Higher vitamin C levels associated with improved vascular function in type 1 diabetes

In an article published online on June 24, 2009 in the American Journal of Clinical Nutrition, Scandinavian researchers report that young type 1 diabetic patients with higher vitamin C levels have better vascular function compared to those with lower levels of the vitamin. Vascular function and structure changes can occur early in type 1 diabetes, and are associated with a greater risk of cardiovascular disease and cardiovascular mortality later in life.




Petru Liuba and Michael Odermarsky of Lund University Hospital in Sweden, along with Jens Lykkesfeldt of the University of Copenhagen in Denmark, recruited 33 male and 26 female diabetic patients between the ages of 10 and 22 for the current study. Carotid intima-media thickness (cIMT, which measures atherosclerosis), assessments of cutaneous microvascular function, cardiac depolarization and repolarization (evaluated via electrocardiogram as QT interval corrected for heart rate, which, when prolonged, is a predictor of adverse cardiovascular prognosis), lipids, and plasma C-reactive protein, fibrinogen, vitamin C and oxidized vitamin C (dehydroascorbic acid) were assessed. Continue Reading

D is for dieting

At The Endocrine Society's 91st Annual Meeting, held this month in Washington, D.C., University of Minnesota assistant professor of medicine Shalamar Sibley, MD, MPH reported that men and women with higher vitamin D levels experienced a greater amount of weight loss when dieting compared to those with lower levels.

For their study, Dr Sibley and colleagues measured plasma 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D (the precursor and hormonal forms of vitamin D) in 38 obese subjects prior to and following an 11 week diet plant that provided 750 calories less per day than the participants' estimated needs. Fat distribution and body composition were measured using dual-energy X-ray absorptiometry and computed tomography before and after the treatment period.

The participants' vitamin D levels were found to be insufficient on average. The researchers observed a linear relationship between baseline vitamin D levels and weight loss, with close to an additional half pound of weight loss associated with each 1 nanogram per milliliter (ng/mL) increase in plasma 25-hydroxyvitamin D, as well as nearly one quarter pound loss with each nanogram increase in 1,25-dihydroxyvitamin D. Higher levels of both forms of the vitamin were associated with more abdominal fat loss, and neither form was associated with lean mass loss. Continue Reading

Review affirms multiple benefits for resveratrol

A review scheduled for publication in the September, 2009 issue of the journal Alcoholism: Clinical & Experimental Research summarizes the health-promoting effects of resveratrol, a polyphenol compound found in red grapes, wine, and other plant foods.

University of Queensland School of Biomedical Sciences associate professor Lindsay Brown and colleagues conclude that resveratrol may help protect against a wide array of diseases and conditions. "The breadth of benefits is remarkable – cancer prevention, protection of the heart and brain from damage, reducing age-related diseases such as inflammation, reversing diabetes and obesity, and many more," Dr Brown stated. "It has long been a question as to how such a simple compound could have these effects but now the puzzle is becoming clearer with the discovery of the pathways, especially the sirtuins, a family of enzymes that regulate the production of cellular components by the nucleus. 'Is resveratrol the only compound with these properties?' This would seem unlikely, with similar effects reported for other components of wine and for other natural products such as curcumin. However, we know much more about resveratrol relative to these other compounds." Continue Reading

Greater adherence to positive dietary practices linked with reduced mortality over 10 year period

An article appearing online on May 27, 2009 in the Journal of Nutrition revealed the finding of researchers at Queens College of the City University of New York, the National Cancer Institute, and the American Association of Retired Persons (AARP) that practicing six beneficial dietary behaviors is associated with a reduction from mortality from all causes.

For their analysis, Ashima Kant and colleagues evaluated data from 350,886 participants in the NIH (National Institutes of Health)-American Association of Retired Persons cohort. Subjects were between the ages of 50 and 71 years and free of disease upon enrollment. Dietary questionnaires completed at the beginning of the study were scored on 6 categories: servings of vegetables consumed per week, servings of fruit consumed per week, consumption of whole grain cereals and breads, consumption of lean meat and poultry (as opposed to fattier meats, unskinned poultry, etc.), consumption of low fat dairy products (as opposed to full fat products), and whether solid fat was added to cooked foods. Continue Reading

New model of cancer development proposed

In an article scheduled to appear in the Annals of Epidemiology, epidemiologist Cedric Garland, DrPH and his associates at the University of California San Diego's Moores Cancer Center propose that cancer, rather than commencing with genetic mutations, is initially caused by a reduction in the of ability of cells to stick together.

Research has shown that inadequate vitamin D can result in a loss of stickiness between cells as well as a loss of differentiation, which causes cells to revert to a stem cell-like state. Additionally, extracellular calcium ions are necessary for intercellular adherence.

"The first event in cancer is loss of communication among cells due to, among other things, low vitamin D and calcium levels," explained Dr Garland, who is a professor of family and preventive medicine at the UC San Diego School of Medicine "In this new model, we propose that this loss may play a key role in cancer by disrupting the communication between cells that is essential to healthy cell turnover, allowing more aggressive cancer cells to take over." Continue Reading

Higher vitamin D levels associated with speedier brain processing

In an article published on May 21, 2009 online in the Journal of Neurology, Neurosurgery and Psychiatry, European researchers report that men with higher vitamin D levels performed better on a test of attention and speed of information processing than those with lower levels of the vitamin.

Dr David M. Lee of the University of Manchester's School of Translational Medicine and his associates administered 3 tests of cognitive function to 3,369 men aged 40 to 79 from 8 centers participating in the European Male Aging Study (EMAS). Fasting blood samples collected from the subjects were analyzed for serum 25-hydroxyvitamin D levels.

Men whose vitamin D levels were higher were found to perform better on all three tests, although the Digit Symbol Substitution test, which measures psychomotor speed and visual scanning, was the only test whose scores were associated with vitamin D levels after adjustment for several factors. Further analysis revealed that higher test scores were particularly associated with increased vitamin D levels in older men. Continue Reading