Dietary docosahexaenoic acid but not arachidonic acid influences central nervous system fatty acid status in baboon neonates

The influence of dietary docosahexaenoic acid (DHA, 22:6n-3) and arachidonic acid (AA, 20:4n-6) on infant central nervous system (CNS) composition has implications for neural development, including vision, cognition, and motor function. We consider here combined results of three published studies of DHA/AA-containing formulas and breastfeeding to evaluate the CNS tissue response of baboon neonates with varied concentration and duration of DHA/AA consumption [G.Y. Diau, A.T. Hsieh, E.A. Sarkadi-Nagy, V. Wijendran, P.W. Nathanielsz, J.T. Brenna, The influence of long chain polyunsaturate supplementation on docosahexaenoic acid and arachidonic acid in baboon neonate central nervous system, BMC Med. 3 (2005) 11; A.T. Hsieh, J.C. Anthony, D.A. Diersen-Schade, et al., The influence of moderate and high dietary long chain polyunsaturated fatty acids (LCPUFA) on baboon neonate tissue fatty acids, Pediatr. Res. 61 (2007) 537–45; E. Sarkadi-Nagy, V. Wijendran, G.Y. Diau, et al., The influence of prematurity and long chain polyunsaturate supplementation in 4-week adjusted age baboon neonate brain and related tissues, Pediatr. Res. 54 (2003) 244–252]. A total of 43 neonates born spontaneously at term, or preterm by Cesarean section, consumed diets with DHA–AA (%w/w) at several levels: none (0,0), moderate (0.3, 0.6), or high (>0.6, 0.67 or 1.2). CNS fatty acids were analyzed at 4 and 12 weeks postpartum for term baboons and 7.5 weeks for preterm neonates. CNS DHA was consistently greater by 5–30% in neonates consuming DHA and nearer 30% for cortex. In contrast, CNS AA was unaffected by dietary AA and decreased in all structures with age. Dietary DHA consistently supports greater CNS DHA and maintenance of cortex DHA concentration with feeding duration, while CNS AA is not related to dietary supply. These data on structure-specific LCPUFA accretion may provide insight into neural mechanisms responsible for suboptimal functional outcomes in infants consuming diets that do not support the highest tissue DHA levels.     

Heart arachidonic acid is uniquely sensitive to dietary arachidonic acid and docosahexaenoic acid content in domestic piglets

This study determined the sensitivity of heart and brain arachidonic acid (ARA) and docosahexaenoic acid (DHA) to the dietary ARA level in a dose–response design with constant, high DHA in neonatal piglets. On day 3 of age, pigs were assigned to 1 of 6 dietary formulas varying in ARA/DHA as follows (% fatty acid, FA/FA): (A1) 0.1/1.0; (A2) 0.53/1.0; (A3–D3) 0.69/1.0; (A4) 1.1/1.0; (D2) 0.67/0.62; and (D1) 0.66/0.33. At necropsy (day 28) higher levels of dietary ARA were associated with increased heart and liver ARA, while brain ARA remained unaffected. Dietary ARA had no effect on tissue DHA accretion. Heart was particularly sensitive, with pigs in the intermediate groups having different ARA (A2, 18.6±0.7%; A3, 19.4±1.0%) and a 0.17% increase in dietary ARA resulted in a 0.84% increase in heart ARA. Further investigations are warranted to determine the clinical significance of heart ARA status in developing neonates.     

A New Labyrinthulid Isolate That Produces Only Docosahexaenoic Acid

We show here that a new labyrinthulid strain, L72, isolated from a fallen leaf in the Seto Inland Sea of Japan, produced only docohexaenoic acid (DHA) among all the long-chain polyunsaturated fatty acids (LCPUFAs). The main fatty acid composition was 16:0 (28.9%), 18:0 (7.2%), 18:1 (5.7%), 18:2 (10.4%), and DHA (45.9%) without any other LCPUFA. The lipid content of the strain was 27.4%. The cells had many lipid bodies, which were densely located in all of the cells. On phylogenetic analysis using the 18S rDNA sequence, the strain was located in the labyrinthulids group, forming a monophyletic group with Labyrinthula sp. (strain s) and Labyrinthuila sp. (strain L59). We further tested the culture optimization of strain L72 to evaluate the ability of the strain to produce DHA. The optimum salt concentration and the temperature of the strain were 100% of artificial seawater and 20°C. Strain L72 could grow well on soybean oil (SBO) or soybean lecithin (SBL) as the carbon source. When 20 g/l of SBL was added to the medium, DHA production reached the maximum amount at 0.67 g/l for 14 d. The two important facts, that the strain can use SBL as the main nutrient and contains only DHA among the LCPUFAs, will be of great advantage for industry.     

