Dietary fish oil increases lipid mobilization but does not decrease lipid storage-related enzyme activities in adipose tissue of insulin-resistant, sucrose-fed rats

Maternal and neonatal red blood cell n-3 polyunsaturated fatty acids inversely associate with infant whole-body fat mass assessed by dual-energy X-ray absorptiometry

Research regarding polyunsaturated fatty acid (PUFA) status and body composition in neonates is limited. This study tested the relationship between newborn docosahexaenoic acid (DHA) status and body composition. Healthy mothers and their term-born infants (n = 100) were studied within 1 month postpartum for anthropometry and whole-body composition using dual-energy X-ray absorptiometry. Maternal and infant red blood cell (RBC) membrane PUFA profiles were measured using gas chromatography (expressed as percentage of total fatty acids). Data were grouped according to infant RBC DHA quartiles and tested for differences in n-3 status and infant body composition using mixed-model ANOVA, Spearman correlations, and regression analyses (P < 0.05). Mothers were 32.2 ± 4.6 years (mean ± SD) of age, infants (54% males) were 0.68 ± 0.23 month of age, and 80% exclusively breastfed. Infant RBC DHA (ranged 3.96% to 7.75% of total fatty acids) inversely associated with infant fat mass (r = -0.22, P = 0.03). Infant and maternal RBC n-6/n-3 PUFA ratio (r² = 0.28, P = 0.043; r² = 0.28, P = 0.041 respectively) were positively associated with fat mass. These results demonstrate that both maternal and infant long-chain PUFA status are associated with neonatal body composition. Novelty Our findings support an early window to further explore the relationship between infant n-3 PUFA status and body composition. Maternal and infant n-3 PUFA status is inversely related to neonatal whole-body fat mass. DHA appears to be the best candidate to test in the development of a lean body phenotype.

Differential Anti-Adipogenic Effects of Eicosapentaenoic and Docosahexaenoic Acids in Obesity

SCOPE

To assess the associations of plasma eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) with body fat in a population-based sample and explore the mechanism of action based on browning of white adipose tissue (WAT) in high-fat-diet-induced obese (DIO) mice and 3T3-L1 adipocytes.

METHODS AND RESULTS

Plasma EPA and DHA of 1719 adults in the National Health and Nutrition Examination Survey (2003-2004) are determined by gas chromatography mass spectrometry, while total body fat is measured by dual-energy X-ray absorptiometry. DIO mice are fed a high-fat diet supplemented with EPA or DHA (1% wt/wt) for 15 weeks and 3T3-L1 preadipocytes are treated with EPA or DHA during differentiation. Plasma DHA but not EPA is associated with lower body fat mass (p_trend < 0.0001), which persists in overweight/obese subjects (p_trend = 0.02). DHA supplementation reduces inguinal WAT and exhibits a more pronounced thermogenic effect than EPA in DIO mice. In vitro, the browning process is induced after 2-day and 6-day treatment with DHA and EPA, respectively.

CONCLUSION

Plasma DHA but not EPA is inversely associated with body fat mass. The more potent anti-adipogenic effect of DHA than EPA may involve a better capability of inducing browning of WAT for DHA.

Dietary fish oil ameliorates adipose tissue dysfunction in insulin-resistant rats fed a sucrose-rich diet improving oxidative stress, peroxisome proliferator-activated receptor γ and uncoupling protein 2

This work aims to assess the possible beneficial effects of dietary fish oil (FO) on the pre-existing adipose tissue dysfunction through the improvement or reversion of the mechanisms underlying oxidative stress and pro-inflammatory cytokines in dyslipemic insulin-resistant rats. Wistar rats were fed a sucrose rich diet (SRD) for 6 months. After that half of the animals continued with the SRD until month 8 while in the other half corn oil was replaced by FO for 2 months (SRD + FO). A reference group consumed a control diet all the time. In an epididymal fat pad, we analyzed antioxidant and oxidant enzyme activities, ROS content, glutathione redox state, the protein level of peroxisome proliferator-activated receptor gamma (PPARγ) and the expression and protein levels of uncoupling protein 2 (UCP2) as well as oxidative stress biomarkers and TNF-α and IL-6 plasma levels. Besides these, insulin sensitivity and the composition of fatty acid phospholipids of adipose tissue were measured. Compared with the SRD the SRD + FO fed group showed a decrease of fat pad weight and the antioxidant and oxidant enzyme activities and ROS content returned to control values along with normal plasma TNF-α and IL-6 levels. FO normalized both the decrease of PPARγ protein and the increase of protein and expression of UCP2. Furthermore, FO increased the n-3/n-6 fatty acid ratio in the adipose tissue phospholipids and normalized dyslipidemia and insulin resistance. Finally, these findings reinforce the view that dietary FO may exert a beneficial effect in ameliorating the dyslipidemia and insulin resistance in this animal model.

