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Article: Cognitive and cardiovascular benefits of docosahexaenoic acid in aging and cognitive decline.
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ABSTRACT: Memory loss is a prominent health concern, second only to heart disease for older individuals. Docosahexaenoic acid (DHA), the principle omega-3 fatty acid in brain and heart, plays an important role in neural and cardiac function. Decreases in plasma DHA are associated with cognitive decline in healthy elderly and Alzheimer's patients. Higher DHA intake and plasma levels are inversely correlated with increased relative risk of Alzheimer's disease (AD) and fatal coronary heart disease. DHA provides well known cardiovascular benefits (e.g. lower triglycerides, increased HDL cholesterol, decreased resting heart rate) in older adults. Preclinically, DHA supplementation restores brain DHA levels, enhances learning and memory tasks in aged animals, and significantly reduces beta amyloid, plaques, and tau in transgenic AD models. To date, clinical studies with DHA+EPA supplementation have shown some positive effects in mild cognitive impairment but not in AD, suggesting that early intervention may be a key factor to providing effective therapies. A recent clinical study examined individual effects of 900mg/d algal DHA as a nutritional supplement for age-related cognitive decline (ARCD). This randomized, double blind, placebo controlled study (n=485) found significantly fewer CANTAB Paired Associate Learning errors with algal DHA at six months versus placebo (diff. score -1.63+/-0.76, p=0.03). Positive effects on Verbal Recognition Memory (p<0.02) and significant decreases in resting heart rate with DHA (p<0.03) were observed, indicating improved learning and episodic memory functions and cardiovascular benefits for ARCD. Collectively, data reveal a potentially beneficial role for DHA in preventing or ameliorating cognitive decline and cardiovascular disease in the aged.Current Alzheimer research 05/2010; 7(3):190-6. · 4.97 Impact Factor -
Article: Docosahexaenoic acid supplementation and cognitive decline in Alzheimer disease: a randomized trial.
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ABSTRACT: Docosahexaenoic acid (DHA) is the most abundant long-chain polyunsaturated fatty acid in the brain. Epidemiological studies suggest that consumption of DHA is associated with a reduced incidence of Alzheimer disease. Animal studies demonstrate that oral intake of DHA reduces Alzheimer-like brain pathology. To determine if supplementation with DHA slows cognitive and functional decline in individuals with Alzheimer disease. A randomized, double-blind, placebo-controlled trial of DHA supplementation in individuals with mild to moderate Alzheimer disease (Mini-Mental State Examination scores, 14-26) was conducted between November 2007 and May 2009 at 51 US clinical research sites of the Alzheimer's Disease Cooperative Study. Participants were randomly assigned to algal DHA at a dose of 2 g/d or to identical placebo (60% were assigned to DHA and 40% were assigned to placebo). Duration of treatment was 18 months. Change in the cognitive subscale of the Alzheimer's Disease Assessment Scale (ADAS-cog) and change in the Clinical Dementia Rating (CDR) sum of boxes. Rate of brain atrophy was also determined by volumetric magnetic resonance imaging in a subsample of participants (n = 102). A total of 402 individuals were randomized and a total of 295 participants completed the trial while taking study medication (DHA: 171; placebo: 124). Supplementation with DHA had no beneficial effect on rate of change on ADAS-cog score, which increased by a mean of 7.98 points (95% confidence interval [CI], 6.51-9.45 points) for the DHA group during 18 months vs 8.27 points (95% CI, 6.72-9.82 points) for the placebo group (linear mixed-effects model: P = .41). The CDR sum of boxes score increased by 2.87 points (95% CI, 2.44-3.30 points) for the DHA group during 18 months compared with 2.93 points (95% CI, 2.44-3.42 points) for the placebo group (linear mixed-effects model: P = .68). In the subpopulation of participants (DHA: 53; placebo: 49), the rate of brain atrophy was not affected by treatment with DHA. Individuals in the DHA group had a mean decline in total brain volume of 24.7 cm(3) (95% CI, 21.4-28.0 cm(3)) during 18 months and a 1.32% (95% CI, 1.14%-1.50%) volume decline per year compared with 24.0 cm(3) (95% CI, 20-28 cm(3)) for the placebo group during 18 months and a 1.29% (95% CI, 1.07%-1.51%) volume decline per year (P = .79). Supplementation with DHA compared with placebo did not slow the rate of cognitive and functional decline in patients with mild to moderate Alzheimer disease. clinicaltrials.gov Identifier: NCT00440050.JAMA The Journal of the American Medical Association 11/2010; 304(17):1903-11. · 30.03 Impact Factor -
Article: Beneficial effects of docosahexaenoic acid on cognition in age-related cognitive decline.
