Heart-targeted Prospective Dietary Intervention with Nutrient-dense, Portion-controlled Foods Improves Blood Pressure in Patients with Hypertension (P12-020-19)

Objectives

High blood pressure (BP) is the major risk factor for cardiovascular disease and affects about 50% of adult population in the US. The objective of this preliminary study was to determine the effectiveness of nutrient-dense, portion-controlled foods on BP in patients with hypertension.

Methods

Twenty-one adults (14 females, 7 males) with a medical diagnosis of hypertension (BP > 120/80 mm Hg) were recruited. Subjects consumed three nutrient-dense, portion-controlled foods daily for 8 weeks. The foods included 25–35% of the Daily Value (DV) for all nutrients (including potassium) except for sodium and chloride. All foods were low in added sugar and saturated fats. The foods and a blood pressure monitor were provided free to the participants. Morning BP, body weight, and waist circumference were measured by participants and self-reported weekly. Quality of life was assessed using a validated questionnaire (SF-12), which measured physical (PCS) and mental (MCS) composite scores.

Results

Baseline mean age, BMI and BP of study participants were 58 ± 7 years, 34 ± 6 kg/m2 and 149 ± 22/89 ± 7 mm Hg, respectively. After 8 weeks of the dietary intervention, systolic pressure decreased by 13% to 130 ± 12 mm Hg (P = 0.002) and diastolic pressure decreased by 17% to 74 ± 10 mm Hg (P < 0.001), compared to baseline. Body weight and waist circumference decreased by 4 ± 3 kg (4.5%weight loss, P < 0.001) and 8 ± 6 cm (7% decrease, P < 0.001), respectively, after 8 weeks compared to baseline. Quality of life indicators for PCS and MCS significantly improved (P < 0.05) after 8 weeks of dietary intervention.

Conclusions

BP decreased significantly, weight loss approached a medically significant amount (5%), and quality of life indicators improved after 8 weeks of a dietary intervention with nutrient-dense, portion-controlled foods. The improved systolic BP reported in this preliminary study is comparable to reported efficacy of the DASH diet intervention. Nutrient-dense meals may help hypertensive patients lower blood pressure and body weight, but further research is needed to confirm these preliminary findings.

Funding Sources

Nutrient Foods LLC, Reno, Nevada.

Human fetal intestinal epithelial cells metabolize and incorporate branched chain fatty acids in a structure specific manner

BACKGROUND

Branched chain fatty acids (BCFA) are constituents of gastrointestinal (GI) tract in healthy newborn human infants, reduce the incidence of necrotizing enterocolitis (NEC) in a neonatal rat model, and are incorporated into small intestine cellular lipids in vivo. We hypothesize that BCFA are taken up, metabolized and incorporated into human fetal cells in vitro.

METHODS

Human H4 cells, a fetal non-transformed primary small intestine cell line, were incubated with albumin-bound non-esterified anteiso-17:0, iso-16:0, iso-18:0 and/or iso-20:0, and FA profiles in lipid fractions were analyzed.

RESULTS

All BCFA were readily incorporated as major constituents of cellular lipids. Anteiso-17:0 was preferentially taken up, and was most effective among BCFA tested in displacing normal (n-) FA. The iso BCFA were preferred in reverse order of chain length, with iso-20:0 appearing at lowest level. BCFA incorporation in phospholipids (PL) followed the same order of preference, accumulating 42% of FA as BCFA with no overt morphological signs of cell death. Though cholesterol esters (CE) are at low cellular concentration among lipid classes examined, CE had the greatest affinity for BCFA, accumulating 65% of FA as BCFA. BCFA most effectively displaced lower saturated FA. Iso-16:0, iso-18:0 and anteiso-17:0 were both elongated and chain shortened by ±C2. Iso-20:0 was chain shortened to iso-18:0 and iso-16:0 but not elongated.

CONCLUSIONS

Nontransformed human fetal intestinal epithelial cells incorporate high levels of BCFA when they are available and metabolize them in a structure specific manner. These findings imply that specific pathways for handling BCFA are present in the lumen-facing cells of the human fetal GI tract that is exposed to vernix-derived BCFA in late gestation.

Long-chain polyunsaturated fatty acids attenuate the IL-1β-induced proinflammatory response in human fetal intestinal epithelial cells

BACKGROUND

Evidence suggests that excessive inflammation of the immature intestine may predispose premature infants to necrotizing enterocolitis (NEC). We investigated the anti-inflammatory effects of docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), and arachidonic acid (ARA) in human fetal and adult intestinal epithelial cells (IEC) in primary culture.

