Consumption of Solnul™ Resistant Potato Starch Produces a Prebiotic Effect in a Randomized, Placebo-Controlled Clinical Trial.

The effects of resistant starch at high doses have been well-characterized, but the potential prebiotic effects of resistant starch at doses comparable to oligosaccharide prebiotics have not been evaluated. A three-arm randomized, double-blind, placebo-controlled clinical trial was conducted to evaluate the effect of 3.5 g and 7 g daily doses of Solnul™ resistant potato starch (RPS) on beneficial populations of gut bacteria and stool consistency after a 4-week period. The relative abundance of Bifidobacterium and Akkermansia was determined by employing 16Sv4 sequencing of stool samples. To assess the effect of RPS on laxation and bowel movements, stools were recorded and scored using the Bristol Stool Form Scale. Participants consuming 3.5 g/day of RPS experienced significantly greater changes in Bifidobacterium and Akkermansia compared to the placebo after 4 weeks. The number of diarrhea- and constipation-associated bowel movements were both significantly lower in the 3.5 g RPS arm compared to the placebo group. Participants consuming 7 g of RPS responded similarly to those in the 3.5 g arm. Our analyses demonstrate that Solnul™ RPS has a prebiotic effect when consumed for 4 weeks at the 3.5 g per day dose, stimulating increases in beneficial health-associated bacteria and reducing diarrhea- and constipation-associated bowel movements when compared to the placebo group.

Palmitic acid-rich oils with and without interesterification lower postprandial lipemia and increase atherogenic lipoproteins compared with a MUFA-rich oil: A randomized controlled trial.

BACKGROUND: Interesterified (IE) fats are widely used in place of trans fats; however, little is known about their metabolism. OBJECTIVES: To test the impact of a commonly consumed IE compared with a non-IE equivalent fat on in vivo postprandial and in vitro lipid metabolism, compared with a reference oil [rapeseed oil (RO)]. METHODS: A double-blinded, 3-phase crossover, randomized controlled trial was performed in healthy adults (n = 20) aged 45-75 y. Postprandial plasma triacylglycerol and lipoprotein responses (including stable isotope tracing) to a test meal (50 g fat) were evaluated over 8 h. The test fats were IE 80:20 palm stearin/palm kernel fat, an identical non-IE fat, and RO (control). In vitro, mechanisms of digestion were explored using a dynamic gastric model (DGM). RESULTS: Plasma triacylglycerol 8-h incremental area under the curves were lower following non-IE compared with RO [-1.7 mmol/L⋅h (95% CI: -3.3, -0.0)], but there were no differences between IE and RO or IE and non-IE. LDL particles were smaller following IE and non-IE compared with RO (P = 0.005). Extra extra large, extra large, and large VLDL particle concentrations were higher following IE and non-IE compared with RO at 6-8 h (P < 0.05). No differences in the appearance of [13C]palmitic acid in plasma triacylglycerol were observed between IE and non-IE fats. DGM revealed differences in phase separation of the IE and non-IE meals and delayed release of SFAs compared with RO. CONCLUSIONS: Interesterification did not modify fat digestion, postprandial lipemia, or lipid metabolism measured by stable isotope and DGM analysis. Despite the lower lipemia following the SFA-rich fats, increased proatherogenic large triacylglycerol-rich lipoprotein remnant and small LDL particles following the SFA-rich fats relative to RO adds a new postprandial dimension to the mechanistic evidence linking SFAs to cardiovascular disease risk.

Evaluating the Lipid-Lowering Effects of α-lipoic Acid Supplementation: A Systematic Review.

Dietary supplementation of α-lipoic acid, an 8-carbon organosulfur compound, has been widely reported to lower blood glucose concentration and/or improve insulin sensitivity in previous randomized controlled trials. Although animal model studies further report fairly consistent lipid lowering in both blood and tissue pools in response to α-lipoic acid supplementation, results from human studies are mixed. According to PRISMA guidelines, we conducted a systematic review of published randomized controlled studies (RCTs) to assess the efficacy of α-lipoic acid supplementation as a strategy to improve dyslipidemia, with a focus on serum lipid endpoints including TC, low density lipoprotein cholesterol (LDL-C), HDL-C, and TG. PubMed, EMBASE, Cochrane Evidence-Based Medicine Reviews, Proquest, Web of Science, and Scopus were searched to identify RCTs that reported the effects of α-lipoic acid on blood lipid concentrations from 1970 to 2017. We included RCTs reporting blood lipid responses in adults supplemented with oral α-lipoic acid versus a placebo or control for at least one month. Studies were reviewed and data were extracted by two independent study authors. Seventeen studies were deemed eligible for inclusion. Overall, mean percent changes in blood lipid endpoints in response to α-lipoic acid varied considerably between studies for total cholesterol (-10.5 to +13.9), low-density lipoprotein cholesterol (-19.67 to +9.06), high-density lipoprotein cholesterol (-12.5 to +29.20), and triglycerides (-38.57 to +17.0). Results of this systematic review suggest little consistent benefit on serum lipids in response to α-lipoic acid supplementation. Further well-controlled studies designed and powered to detect improvements in blood lipids in hypercholesterolemic individuals are warranted (PROSPERO registration number: CRD42018105933).

