In This Issue….                                                                           

-   Has a novel early diagnostic test for Alzheimer’s been discovered?
-   Conflicting conclusions on vitamin D highlight problems in vitamin studies
-   Vitamin B5 improves lipid profile
-   Zinc bioavailability may be overestimated in common foods, says study
-   CoQ10 treatment efficacy for insulin resistance surpasses that of common drug
-   Vitamin D linked to adiponectin levels
-   Vitamin A deficiency in mom affects immunity in offspring

CLINICAL UPDATE – Has a novel early diagnostic test for Alzheimer’s been discovered?

Researchers followed 525 community dwelling adults all over age 70 for five years and monitored their cognitive ability and memory impairment over time. They evaluated several phospholipid markers in their blood before and at the end of the study and compared these phospholipid markers in subjects who retained normal memory and congition to those who showed progressive dementia. Ten biomarkers were identified that, according to the study’s authors, “predicted phenoconversion to either amnesiac mild cognitive impairment or Alzheimer’s disease within a 2-3 year time frame with over 90% accuracy.” The biomarkers were primarily phosphatidlycholine and carnitine based lipids which reflect cell membrane integrity.

The authors state that these ten lipid markers “reveal the breakdown of neural cell membranes in those individuals destined to phenoconvert from cognitive intactness to [dementia],” suggesting this as a potentially useful, non-invasive, accurate and inexpensive measure of neurodegeneration in preclinical Alzheimers.
(Nature Medicine, April 2014)

Plasma phospholipids identify antecedent memory impairment in older adults.

CLINICAL UPDATE – Conflicting conclusions on vitamin D highlight problems in vitamin studies

Two major reviews and meta-analysis on vitamin D were published in the same journal this month but with different conclusions. In one review that covered 73 cohort studies and 22 randomized controlled trials, the authors concluded that higher circulating vitamin D levels are linked to lower overall mortality risk due to heart disease, cancer or other causes. In the same journal, a review of vitamin D that covered 107 review papers and 161 meta-analyses on vitamin D and its link to ten health outcomes including heart disease, autoimmune, metabolic disease and others concluded that “highly convincing evidence of a clear role of vitamin D does not exist for any outcome.”

The authors of these studies acknowledged that (1) low dosages and (2) varying baseline levels of vitamin D would complicate results. Some experts state that the randomized controlled trial model for evaluation of nutrients, including vitamin D, is inappropriate, since this model was developed for pharmacological trials of drugs with singular metabolic pathways. Since vitamin D’s interaction with other nutrients and hormones is very complex, some propose the current paradigm of nutrient evaluation is fundamentally flawed.
(British Medical Journal, April 2014)

LINK to ABSTRACT Vitamin D and multiple health outcomes: umbrella review of systematic reviews and meta-analyses of observational studies and randomised trials. LINK to FREE FULL TEXT

 Vitamin D and risk of cause specific death: systematic review and meta-analysis of observational cohort and randomised intervention studies. LINK to FREE FULL TEXT 

CLINICAL UPDATE – Vitamin B5 improves lipid profile

32 people with low to moderate cardiovascular risk who would, according to current NCEP guidelines, be eligible for statin therapy, were given pantethine, a form of vitamin B5 or placebo for sixteen weeks. At the end of the study, low density lipoprotein cholesterol decreased by 11% only in the B5 group, leading researchers to conclude that “this study confirms that pantethine lowers cardiovascular risk markers in low to moderate CVD risk participants.”
(Vascular Health and Risk Management, February 2014)

LINK to ABSTRACT Pantethine, a derivative of vitamin B5, favorably alters total, LDL and non-HDL cholesterol in low to moderate cardiovascular risk subjects eligible for statin therapy: a triple-blinded placebo and diet-controlled investigation. LINK to FREE FULL TEXT 

CLINICAL UPDATE – Zinc bioavailability may be overestimated in common foods, says study

In a comprehensive review of 116 papers, researchers described several factors that affect zinc bioavailability in adult populations. Phytates, which are non-digestible compounds in grains and beans that chelate, or bind to minerals making them unavailable for absorption in the intestinal tract, reduced zinc bioavailability by more than half.
(Nutrition Reviews, April 2014)

LINK to ABSTRACT Factors that affect zinc bioavailability and losses in adult and elderly populations. 

CLINICAL UPDATE – CoQ10 treatment efficacy for insulin resistance surpasses that of common drug

After an insulin resistant state was induced in this animal study, rats were given either coenzyme Q10 or glimepiride, a sulfonylurea anti-diabetic drug for two weeks. CoQ10 increased the beneficial action of enzymes that help energy production and improve metabolic health (tyrosine kinase, phosphatidylinositol kinase).   CoQ10 also lowered glucose and insulin levels , improved lipids, increased glutathione (potent antioxidant) and increased adiponectin (beneficial energy producing hormone). Researchers stated that “CoQ10 effects surpassed that of glimepiride in almost all the assessed parameters” and concluded that the study “points to the potential positive effect of CoQ10 as an adds-n to conventional antidiabetic therapies.”
(Public Library of Science, February 2014)

LINK to ABSTRACT Novel CoQ10 antidiabetic mechanisms underlie its positive effect: modulation of insulin and adiponectine receptors, Tyrosine kinase, PI3K, glucose transporters, sRAGE and visfatin in insulin resistant/diabetic rats. LINK to FREE FULL TEXT

CLINICAL UPDATE – Vitamin D linked to adiponectin levels

Blood levels of vitamin D were measured in over 9000 adults and compared to levels of the fat-burning hormone adiponectin in the same people. Researchers found that vitamin D “was positively associated with total adiponectin” and suggest a “possible causal association between serum 25(OH)D and total adiponectin.”
(European Journal of Nutrition, February 2014)

LINK to ABSTRACT Investigating the causal effect of vitamin D on serum adiponectin using a mendelian randomization approach. 

CLINICAL UPDATE – Vitamin A deficiency in mom affects immunity in offspring

Vitamin A is one of the key micronutrients in regulating tissue growth and development and this animal study examined how gestational vitamin A deficiency during gestation (pregnancy) affects immune function offspring, especially in the gut. Researchers found that early life vitamin A deficiency decreases immune cells (lymphocytes) and negatively alters gut function. They concluded “this suggests that more attention should be given to the vitamin A nutritional state of children and women of reproductive age.”

In a similar but unrelated animal study, researchers showed that vitamin A deficiency in early life development was correlated with a high rate of heart defects. Through gene analysis, the researchers concluded “that aberrant methylation is one of the key mechanisms to heart defects in vitamin A-deficient offspring.”
(Nutrition, March 2014)
(Journal of Nutritional Biochemistry, July 2013)

LINK to ABSTRACT Gestational vitamin A deficiency reduces the intestinal immune response by decreasing the number of immune cells in rat offspring.

LINK to ABSTRACT Alteration in methylation pattern of GATA-4 promoter region in vitamin A-deficient offspring's heart.