Long-Chain Omega-3 Polyunsaturated Fatty Acids Modulate Mammary Gland Composition and Inflammation

Studies in rodents have shown that dietary modifications as mammary glands (MG) develop, regulates susceptibility to mammary tumor initiation. However, the effects of dietary PUFA composition on MGs in adult life, remains poorly understood. This study investigated morphological alterations and inflammatory microenvironments in the MGs of adult mice fed isocaloric and isolipidic liquid diets with varying compositions of omega (ω)-6 and long-chain (Lc)-ω3FA that were pair-fed. Despite similar consumption levels of the diets, mice fed the ω-3 diet had significantly lower body-weight gains, and abdominal-fat and mammary fat pad (MFP) weights. Fatty acid analysis showed significantly higher levels of Lc-ω-3FAs in the MFPs of mice on the ω-3 diet, while in the MFPs from the ω-6 group, Lc-ω-3FAs were undetectable. Our study revealed that MGs from ω-3 group had a significantly lower ductal end-point density, branching density, an absence of ductal sprouts, a thinner ductal stroma, fewer proliferating epithelial cells and a lower transcription levels of estrogen receptor 1 and amphiregulin. An analysis of the MFP and abdominal-fat showed significantly smaller adipocytes in the ω-3 group, which was accompanied by lower transcription levels of leptin, IGF1, and IGF1R. Further, MFPs from the ω-3 group had significantly decreased numbers and sizes of crown-like-structures (CLS), F4/80+ macrophages and decreased expression of proinflammatory mediators including Ptgs2, IL6, CCL2, TNFα, NFκB, and IFNγ. Together, these results support dietary Lc-ω-3FA regulation of MG structure and density and adipose tissue inflammation with the potential for dietary Lc-ω-3FA to decrease the risk of mammary gland tumor formation.

A practical guide for induction of type-2 diabetes in rat: Incorporating a high-fat diet and streptozotocin

Prevalence of diabetes, a serious public health problem is rapidly increasing worldwide. Type-2 diabetes is the common form of diabetes characterized by insulin resistance and abnormalities in insulin production. Despite the current development of therapeutic agents, there is no effective treatment without side effects; it is therefore necessary to find new prevention strategies and better treatments. For this purpose animal models of diabetes are appropriate tools, of which rodents due to the short generation time and economic considerations are the first choice. The aim of this review is to present features of a frequently used model of type-2 diabetes in rat, induced by a high fat diet and streptozotocin, taking into account its advantages/disadvantages and presenting a practical guide.

EPA prevents fat mass expansion and metabolic disturbances in mice fed with a Western diet

The impact of alpha linolenic acid (ALA), EPA, and DHA on obesity and metabolic complications was studied in mice fed a high-fat, high-sucrose (HF) diet. HF diets were supplemented with ALA, EPA, or DHA (1% w/w) and given to C57BL/6J mice for 16 weeks and to Ob/Ob mice for 6 weeks. In C57BL/6J mice, EPA reduced plasma cholesterol (-20%), limited fat mass accumulation (-23%) and adipose cell hypertrophy (-50%), and reduced plasma leptin concentration (-60%) compared with HF-fed mice. Furthermore, mice supplemented with EPA exhibited a higher insulin sensitivity (+24%) and glucose tolerance (+20%) compared with HF-fed mice. Similar effects were observed in EPA-supplemented Ob/Ob mice, although fat mass accumulation was not prevented. By contrast, in comparison with HF-fed mice, DHA did not prevent fat mass accumulation, increased plasma leptin concentration (+128%) in C57BL/6J mice, and did not improve glucose homeostasis in C57BL/6J and Ob/Ob mice. In 3T3-L1 adipocytes, DHA stimulated leptin expression whereas EPA induced adiponectin expression, suggesting that improved leptin/adiponectin balance may contribute to the protective effect of EPA. In conclusion, supplementation with EPA, but not ALA and DHA, could preserve glucose homeostasis in an obesogenic environment and limit fat mass accumulation in the early stage of weight gain.