Formula feeding potentiates docosahexaenoic and arachidonic acid biosynthesis in term and preterm baboon neonates

Infant formulas supplemented with docosahexaenoic acid (DHA) and arachidonic acid (ARA) are now available in the United States; however, little is known about the factors that affect biosynthesis. Baboon neonates were assigned to one of four treatments: term, breast-fed; term, formula-fed; preterm (155 of 182 days gestation), formula-fed; and preterm, formula+DHA/ARA-fed. Standard formula had no DHA/ARA; supplemented formula had 0.61%wt DHA (0.3% of calories) and 1.21%wt ARA (0.6% of calories), and baboon breast milk contained 0.68 +/- 0.22%wt DHA and 0.62 +/- 0.12%wt ARA. At 14 days adjusted age, neonates received a combined oral dose of [U-13C]alpha-linolenic acid (LNA*) and [U-13C]linoleic acid (LA*), and tissues were analyzed 14 days after dose. Brain accretion of linolenic acid-derived DHA was approximately 3-fold greater for the formula groups than for the breast-fed group, and dietary DHA partially attenuated excess DHA synthesis among preterms. A similar, significant pattern was found in other organs. Brain linoleic acid-derived ARA accretion was significantly greater in the unsupplemented term group but not in the preterm groups compared with the breast-fed group. These data show that formula potentiates the biosynthesis/accretion of DHA/ARA in term and preterm neonates compared with breast-fed neonates and that the inclusion of DHA/ARA in preterm formula partially restores DHA/ARA biosynthesis to lower, breast-fed levels. Current formula DHA concentrations are inadequate to normalize long-chain polyunsaturated fatty acids synthesis to that of breast-fed levels.     

Toward optimizing vision and cognition in term infants by dietary docosahexaenoic and arachidonic acid supplementation: A review of randomized controlled trials

The question of whether a dietary supply of docosahexaenoic acid (DHA) and arachidonic acid (ARA) imparts advantages to visual or cognitive development in term infants has been debated for many years. DHA and ARA are present in human milk, and nursing infants consume these fatty acids needed for rapid synthesis of cell membranes, particularly neural cells. The reported mean DHA and ARA levels of human milk worldwide are 0.32% and 0.47% of total fatty acids, respectively. Prior to 2002 in the US, formula-fed infants did not receive these fatty acids and relied solely on endogenous conversion of the dietary essential omega-3 (n-3) and omega-6 (n-6) fatty acids, α-linolenic and linoleic acids, to DHA and ARA, respectively. Formula-fed infants were found to have significantly less accretion of DHA in brain cortex after death than breastfed infants. Numerous studies have found positive correlations between blood DHA levels and improvements in cognitive or visual function outcomes of breastfed and formula-fed infants. Results of randomized controlled clinical trials of term formula-fed infants evaluating functional benefits of dietary DHA and ARA have been mixed, likely due to study design heterogeneity. A comparison of visual and cognitive outcomes in these trials suggests that dietary DHA level is particularly relevant. Trials with formulas providing close to the worldwide human milk mean of 0.32% DHA were more likely to yield functional benefits attributable to DHA. We agree with several expert groups in recommending that infants receive at least 0.3% DHA, with at least 0.3% ARA, in infant feedings; in addition, some clinical evidence suggests that an ARA:DHA ratio greater than 1:1 is associated with improved cognitive outcomes.     