Betaine or folate can equally furnish remethylation to methionine and increase transmethylation in methionine-restricted neonates.

Methionine partitioning between protein turnover and a considerable pool of transmethylation precursors is a critical process in the neonate. Transmethylation yields homocysteine, which is either oxidized to cysteine (i.e., transsulfuration), or is remethylated to methionine by folate- or betaine- (from choline) mediated remethylation pathways. The present investigation quantifies the individual and synergistic importance of folate and betaine for methionine partitioning in neonates. To minimize whole body remethylation, 4-8-d-old piglets were orally fed an otherwise complete diet without remethylation precursors folate, betaine and choline (i.e. methyl-deplete, MD-) (n=18). Dietary methionine was reduced from 0.3 to 0.2 g/(kg∙d) on day-5 to limit methionine availability, and methionine kinetics were assessed during a gastric infusion of [13C1]methionine and [2H3-methyl]methionine. Methionine kinetics were reevaluated 2 d after pigs were rescued with either dietary folate (38 µg/(kg∙d)) (MD + F) (n=6), betaine (235 mg/(kg∙d)) (MD + B) (n=6) or folate and betaine (MD + FB) (n=6). Plasma choline, betaine, dimethylglycine (DMG), folate and cysteine were all diminished or undetectable after 7 d of methyl restriction (P<.05). Post-rescue, plasma betaine and folate concentrations responded to their provision, and homocysteine and glycine concentrations were lower (P<.05). Post-rescue, remethylation and transmethylation rates were~70-80% higher (P<.05), and protein breakdown was spared by 27% (P<.05). However, rescue did not affect transsulfuration (oxidation), plasma methionine, protein synthesis or protein deposition (P>.05). There were no differences among rescue treatments; thus betaine was as effective as folate at furnishing remethylation. Supplemental betaine or folate can furnish the transmethylation requirement during acute protein restriction in the neonate.

Barley ß-glucan reduces blood cholesterol levels via interrupting bile acid metabolism.

Underlying mechanisms responsible for the cholesterol-lowering effect of ß-glucan have been proposed, yet have not been fully demonstrated. The primary aim of this study was to determine whether the consumption of barley ß-glucan lowers cholesterol by affecting the cholesterol absorption, cholesterol synthesis or bile acid synthesis. In addition, this study was aimed to assess whether the underlying mechanisms are related to cholesterol 7α hydroxylase (CYP7A1) SNP rs3808607 as proposed by us earlier. In a controlled, randomised, cross-over study, participants with mild hypercholesterolaemia (n 30) were randomly assigned to receive breakfast containing 3 g high-molecular weight (HMW), 5 g low-molecular weight (LMW), 3 g LMW barley ß-glucan or a control diet, each for 5 weeks. Cholesterol absorption was determined by assessing the enrichment of circulating 13C-cholesterol over 96 h following oral administration; fractional rate of synthesis for cholesterol was assessed by measuring the incorporation rate of 2H derived from deuterium oxide within the body water pool into the erythrocyte cholesterol pool over 24 h; bile acid synthesis was determined by measuring serum 7α-hydroxy-4-cholesten-3-one concentrations. Consumption of 3 g HMW ß-glucan decreased total cholesterol (TC) levels (P=0·029), but did not affect cholesterol absorption (P=0·25) or cholesterol synthesis (P=0·14). Increased bile acid synthesis after consumption of 3 g HMW ß-glucan was observed in all participants (P=0·049), and more pronounced in individuals carrying homozygous G of rs3808607 (P=0·033). In addition, a linear relationship between log (viscosity) of ß-glucan and serum 7α-HC concentration was observed in homozygous G allele carriers. Results indicate that increased bile acid synthesis rather than inhibition of cholesterol absorption or synthesis may be responsible for the cholesterol-lowering effect of barley ß-glucan. The pronounced TC reduction in G allele carriers of rs3808607 observed in the previous study may be due to enhanced bile acid synthesis in response to high-viscosity ß-glucan consumption in those individuals.

