Higher Docosahexaenoic Acid Intake Research Articles

Effects of DHA Supplementation on Hippocampal Volume and Cognitive Function in Older Adults with Mild Cognitive Impairment: A 12-Month Randomized, Double-Blind, Placebo-Controlled Trial.

Docosahexaenoic acid (DHA) is important for brain function, and higher DHA intake is inversely correlated with relative risk of Alzheimer's disease. The potential benefits of DHA supplementation in people with mild cognitive impairment (MCI) have not been fully examined. Our study aimed to determine the effect of DHA supplementation on cognitive function and hippocampal atrophy in elderly subjects with MCI. This was a randomized, double-blind, placebo-controlled trial in Tianjin, China. 240 individuals with MCI aged 65 years and over were recruited and equalized randomly allocated to the DHA or the placebo group. Participants received 12-month DHA supplementation (2 g/day) or corn oil as placebo. Both global and specific subdomains of cognitive function and hippocampal volume were measured at baseline, 6 months, and 12 months. Both changes were analyzed by repeated-measure analysis of variance (ANOVA). This trial has been registered: ChiCTR-IOR-15006058. A total of 219 participants (DHA: 110, Placebo: 109) completed the trial. The change in mean serum DHA levels was greater in the intervention group (+3.85%) compared to the control group (+1.06%). Repeated-measures analyses of covariance showed that, over 12 months, there was a significant difference in the Full-Scale Intelligence Quotient (ηp2 = 0.084; p = 0.039), Information (ηp2 = 0.439; p = 0.000), and Digit Span (ηp2 = 0.375; p = 0.000) between DHA-treated versus the placebo group. In addition, there were significant differences in volumes of left hippocampus (ηp2 = 0.121, p = 0.016), right hippocampus (ηp2 = 0.757, p = 0.008), total hippocampus (ηp2 = 0.124, p = 0.023), and global cerebrum (ηp2 = 0.145, p = 0.032) between the two groups. These findings suggest that DHA supplementation (2 g/day) for 12 months in MCI subjects can significantly improve cognitive function and slow the progression of hippocampal atrophy. Larger, longer-term confirmatory studies are warranted.

High DHA dosage from algae oil improves postprandial hypertriglyceridemia and is safe for type-2 diabetics

Postprandial refers to diet induced changes in plasma concentrations of sugars, amino acids and fats be- tween 0 and 6 h following a meal. This review details the fat transport through lipoprotein particles and triglyceride frac- tions in the postprandial plasma. The long-chain omega-3 fatty acid docosahexaenoic acid (DHA) is more active in postprandial plasma and is more abundantly incorporated into the surface phospholipid fraction of lipoproteins. A survey of controlled clinical trials in the literature demon- strates that 1,000 mg to 2,000 mg DHA daily is effective to treat hypertriglyceridemia (HTG), mixed dyslipidemia and most effectively controls elevated postprandial triglycerides (TG). TG is a marker for total fat in circulation. Omega-3 fatty acids lower fasting and postprandial TG, an activity first discovered in 1971 in Greenlandic Inuits. Low TG and high DHA were coincident with the absence of type 2 diabetes. It is now known that DHA is the major structural and functional omega-3 component of lipoproteins in hu- man plasma. DHA is the omega-3 to most substantially increase by mass in the phospholipid fraction of very low- density lipoproteins (VLDL), low density lipoproteins (LDL) and high density lipoproteins (HDL). DHA is most effective at raising HDL levels and improves the omega-3 index in red blood cells (RBC). DHA intake also correlates with greater than 25 % reductions of fasting TG and greater than 40 % reductions in postprandial TG. Postprandial HTG is common in the type 2 diabetes; therefore, we considered the safety of DHA from Schizochytrium sp. algae oil and the evidence for risk reduction of coronary vascular disease (CVD) and type 2 diabetes. Recent clinical trials suggest high DHA intake from Chromista algae controls plasma TG, but does not appear to control glucocentric markers or cholesterol levels. DHA directly affects postprandial TG transport, but has little effect on insulin function and insulin resistance. Applications for use in South Asian diabetics are considered. 1,200 mg algae DHA daily over 3 months is an optimized program for direct control of postprandial HTG and is safe for type 2 diabetics.

