Craig S Patch

Impact of foods enriched with n-3 long-chain polyunsaturated fatty acids on erythrocyte n-3 levels and cardiovascular risk factors

Consumption of fish or fish oils rich in the n-3 long chain PUFA EPA and DHA may improve multiple risk factors for CVD. The objective of this study was to determine whether regular consumption of foods enriched with n-3 long-chain PUFA can improve n-3 long-chain PUFA status (erythrocytes) and cardiovascular health. Overweight volunteers with high levels of triacylglycerols (TG; >1.6 mmol/l) were enrolled in a 6-month dietary intervention trial conducted in Adelaide (n 47) and Perth (n 39), and randomised to consume control foods or n-3-enriched foods to achieve an EPA + DHA intake of 1 g/d. Test foods were substituted for equivalent foods in their regular diet. Erythrocyte fatty acids, plasma TG and other CVD risk factors were monitored at 0, 3 and 6 months. There were no significant differences between groups for blood pressure, arterial compliance, glucose, insulin, lipids, C-reactive protein (CRP) or urinary 11-dehydro-thromboxane B2 (TXB2) over 6 months, even though regular consumption of n-3-enriched foods increased EPA + DHA intake from 0.2 to 1.0 g/d. However, the n-3 long-chain PUFA content of erythrocytes increased by 35 and 53 % at 3 and 6 months, respectively, in subjects consuming the n-3-enriched foods. These increases were positively associated with measures of arterial compliance and negatively associated with serum CRP and urinary 11-dehydro-TXB2 excretion. Sustainable increases in dietary intakes and erythrocyte levels of n-3 long-chain PUFA can be achieved through regular consumption of suitably enriched processed foods. Such increases may be associated with reduced CV risk.

Attitudes and Intentions toward Purchasing Novel Foods Enriched with Omega-3 Fatty Acids

OBJECTIVE To identify the nature, strength, and relative importance of influences on intentions to consume foods that are enriched with omega-3 fatty acids using the Theory of Planned Behavior (TPB). DESIGN A cross-sectional self-administered questionnaire. SETTING Community-based residents living in the Illawarra region of New South Wales, Australia. SUBJECTS Two subsamples were surveyed via questionnaire: community members who responded to a local media advertisement (n = 79), and subjects in a dietary intervention trial for type 2 diabetes mellitus (n = 50). VARIABLES MEASURED Using the TPB variables-intention, attitude, subjective norm, and perceived behavioral control-questionnaire items were constructed to measure intention to consume omega-3-enriched novel foods. ANALYSIS The results from subsamples did not differ and were combined for analysis. The determinants of intention defined in the TPB were investigated using multiple linear regressions. RESULTS Regression analysis showed that the model was a significant determinant of intention (R2 = .725; P < .001). Attitude was a significant determinant of intention, whereas subjective norms and control beliefs were not. DISCUSSION With attitude having the greatest influence on intentions, immediate prospects for modifying behavior are likely to come through a change in attitude, specifically in beliefs about the effectiveness of enriched products in achieving specific health benefits. CONCLUSIONS AND IMPLICATIONS Promoters of omega-3-enriched foods would be advised to direct their promotions toward changing the attitudes of consumers about the effectiveness of the functional ingredient.

Overweight Consumers' Salient Beliefs on Omega-3-Enriched Functional Foods in Australia's Illawarra Region

OBJECTIVE To determine consumer salient beliefs toward functional foods enriched with omega-3 fatty acids. DESIGN Focus group interviews with adult consumers using the Theory of Planned Behavior (TPB) as a theoretical framework. SETTING Community-based residents living in the Illawarra region of New South Wales, Australia. PARTICIPANTS Forty-two overweight participants (29 female, 13 male) aged 30 to 80 years recruited by advertisement and attending 1 of 6 focus groups, which were recorded and transcribed verbatim. ANALYSIS Content analysis was carried out, and subcategories were developed to capture the emerging themes according to the TPB model. RESULTS Most participants were aware of a range of potential benefits of omega-3 fatty acids, but they had reservations about the ability of omega-3-enriched foods to deliver a health benefit. They were concerned about whether these foods were labeled clearly and about the possibility of overdosing. Family and friends were viewed as important in introducing participants to novel foods on the market. Participants regarded dietitians as a credible source and were least trusting of food companies and scientists. Overall, participants reported that cost was a major barrier, and that they would not necessarily trade taste for health benefits. Adding omega-3 fatty acids to foods regarded as less healthful was viewed more as a gimmick rather than a real health benefit. CONCLUSIONS AND IMPLICATIONS The consumer attitudes and purchase intentions identified in this study will be helpful to educators as they plan messages and strategies to guide dietary choices related to products enriched with omega-3 fatty acids.