Chronic dietary n-6 PUFA deprivation leads to conservation of arachidonic acid and more rapid loss of DHA in rat brain phospholipids

To determine how the level of dietary n-6 PUFA affects the rate of loss of arachidonic acid (ARA) and DHA in brain phospholipids, male rats were fed either a deprived or adequate n-6 PUFA diet for 15 weeks postweaning, and then subjected to an intracerebroventricular infusion of ³H-ARA or ³H-DHA. Brains were collected at fixed times over 128 days to determine half-lives and the rates of loss from brain phospholipids (J_out). Compared with the adequate n-6 PUFA rats, the deprived n-6-PUFA rats had a 15% lower concentration of ARA and an 18% higher concentration of DHA in their brain total phospholipids. Loss half-lives of ARA in brain total phospholipids and fractions (except phosphatidylserine) were longer in the deprived n-6 PUFA rats, whereas the J_out was decreased. In the deprived versus adequate n-6 PUFA rats, the J_out of DHA was higher. In conclusion, chronic n-6 PUFA deprivation decreases the rate of loss of ARA and increases the rate of loss of DHA in brain phospholipids. Thus, a low n-6 PUFA diet can be used to target brain ARA and DHA metabolism.     

Dietary conjugated linoleic acid alters long chain polyunsaturated fatty acid metabolism in brain and liver of neonatal pigs

Effects of dietary conjugated linoleic acid (CLA, 1% mixed isomers) on n-6 long-chain polyunsaturated fatty acid (LCPUFA) oxidation and biosynthesis were investigated in liver and brain tissues of neonatal piglets. Fatty acid β-oxidation was measured in tissue homogenates using [1-¹⁴C]linoleic acid (LA) and -arachidonic acid (ARA) substrates, while fatty acid desaturation and elongation were traced using [U-¹³C]LA and GC-MS. Dietary CLA had no effect on fatty acid β-oxidation, but significantly decreased n-6 LCPUFA biosynthesis by inhibition of LA elongation and desaturation. Differences were noted between our ¹³C tracer assessment of desaturation/elongation and simple precursor-product indices computed from fatty acid composition data, indicating that caution should be exercised when employing the later. The inhibitory effects of CLA on elongation/desaturation were more pronounced in pigs fed a low fat diet (3% fat) than a high fat diet (25% fat). Direct elongation of linoleic acid to C20:2n-6 via the alternate elongation pathway might play an important role in n-6 LCPUFA synthesis because more than 40% of the synthetic products of [U-¹³C]LA accumulated in [¹³C]20:2n-6. Overall, the data show that dietary CLA shifted the distribution of the synthetic products of [U-¹³C]LA between elongation and desaturation in liver and decreased the total synthetic products of [U-¹³C]LA in brain by inhibiting LA elongation to C20:2n-6. The impact of CLA on brain LCPUFA metabolism of the developing neonate merits consideration and further investigation.     

Correlations between blood and tissue omega-3 LCPUFA status following dietary ALA intervention in rats

The aim of this study was to assess relationships between the fatty acid contents of plasma and erythrocyte phospholipids and those in liver, heart, brain, kidney and quadriceps muscle in rats. To obtain a wide range of tissue omega-3 (n-3) long chain polyunsaturated fatty acids (LCPUFA) we subjected weanling rats to dietary treatment with the n-3 LCPUFA precursor, alpha linolenic acid (ALA, 18:3 n-3) for 3 weeks. With the exception of the brain, we found strong and consistent correlations between the total n-3 LCPUFA fatty acid content of both plasma and erythrocyte phospholipids with fatty acid levels in all tissues. The relationships between eicosapentaenoic acid (EPA, 20:5 n-3) and docosapentaenoic acid (DPA, 22:5 n-3) content in both blood fractions with levels in liver, kidney, heart and quadriceps muscle phospholipids were stronger than those for docosahexaenoic acid (DHA, 22:6 n-3). The strong correlations between the EPA+DHA (the Omega-3 Index), total n-3 LCPUFA and total n-3 PUFA contents in both plasma and erythrocyte phospholipids and tissues investigated in this study suggest that, under a wide range of n-3 LCPUFA values, plasma and erythrocyte n-3 fatty acid content reflect not only dietary PUFA intakes but also accumulation of endogenously synthesised n-3 LCPUFA, and thus can be used as a reliable surrogate for assessing n-3 status in key peripheral tissues.     