METHODS

Human fetal IEC in culture were derived from a healthy fetal small intestine (H4) or resected small intestine of a neonate with NEC (NEC-IEC). Intestinal cell lines Caco2 and NCM460 in culture were used as models for mature IEC. IEC in culture were pretreated with 100 µmol/l palmitic acid (PAL), DHA, EPA, ARA, or ARA+DHA for 48 h and then stimulated with proinflammatory IL-1β.

RESULTS

DHA significantly attenuated IL-1β induced proinflammatory IL-8 and IL-6 protein and mRNA in fetal H4, NEC-IEC, and mature Caco2, NCM460 IEC, compared to control and PAL treatment. DHA downregulated IL-1R1 (IL-1β receptor) and NFk β1 mRNA expression in fetal and adult IEC. ARA had potent anti-inflammatory effects with lower IL-8 and IL-6 (protein and mRNA) in fetal H4 but not in NEC-IEC or adult IEC.

CONCLUSION

The present study provides evidence that DHA and ARA may have important anti-inflammatory functions for prevention of NEC in premature infants.

Toll-like receptor-4 in human and mouse colonic epithelium is developmentally regulated: a possible role in necrotizing enterocolitis

BACKGROUND

Necrotizing enterocolitis (NEC) is an immature intestinal condition resulting in devastating intestinal inflammation due to unknown mechanisms. Evidence has suggested that intestinal maturation attenuates the severity of NEC and Toll-like receptor 4 (TLR4) has been suggested to play a critical role in its pathogenesis. We investigated whether maturational effects of TLR4 expression in immature colon might contribute to the development of NEC.

METHODS

TLR4 colonocyte expression was detected by immunofluorescence confocal microscopy. Interleukin-6 (IL-6) levels were assayed by an enzyme-linked immunosorbent assay (ELISA).

RESULTS

TLR4 expression was high in fetal colonic epithelium in human and mouse, with earlier gestation having a higher surface/cytoplasm distribution. TLR4 remained high in mouse postnatal day 1 but the surface/cytoplasm distribution was reduced. TLR4 decreased in amount and then was expressed in crypts in the mature human and mouse colon. Hydrocortisone (HC) reduced the surface/cytoplasm distribution of TLR4 in human fetal colon. Elevated IL-6 levels in immature colon after lipopolysaccharide were attenuated by HC in human and mouse.

CONCLUSION

Expression, localization, and signaling of TLR4 in colonic epithelium may be developmentally regulated. HC may accelerate the TLR developmental pathway change to an adult type, which may account for its impact on TLR4 signaling.

Dietary arachidonic acid and docosahexaenoic acid regulate liver fatty acid desaturase (FADS) alternative transcript expression in suckling piglets

Molecular regulation of fatty acid desaturase (Fads) gene expression by dietary arachidonic acid (ARA) and docosahexaenoic acid (DHA) during early post-natal period, when the demand for long chain polyunsaturated fatty acids (LC-PUFA) is very high, has not been well defined. The objective of the current study was to determine regulation of liver Fads1, Fads2 and Fads3 classical (CS) and alternative transcripts (AT) expression by dietary ARA and DHA, within the physiological range present in human breast milk, in suckling piglets. Piglets were fed one of six milk replacer formula diets (formula-reared groups, FR) with varying ARA and DHA content from days 3-28 of age. The ARA/DHA levels of the six formula diets were as follows (% total 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. The control maternal-reared (MR) group remained with the dam. Fads1 expression was not significantly different between FR and MR groups. Fads2 expression was down-regulated significantly in diets with 1:1 ratio of ARA:DHA, compared to MR. Fads2 AT1 expression was highly correlated to Fads2 expression. Fads3 AT7 was the only Fads3 transcript sensitive to dietary LC-PUFA intake and was up-regulated in the formula diets with lowest ARA and DHA contents compared to MR. Thus, the present study provides evidence that the proportion of dietary ARA:DHA is a significant determinant of Fads2 expression and LC-PUFA metabolism during the early postnatal period. Further, the data suggest that Fads3 AT7 may have functional significance when dietary supply of ARA and DHA are low during early development.