Acetylated and propionated derivatives of swertiamarin have anti-adipogenic effects

Objective:

To investigate whether the acetylated and propionated derivatives (LMP-09-1 and -2) of swertiamarin have anti-adipogenic effects.

Materials and Methods:

3T3-L1 pre-adipocytes were grown in Dulbecco's Modified Eagle's Medium (DMEM) containing 10% calf serum; fully confluent cells were differentiated with insulin, dexamethasone, and 3-isobutylmethylxanthine in the presence and absence of LMP-09-1 and -2 (100 μg/mL) for 10 days. Control cells received same amount of dimethylsulfoxide (DMSO). On day ten, cells were analyzed for triglycerides accumulation and the expression of genes involved in adipogenesis, lipogenesis, and lipolysis. In another set of experiment, effects of LMP-09-1 and 2 were studied for isoproterenol induced lipolysis using fully mature adipocytes.

Results:

LMP-09-1 and -2 caused a significant (P < 0.001) reduction in intracellular triglycerides accumulation. Both LMP-09-1 and -2 significantly (P < 0.001) decreased the mRNA expression of peroxisome proliferator activated receptor-γ and acetyl-CoA carboxylase-1, and increased isoproterenol induced lipolysis in adipocytes. LMP-09-1 induced lipolysis even in the absence of isoproterenol, and also showed a significant up-regulation of carnitine palmitoyl transferase-1α and hormone sensitive lipase (HSL) gene expression.

Conclusions:

These findings show that swertiamarin derivatives, LMP-09-1 and -2 have a potent anti-adipogenic effect.

N-3 polyunsaturated fatty acids, body fat and inflammation

BACKGROUND

Based on animal studies, n-3 polyunsaturated fatty acids (PUFAs) have been suggested to lower the risk of obesity and inflammation. We aimed to investigate if, among humans, intake of n-3 PUFAs was associated with i) total body fat, ii) body fat distribution and iii) obesity-related inflammatory markers.

METHODS

The study population consisted of 1,212 healthy individuals with information on habitual food intake from food frequency questionnaires, six different measures of body fat, and levels of six circulating inflammatory markers. Multiple linear regression analysis of intakes of PUFAs in relation to outcomes were performed and adjusted for potential confounders.

RESULTS

Absolute n-3 PUFA intake, but not n-3/n-6, was inversely associated with the different measures of body fat. Among n-3 PUFA derivatives, only α-linolenic acid (ALA) was inversely associated with body fat measures. No significant interactions with the dietary macronutrient composition were observed. Pro-inflammatory cytokines were not associated with absolute PUFA intake, but the macrophage inflammatory protein-1α (MIP-1α) was associated with the n-3/n-6 ratio.

CONCLUSION

In humans, intake of n-3 PUFAs, in particular ALA, is beneficially associated with body fatness. The favourable association is, however, not reflected in systemic levels of pro-inflammatory cytokines, nor is it influenced by macronutrients in the diet.

ω-3 polyunsaturated fatty acid supplementation does not influence body composition, insulin resistance, and lipemia in women with type 2 diabetes and obesity

To evaluate the influence of ω-3 polyunsaturated fatty acid (ω-3 PUFA) supplementation on body composition, insulin resistance, and lipemia of women with type 2 diabetes, the authors evaluated 41 women (60.64 ± 7.82 years) with high blood pressure and diabetes mellitus in a randomized and single-blind longitudinal intervention study. The women were divided into 3 groups: GA (2.5 g/d fish oil), GB (1.5 g/d fish oil), and GC (control). The capsules with the supplement contained 21.9% of eicosapentaenoic acid and 14.1% of docosapentaenoic acid. Biochemical (glucose, glycated hemoglobin, total and fractional cholesterol, triglycerides, and insulin) and anthropometric (body mass, stature, waist circumference [WC], and body composition) evaluations were performed before and after the 30 days of intervention. Homeostasis model assessment-insulin resistance and the Quantitative Insulin Sensitivity Check Index were used to evaluate the insulin resistance and insulin sensitivity (IS), respectively. GB presented a greater loss of body mass and WC (P < .05), greater frequency of glycemic and total cholesterol reduction, and an increase of high-density lipoprotein cholesterol compared with GA. Thus, a high dose of ω-3 PUFA can reduce IS. A lower dose of ω-3 PUFA positively influenced body composition and lipid metabolism.