Abstract 3757: PTGS1 and PTGS2 polymorphisms, fatty acid intake, and risk of colon and rectal cancer

Abstract Introduction: Inflammation plays a major role in colorectal cancer. COX-1 and COX-2 convert n-3 and n-6 fatty acids into prostaglandins which have anti- and pro-inflammatory effects, respectively. We examined potential interactions between polymorphisms in PTGS1 (COX-1) and PTGS2 (COX-2) and fat and fatty acid (FA) intake in relation to colon and rectal cancer risk. Methods: A linkage-disequilibrium-based tagSNP-selection algorithm (r2=0.90, MAF=4%) identified tagSNPs in PTGS1 and PTGS2. We genotyped 16 SNPs in PTGS1 and 17 SNPs in PTGS2 on the same Illumina platform in two independent study populations (colon cancer: 1502 cases, 1862 controls; rectal cancer 713 cases, 914 controls). We investigated potential interactions with intake of total fat, saturated FA (SFA), monounsaturated FA (MUFA), polyunsaturated FA (PUFA), arachidonic acid (AA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) on risk of colon or rectal cancer. Results: We observed several statistically significant interactions between PTGS1 and PTGS2 genotypes and fat and FA intake (Table). However, few interactions were consistent across fat variables and fell into three general categories of associations: a) individuals with the variant allele and low intake of total fat, SFA, or MUFA were at increased risk for rectal cancer (PTGS1 rs10306122-G, p int=0.01-0.01; PTGS2 rs4648268-A; p int=0.01-0.02); b) individuals with the variant allele and high EPA and DHA intake were less likely to develop colon cancer (PTGS1 rs10306110-G, p int=0.003-0.006); and c) individuals with the wildtype genotype and high EPA and DHA intake had stronger protection from colon cancer (PTGS2 rs4648310-A, p int=0.01-0.05). No interactions were observed for AA. Conclusion: Our study provides some evidence that genetic variability in PTGS1 and PTGS2 and intake of total fat, SFA, or MUFA and EPA or DHA may interact in causing rectal and colon cancer, respectively. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3757. doi:10.1158/1538-7445.AM2011-3757

Cognitive and Cardiovascular Benefits of Docosahexaenoic Acid in Aging and Cognitive Decline

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.

Beneficial effects of docosahexaenoic acid on cognition in age-related cognitive decline

Background 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. Objective Determine effects of DHA administration on improving cognitive functions in healthy older adults with ARCD. Methods 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. Results 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. Conclusions 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. Trial Registration Clinicaltrials.gov, Identifier: NCT0027813.

Intake of very long chain n‐3 fatty acids from fish and the incidence of heart failure: the Rotterdam Study

Evidence is accumulating for a cardioprotective effect of fish or its n-3 fatty acids, eicosapentaenoic acid (EPA) plus docosahexaenoic acid (DHA). We examined EPA plus DHA and fish intake in relation to incident heart failure in the population-based Rotterdam Study. The analysis comprised 5299 subjects (41% men, age approximately 68 years) free from heart failure for whom dietary data were available. During 11.4 years of follow-up, 669 subjects developed heart failure. The relative risk (RR) of heart failure in the top vs. bottom quintile of EPA plus DHA intake was 0.89 (95% CI 0.69-1.14), after adjustment for lifestyle and dietary factors. For fish intakes > or = 20 g/day, the RR was 0.96 (0.78-1.18) compared with no fish intake. In sex-specific analysis, a high EPA plus DHA intake tended to be protective in women (RR = 0.75, 0.54-1.04) but not in men (RR = 1.00, 0.73-1.36). An inverse association for EPA plus DHA was also observed in diabetics (RR = 0.58, 0.32-1.06), which was borderline statistically significant. Our findings do not support a major role for fish intake in the prevention of heart failure. The potentially protective effect of EPA plus DHA in diabetic patients, however, warrants further investigation.

Does eating particular diets alter the risk of age-related macular degeneration in users of the Age-Related Eye Disease Study supplements?

Background:Recent information suggests that the Age-Related Eye Disease Study (AREDS) supplement, enhanced intake of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), and reducing dietary glycaemic index (dGI) are protective against...