The influence of long chain polyunsaturate supplementation on docosahexaenoic acid and arachidonic acid in baboon neonate central nervous system

BACKGROUND

Docosahexaenoic acid (DHA) and arachidonic acid (ARA) are major components of the cerebral cortex and visual system, where they play a critical role in neural development. We quantitatively mapped fatty acids in 26 regions of the four-week-old breastfed baboon CNS, and studied the influence of dietary DHA and ARA supplementation and prematurity on CNS DHA and ARA concentrations.

METHODS

Baboons were randomized into a breastfed (B) and four formula-fed groups: term, no DHA/ARA (T-); term, DHA/ARA supplemented (T+); preterm, no DHA/ARA (P-); preterm and DHA/ARA supplemented (P+). At four weeks adjusted age, brains were dissected and total fatty acids analyzed by gas chromatography and mass spectrometry.

RESULTS

DHA and ARA are rich in many more structures than previously reported. They are most concentrated in structures local to the brain stem and diencephalon, particularly the basal ganglia, limbic regions, thalamus and midbrain, and comparatively lower in white matter. Dietary supplementation increased DHA in all structures but had little influence on ARA concentrations. Supplementation restored DHA concentrations to levels of breastfed neonates in all regions except the cerebral cortex and cerebellum. Prematurity per se did not exert a strong influence on DHA or ARA concentrations.

CONCLUSION

1) DHA and ARA are found in high concentration throughout the primate CNS, particularly in gray matter such as basal ganglia; 2) DHA concentrations drop across most CNS structures in neonates consuming formulas with no DHA, but ARA levels are relatively immune to ARA in the diet; 3) supplementation of infant formula is effective at restoring DHA concentration in structures other than the cerebral cortex. These results will be useful as a guide to future investigations of CNS function in the absence of dietary DHA and ARA.

Free phytosterols facilitate excretion of endogenous cholesterol in gerbils

To determine whether phytosterols (PST) facilitate excretion of whole body cholesterol and whether dietary fat or enhancing gallbladder contraction with curcumin might influence this process, four experiments were conducted in gerbils. In Experiment 1, naive gerbils received cholesterol-free purified diets with 30% energy from fat and 0% or 0.75% free PST from tall oil for 4 weeks. In Experiment 2, body cholesterol pools were expanded by feeding a diet containing 0.3% cholesterol for 3 weeks. Subsequently, PST was provided in either fat-free or normal-fat diets without cholesterol for only 2 h each morning, followed by a low-fat diet for the rest of the day and food restriction overnight. In Experiment 3, gerbils were preloaded with cholesterol, followed by either PST alone or PST+curcumin to enhance gallbladder contraction. In Experiment 4, curcumin or curcumin+PST were fed with 30% as fat and 0.15% cholesterol throughout the study. Because of the small whole body cholesterol pool in Experiment 1, the impact of PST was limited. When whole body cholesterol was expanded in Experiments 2 and 3, subsequent reductions of liver esterified cholesterol by PST were significant. In the presence of dietary fat, PST caused a greater reduction (23%) than in a fat-free diet (8%) compared to respective controls. Curcumin (Experiments 3 and 4) proved ineffective in reducing liver or plasma cholesterol pools, and the 3:1 ratio between PST/diet cholesterol was less effective at blocking cholesterol absorption than a 5:1 ratio previously employed. Thus, free PST removed whole body cholesterol, which was enhanced by concomitant fat intake, but was unaffected by a gallbladder contracting agent.

Dietary n-6 and n-3 fatty acid balance and cardiovascular health

Epidemiological and clinical studies have established that the n-6 fatty acid, linoleic acid (LA), and the n-3 fatty acids, linolenic acid (LNA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) collectively protect against coronary heart disease (CHD). LA is the major dietary fatty acid regulating low-density lipoprotein (LDL)-C metabolism by downregulating LDL-C production and enhancing its clearance. Further, the available mass of LA is a critical factor determining the hyperlipemic effects of other dietary fat components, such as saturated and trans fatty acids, as well as cholesterol. By contrast, n-3 fatty acids, especially EPA and DHA, are potent antiarryhthmic agents. EPA and DHA also improve vascular endothelial function and help lower blood pressure, platelet sensitivity, and the serum triglyceride level. The distinct functions of these two families make the balance between dietary n-6 and n-3 fatty acids an important consideration influencing cardiovascular health. Based on published literature describing practical dietary intakes, we suggest that consumption of ~6% en LA, 0.75% en LNA, and 0.25% en EPA + DHA represents adequate and achievable intakes for most healthy adults. This corresponds to an n-6/n-3 ratio of ~6:1. However, the absolute mass of essential fatty acids consumed, rather than their n-6/n-3 ratio, should be the first consideration when contemplating lifelong dietary habits affecting cardiovascular benefit from their intake.