Eicosapentaenoic acid increases lipolysis through up-regulation of the lipolytic gene expression and down-regulation of the adipogenic gene expression in 3T3-L1 adipocytes

In this study, we investigated the lipolytic effects of eicosapentaenoic acid (EPA) in 3T3-L1 adipocytes. The differentiated 3T3-L1 adipocytes were treated in a serum-free medium with 300 muM of EPA for 3, 6, 12, and 24 h. In comparison with the control, intracellular lipid accumulation was significantly decreased by 24% at 24 h following the addition of EPA (P < 0.05). Under the same experimental conditions, there was an increase of glycerol and free fatty acids (FFAs). The mRNA level of carnitine palmitoyltransferase I-a, a component of the fatty-acid shuttle system involved in the mitochondrial oxidation of long-chain fatty acids, was also significantly elevated by EPA (P < 0.05). However, the expression of peroxisome proliferator-activated receptor-gamma and acetyl-CoA carboxylase (ACC), which are involved in adipogenesis, was significantly down-regulated by EPA (P < 0.05). These results suggest that EPA may modulate lipid metabolism by stimulation of lipolysis, which was associated with induction of lipolytic gene expression and suppression of adipogenic gene expression in 3T3-L1 adipocytes.

The role of adipose tissue in mediating the beneficial effects of dietary fish oil

Fish oil improves several features of metabolic syndrome (MetS), such as dyslipidemia, insulin resistance and hepatic steatosis. Fish oil may mediate some of its beneficial effects by modulating the storage and/or secretory functions of adipose tissue (AT). The storage of triglycerides in AT is regulated by the availability of free fatty acids and the degree of lipolysis in AT. Fish oil has been shown to reduce lipolysis in several studies, indicating improved triglyceride storage. Importantly, AT secretes a variety of adipokines and fish oil feeding is associated with remarkable changes in the plasma levels of two key adipokines, adiponectin and leptin. Much attention has been focused on the contribution of adiponectin in fish oil-mediated improvements in MetS. However, emerging evidence also indicates a role of leptin in modulating the components of the MetS upon fish oil feeding. In addition to improving the storage and secretory functions of AT, fish oil, and the n-3 fatty acids found in fish oil, has been shown to reduce inflammation in AT. These effects may be in part a result of activation of peroxisome proliferator-activated receptor γ or inhibition of Toll-like receptor 4. Thus, there is compelling evidence that fish oil mediates its beneficial effects on MetS by improving AT storage and secretory functions and by reducing inflammation.

Lipogenic enzyme activities and glucose uptake in fat tissue of dyslipemic, insulin-resistant rats: effects of fish oil

OBJECTIVE

The purposes of the present work were twofold: (1) investigate same mechanisms involved in the development of fat cell hypertrophy in the experimental model of dyslipidemia and whole-body insulin resistance induced in rats chronically fed a sucrose-rich diet (SRD); and (2) analyze the possible beneficial effect of fish oil on these mechanisms.

METHODS

For 6 mo, male Wistar rats received a sucrose-rich diet (62.5% w/w sucrose, 8% corn oil) or a control diet in which sucrose was replaced by starch. After this period, the sucrose-fed animals were divided randomly into two groups: the first one continued with the same diet up to 8 mo and the second one received the same diet, but with corn oil replaced by 7% fish oil+1 % corn oil. Rats were fed with this diet for the next 2 mo.

RESULTS

Although an enlarged fat cell lipolysis and an impaired insulin-stimulated glucose uptake were present in the fat cells of SRD-fed rats, an increase of several key enzymes of the novo lipogenesis could be one of the possible mechanisms involved in visceral adiposity. The addition of dietary fish oil restored or improved the above abnormalities.

CONCLUSION

This study shows possible mechanisms conditioning the influence of nutrients on the development and management of dyslipidemia, insulin sensitivity, and fat cell accretion, all abnormalities present in the metabolic syndrome.