Improved mitochondrial function with diet-induced increase in either docosahexaenoic acid or arachidonic acid in membrane phospholipids

Mitochondria can depolarize and trigger cell death through the opening of the mitochondrial permeability transition pore (MPTP). We recently showed that an increase in the long chain n3 polyunsaturated fatty acids (PUFA) docosahexaenoic acid (DHA; 22:6n3) and depletion of the n6 PUFA arachidonic acid (ARA; 20:4n6) in mitochondrial membranes is associated with a greater Ca(2+) load required to induce MPTP opening. Here we manipulated mitochondrial phospholipid composition by supplementing the diet with DHA, ARA or combined DHA+ARA in rats for 10 weeks. There were no effects on cardiac function, or respiration of isolated mitochondria. Analysis of mitochondrial phospholipids showed DHA supplementation increased DHA and displaced ARA in mitochondrial membranes, while supplementation with ARA or DHA+ARA increased ARA and depleted linoleic acid (18:2n6). Phospholipid analysis revealed a similar pattern, particularly in cardiolipin. Tetralinoleoyl cardiolipin was depleted by 80% with ARA or DHA+ARA supplementation, with linoleic acid side chains replaced by ARA. Both the DHA and ARA groups had delayed Ca(2+)-induced MPTP opening, but the DHA+ARA group was similar to the control diet. In conclusion, alterations in mitochondria membrane phospholipid fatty acid composition caused by dietary DHA or ARA was associated with a greater cumulative Ca(2+) load required to induced MPTP opening. Further, high levels of tetralinoleoyl cardiolipin were not essential for normal mitochondrial function if replaced with very-long chain n3 or n6 PUFAs.     

n-6 and n-3 Long-chain polyunsaturated fatty acids in the erythrocyte membrane of Brazilian preterm and term neonates and their mothers at delivery

Placental transfer of the long-chain polyunsaturated fatty acids (LCPUFA) arachidonic (AA) and docosahexaenoic (DHA) acids is selectively high to maintain accretion to fetal tissues, especially the brain. The objectives of the present study were to investigate the essential fatty acid (EFA) and LCPUFA status at birth of preterm and term Brazilian infants and their mothers, from a population of characteristically low intake of n-3 LCPUFA, and to evaluate the association between fetal and maternal status, by the determination of the fatty acid composition of the erythrocyte membrane. Blood samples from umbilical cord of preterm (26-36 weeks of gestation; n = 30) and term (37-42 weeks of gestation; n = 30) infants and the corresponding maternal venous blood were collected at delivery. The LCPUFA composition of the erythrocyte membrane and DHA status were similar for mothers of preterm and term infants. Neonatal AA was higher (P < 0.01) whereas its precursor 18:2n-6 was lower (P < 0.01) than maternal levels, as expected. There was no difference in LCPUFA erythrocyte composition between preterm and term infants, except for DHA. Term infants presented a worse DHA status than preterm infants (P < 0.01) and than their mothers (P < 0.01) at delivery. There was a negative correlation of neonatal DHA with maternal AA and a positive correlation between neonatal AA and maternal AA and 18:2n-6 only at term. These results suggest that the persistent low DHA maternal status, together with the comparatively better AA and 18:2n-6 status, might have affected maternal-fetal transfer of DHA when gestation was completed up to term, and possibly contributed to the worse DHA status of term neonates compared with the preterm neonates.     

Expression of E-FABP in PC12 cells increases neurite extension during differentiation: involvement of n-3 and n-6 fatty acids