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.

Dietary trans-18:1 raises plasma triglycerides and VLDL cholesterol when replacing either 16:0 or 18:0 in gerbils

To compare the relative impact of trans-18:1 with the two main dietary saturated fatty acids it replaces, plasma lipid response was assessed in Mongolian gerbils fed diets rich in 16:0 (24%en),18:0 (10%en), or trans-18:1 (4 or 6%en). The diets were designed such that the 18:0-rich diet substituted 7%en as 18:0 for 16:0, whereas 4%en and 6%en from trans-18:1 was substituted for 16:0 in the two trans diets. The control group was fed a diet formulated according to the fatty acid balance of American Heart Association (AHA), but provided 40%en as fat. Gerbils (n = 10 per dietary group) were fed one of the five diets for 8 weeks. The control diet, with 4 times the polyunsaturated fatty acids (PUFA) content and a P:S ratio about 10 times greater than the test diets, resulted in the lowest plasma TC, LDL cholesterol (LDL-C) and VLDL cholesterol (VLDL-C). Among the test diets, plasma TC and TG were lowest with the 18:0-rich diet. TC in gerbils fed the 16:0-rich diet and 4%en-trans were 20% higher than the 18:0-rich diet, while the 6%en-trans diet was 35% higher. VLDL-C was significantly higher in the 6%en-trans diet compared to all other groups at 8 weeks. Both trans fatty acid diets elevated plasma TG approximately 2- and 3-fold, respectively, compared to the 16:0-rich and 18:0-rich diets at 8 weeks. Further, plasma TG continued to rise over time with trans fatty acids compared to 16:0 or 18:0. Thus, in the fatty acid-sensitive gerbil, impaired TG metabolism represents a major aspect of the hyperlipemia caused by trans fatty acid substitution for major saturated fatty acids.

Docosahexaenoic and Arachidonic Acid Influence on Preterm Baboon Retinal Composition and Function

PURPOSE

Dietary n-3 polyunsaturated fatty acid deficiency and prematurity are both associated with suboptimal visual function in nonhuman primates and in humans. This study reports measurements of retinal long chain polyunsaturate (LCP) concentrations and electroretinogram (ERG) parameters for term and preterm neonatal baboons consuming clinically relevant diets.

METHODS

ERGs and retinal fatty acid compositions were obtained from baboon neonates in four groups: term-delivered/breast-fed (B), term/formula-fed (T-), preterm/formula-fed (P-), and preterm/formula (P+) supplemented with long chain polyunsaturates. Initial a-wave slope change (ä), a-wave amplitude (a(amp)) and implicit time (a(i)), and b-wave amplitude (b(amp)) and implicit time (b(i)) were determined and correlations to retinal fatty acid concentrations were evaluated.

RESULTS

The P+ group ä and b(amp) significantly improved between 0 and 4 weeks' adjusted age, whereas no P- group parameter improved with age. At four weeks, both a(amp) and b(amp) were significantly greater in group B than in all other groups, and ä and a(i) were greater for P+ than for P-. Concentrations of 22:6n-3, 22:5n-3, and Sigman-3 and the 22:5n-6/22:6n-3 ratio correlated positively with improved retinal response parameters, whereas 22:5n-6, 22:4n-6, 20:4n-6, 20:3n-6, 20:2n-9, 20:1n-9, and 18:1n-9 all correlated negatively (P < 0.05); saturates were uncorrelated. The parameters most linearly related to retinal 22:6n-3 were ä, a(i), and a(amp). Retinal 20:4n-6 concentrations were not influenced by prematurity or supplementation.

CONCLUSIONS

Breast-feeding optimizes retinal response in 4-week-old baboons. Formula supplemented with 22:6n-3 prevents a decrease in retinal 22:6n-3 and improves preterm ERG parameters compared with unsupplemented formula. Retinal 22:6n-3 status is most closely associated with a-wave parameters.