Down-regulation in muscle and liver lipogenic genes: EPA ethyl ester treatment in lean and overweight (high-fat-fed) rats

The precise mechanisms by which omega-3 fatty acids improve fat metabolism are not completely understood. This study was designed to determine the effects of eicosapentaenoic acid (EPA) ethyl ester administration on the expression levels of several muscle, liver and adipose tissue genes involved in lipogenesis and fatty acid oxidation pathways. Male Wistar rats fed a standard diet (control animals) or a high-fat diet were treated daily by oral gavage with EPA ethyl ester (1g/kg) for 5 weeks. The high-fat diet caused a very significant increase in plasma cholesterol (P<.01) levels, which was reverted by EPA (P<.001). A significant decrease in circulating triglyceride levels (P<.05) was also observed in EPA-treated groups. EPA administration induced a significant down-regulation in some lipogenic genes such as muscle acetyl CoA carboxylase beta (ACC beta) (P<.05) and liver fatty acid synthase (FAS) (P<.05). Furthermore, a decrease in glucokinase (GK) gene expression was observed in EPA-treated animals fed a control diet (P<.01), whereas a significant increase in GK mRNA levels was found in groups fed a high-fat diet. On the other hand, no alterations in genes involved in beta-oxidation, such acetyl CoA synthase 4 (ACS4), acetyl CoA synthase 5 (ACS5) or acetyl CoA oxidase (ACO), were found in EPA-treated groups. Surprisingly and opposite to the expectations, a very significant decrease in the expression levels of liver PPARalpha (P<.01) was observed after EPA treatment. These findings show the ability of EPA ethyl ester treatment to down-regulate some genes involved in fatty acid synthesis without affecting the transcriptional activation of beta-oxidation-related genes.

Treatment for 2 mo with n 3 polyunsaturated fatty acids reduces adiposity and some atherogenic factors but does not improve insulin sensitivity in women with type 2 diabetes: a randomized controlled study

BACKGROUND

Information is lacking on the potential effect of n-3 polyunsaturated fatty acids (PUFAs) on the adipose tissue of patients with type 2 diabetes.

OBJECTIVE

We evaluated whether n-3 PUFAs have additional effects on adiposity, insulin sensitivity, adipose tissue function (production of adipokines and inflammatory and atherogenic factors), and gene expression in type 2 diabetes.

DESIGN

Twenty-seven women with type 2 diabetes without hypertriglyceridemia were randomly allocated in a double-blind parallel design to 2 mo of 3 g/d of either fish oil (1.8 g n-3 PUFAs) or placebo (paraffin oil).

RESULTS

Although body weight and energy intake measured by use of a food diary were unchanged, total fat mass (P < 0.019) and subcutaneous adipocyte diameter (P < 0.0018) were lower in the fish oil group than in the placebo group. Insulin sensitivity was not significantly different between the 2 groups (measured by homeostasis model assessment in all patients and by euglycemic-hyperinsulinemic clamp in a subgroup of 5 patients per group). By contrast, atherogenic risk factors, including plasma triacylglycerol (P < 0.03), the ratio of triacylglycerol to HDL cholesterol (atherogenic index, P < 0.03), and plasma plasminogen activator inhibitor-1 (P < 0.01), were lower in the fish oil group than in the placebo group. In addition, a subset of inflammation-related genes was reduced in subcutaneous adipose tissue after the fish oil, but not the placebo, treatment.

CONCLUSIONS

A moderate dose of n-3 PUFAs for 2 mo reduced adiposity and atherogenic markers without deterioration of insulin sensitivity in subjects with type 2 diabetes. Some adipose tissue inflammation-related genes were also reduced. These beneficial effects could be linked to morphologic and inflammatory changes in adipose tissue. This trial was registered at clinicaltrials.gov as NCT0037.

A high oxidised frying oil content diet is less adipogenic, but induces glucose intolerance in rodents

Oxidised frying oil (OFO) and fish oil have been shown to be peroxisome proliferator-activated receptor (PPAR)α activators and their ingestion results in pleotropic peroxisome proliferator responses in rats. To examine the effect of dietary OFO on adiposity, four groups of weanling Sprague–Dawley rats were fed isoenergetically with, respectively, a low fat basal diet containing 5 g/100 g of fresh soybean oil (LSB) or a high fat diet containing 20 g/100 g of fresh soybean oil (HSB), OFO (HO) or fish oil (HF). The tissue mass, cell size and lipid/DNA ratio in the retroperitoneal fat pad and serum leptin levels were lowest in the HO group (P < 0·05), indicating that dietary OFO has a greater anti-adipogenic action than dietary fish oil. However, a tendency to hyperglycaemia was observed in the HO group (P = 0·0528). To examine the effect of dietary OFO on glucose tolerance, three groups of rats and three groups of mice were fed, respectively, the LSB, HSB or HO diet, and an oral glucose tolerance test was performed. After oral glucose load, the area under the curve for blood glucose (AUCglu) over 2 h was significantly higher, and that for serum insulin (AUCins) over 90 min was significantly lower, in the HO group than in the other two groups (P < 0·05). These results demonstrate that, in rats and mice, a high OFO diet is less adipogenic, but induces glucose intolerance.