DHA prevents altered 5-HT1A, 5-HT2A, CB1 and GABAA receptor binding densities in the brain of male rats fed a high-saturated-fat diet

Low levels of docosahexaenoic acid (DHA) have been linked to a number of mental illnesses such as memory loss, depression and schizophrenia. While supplementation of DHA is beneficial in improving memory and cognition, the influence of dietary fats on the neurotransmitters and receptors involved in cognitive function is still not known. The aim of this study was to investigate serotonin receptor (5-HT(1A) and 5-HT2A), cannabinoid receptor (CB1) and gamma-aminobutyric acid type A (GABA(A)) receptor binding densities in the brain of male rats fed a high-saturated-fat (HF) diet, as well as the effect of DHA supplementation on HF diet. Alterations of these receptors in the post-mortem rat brain were detected by [(3)H]-WAY-100635, [(3)H]-ketanserin, [(3)H]-CP-55,940 and [(3)H]-muscimol binding autoradiography, respectively. In the hippocampus, the 5-HT(1A), CB1 and GABA(A) receptor binding densities significantly increased in response to an HF diet, while in the hypothalamus, 5-HT(1A) and CB1 binding densities significantly increased in HF-fed rats. Importantly, DHA supplementation prevented the HF-induced increase of receptors binding density in the hippocampus and hypothalamus. Furthermore, DHA supplementation attenuated 5-HT2A receptor binding density in the caudate putamen, anterior cingulate cortex and medial mammillary nucleus, which was also increased in HF group. This study showed that an HF diet increased 5-HT(1A), 5-HT2A, CB1 and GABA(A) receptor binding densities in the brain regions involved in cognitive function and that dietary DHA can attenuate such alterations. These findings provide insight into the mechanism by which DHA supplementation ameliorates reduced cognitive function associated with an HF diet.

Reduction of histamine H1 receptor binding induced by high-fat diet can be prevented by DHA and dietary fiber in specific brain areas of male rats.

High-fat (HF) diet and obesity are risk factors for a number of mental health problems including depression, cognitive dysfunction, dementia, and neurodegenerative diseases. Histamine H1 receptors (H1Rs) are involved in many of these conditions. This study examined H1R receptor binding density in the brain of male rats fed a high-saturated fat (HF) diet, as well as the effect of docosahexaenoic acid (DHA), galacto-oligosaccharide (GOS) and resistant starch (RS) supplementation of HF diet. Alterations of H1R expression in the post-mortem rat brain were detected by [(3)H]-pyrilamine binding autoradiography. We found that HF diet significantly decreased H1R binding densities in the substantia nigra (SN), caudate putamen (CPu), hypothalamic arcuate nucleus (Arc), ventral tegmental area (VTA), piriform cortex (Pir) and primary motor cortex (M1), compared with low-fat fed rats, and the suppression of receptor binding density ranged from 31% to 48%. Interestingly, supplementing the HF diet with 0.5% n-3 polyunsaturated docosahexaenoic acid (DHA) prevented reduction of H1R binding densities in the SN and CPu. Addition of galacto-oligosaccharide (GOS) and resistant starch (RS) to the diet blunted HF induced reduction of H1R ligand binding in the SN and Pir, respectively. In conclusion this study showed that HF diet can alter H1R binding densities in various brain regions, and many of these changes can be prevented by adding DHA, GOS or RS to the diet.

Microencapsulated krill and tuna oil blend raises plasma long-chain n-3 polyunsaturated fatty acid levels compared to tuna oil with similar increases in ileal contractility in rats

Abstract Long-chain n-3 polyunsaturated fatty acids (LC n-3 PUFA) may be more bioavailable from krill oil compared to fish oil due to their phospholipid structure. We tested whether a microencapsulated krill and tuna oil blend (ME-TOKO) provided greater LC n-3 PUFA bioavailability, improved blood lipid profiles and increased intestinal contractility compared to microencapsulated tuna oil (ME-TO). Rats were divided into three groups to receive isocaloric diets containing ME-TO, ME-TOKO and microencapsulated olive oil (ME-OO) at 0.3 or 2 g/100 g for 4 weeks. Final body and organ weights, feed intake and waste output were similar. ME-TOKO rats had higher plasma total LC n-3 PUFA levels compared to ME-TO, but liver LC n-3 PUFA levels and plasma triglyceride and cholesterol levels were similar in non-fasted rats. Diets containing 2% ME-TO and ME-TOKO also showed similar increases in ileal contractility. In summary, ME-TO bioavailability of LC n-3 PUFA was similar to ME-TOKO.