The influence of prematurity and long chain polyunsaturate supplementation in 4-week adjusted age baboon neonate brain and related tissues

Clinical studies show that docosahexaenoic acid (DHA) and arachidonic acid (ARA) supplemented formula improve visual function in preterm infants, however improved fatty acid status is known only for plasma and red blood cells (RBC) since target organs cannot be sampled from humans. Baboons were randomized to one of four groups: Term breast-fed (B); Term formula-fed (T-); Preterm formula-fed (P-); and Preterm DHA/ARA-supplemented formula-fed (P+). The P+ contained 0.61 +/- 0.03% DHA and 1.21 +/- 0.09% ARA, and breast milk had 0.68 +/- 0.22% and 0.62 +/- 0.12% as DHA and ARA, respectively. The B and P+ groups had significantly higher DHA concentration in all tissues than T- and P-. The P- group showed dramatically lower DHA content of 35%, 27%, 66%, and 75% in the brain, retina, liver, and plasma, respectively, compared with B. Supplementation prevented declines in DHA levels in the retina, and liver, and attenuated the decline in brain, plasma and RBC of preterm animals. In contrast, ARA was not significantly lower compared with B in any group in any tissue but was significantly elevated in liver and brain. RBC and plasma DHA were correlated with DHA in tissues; RBC/plasma ARA were uncorrelated with tissue ARA. We conclude that 1) DHA drops precipitously in term and preterm primates consuming formula without long chain polyunsaturates, while 22:5n-6 concentration rises; 2) tissue ARA levels are insensitive to dietary LCP supplementation or prematurity, 3) plasma and RBC levels of ARA are uncorrelated with total ARA levels; 4) DHA levels are correlated with group effects and are uncorrelated within groups.

Influence of dietary long-chain PUFA on premature baboon lung FA and dipalmitoyl PC composition

One of the major survival challenges of premature birth is production of lung surfactant. The lipid component of surfactant, dipalmitoyl PC (DPPC), increases in concentration in the period before normal term birth via a net shift in FA composition away from unsaturates. We investigated the influence of dietary DHA and arachidonic acid (AA) on lung FA composition and DPPC concentration in term and preterm baboons. Pregnant animals/neonates were randomized to one of four groups: breast-fed (B), term formula-fed (T-, preterm formula-fed (P-, and preterm fed formula supplemented with DHA-AA (P+). Breast milk contained 0.68%wt DHA and the P+ group formula contained 0.61%wt DHA. In the preterm groups (P- and P+), pregnant females received a course of antenatal corticosteroids. At the adjusted age of 4 wk, neonate lung tissue was harvested, and FA composition and DPPC were analyzed. Palmitate was approximately 28%wt of lung total FA and no significant differences were found among the four treatment groups. In contrast, DPPC in the B group lung tissue was significantly greater than DPPC in the unsupplemented groups, but not compared with the P+ group. The B and P+ groups were not significantly different in DHA and AA, but were different compared with the unsupplemented (T, P-) groups. These results indicate that LCP supplementation increases lung DHA and AA, without compromising overall lung 16:0 or DPPC. The shift in FA composition toward greater unsaturation in the groups consuming LCP supported improved surfactant lipid concentration in preterm neonate lungs.

Free phytosterols effectively reduce plasma and liver cholesterol in gerbils fed cholesterol

The potential of free phytosterols (including 20% stanols) to lower plasma and liver lipids was assessed in three experiments with gerbils fed diets containing cholesterol. The first explored the ability of phytosterols (0.5%) to block absorption of 0.05, 0.10, and 0.5% cholesterol. The second assessed the importance of consuming phytosterols (0.75%) simultaneously with cholesterol (0.15%). The third compared free phytosterols (0.75%) with similar levels of esterified sterols or stanols using diets containing 0.15% cholesterol. A 5:1 ratio of phytosterols:cholesterol effectively blocked cholesterol absorption when the dietary cholesterol load was moderate. Consuming a 5:1 ratio with every meal was more effective than receiving equal phytosterols in a 10:1 ratio every other day. Finally, free phytosterols dissolved in fat were as effective as esterified sterols and stanols in lowering plasma and liver cholesterol, and all were equally effective at blocking cholesterol absorption as shown by increased fecal cholesterol output. Plant sterol accumulation in the liver was minimal for all test groups.

