The effect of camelina sativa oil and fish intakes on fatty acid compositions of blood lipid fractions.

BACKGROUND AND AIMS: Blood lipid fractions serve as objective biomarkers of dietary fat intake. It is unclear which fatty acid pool most accurately reflects the dietary intakes of different n-3 PUFAs. We aimed to investigate the effect of fish and camelina sativa oil (CSO) intakes on fatty acid composition of erythrocyte membranes (EM), plasma phospholipids (PL), cholesteryl esters (CE) and triglycerides (TG). We also aimed to identify the most appropriate blood lipid fraction for assessing n-3 PUFA intake. METHODS AND RESULTS: Altogether 79 volunteers with impaired glucose metabolism were randomly assigned either to CSO, fatty fish, lean fish or control groups for 12 weeks. Fatty acid compositions of lipid pools were measured by gas chromatography. The proportion of alpha-linolenic acid (ALA) increased in all lipid pools in the CSO group (false discovery rate (FDR) p < 0.001 for all). Similarly, the proportions of EPA and DHA increased in all lipid fractions in the fatty fish group (FDR p < 0.001 for EM, PL and CE; FDR p = 0.005 for TG; FDR p < 0.001 for EM, PL, CE; FDR p < 0.007 for TG, respectively). Changes in the dietary intakes of ALA, EPA and DHA correlated with the changes in their proportions in all lipid pools (r = 0.3-0.5, p < 0.05). CONCLUSION: There is no difference in the ability of blood lipid fractions in reflecting the dietary intake of different n-3 PUFAs over a time period of 12 weeks in subjects with high baseline omega-3 index. This trial was registered in Clinicaltrials.gov (NCT01768429).

Association of Protein Intake with Bone Mineral Density and Bone Mineral Content among Elderly Women: The OSTPRE Fracture Prevention Study.

It has been hypothesized that high protein intakes are associated with lower bone mineral content (BMC). Previous studies yield conflicting results and thus far no studies have undertaken the interaction of body mass index (BMI) and physical activity with protein intakes in relation to BMC and bone mineral density (BMD). OBJECTIVE: To evaluate the associations of dietary total protein (TP), animal protein (AP) and plant protein (PP) intakes with BMC and BMD and their changes. We tested also the interactions of protein intake with, obesity (BMI ≤30 vs. >30 kg/m2) and physical activity level (passive vs. active). Design/ Setting: Prospective cohort study (Osteoporosis Risk-Factor and Fracture-Prevention Study). Participants/measures: At the baseline, 554 women aged 65-72 years filled out a 3-day food record and a questionnaire covering data on lifestyle, physical activity, diseases, and medications. Intervention group received calcium 1000 mg/d and cholecalciferol 800 IU for 3 years. Control group received neither supplementation nor placebo. Bone density was measured at baseline and year 3, using dual energy x-ray absorptiometry. Multivariable regression analyses were conducted to examine the associations between protein intake and BMD and BMC. RESULTS: In cross-sectional analyses energy-adjusted TP (P≤0·029) and AP (P≤0·045) but not PP (g/d) were negatively associated with femoral neck (FN) BMD and BMC. Women with TP≥1·2 g/kg/body weight (BW) (Ptrend≤0·009) had lower FN, lumbar spine (LS) and total BMD and BMC. In follow-up analysis, TP (g/kg/BW) was inversely associated with LS BMD and LS BMC. The detrimental associations were stronger in women with BMI<30 kg/m2. In active women, TP (g/kg/BW) was positively associated with LS BMD and FN BMC changes. CONCLUSIONS: This study suggests detrimental associations between protein intake and bone health. However, these negative associations maybe counteracted by BMI>30 kg/m2 and physical activity.

Associations of dietary polyunsaturated fatty acids with bone mineral density in elderly women.

BACKGROUND/OBJECTIVES: Significance of dietary fatty acids on bone health is not clear, and the evidence is controversial. This study aimed to investigate the relationship between dietary polyunsaturated fatty acids (PUFAs) and bone mineral density (BMD) among elderly women. SUBJECTS/METHODS: Subjects (n=554) were drawn from the Kuopio OSTPRE Fracture Prevention Study. At baseline they filled a 3-day food record and a questionnaire on lifestyle factors, diseases and medications. BMD was measured at lumbar spine (L2-L4), femoral neck and total body by dual energy X-ray absorptiometry at baseline and after 3 years. The associations between dietary fatty acids and BMD were analyzed by a linear mixed model adjusting for potential dietary and non-dietary confounders. RESULTS: Our findings suggested a positive relationship between the dietary PUFAs and BMD at lumbar spine and in total body but not at femoral neck. Further analyses revealed that these results were due to associations among the women without hormone therapy (HT) at baseline. Among them, the intake of total PUFAs as well the intakes of linoleic and linolenic acids and total n-3 and n-6 fatty acids were significantly associated with BMD at lumbar spine; P for trend over the quartiles ranged between 0.013 and 0.001. Similarly, significant associations were demonstrated for total body BMD and fatty acids with an exception of total PUFA. No significant associations were found among women with HT at baseline. CONCLUSIONS: Our findings among elderly women without HT support the suggested beneficial effect of dietary PUFAs on bone health.

Comparison of the effects of plant sterol ester and plant stanol ester-enriched margarines in lowering serum cholesterol concentrations in hypercholesterolaemic subjects on a low-fat diet.

OBJECTIVE: To investigate cholesterol-lowering effects of stanol ester (STAEST) and sterol ester (STEEST)-enriched margarines as part of a low-fat diet. DESIGN: According to a Latin square model randomized double-blind repeated measures design with three test margarines and three periods. SETTING: Outpatient clinical trial with free-living subjects. SUBJECTS: Thirty-four hypercholesterolaemic subjects completed the study. INTERVENTIONS: Subjects consumed three rapeseed oil-based test margarines (STAEST, STEEST and control (no added stanols or sterols)) as part of a low-fat diet each for 4 weeks. RESULTS: Mean daily intake of total plant sterols plus stanols was 2.01-2.04 g during the two test margarine periods. In reference to control, serum total cholesterol was reduced by 9.2 and 7.3% with the STAEST and STEEST margarine, respectively (P<0.001 for both). The respective reductions for low-density lipoprotein (LDL) cholesterol were 12.7 and 10.4% (P<0. 001). The cholesterol-lowering effects of the test margarines did not differ significantly. The presence of apolipoprotein E4 allele had a significant effect on LDL cholesterol response during the STAEST margarine only. Serum sitosterol and campesterol increased by 0.83 and 2.77 mg/l with the STEEST (P<0.001), respectively and decreased by 1.18 and 2.60 mg/l with the STAEST margarine (P<0.001). Increases of serum sitostanol and campestanol were 0.11 and 0.19 mg/l with the STAEST margarine (P<0.001), repsectively. No significant changes were found in serum fat-soluble vitamin and carotenoid concentrations when related to serum total cholesterol. CONCLUSIONS: STAEST and STEEST margarines reduced significantly and equally serum total and LDL cholesterol concentrations as part of a low-fat diet. SPONSORSHIP: Grant to the University of Kuopio by Raisio Benecol Ltd, Raisio, Finland.