Epidermal fatty acid-binding protein (E-FABP), a member of the family of FABPs, exhibits a robust expression in neurons during axonal growth in development and in nerve regeneration following nerve injury. This study examines the impact of E-FABP expression in normal neurite extension in differentiating pheochromocytoma cell (PC12) cultures supplemented with selected long chain free fatty acids (LCFFA). We found that E-FABP binds to a broad range of saturated and unsaturated LCFFAs, including those with potential interest for neuronal differentiation and axonal growth such as C22:6n-3 docosahexaenoic acid (DHA), C20:5n-3 eicosapentaenoic acid (EPA), and C20:4n-6 arachidonic acid (ARA). PC12 cells exposed to nerve growth factor (NGFDPC12) exhibit high E-FABP expression that is blocked by mitogen-activated protein kinase kinase (MEK) inhibitor U0126. Nerve growth factor-differentiated pheochromocytoma cells (NGFDPC12) antisense clones (NGFDPC12-AS) which exhibit low E-FABP expression have fewer/shorter neurites than cells transfected with vector only or NGFDPC12 sense cells (NGFDPC12-S). Replenishing NGFDPC12-AS cells with biotinylated recombinant E-FABP (biotin-E-FABP) protein restores normal neurite outgrowth. Cellular localization of biotin-E-FABP in NGFDPC12 was detected mostly in the cytoplasm and in the nuclear region. Treatment of NGFDPC12 with DHA, EPA, or ARA further enhances neurite length but it does not trigger further induction of TrkA or MEK phosphorylation or E-FABP mRNA observed in differentiating PC12 cells without LCFFA supplementation. Significantly, DHA and EPA neurite stimulating effects are higher in NGFDPC12-S than in NGFDPC12-AS cells. These findings are consistent with the scenario that neurite extension of differentiating PC12 cells, including further stimulation by DHA and EPA, requires sufficient cellular levels of E-FABP.     

Dietary supplementation with docosahexaenoic acid, but not eicosapentaenoic acid, dramatically alters cardiac mitochondrial phospholipid fatty acid composition and prevents permeability transition

Treatment with the ω-3 polyunsaturated fatty acids (PUFAs) docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) exerts cardioprotective effects, and suppresses Ca²⁺-induced opening of the mitochondrial permeability transition pore (MPTP). These effects are associated with increased DHA and EPA, and lower arachidonic acid (ARA) in cardiac phospholipids. While clinical studies suggest the triglyceride lowering effects of DHA and EPA are equivalent, little is known about the independent effects of DHA and EPA on mitochondria function. We compared the effects of dietary supplementation with the ω-3 PUFAs DHA and EPA on cardiac mitochondrial phospholipid fatty acid composition and Ca²⁺-induced MPTP opening. Rats were fed a standard lab diet with either normal low levels of ω-3 PUFA, or DHA or EPA at 2.5% of energy intake for 8 weeks, and cardiac mitochondria were isolated and analyzed for Ca²⁺-induced MPTP opening and phospholipid fatty acyl composition. DHA supplementation increased both DHA and EPA and decreased ARA in mitochondrial phospholipid, and significantly delayed MPTP opening as assessed by increased Ca²⁺ retention capacity and decreased Ca²⁺-induced mitochondria swelling. EPA supplementation increased EPA in mitochondrial phospholipids, but did not affect DHA, only modestly lowered ARA, and did not affect MPTP opening. In summary, dietary supplementation with DHA but not EPA, profoundly altered mitochondrial phospholipid fatty acid composition and delayed Ca²⁺-induced MPTP opening.     

Biochemical effects of supplemented long-chain polyunsaturated fatty acids in hyperphenylalaninemia

Hyperphenylalaninemic (HPA) children display low levels of long-chain polyunsaturated fatty acids (LCPUFA), particularly docosahexaenoic acid (DHA), in circulating lipids and erythrocytes. We have investigated the effects on the blood fatty acid status and lipid picture of a balanced supplementation with LCPUFA in HPA children through a double-blind, placebo-controlled trial. A total of 20 well-controlled HPA, school-age children were randomized to receive through a 12-month trial fat capsules supplying either 26% fatty acid as LCPUFA (including 4.6%gamma -linolenic acid, 7.4% arachidonic acid, AA, 5.5% eicosapentaenoic acid and 8% DHA) or placebo (olive oil). The study supplementation was administered in order to provide 0.3-0.5% of the individual daily energy requirements as LCPUFA. Reference data were obtained from healthy children of comparable age. Among HPA children (whose DHA status was poor at baseline), those supplemented with LCPUFA showed an increase of around 100% in the baseline DHA levels in plasma phospholipids and erythrocytes. No changes of AA levels were observed. Blood lipid levels did not significantly change. A balanced supplementation with LCPUFA in treated HPA children may improve the DHA status without adversely affecting the AA status.     

