Jessica A. Grieger

Flow-Mediated Dilatation Is Impaired by a High–Saturated Fat Diet but Not by a High-Carbohydrate Diet

Objective—It is unknown whether a low-fat diet, which may elevate triglycerides and lower high-density lipoprotein (HDL) cholesterol, harms the endothelium. Our aim was to determine whether a low-fat, high-carbohydrate (CARB) diet impaired endothelial vasodilation compared with high saturated fat (SFA), monounsaturated fat (MUFA), or polyunsaturated fat (PUFA) diets. Methods and Results—Forty healthy subjects were randomly crossed over to 4, 3-week isocaloric diets high in PUFA, MUFA, or SFA, containing at least 25 g of the relevant fat or a low-fat, CARB, high–glycemic load diet. Flow-mediated dilatation (FMD), fasting blood lipids, high sensitivity C-reactive protein, plasma intercellular, and vascular adhesion molecules plasma E- and P-selectin were measured after each intervention. SFA impaired FMD compared with all other diets (5.41±2.45% versus 10.80±3.69%; P=0.01). FMD did not change on CARB relative to MUFA or PUFA, despite 23% to 39% rises in triglyceride and 10% to 15% falls in HDL cholesterol. P-selectin was highest after SFA (121±52.7 ng/mL) versus MUFA (98±44.5 ng/mL; P=0.001) and PUFA (96±36.4 ng/mL; P=0.001). Conclusion—High SFA caused deterioration in FMD compared with high PUFA, MUFA, or CARB diets. Inflammatory responses may also be increased on this diet.

Milk products, dietary patterns and blood pressure management.

High blood pressure (BP) is a major risk factor for heart disease, stroke, congestive heart failure, and kidney disease. Inverse associations between dairy product consumption and systolic blood pressure (SBP) and diastolic blood pressure (DBP) have been observed in cross-sectional studies; some studies, however, have reported an inverse association with only one BP parameter, predominantly SBP. Randomized clinical trials examining the effect of calcium and the combination of calcium, potassium and magnesium provide evidence for causality. In these studies, reductions in BP were generally modest (−1.27 to −4.6 mmHg for SBP, and −0.24 to −3.8 mmHg for DBP). Dairy nutrients, most notably calcium, potassium and magnesium, have been shown to have a blood pressure lowering effect. A low calcium intake increases intracellular calcium concentrations which increases 1,25-dihydroxyvitamin D3 and parathyroid hormone (PTH), causing calcium influx into vascular smooth muscle cells, resulting in greater vascular resistance. New research indicates that dairy peptides may act as angiotensin converting enzyme (ACE) inhibitors, thereby inhibiting the renin angiotensin system with consequent vasodilation. A growing evidence base shows that dairy product consumption is involved in the regulation of BP. Consequently, inclusion of dairy products in a heart healthy diet is an important focal point to attain BP benefits.

Acute Consumption of Walnuts and Walnut Components Differentially Affect Postprandial Lipemia, Endothelial Function, Oxidative Stress, and Cholesterol Efflux in Humans with Mild Hypercholesterolemia

Walnut consumption improves cardiovascular disease risk; however, to our knowledge, the contribution of individual walnut components has not been assessed. This study evaluated the acute consumption of whole walnuts (85 g), separated nut skins (5.6 g), de-fatted nutmeat (34 g), and nut oil (51 g) on postprandial lipemia, endothelial function, and oxidative stress. Cholesterol efflux (ex vivo) was assessed in the whole walnut treatment only. A randomized, 4-period, crossover trial was conducted in healthy overweight and obese adults (n = 15) with moderate hypercholesterolemia. There was a treatment × time point interaction for triglycerides (P < 0.01) and increased postprandial concentrations were observed for the oil and whole walnut treatments (P < 0.01). Walnut skins decreased the reactive hyperemia index (RHI) compared with baseline (P = 0.02) such that a difference persisted between the skin and oil treatments (P = 0.01). The Framingham RHI was maintained with the oil treatment compared with the skins and whole nut (P < 0.05). There was a treatment effect for the ferric reducing antioxidant potential (FRAP) (P < 0.01), and mean FRAP was greater with the oil and skin treatments compared with the nutmeat (P < 0.01). Cholesterol efflux increased by 3.3% following whole walnut consumption in J774 cells cultured with postprandial serum compared with fasting baseline (P = 0.02). Walnut oil favorably affected endothelial function and whole walnuts increased cholesterol efflux. These 2 novel mechanisms may explain in part the cardiovascular benefits of walnuts.