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ABSTRACT: Docosahexaenoic acid (DHA) plays an important role in neural function. Decreases in plasma DHA are associated with cognitive decline in healthy elderly adults and in patients with Alzheimer's disease. Higher DHA intake is inversely correlated with relative risk of Alzheimer's disease. The potential benefits of DHA supplementation in age-related cognitive decline (ARCD) have not been fully examined. Determine effects of DHA administration on improving cognitive functions in healthy older adults with ARCD. Randomized, double-blind, placebo-controlled, clinical study was conducted at 19 U.S. clinical sites. A total of 485 healthy subjects, aged ≥55 with Mini-Mental State Examination >26 and a Logical Memory (Wechsler Memory Scale III) baseline score ≥1 standard deviation below younger adults, were randomly assigned to 900 mg/d of DHA orally or matching placebo for 24 weeks. The primary outcome was the CANTAB Paired Associate Learning (PAL), a visuospatial learning and episodic memory test. Intention-to-treat analysis demonstrated significantly fewer PAL six pattern errors with DHA versus placebo at 24 weeks (difference score, -1.63 ± 0.76 [-3.1, -0.14, 95% CI], P = .03). DHA supplementation was also associated with improved immediate and delayed Verbal Recognition Memory scores (P < .02), but not working memory or executive function tests. Plasma DHA levels doubled and correlated with improved PAL scores (P < .02) in the DHA group. DHA was well tolerated with no reported treatment-related serious adverse events. Twenty-four week supplementation with 900 mg/d DHA improved learning and memory function in ARCD and is a beneficial supplement that supports cognitive health with aging. Clinicaltrials.gov, Identifier: NCT0027813.Alzheimer's & dementia: the journal of the Alzheimer's Association 04/2010; 6(6):456-64. · 5.90 Impact Factor -
Article: CFTR is functionally active in GnRH-expressing GT1-7 hypothalamic neurons.
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ABSTRACT: We have demonstrated the expression of the cystic fibrosis transmembrane conductance regulator (CFTR) gene, mRNA, and protein within the rat and human brains, in areas regulating sexual differentiation and function. We have found that GT1-7, a gonadotropin-releasing hormone (GnRH)-secreting hypothalamic neuronal cell line, expresses the CFTR gene, mRNA, and protein and cAMP-dependent (36)Cl efflux. A linear 7-pS Cl- conductance, which is stimulated by ATP and cAMP analogs and inhibited by glibenclamide, consistent with CFTR activity, has been identified in GT1-7 cells. Antisense oligo(dN) generated against exon 10 of the CFTR gene transcript (mRNA) inhibit GnRH secretion into media [312 +/- 73, 850 +/- 150, 963 +/- 304, and 912 +/- 74 pg GnRH/4 x 10(6) cells for antisense, sense, missense, and no oligo(dN), respectively; P < 0. 029 for antisense oligo(dN)-treated vs. normal cells]. No changes in intracellular synthesis of GnRH were noted [1,400 +/- 371 and 1,395 +/- 384 pg GnRH/4 x 10(6) cells for antisense and sense oligo(dN), respectively]. Antisense oligo(dN), but not sense or missense oligo(dN), inhibited cAMP-dependent 36Cl efflux. The expression of CFTR protein, detected by Western blotting, was also inhibited 68% by preincubation of cells with antisense oligo(dN). GT1-7 hypothalamic neurons express the CFTR gene, mRNA, and protein, which modulate neurosecretion. Abnormal neuropeptide vesicle trafficking by mutant CFTR may help to explain some of the diverse manifestations of cystic fibrosis.The American journal of physiology 09/1999; 277(3 Pt 1):C563-71. -
Article: Prostaglandin F2alpha stimulates CFTR activity by PKA- and PKC-dependent phosphorylation.
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ABSTRACT: The cystic fibrosis transmembrane conductance regulator (CFTR) can be activated by protein kinase A (PKA)- or protein kinase C (PKC)-dependent phosphorylation. To understand how activation of both kinases affects CFTR activity, transfected NIH/3T3 cells were stimulated with forskolin (FSK), phorbol myristate acetate (PMA), or prostaglandin F2alpha (PGF). PGF stimulates inositol trisphosphate and cAMP production in NIH/3T3 cells. As measured by I- efflux, maximal CFTR activity with PGF and FSK was equivalent and fivefold greater than that with PMA. Both PGF and PMA had additive effects on FSK-dependent CFTR activity. PMA did not increase cellular cAMP, and maximal PGF-dependent CFTR activity occurred with approximately 20% of the cellular cAMP observed with FSK-dependent activation. Staurosporine, but not H-89, inhibited CFTR activation and in vivo phosphorylation at low PGF concentrations. In contrast, at high PGF concentrations, CFTR activation and in vivo phosphorylation were inhibited by H-89. As judged by protease digestion, the sites of in vivo CFTR phosphorylation with FSK and PMA differed. For PGF, the data were most consistent with in vivo CFTR phosphorylation by PKA and PKC. Our data suggest that activation of PKC can enhance PKA-dependent CFTR activation.The American journal of physiology 10/1998; 275(3 Pt 1):C653-60.
