Amy Maxmen captures the extreme opinions which co-exist among experts on vitamin D recommendations. With the advent of the internet and social media, these debates are no longer restricted to correspondence in prestigious scientific journals. Arguments have moved outside the hallowed halls of academia to the internet.
The effect of artificial dyes and colorants in foods/beverages on attention deficit hyperactivity disorder (ADHD) in children is contentious. An article published by Stevens and colleagues online yesterday in Nutrition Reviews asks the question, “Are there foods or food additives in the diet that the child needs to avoid because they increase symptoms of ADHD?” Stevens and associates don’t really answer the question but they do summarize a paper by Kanarek which concludes, “Parents of children with ADHD should be counseled to make careful food selections, choosing natural foods with no or limited amounts of synthetic food dyes.”
The FDA released the New Dietary Ingredient (NDI) Draft Guidance today to guide the supplement industry when a new dietary ingredient requires premarket safety notification. In October 1994, the Dietary Supplement Health and Education Act (DSHEA) was passed which defined ‘dietary supplement’ and ‘new dietary ingredient’. It also required industry to to submit a premarket notification to the FDA at least 75 days before marketing a supplement with an NDI across state lines. If an NDI is not submitted, the product is considered to be adulterated. Even if notification is submitted, the dietary supplement would be considered adulterated unless there was a history of use or other evidence establishing evidence of safety.
The American College of Obstetricians and Gynecologists (ACOG) Committee on Obstetric Practice issued an opinion in the July issue of Obstetrics and Gynecology that “there is insufficient evidence to support a recommendation for screening all pregnant women for vitamin D deficiency.” Later, the Committee writes, “When vitamin D deficiency is identified during pregnancy, most experts agree that 1,000-2,000 international units per day of vitamin E is safe.” How does ACOG expect physicians to ‘identify’ vitamin D deficiencies in patients without lab tests? Is this really sound clinical practice? In fairness to ACOG, the majority of Americans are vitamin D deficient so it is possible the intent is to have ALL doctors advise their patients to take a vitamin D supplement. However, in a press release on June 20, the Chair of the Committee, Dr George Macones, states, "I have no problem