Preconception Dietary Patterns in Human Pregnancies Are Associated with Preterm Delivery

Maternal nutrition can have a profound effect on fetal growth, development, and subsequent infant birth weight. Preconception dietary patterns have not been assessed in relation to perinatal outcomes. The objectives of this study were to identify associations between maternal dietary patterns in the 12 mo before conception on fetal growth and preterm delivery. Preconception food frequency data were collected retrospectively in 309 women. Dietary patterns were derived using factor analysis. Perinatal outcomes were collected at delivery with birth weight data calculated into percentiles to assess small and large for gestational age and preterm delivery at <37 wk. Three dietary patterns were identified: 1) high-protein/fruit (characterized by fish, meat, chicken, fruit, and some whole grains); 2) high-fat/sugar/takeaway (takeaway foods, potato chips, refined grains); and 3) vegetarian-type (vegetables, legumes, whole grains). A 1-SD increase in the scores on the high-protein/fruit pattern was associated with decreased likelihood of preterm birth (adjusted OR: 0.31; 95% CI: 0.13, 0.72; P = 0.007), whereas the reverse direction was apparent for the high-fat/sugar/takeaway pattern (adjusted OR: 1.54; 95% CI: 1.10, 2.15; P = 0.011). A 1-SD increase in the scores on the high fat/sugar/takeaway pattern was also associated with shorter gestation (adjusted regression coefficient: -2.7; 95% CI: -4.3, -1.1; P = 0.001) and birth length (adjusted regression coefficient: -0.5; 95% CI: -0.8, -0.1; P = 0.004). Nutrition before pregnancy is associated with perinatal outcomes. A dietary pattern containing several protein-rich food sources, fruit, and some whole grains is associated with reduced likelihood for preterm delivery, whereas a dietary pattern mainly consisting of discretionary items is associated with preterm delivery, shorter birth length, and earlier gestation. Poor dietary behaviors in the periconceptional period could be altered to promote behavior change in dietary intake to improve perinatal outcomes and the long-term health of the child.

A Review of the Impact of Dietary Intakes in Human Pregnancy on Infant Birthweight

Studies assessing maternal dietary intakes and the relationship with birthweight are inconsistent, thus attempting to draw inferences on the role of maternal nutrition in determining the fetal growth trajectory is difficult. The aim of this review is to provide updated evidence from epidemiological and randomized controlled trials on the impact of dietary and supplemental intakes of omega-3 long-chain polyunsaturated fatty acids, zinc, folate, iron, calcium, and vitamin D, as well as dietary patterns, on infant birthweight. A comprehensive review of the literature was undertaken via the electronic databases Pubmed, Cochrane Library, and Medline. Included articles were those published in English, in scholarly journals, and which provided information about diet and nutrition during pregnancy and infant birthweight. There is insufficient evidence for omega-3 fatty acid supplements’ ability to reduce risk of low birthweight (LBW), and more robust evidence from studies supplementing with zinc, calcium, and/or vitamin D needs to be established. Iron supplementation appears to increase birthweight, particularly when there are increases in maternal hemoglobin concentrations in the third trimester. There is limited evidence supporting the use of folic acid supplements to reduce the risk for LBW; however, supplementation may increase birthweight by ~130 g. Consumption of whole foods such as fruit, vegetables, low-fat dairy, and lean meats throughout pregnancy appears beneficial for appropriate birthweight. Intervention studies with an understanding of optimal dietary patterns may provide promising results for both maternal and perinatal health. Outcomes from these studies will help determine what sort of dietary advice could be promoted to women during pregnancy in order to promote the best health for themselves and their baby.