Dietary Resistant Starch Supplementation Increases High-Density Lipoprotein Particle Number in Pigs Fed a Western Diet.

Resistant starch (RS) has been well characterized for its glycemic control properties; however, there is little consensus regarding the influence of RS on blood lipid concentrations and lipoprotein distribution and size. Therefore, this study aimed to characterize the effect of daily RS supplementation in a controlled capsule delivery on biomarkers of cardiovascular (blood lipids, lipoproteins) and diabetes (glucose, insulin) risk in a pig model. Twelve 8-week-old male Yorkshire pigs were placed on a synthetic Western diet and randomly divided into two groups (n = 6/group) for 30 days: (1) a placebo group supplemented with capsules containing unmodified pre-gelatinized potato starch (0 g/RS/day); and (2) an RS group supplemented with capsules containing resistant potato starch (10 g/RS/day). Serum lipids including total-cholesterol (C), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and triglycerides did not differ (p > 0.05) between the RS and placebo groups. Although the total numbers of very low-density lipoprotein (VLDL) and low-density lipoprotein (LDL) particles were similar (p > 0.05) between the two groups, total high-density lipoprotein (HDL) particles were higher (+28%, p < 0.05) in the RS group compared with placebo, resulting from an increase (p < 0.05) in the small HDL subclass particles (+32%). Compared with the placebo group, RS supplementation lowered (p < 0.05) fasting serum glucose (-20%) and improved (p < 0.05) insulin resistance as estimated by Homeostatic Model Assessment-Insulin Resistance (HOMA-IR) without a change in insulin. Additionally, total serum glucagon-like-peptide 1 (GLP-1) was higher (+141%, p < 0.05) following RS supplementation compared with placebo. This data suggests that in addition to the more well-characterized effect of RS intake in lowering blood glucose and improving insulin sensitivity, the consumption of RS may be beneficial in lipid management strategies by enhancing total HDL particle number.

Complementary Cholesterol-Lowering Response of a Phytosterol/α-Lipoic Acid Combination in Obese Zucker Rats.

To investigate the cholesterol-lowering effectiveness of a phytosterol/α-lipoic acid (PS/αLA) therapy, thirty-two male Zucker rats were randomly assigned to 1 of 4 diets for 30 days: (i) high fat diet (HF, 40% energy from fat); (ii) HF diet supplemented with 3% phytosterols; (iii) HF diet supplemented with 0.25% αLA; or (iv) HF diet supplemented with PS (3%) and αLA (0.25%, PS/αLA). Compared with the HF diet, combination PS/αLA proved more effective in reducing non-HDL cholesterol (-55%) than either the PS (-24%) or the αLA (-25%) therapies alone. PS supplementation did not affect LDL particle number, however, αLA supplementation reduced LDL particle number when supplemented alone (-47%) or in combination with PS (-54%). Compared with the HF-fed animals, evidence of increased HDL-particle number was evident in all treatment groups to a similar extent (21-22%). PS-mediated interruption of intestinal cholesterol absorption was evident by increased fecal cholesterol loss (+52%) and compensatory increase in HMG-CoA reductase mRNA (1.6 fold of HF), however, αLA supplementation did not affect fecal cholesterol loss. Hepatic mRNA and protein expression patterns suggested that αLA modulated multiple aspects of cholesterol homeostasis including reduced synthesis (HMG-CoA reductase mRNA, 0.7 fold of HF), reduced bile acid synthesis (CYP7a1 expression, 0.17 of HF), and increased cholesterol clearance (reduced PCSK9 mRNA, 0.5 fold of HF; increased LDLr protein, 2 fold of HF). Taken together, this data suggests that PS and αLA work through unique and complementary mechanisms to provide a superior and more comprehensive cholesterol lowering response than either therapy alone.

Betaine is as effective as folate at re-synthesizing methionine for protein synthesis during moderate methionine deficiency in piglets.