Long-chain n−3 polyunsaturated fatty acid production by members of the marine protistan group the thraustochytrids: screening of isolates and optimisation of docosahexaenoic acid production

Following an isolation programme for thraustochytrids (marine fungoid protists) from three different locations, 57 isolates were screened for biomass, oil and docosahexaenoic acid production (DHA). Although a common fatty acid profile for the thraustochytrid isolates emerged, there was considerable variation in the DHA content of the oil. In some isolates from a cold temperate environment, DHA represented almost 50% of the total fatty acids present. Although isolates from a sub-tropical environment produced higher levels of biomass, with up to 37% (w/w) oil, the DHA fraction of the fatty acids was low. Cool temperate isolates gave intermediate values. Studies to optimise biomass and DHA production by manipulation of growth medium composition were carried out on a tropical strain. Results indicated that medium with a high C:N ratio stimulated DHA production. The use of such media in bioreactor cultivations gave maximum biomass, lipid and DHA content of 14 g l⁻¹, 78 and 25% (w/w), respectively. Optimum DHA production was 2.17 g l⁻¹ after 107 h cultivation.     

Effect of arachidonic, eicosapentaenoic and docosahexaenoic acids on the oxidative status of C6 glioma cells

n-3 polyunsaturated fatty acids (PUFAs) have been described to have beneficial effects on brain development and in the prevention and treatment of brain damage. C6 glioma cells were incubated with 100 microM of either C20:4n-6 (ARA), or C20:5n-3 (EPA), or C22:6n-3 (DHA) for different time periods to assess whether these acids altered the cellular oxidative state. The ARA and EPA were promptly metabolised to C22:4n-6 and C22:5n-3, respectively, whereas DHA treatment simply increased the amount of DHA in the cells. Cell viability was not affected by ARA, while a cytotoxic effect was observed 72 h after n-3 PUFAs supplementation. The levels of reactive oxygen species and thiobarbituric acid-reactive substances were significantly higher in DHA-treated cells than in EPA- and ARA-treated groups. This modification in the oxidative cellular status was also highlighted by a significant increase in catalase activity and a decrease in glutathione content in DHA-supplemented cells. Glucose-6-phosphate dehydrogenase activity, an enzyme involved in redox regulation, and O2*- release were significantly increased both in EPA and DHA groups. The effect of DHA was more severe than that of EPA. No significant changes were observed in the ARA group with respect to untreated cells. These data show that EPA and DHA induce alterations in the oxidative status that could affect the glial function.     

Reduced levels of placental long chain polyunsaturated fatty acids in preterm deliveries

Reports suggest that the placenta in preterm birth may provide clues to predicting the risk of individuals developing chronic diseases in later life. Placental delivery of long chain polyunsaturated fatty acids (LCPUFA) (constituents of the cell membrane and precursors of prostaglandins) is essential for the optimal development of the central nervous system of the fetus. The present study examines the levels of LCPUFA and their association with placental weight and birth outcome in 58 women delivering preterm and 44 women delivering at term. Docosahexaenoic acid (DHA) and arachidonic acid (ARA) levels were lower (p<0.01) in women delivering preterm. There was a positive association of placental DHA with placental weight (p=0.036) and nervonic acid with head circumference (p=0.040) in the preterm group. Altered placental LCPUFA status exists in Indian mothers delivering preterm, which may influence the birth outcome.     