Comparison of dietary intakes according to breakfast choice in Australian boys

Background:There is little information on how breakfast choices are associated with dietary intakes in Australian boys.Objective:(i) To determine the proportion of breakfast skippers, ready-to-eat cereal (RTEC) consumers and non-RTEC consumers at breakfast; (ii) to compare breakfast, and daily nutrient intakes and nutrient density, between the three groups; and (iii) to compare daily nutrient intakes against nutrient recommendations.Subjects/Methods:Cross-sectional analysis of 12 to 16-year-old boys (n=781) from the 2007 Australian National Childrens Nutrition and Physical Activity Survey.Results:Forty-two percent of boys consumed RTEC at breakfast; 38% did not consume RTECs; and 20% skipped breakfast. Breakfast skippers had a higher body mass index and waist circumference compared with RTEC consumers (P⩽0.05). At breakfast, RTEC consumers had a higher intake of total sugars and a lower intake of fat and sodium versus non-RTEC consumers. Total daily nutrient density for calcium, iron, thiamin, riboflavin, zinc, dietary folate equivalents, magnesium and iodine was higher for RTEC consumers versus non-RTEC consumers and breakfast skippers (all P⩽0.05). Fifty-nine percent of 14 to 16-year-old RTEC consumers reached the fibre adequate intake versus 34% and 24% of non-RTEC consumers and breakfast skippers, respectively (all P⩽0.01). More RTEC consumers met the calcium estimated average requirements versus non-RTEC consumers and breakfast skippers (P⩽0.01).Conclusions:Breakfast choice, specifically RTECs and the foods consumed with them, provide valuable nutrients that may assist boys in meeting nutrient requirements. Consumption of RTECs may be one way in which intakes of key nutrients, relevant for growth and development, could be increased in older boys.

Effects of whole and refined grains in a weight-loss diet on markers of metabolic syndrome in individuals with increased waist circumference: a randomized controlled-feeding trial

BACKGROUND Higher whole-grain (WG) intake is associated with a lower prevalence of metabolic syndrome (MetS); however, there is inconsistent clinical evidence with regard to the benefit of WGs compared with refined grains (RGs) on MetS. OBJECTIVE We hypothesized that consuming WGs in the place of RGs would improve MetS criteria in individuals with or at risk of MetS. DESIGN A randomized, controlled, open-label parallel study was conducted in 50 overweight and obese individuals with increased waist circumference and one or more other MetS criteria. Participants consumed a controlled weight-loss diet containing either WG or RG (control) products for 12 wk. Body composition, MetS criteria and related markers, and plasma alkylresorcinols (compliance marker of WG intake) were measured at baseline and at 6 and 12 wk. A subgroup (n = 28) underwent magnetic resonance imaging to quantify subcutaneous and visceral adipose tissue (AT). RESULTS Baseline variables were not significantly different between groups; however, the RG group tended to have higher triglycerides and lower high-density lipoprotein (HDL) cholesterol (P = 0.06). Alkylresorcinols increased with consumption of the WG diet and did not change with consumption of the RG diet (time × treatment, P < 0.0001), which showed dietary compliance. There were no differences in anthropometric changes between groups; however, weight, body mass index, and percentage of body AT decreased at both 6 and 12 wk (P < 0.05), and reductions in percentage of abdominal AT occurred by 6 wk and did not change between 6 and 12 wk (P = 0.09). Both glucose (P = 0.02) and HDL cholesterol (P = 0.04) were lower with the consumption of the WG compared with the RG diet. However, when noncompliant individuals (n = 3) were removed, the glucose effect was stronger (P = 0.01) and the HDL-cholesterol effect was no longer significant (P = 0.14). CONCLUSIONS Replacing RGs with WGs within a weight-loss diet does not beneficially affect abdominal AT loss and has modest effects on markers of MetS. WGs appear to be effective at normalizing blood glucose concentrations, especially in those individuals with prediabetes.