PURPOSE: Both folate and betaine (synthesized from choline) are nutrients used to methylate homocysteine to reform the amino acid methionine following donation of its methyl group; however, it is unclear whether both remethylation pathways are of equal importance during the neonatal period when remethylation rates are high. Methionine is an indispensable amino acid that is in high demand in neonates not only for protein synthesis, but is also particularly important for transmethylation reactions, such as creatine and phosphatidylcholine synthesis. The objective of this study was to determine whether supplementation with folate, betaine, or a combination of both can equally re-synthesize methionine for protein synthesis when dietary methionine is limiting. METHODS: Piglets were fed a low methionine diet devoid of folate, choline, and betaine, and on day 6, piglets were supplemented with either folate, betaine, or folate + betaine (n = 6 per treatment) until day 10. [1-13C]-phenylalanine oxidation was measured as an indicator of methionine availability for protein synthesis both before and after 2 days of supplementation. RESULTS: Prior to supplementation, piglets had lower concentrations of plasma folate, betaine, and choline compared to baseline with no change in homocysteine. Post-supplementation, phenylalanine oxidation levels were 20-46 % lower with any methyl donor supplementation (P = 0.006) with no difference among different supplementation groups. Furthermore, both methyl donors led to similarly lower concentrations of homocysteine following supplementation (P < 0.05). CONCLUSIONS: These data demonstrate an equal capacity for betaine and folate to remethylate methionine for protein synthesis, as indicated by lower phenylalanine oxidation.

Phytosterols protect against diet-induced hypertriglyceridemia in Syrian golden hamsters.

BACKGROUND: In addition to lowering LDL-C, emerging data suggests that phytosterols (PS) may reduce blood triglycerides (TG), however, the underlying mechanisms are not known. METHODS: We examined the TG-lowering mechanisms of dietary PS in Syrian golden hamsters randomly assigned to a high fat (HF) diet or the HF diet supplemented with PS (2%) for 6 weeks (n = 12/group). An additional subset of animals (n = 12) was provided the HF diet supplemented with ezetimibe (EZ, 0.002%) as a positive control as it is a cholesterol-lowering agent with known TG-lowering properties. RESULTS: In confirmation of diet formulation and compound delivery, both the PS and EZ treatments lowered (p < 0.05) intestinal cholesterol absorption (24 and 31%, respectively), blood non-HDL cholesterol (61 and 66%, respectively), and hepatic cholesterol (45 and 55%, respectively) compared with the HF-fed animals. Blood TG concentrations were lower (p < 0.05) in the PS (49%) and EZ (68%)-treated animals compared with the HF group. The TG-lowering response in the PS-supplemented group was associated with reduced (p < 0.05) intestinal SREBP1c mRNA (0.45 fold of HF), hepatic PPARα mRNA (0.73 fold of HF), hepatic FAS protein abundance (0.68 fold of HD), and de novo lipogenesis (44%) compared with the HF group. Similarly, lipogenesis was lower in the EZ-treated animals, albeit through a reduction in the hepatic protein abundance of ACC (0.47 fold of HF). CONCLUSIONS: Study results suggest that dietary PS are protective against diet-induced hypertriglyceridemia, likely through multiple mechanisms that involve modulation of intestinal fatty acid metabolism and a reduction in hepatic lipogenesis.

Consumption of wheat bran modified by autoclaving reduces fat mass in hamsters.

PURPOSE: To investigate the effect that wheat bran modified by autoclaving (MWB) had on reducing fat accumulation in hamsters fed a hypercholesterolemia- and obesity-inducing diet. METHODS: Male hamsters (n = 45) were randomized into 3 groups and fed a hypercholesterolemia- and obesity-inducing diet with or without 10% standard wheat bran or MWB for 28 days. Our outcome measures included body composition measured by DXA, oxygen consumption and plasma lipids and glucose concentrations. RESULTS: Animals fed the MWB diet had lower % fat mass (49.8 vs. 53.4%; p = 0.02) and higher % lean body mass (47.2 vs. 44.1%; p = 0.02) compared with controls despite no differences in food intake or weight gain. Additionally, plasma glucose tended to be lower (6.9 vs. 8.5 mmol/l; p < 0.08) in the MWB animals compared with controls. CONCLUSIONS: Our data suggest that the compositional changes in autoclaved wheat bran, specifically solubility of phenolic antioxidants and fiber, may have contributed to the lower fat accumulation in our animals. Further study is needed to determine whether the exact mechanism involved increased lipolysis and energy utilization from adipose.

Dietary oils and FADS1-FADS2 genetic variants modulate [13C]α-linolenic acid metabolism and plasma fatty acid composition.