Fish Consumption, Allergic Sensitisation and Allergic Diseases in Adults

Background: Previous studies have suggested that fish intake plays a protective role in the development of allergic diseases because of its high content of n-3 very long chain polyunsaturated fatty acid (VLC-PUFA). However, it is not clear whether fish intake also has a beneficial effect in adulthood, when allergic diseases are thought to be predominantly manifested. Methods: Data from 388 adults from German study centres within the European Community Respiratory Health Study II were analysed. These subjects completed an extensive interviewer-administered questionnaire as well as a food frequency questionnaire, lung function measurement and blood drawing for specific IgE testing at the study centre. Results: Allergic sensitisation (RAST ≥2) was negatively associated with high fish consumption (adjusted OR 0.20, 95% CI 0.05–0.83) and high docosahexaenoic acid (DHA) intake (adjusted OR 0.26, 95% CI 0.07–0.95) in females but not in males when comparing the fourth quartile with the first quartile of intake. No other outcome was related to fish or DHA consumption. Conclusions: The findings of this study suggest that adult females with a high fish and DHA intake have a lower rate of allergic sensitisation. It is not understood why this association was only seen in females, but gender-related differences in metabolism of PUFAs could be a possible explanation.

Intake of specific carotenoids and essential fatty acids and breast cancer risk in Montreal, Canada

Evidence from previous investigations into the possible role of dietary and serum carotenoid concentrations in the etiology of breast cancer is inconsistent. No study has examined the combined effect of carotenoids and essential fatty acids on the risk of breast cancer. The objective was to assess the possible association between specific and total carotenoids and breast cancer risk and to evaluate the effect modification by diet-related fatty acids and lifestyle factors in the development of breast cancer. A population-based case-control study involving 414 incident cases and 429 controls was conducted in French Canadians in Montreal. Dietary intake was estimated with the use of a validated food-frequency questionnaire in face-to-face interviews. No significant association was apparent between any of the individual or total carotenoids and the risk of breast cancer after adjustment for major underlying determinants of breast cancer. In premenopausal women who ever smoked, an increased risk was related to alpha-carotene [odds ratio (OR) for the upper relative to the lowest quartiles of intake: 2.40; 95% CI: 0.90, 6.41; P for trend = 0.046]. Conversely, a reduced risk was related to beta-carotene (OR: 0.57; 95% CI: 0.26, 1.24; P for trend = 0.05) in women who never used hormone replacement therapy. In postmenopausal women, total carotenoids were positively associated with breast cancer risk in those with a high arachidonic acid intake (OR: 1.92; 95% CI: 0.93, 3.94; P = 0.028 for trend) and inversely associated in those with a high docosahexaenoic acid intake (OR: 0.52; 95% CI: 0.25, 1.07; P for trend = 0.054). These findings suggest that the combined high intake of total carotenoids and docosahexaenoic acid may reduce the risk of breast cancer.

A randomized trial of docosahexaenoic acid supplementation during the third trimester of pregnancy

Objective To hypothesize that higher intake of docosahexaenoic acid, an n-3 long chain polyunsaturated fatty acid, would increase duration of gestation and birth weight in US women. Methods This was a randomized, double-blind, controlled, clinical trial. Subjects were enrolled in an ambulatory clinic where they received prenatal care. This was a population-based sample. Most subjects received government assistance for medical care and most were black (73%). Subjects were enrolled between the 24th and 28th week of pregnancy and consumed docosahexaenoic acid (33 or 133 mg) from eggs until parturition. Gestational age and birth weight were the main study outcomes. Infant length and head circumference, preterm birth, and low birth weight were secondary outcomes. Results Eighty-three percent of subjects completed the study (291 of 350 enrolled). No subject was discontinued for an adverse event. After controlling for important predefined risk factors and confounding variables, gestation increased by 6.0 ± 2.3 days ( P = .009) in the higher docosahexaenoic acid group. Birth weight, length, and head circumference increased, but did not reach statistical significance ( P = .06–.18), although the increases could be clinically important indications of enhanced intrauterine growth. No safety concerns were raised by the study. Conclusion Duration of gestation increased significantly when docosahexaenoic acid intake was increased during the last trimester of pregnancy. The increase in gestation was similar to that reported for interventions with much larger amounts of n-3 long chain polyunsaturated fatty acids.