Mechanistic Examination of Walnuts in Prevention of Breast Cancer

Walnuts contain bioactive molecules that may contribute to their beneficial effects, including alpha-linolenic acid (ALA) and phytosterols. In these studies, extracts of walnut, purified compounds, or postprandial serum were examined for effects on breast cancer cell proliferation and gene expression. Extracts derived from walnut oil decreased proliferation of MCF-7 cells, as did ALA and β-sitosterol. The gene expression response of ALA in the mouse breast cancer cell line TM2H indicates this molecule has multiple cellular targets with peroxisome proliferator-activated receptor (PPAR) target genes, liver X receptor (LXR), and farnesoid X receptor (FXR) target genes being affected. In transactivation assays, walnut oil extracts increased activity of FXR to a greater extent than the other tested nuclear receptors. When examined separately, walnut components ALA and β-sitosterol were the most efficacious activators of FXR. When serum from individuals fed walnut components were applied to MCF-7 cells, there was a correlation between body mass index and breast cancer cell proliferation in vitro. Taken together, these data support an effect of walnut and its bioactive constituents on mammary epithelial cells and that multiple molecular targets may be involved.

Multivitamin supplementation improves nutritional status and bone quality in aged care residents

Objectives:To assess the effectiveness of a multivitamin (MV) tablet on nutritional status, quantitative heel ultrasound (QUS), mobility, muscle strength and falls. The design comprised two groups matched on mobility levels, randomized to receive a daily MV or placebo (P) tablet for 6 months. The setting was an Australian residential care facility.Subjects:A total of 92 aged care residents. Serum micronutrients, body weight, QUS, rate of falls, hand grip strength, and the timed up and go test were assessed at baseline and 6 months.Results:A total of 49 participants consumed a MV and 43, a matched P for 6 months. There was a greater increase in the MV vs P group for serum 25(OH)D (mean difference±standard error, 33.4±2.6 nmol l−1), folate (13.4±2.8 nmol l−1), and vitamin B12 (178.0±40.3 pmol l−1) (all P<0.001). Adequate 25(OH)D concentrations (⩾50 nmol l−1) were found among 77% of participants in the MV group vs 10% taking P (P<0.001). Adjusting for baseline levels, the increase in QUS was greater in the MV vs P group (3.0±2.0 dB MHz−1 vs −2.9±2.1 dB MHz−1, respectively, P=0.041). There was a trend towards a 63% lower mean number of falls in the MV vs P group (0.3±0.1 falls vs 0.8±0.3 falls, P=0.078).Conclusions:MV supplementation raised serum vitamin B12 and folate concentrations and increased serum 25(OH)D, which was accompanied by an apparent positive effect on bone density. We also found a trend towards a reduction in falls and this could contribute to a reduction in fractures.

Nutritional and Functional Status Indicators in Residents of a Long-Term Care Facility

In a cross-sectional study, we determined whether results from the Mini Nutritional Assessment (MNA), Geriatric Depression Scale (GDS), and Katz Activities of Daily Living (ADL), were associated with nutritional status and mobility in long-term care residents. One hundred and fifteen study participants (mean [SD] age: 80.2 [10.6]) provided informed consent. Fifty eight percent (n = 66) responded to all three questionnaires: 12 were assessed as malnourished (MNA < 17) and 28 were depressed (GDS ≥ 6). Higher levels of depression were associated with lower serum zinc (n = 71, r = −.356, p = .001) and associated with a slower Timed Up and Go test (TUG, n = 38, r = .301, p = .030). MNA was also associated with serum zinc (n = 44, r = .307, P = .021). Non responders to questionnaires (n = 36) had a lower BMI (mean difference: −2.5 ± 1.0 kg/m2, p = .013) and serum 25(OH)D (−8.7 ± 3.8 nmol/l, p = .023) vs. responders. The GDS, in addition to the MNA, is useful in identifying poor nutritional status in residential care. Intervention programs that target depression and poor nutritional status could potentially improve overall quality of life, but it is not clear if depression is leading to poor nutritional status or if poor nutrition is leading to depression.