BACKGROUND: Desaturation of dietary α-linolenic acid (ALA) to omega-3 (n-3) long-chain fatty acids (FAs) is mediated through FA desaturases (FADS1-FADS2) and may be influenced by dietary FA composition. OBJECTIVE: We investigated the effects of diets enriched in flaxseed oil (FXCO) or high-oleic acid canola oil (HOCO) compared with a Western diet (WD) and FADS1-FADS2 single nucleotide polymorphisms (SNPs) on plasma FAs and [U-(13)C]ALA metabolism. DESIGN: In a randomized crossover design, 36 hyperlipidemic subjects consumed 3 isoenergetic diets enriched in FXCO (20.6 g ALA/d), HOCO (2.4 g ALA/d), or WD (1.3 g ALA/d) for 4 wk. On day 27, blood was sampled 0, 24, and 48 h after the subjects (n = 26) consumed 45 mg [U-(13)C]ALA. The subjects were genotyped for 4 FADS SNPs. RESULTS: FXCO increased (P < 0.001) plasma ALA, EPA, and docosapentaenoic acid (DPA), with no change in DHA compared with the HOCO or WD diets. At 24 and 48 h, [U-(13)C]ALA recovered as plasma [(13)C]EPA and [(13)C]DPA were lower (P < 0.001) after the FXCO diet than after the HOCO and WD diets. No change in [(13)C]DHA was observed between diets. Minor allele homozygotes of rs174545, rs174583, rs174561, and rs174537 had lower (P < 0.05) plasma EPA, arachidonic acid (AA), EPA/ALA, and AA/linoleic acid compositions and lower (P < 0.05) plasma [(13)C]EPA enrichment at 24 and 48 h in comparison with carriers of the major allele after all diets. SNPs were not associated with plasma composition of DHA or [(13)C]DHA enrichment. CONCLUSION: An increase in ALA intake resulting in increased plasma EPA composition may be cardioprotective, especially in minor allele homozygotes. This trial was registered at www.clinicaltrials.gov as NCT00927199.

Evidence for using alpha-lipoic acid in reducing lipoprotein and inflammatory related atherosclerotic risk.

Alpha lipoic acid (α-LA) is a potent biological antioxidant that is found naturally in the human body at very low concentrations, primarily in the mitochondria. However, synthetic α-LA is commercially available as a nutritional supplement and has been shown to be effective at ameliorating symptoms in diseases with an underlying oxidative stress component. High blood cholesterol is a major cardiovascular disease (CVD) risk factor and is responsive to diet and lifestyle modifications. In addition to high blood cholesterol, there is increasing evidence that supports the independent role of oxidized lipids and lipoproteins, chiefly oxidized low-density lipoproteins (Ox-LDL), in the development of CVD. Lowering total blood cholesterol (TC), LDL cholesterol (LDL-C), and triglycerides (TG) and raising high-density lipoprotein cholesterol (HDL-C) levels is the most desirable metabolic state for maximum protection against CVD, but can be difficult to achieve through diet and exercise alone. With emerging evidence of reduced LDL-C and TG, increased HDL-C, and blunting of oxidative susceptibility of lipoproteins by α-LA, its use alone or in combination with other dietary supplements may be an effective strategy to modulate multiple metabolic targets of oxidative stress and cholesterol metabolism to reduce CVD risk. This review examines the current evidence for the use of α-LA in CVD risk reduction and identifies the remaining gaps that must be addressed in this area of research.

Consumption of plant sterols reduces plasma and hepatic triglycerides and modulates the expression of lipid regulatory genes and de novo lipogenesis in C57BL/6J mice.

To investigate emerging clinical data suggesting a triglyceride (TAG)-lowering response to plant sterol (PS) therapy, we characterized changes in TAG metabolism in 16 C57BL/6J mice fed a basal control diet (CON) or the CON diet supplemented with 2% PS for 6 wk. PS consumption reduced (p<0.05) plasma (-28%) and hepatic (-30%) TAG concentrations compared with CON mice. PS consumption increased (p<0.05) hepatic lipogenic gene expression (sterol-regulatory-element-binding protein 1c, 2.4-fold of CON; fatty acid synthase, 6.5-fold of CON) and de novo lipogenesis (4.51+/-0.72 versus 2.82+/-0.61%/day) compared with CON. PS consumption increased (p<0.05) fecal palmitate and stearate excretion and reduced body weight gain compared with CON mice. Although no change in the transcription of intestinal fatty acid absorptive genes was observed, peroxisome proliferator-activated receptor alpha mRNA was reduced (p<0.05, 2.0-fold of CON) in the PS-fed mice. In conclusion, PS-fed C57BL/6J mice showed pronounced reductions in plasma and hepatic TAG concentrations despite increases in hepatic lipogenic gene expression and de novo lipogenesis. Interference with intestinal fatty acid/TAG metabolism as suggested by increased fecal fatty acid loss and reduced weight gain may be associated with the TAG-lowering response to PS consumption.