Docosahexaenoic acid inhibits adipocyte differentiation and induces apoptosis in 3T3-L1 preadipocytes

Docosahexaenoic acid (DHA, C22:6), a (n-3) fatty acid in fish oil, has been shown to decrease body fat and fat accumulation in rodents. We investigated the direct effect of DHA on cell growth, differentiation, apoptosis, and lipolysis using 3T3-L1 adipocytes. Cells were treated with 25-200 mumol/L DHA containing 0.2 mmol/L alpha-tocopherol or bovine serum albumin vehicle as a control. Proliferation of preconfluent preadipocytes was not affected by the DHA treatment. When added to postconfluent preadipocytes, all concentrations of DHA inhibited differentiation-associated mitotic clonal expansion (P < 0.01). Postconfluent preadipocytes demonstrated apoptosis after 48 h with 100 mumol/L DHA and after 24 and 48 h with 200 mumol/L DHA (P < 0.01). Differentiation was examined by Oil Red O staining and glycerol-3-phosphate dehydrogenase (GPDH) activity after DHA treatment for 6 d. DHA decreased mean droplet size and percent lipid area in a dose-dependent manner (P < 0.01). GPDH activity was also decreased by DHA treatment (P < 0.01). In fully differentiated adipocytes, DHA increased basal lipolysis compared with the control (P < 0.01). These results demonstrate that DHA may exert its antiobesity effect by inhibiting differentiation to adipocytes, inducing apoptosis in postconfluent preadipocytes and promoting lipolysis.

Effects of dietary polyunsaturated n-3 fatty acids on dyslipidemia and insulin resistance in rodents and humans. A review

For many years, clinical and animal studies on polyunsaturated n-3 fatty acids (PUFAs), especially those from marine oil, eicosapentaenoic acid (20:5,n-3) and docosahexaenoic acid (22:6,n-3), have reported the impact of their beneficial effects on both health and diseases. Among other things, they regulate lipid levels, cardiovascular and immune functions as well as insulin action. Polyunsaturated fatty acids are vital components of the phospholipids of membrane cells and serve as important mediators of the nuclear events governing the specific gene expression involved in lipid and glucose metabolism and adipogenesis. Besides, dietary n-3 PUFAs seem to play an important protecting role against the adverse symptoms of the Plurimetabolic syndrome. This review highlights some recent advances in the understanding of metabolic and molecular mechanisms concerning the effect of dietary PUFAs (fish oil) and focuses on the prevention and/or improvement of dyslipidemia, insulin resistance, impaired glucose homeostasis, diabetes and obesity in experimental animal models, with some extension to humans.

Body composition in preterm infants who are fed long-chain polyunsaturated fatty acids: a prospective, randomized, controlled trial

The objective of this study was to evaluate growth and body composition of premature infants who were fed formulas with arachidonic acid (ARA; 20:4n6) and docosahexaenoic acid (DHA; 22:6n3) to 1 y of gestation-corrected age (CA). Preterm infants (750-1800 g birth weight and <33 wk gestational age) were assigned within 72 h of first enteral feeding to one of three formulas: control (n = 22), DHA+ARA from fish/fungal oil [DHA+ARA(FF); n = 20], or DHA+ARA from egg/fish oil [DHA+ARA(EF); n = 18]. Human milk feeding was allowed on the basis of the mother's choice. Infants were fed breast milk and/or preterm formulas with or without 0.26% DHA and 0.42% ARA to term CA followed by breast milk or postdischarge preterm formulas with or without 0.16% DHA and 0.42% ARA to 12 mo CA. Body composition was measured by dual-energy x-ray absorptiometry. There were no significant differences among the three study groups at any time point in weight, length, or head circumference. Bone mineral content and bone mineral density did not differ among groups. At 12 mo CA, infants who were fed DHA+ARA-supplemented formulas had significantly greater lean body mass (p < 0.05) and significantly less fat mass (p < 0.05) than infants who were fed the unsupplemented control formula. The DHA+ARA-supplemented formulas supported normal growth and bone mineralization in premature infants who were born at <33 wk gestation. Preterm formulas that had DHA+ARA at the levels and ratios in this study and were fed to 1 y CA led to increased lean body mass and reduced fat mass by 1 y of age.