Dietary alpha-linolenic acid does not enhance accumulation of omega-3 long-chain polyunsaturated fatty acids in barramundi (Lates calcarifer)

This study examined the effects of substituting fish oil and fish meal with a blend of alpha-linolenic acid (ALA, 18:3 n ? 3) rich vegetable oils (14%, w/w) and defatted poultry meal (34%, w/w) in a formulated diet, on growth and tissue fatty acid profiles in barramundi fingerlings. Results indicated that on average, while the ALA levels of the barramundi liver and fillet increased with increasing dietary ALA, there was no corresponding increase in the levels of the omega-3 (n ? 3) long chain polyunsaturated fatty acid (LCPUFA). Compared to fish consuming a commercial feed, which contained fish meal and fish oil, fish on the ALA diets grew slower, had a lower feed intake and lower n ? 3 LCPUFA levels in the tissues. Hepatic mRNA expression of Δ6 desaturase (FADS2) and elongase (ELOVL5/2) was ~ 10 fold and ~ 3 fold higher, respectively, in all the ALA dietary groups, relative to those fed the commercial feed. However, the level of expression of the two genes was not different between fish fed differing ALA levels. These data demonstrate that increasing the ALA level of the diet is not an appropriate strategy for replacing marine sources of n ? 3 LCPUFA in barramundi. It was also noted, however, that within the different ALA dietary groups there was a large amount of variation between individual fish in their tissue DHA levels, suggesting a significant heterogeneity in their capacity for conversion of ALA and/or retention of n ? 3 LCPUFA. When dietary ALA intakes were greater than 0.8% en, tissue DHA levels were inversely related to ALA intake, suggesting that high intake of dietary ALA may inhibit DHA synthesis.     

Neonatal lamb vigour is improved by feeding docosahexaenoic acid in the form of algal biomass during late gestation

To determine whether feeding a sustainable, algal source of docosahexaenoic acid (DHA) to sheep during late pregnancy would improve neonatal lamb vigour, 48 English mule ewes, of known conception date, were divided into four treatment groups. For the last 9 weeks of gestation, ewes received one of two dietary supplements: either a DHA-rich algal biomass providing 12 g DHA/ewe per day, or a control supplement based on vegetable oil. The four dietary treatment groups (n = 12) were: control supplement for the duration of the trial (C), DHA supplement from 9 to 6 weeks before parturition (3 week), DHA supplement from 9 to 3 weeks before parturition (6 week) and DHA supplement for the duration of the trial (9 week). Dietary supplements were fed alongside grass silage and commercial concentrate. There was a tendency for gestation length to be extended with increased duration of DHA supplementation (P = 0.08). After parturition, the concentrations of eicosapentaenoic acid (EPA) and DHA in ewe and lamb plasma and colostrum were elevated in line with increased periods of DHA supplementation. Lambs from the 6-week and 9-week groups stood significantly sooner after birth than lambs from the C group (P < 0.05). These data show that neonatal vigour may be improved by the supplementation of maternal diets with DHA-rich algal biomass and that this beneficial effect depends upon the timing and/or duration of DHA allocation.     

Early intake of long-chain polyunsaturated fatty acids preserves brain structure and function in diet-induced obesity

Worldwide, the incidence of obesity is increasing at an alarming rate, and the number of children with obesity is especially worrisome. These developments raise concerns about the physical, psychosocial and cognitive consequences of obesity. It was shown that early dietary intake of arachidonic acid (ARA) and docosahexaenoic acid (DHA) can reduce the detrimental effects of later obesogenic feeding on lipid metabolism and adipogenesis in an animal model of mild obesity. In the present study, the effects of early dietary ARA and DHA on cognition and brain structure were examined in mildly obesogenic ApoE*3Leiden mouse model. We used cognitive tests and neuroimaging during early and later life. During their early development after weaning (4–13 weeks of age), mice were fed a chow diet or ARA and DHA diet for 8 weeks and then switched to a high-fat and high-carbohydrate (HFHC) diet for 12 weeks (14–26 weeks of age). An HFHC-diet led to increased energy storage in white adipose tissue, increased cholesterol levels, decreased triglycerides levels, increased cerebral blood flow and decreased functional connectivity between brain regions as well as cerebrovascular and gray matter integrity. ARA and DHA intake reduced the HFHC-diet-induced increase in body weight, attenuated plasma triglycerides levels and improved cerebrovasculature, gray matter integrity and functional connectivity in later life. In conclusion, an HFHC diet causes adverse structural brain and metabolic adaptations, most of which can be averted by dietary ARA and DHA intake early in life supporting metabolic flexibility and cerebral integrity later in life.