Parenteral infusion of a lactating woman with intralipid: changes in milk and plasma fatty acids

A nursing woman afflicted with short bowel syndrome received parenteral infusions of Intralipid. In the morning following 2 nights of infusion, samples of milk and blood were taken; additional samples were taken the morning after 1 and 2 nights of no infusion. The fatty acid composition of these samples was determined by gas chromatography. The Intralipid infusion contained 51.5% linoleic acid (C18:2). The C18:2 content of the milk was highest (14%) after each infusion and dropped to about 10% on days 1 and 2. Inverse changes were seen in stearic acid (C18:0). The C18:2 content of the plasma showed little change, remaining at about 23%. These results provide further direct evidence that the composition of milk fatty acids can be influenced by changes in the composition of external sources of fatty acids to the lactating mother.

Significant utilization of dietary arachidonic acid is for brain adrenic acid in baboon neonates

Dietary arachidonic acid (20:4n-6) utilization in-vivo for carbon recycling into de-novo lipogenesis and conversion to n-6 long chain polyunsaturates was investigated in baboon neonates using [U-(13)C]20:4n-6. Neonates consuming a formula typical of human milk received a single oral dose of [(13)C]arachidonic acid in sn-2 position of either triglyceride or phosphatidylcholine at 18-19 days of postnatal life. Neonate brain, retina, liver, and plasma were obtained 10 days later (28-29 days of life). Low isotopic enrichment (0.27-1.0%Total label) was detected in dihomo-gamma-linolenic acid (20:3n-6) in all tissues, but label incorporation into saturates or monounsaturates was not detected. In neonate brain and retina, 16% and 11% of total label was recovered in 22:4n-6, respectively. The relative contribution of dietary fatty acids to postnatal brain 22:4n-6 accretion can be estimated for dietary 20:4n-6 and preformed 22:4n-6 as 17% and 8%, respectively, corresponding to efficiencies of 0.48% and 0.54% of dietary levels, respectively. These results demonstrate in term baboon neonates that in vivo 1) 20:4n-6 was retroconverted to 20:3n-6, 2) 20:4n-6 did not contribute significantly to de novo lipogenesis of saturates and monounsaturates, and 3) the preformed 20:4n-6 contribution to brain 22:4n-6 accumulation was quantitatively a significant metabolic fate for dietary 20:4n-6.

Efficacy of dietary arachidonic acid provided as triglyceride or phospholipid as substrates for brain arachidonic acid accretion in baboon neonates

Arachidonic acid (AA) is a long-chain polyunsaturate (LCP) present in human breast milk as both triglyceride (TG) and as phospholipid (PL). There has been little attention to the metabolic consequences of lipid form of AA in infant formulas. Our objective was to investigate the efficacy of dietary TG and PL as carriers of AA for accretion in the brain and associated organs of term baboon neonates consuming a formula with LCP composition typical of human milk. TG and phosphatidylcholine (PC) with [U-(13)C]-AA in the sn-2 position and with unlabeled 16:0 in the remaining positions (TG-AA* or PL-AA*, respectively) were used as tracers to study the tissue AA* incorporation. Baboon neonates received a single oral dose of either TG-AA* (n = 3) or PL-AA* (n = 4) at 18-19 d of life. Tissues were obtained 10 d later (28-29 d of life) and isotopic enrichment was measured. In the brain, 4.5% of the PL-AA* dose and 2.1% of the TG-AA* dose were recovered as brain AA*, respectively, indicating that PL was about 2.1-fold more effective than TG as a substrate for brain AA accretion. Preferential incorporation of PL-derived AA* over TG source of AA* was also observed in the liver, lung, plasma, and erythrocytes. Because of the quantitative predominance of TG-AA in formula, total brain AA accretion, expressed as absolute weight, was 5.0-fold greater from TG-AA than from PL-AA. We estimate that about half of postnatal brain AA accretion is derived from dietary preformed AA in term baboon neonates consuming a formula with lipid composition similar to that of human milk.

Fetal erythrocyte phospholipid polyunsaturated fatty acids are altered in pregnancy complicated with gestational diabetes mellitus

Insulin resistance and altered maternal metabolism in gestational diabetes mellitus (GDM) may impair fetal arachidonic acid (AA) and docosahexaenoic acid (DHA) status. The objectives were to test the hypothesis that fetal polyunsaturated fatty acids would be altered with GDM and identify factors related to fetal phospholipid (PL) AA and DHA. Maternal and cord vein erythrocyte PL fatty acids were determined in GDM (n = 13) and healthy pregnant women (controls, n = 12). Cord vein erythrocyte PL AA and DHA concentrations were significantly lower in GDM vs. controls. Maternal blood hemoglobin A1C was inversely correlated to fetal erythrocyte PL DHA and AA in controls and GDM (n = 25). Pregravid body mass index was negatively associated with fetal PL DHA. The data support the hypothesis that there is impairment in fetal accretion of DHA and AA in GDM.