Guar gum and similar soluble fibers in the regulation of cholesterol metabolism: current understandings and future research priorities.

The hypocholesterolemic effects associated with soluble fiber consumption are clear from animal model and human clinical investigations. Moreover, the modulation of whole-body cholesterol metabolism in response to dietary fiber consumption, including intestinal cholesterol absorption and fecal sterol and bile acid loss, has been the subject of many published reports. However, our understanding of how dietary fibers regulate molecular events at the gene/protein level and alter cellular cholesterol metabolism is limited. The modern emphasis on molecular nutrition and rapid progress in 'high-dimensional' biological techniques will permit further explorations of the role of genetic polymorphisms in determining the variable interindividual responses to soluble fibers. Furthermore, with traditional molecular biology tools and the application of 'omic' technology, specific insight into how fibers modulate the expression of genes and proteins that regulate intestinal cholesterol absorption and alter hepatic sterol balance will be gained. Detailed knowledge of the molecular mechanisms by which soluble fibers reduce plasma cholesterol concentrations is paramount to developing novel fiber-based "cocktails" that target specific metabolic pathways to gain maximal cholesterol reductions.

Evidence of oxidative stress in full-term healthy infants.

We hypothesized that early infancy would be a time of oxidative stress due to the difficulty of adapting to ambient oxygen. Therefore, we measured levels of products of lipid peroxidation (F2-isoprostanes), antioxidant enzyme activity (catalase (CAT) and superoxide dismutase (SOD)), and ability to resist oxidative stress (ferric reducing ability of plasma (FRAP)) in full-term infants (38-42 wk) fed human milk from birth. Seventy-seven infants were followed at 1, 3.5, 6, and 12 mo of age. F2-isoprostanes in plasma declined significantly (p < 0.05) from 1 to 6 mo (160 +/- 43; 90 +/- 33; 41 +/- 27 pg/mL (mean +/- SD)). FRAP values (775 +/- 196, 723 +/- 133, 697 +/- 126, 669 +/- 145 microM) 1, 3.5, 6, and 12, respectively) declined (p = 0.06) from 1 to 3.5 mo and from 3.5 to 6 mo of age. RBC-SOD (2.7 +/- 2, 3.2 +/- 2.8, 2.1 +/- 1.8, 2.5 +/- 1.8 U, 1, 3.5, 6, 12 mo, respectively) declined from 3.5 to 6 mo. RBC-CAT (76 +/- 23, 94 +/- 28, 81 +/- 22, 85 +/- 31 U, 1, 3.5, 6, 12 mo, respectively) also declined between 3.5 and 6 mo, after a significant increase between 1 and 3.5 mo. These data suggest that the human infant is under oxidative stress early in infancy and further study may be warranted to assess the potential benefits of antioxidant supplementation for either the mother or the infant.

A double-masked, randomized control trial of iron supplementation in early infancy in healthy term breast-fed infants.

OBJECTIVES: To test whether iron supplementation affects hematologic, biochemical, and developmental status in term breast-fed infants. STUDY DESIGN: Term breast-fed infants (n=77) were randomly selected to receive either 7.5 mg per day of elemental iron as ferrous sulfate or placebo from 1 to 6 months of age. Investigators and families were unaware of group assignment. Complete blood count and ferritin, red cell superoxide dismutase, catalase, plasma ferric reducing antioxidant power, and zinc and copper levels were analyzed at 1, 3.5, 6, and 12 months of age. Bayley mental and psychomotor developmental indexes (MDI and PDI) and visual acuity (with the use of Teller acuity cards) were assessed from 12 to 18 months of age. Analysis performed by analysis of variance and t tests was by intention to treat. RESULTS: Iron supplementation resulted in higher hemoglobin and mean corpuscular volume at 6 months of age and significantly higher visual acuity and PDI at 13 months of age (100+/-12 vs 93+/-9 [+/-SD]). Treatment and placebo groups did not differ in anthropometric indexes, compliance, biochemical status, or demographic characteristics. CONCLUSIONS: Iron supplementation of breast-fed infants appears safe and might have beneficial hematologic and developmental effects for some infants.