Maternal plasma phospholipid polyunsaturated fatty acids in pregnancy with and without gestational diabetes mellitus: relations with maternal factors

BACKGROUND

The fatty acids arachidonic acid (AA; 20:4n-6) and docosahexaenoic acid (DHA; 22:6n-3) are essential for fetal growth and development, but their metabolism may be altered in insulin resistance.

OBJECTIVES

The objectives were to determine maternal plasma phospholipid polyunsaturated fatty acid concentrations in pregnant women receiving dietary therapy for gestational diabetes mellitus (GDM) and to identify maternal factors associated with plasma phospholipid AA and DHA concentrations in the third trimester.

DESIGN

Fasting plasma phospholipid fatty acids were determined in women with GDM (n = 15) receiving dietary therapy only and in healthy, pregnant women without GDM (control group, n = 15) at 27-30, 33-35, and 36-39 wk gestation.

RESULTS

Maternal plasma phospholipid (as % by wt of total fatty acids and mg/L) linoleic acid (18:2n-6), AA, and 22:5n-6 concentrations did not differ significantly between women with GDM and control subjects. The other n-6 long-chain polyunsaturated fatty acids (% by wt) were lower in GDM subjects than in control subjects. Plasma phospholipid (expressed as % by wt and mg/L) linolenic acid (18:3n-3) and summed precursors of DHA were lower and DHA (% by wt and mg/L), adjusted for dietary DHA intake, was 13% higher in GDM subjects than in control subjects. Maternal blood hemoglobin A1C was inversely related to plasma phospholipid AA (% by wt) (r = -0.56, P = 0.03) in control subjects and positively associated with plasma phospholipid AA (% by wt) in women with GDM (r = 0.76, P = 0.001). Pregravid body mass index was negatively associated with plasma phospholipid DHA (% by wt) in control subjects (r = -0.55, P = 0.04) and in women with GDM with a body mass index (in kg/m2) <30 (r = -0.76, P = 0.007).

CONCLUSIONS

This is the first report documenting alterations in maternal plasma phospholipid PUFAs in pregnant women receiving dietary therapy for GDM. In pregnant woman, both with and without GDM, maternal glycemic control and pregravid BMI appear to be significant predictors of plasma phospholipid AA and DHA, respectively, during the third trimester. Additionally, dietary DHA significantly affects phospholipid DHA concentrations.

Maternal and cord plasma lipid and lipoprotein concentrations in women with and without gestational diabetes mellitus. Predictors of birth weight?

OBJECTIVE

To describe lipid and lipoprotein perturbations in gestational diabetes mellitus (GDM) and to examine the potential consequences--e.g, increased birth weight and increased placental lipid transfer.

STUDY DESIGN

Maternal and cord free fatty acids (FFAs) and total, very low density lipoprotein (VLDL), low density lipoprotein (LDL), high density lipoprotein (HDL) (and maternal HDL2 and HDL3), triglyceride (TG), and cholesterol and dietary intake were determined for women with diet-treated GDM and for healthy pregnant women with normal glucose tolerance.

RESULTS

Women with GDM had higher hemoglobin A1c than controls, while body weight gain was significantly lower for women with GDM as compared to controls. Plasma and lipoprotein TG concentrations were greater for women with GDM, and although plasma FFAs were higher in women with GDM versus controls, the difference was not significant. No differences were observed between groups with respect to maternal plasma or lipoprotein cholesterol. Cord plasma and lipoprotein lipids were similar between groups; with the exception of VLDL + LDL TG, which was lower in women with GDM. In controls, there were significant correlations between maternal plasma TG and cord FFAs; maternal HDL2 cholesterol and cord plasma cholesterol; and maternal plasma TG, maternal HDL2 cholesterol, cord FFAs, and infant birth weight. In GDM, maternal plasma cholesterol and cord VLDL + LDL cholesterol correlated. There were no significant correlations between maternal or cord lipids and infant birth weight in women with GDM.

CONCLUSION

Hypertriglyceridemia, rather than hypercholesterolemia, is a feature of GDM. However, elevations in maternal plasma and lipoprotein TGs in women with GDM were not related to fetal lipid concentrations or infant birth weight.