Atherosclerosis, an inflammatory disease characterized by plaque formation in the arteries, commonly occurs in mammals, including humans, and some avian species. Polyunsaturated n-3 fatty acids have been shown to reduce known mammalian risk factors associated with the development of atherosclerosis in mammals. N-3 polyunsaturated fatty acids (PUFA) have also been linked to improving retinal, neurological, and brain development and functioning. In order to assess the effects of n-3 PUFA on potential risk factors for atherosclerosis in avian species and learning ability, a series of studies were conducted in Monk parrots: 1) alterations comparing a high linoleic acid diet with -linolenic acid (ALA) diet on lipid metabolism, fatty acid conversions, and lipoproteins, 2) the dose response of ALA and comparison with a high docosahexaenoic acid (DHA) diet on lipid metabolism, fatty acid conversions, and markers of oxidation, 3) the effect of a high DHA diet on learning ability, and 4) assessment of growing energy requirement estimations to improve adult health. Monk parrots were able to convert ALA to DHA and also retro-convert DHA/docosapentaenoic acid (DPA) to eicosapentaenoic acid (EPA). Feeding Monk parrots a high ALA diet resulted in a shift in the peak density of the high-density lipoproteins after 70 days. Decreased superoxide dismutase and increased malondialdehyde were observed by day 63 regardless of dietary n-3 PUFA levels or source. Higher plasma phospholipid DHA levels at day 28 were obtained when n-3 PUFA were provided in the diet as DHA rather than ALA (at equivalent amounts). Total plasma cholesterol, free cholesterol, esterified cholesterol, and triacylglycerol concentrations were not altered by increasing dietary n-3 PUFA. An effect of DHA on learning ability could not be concluded due to decreased power from adjusting for an age effect. Additionally, the growing energy needs for Monk parrots through day 23 after hatching were estimated and, unlike previous general equations, accounted for changes in growth energy requirements. These closer energy estimations that accounted for growth energy variations will hopefully prevent negative fluctuations in growth rate which were observed in the study and prevent obese fledgling and young adult birds. In conclusion, Monk parrots are able to benefit from dietary n-3 PUFA provided as either ALA or DHA. Although, dietary DHA may provide more protection against the development of atherosclerosis due to its higher accumulation into plasma phospholipids and retro-conversion to EPA. However, caution should be used when feeding PUFA, as they increase oxidation in the body. While many risk factors for atherosclerosis have been determined in humans and other mammals, some of these do not appear to hold for Monk parrots and possibly other avian species prone to atherosclerosis.

The primary objective of this study was to determine if the intake of omega-3 fatty acids (O3FA), from self-selected foods and supplements, was associated with a reduction in muscle soreness in collegiate rowers. Several groups of collegiate rowers were identified as potential subjects and, using an IRB-approved protocol, 61 volunteers from this subject pool agreed to participate in the study. At the end of the first week of fall practice, subjects were asked to provide information on age, weight, height, ethnicity, rowing level, sun exposure, exercise regimen, pre- and peak-soreness and exertion levels, hydration status, and food/supplement intake. A Talag scale was used to determine the severity of muscle soreness, and a modified Borg scale was used to determine the exertion intensity level. A food frequency questionnaire using a 10-point Likert scale was used to assess food and supplement intake, with a special focus on O3FA. Subjects with a higher intake of EPA/DHA rich bottled supplemental fish oil, taken by spoon, had significantly higher soreness levels than those with lower intakes (p = 0.028). Higher soreness was also significantly associated with higher intake of EPA/DHA rich fish oil capsules (p < 0.001). Lower soreness was significantly associated with higher fruit intake (p = 0.030). These findings suggest that high intakes of O3FA from fish oils, regardless of liquid or capsule form, may be contraindicated for collegiate rowers wishing to reduce muscle soreness. Recommending fruit intake may be warranted for rowers wishing to reduce muscle soreness.

Docosahexaenoic acid (DHA) is an omega-3 polyunsaturated fatty acid (n-3 PUFA) required for fetal neurodevelopment. Increased DHA levels are associated with 17β-estradiol levels, as DHA is higher in women relative to men and in pregnant relative to non-pregnant women, suggesting a maternal adaptation to supply DHA to the fetus. DHA can be synthesized in the body from shorter n-3 PUFA through sequential elongation-desaturation, with Δ6-desaturase being the rate-limiting enzyme. The goal of the present thesis was to characterize the mechanism underlying higher DHA in situations of altered 17β-estradiol status by examining the expression of DHA synthesis enzymes in rodent models. Fatty acid composition of several lipid classes was measured by gas chromatography and enzyme expression was measured by RT-qPCR and immunoblotting. Hepatic Δ6-desaturase and phospholipid DHA was higher in female relative to male, and in pregnant relative to non-pregnant rats. Similarly, 17β-estradiol supplementation of ovariectomized rats resulted in increased hepatic Δ6-desaturase expression and DHA content, while ovariectomy itself had no effects on DHA levels despite controlling for hyperphagia. Mice deficient in the DNA binding activity of estrogen receptor α (ERα) had no differences in hepatic Δ6-desaturase or DHA levels. These results suggest that 17β-estradiol mediates the higher DHA levels in females and during pregnancy through increasing hepatic Δ6-desaturase expression, although the effects of removing 17β-estradiol signalling through ovariectomy or ERα disruption are less clear. This work helps to explain findings of altered DHA status in response to changes in 17β-estradiol concentrations, possibly resulting in more appropriately tailored dietary DHA recommendations. Also, increased understanding of the regulation of DHA synthesis may improve DHA yields in agri/aquaculture and enable increased content of DHA in the food supply.

A series of experiments was conducted to test the overall hypothesis that reducing the omega-6 (n-6) to omega-3 (n-3) fatty acid (FA) ratio in sow diets would improve sow reproductive performance (characterized by increases in numbers and body weight of piglets born alive and weaned) and would lessen the inflammatory responses of their offspring post weaning. Diets were wheat/barley based and consisted of a control (tallow based, similar to a standard production diet), 3 diets with plant oil based n-6:n-3 ratios (9:1P, 5:1P, and 1:1P) and a 5:1 fish oil diet (5:1F). The control diet had a ratio of 8:1, but contained approximately half the polyunsaturated FA content of the other diets. Sows were randomly assigned to a treatment diet on d 80 of gestation, and remained on that treatment for three consecutive reproductive cycles (gestation/lactation 1 = P1, gestation/lactation 2 = P2, gestation/lactation 3 = P3). Experiment 1 was designed to test the hypothesis that reducing the n-6:n-3 FA ratio in sow diets would increase circulating concentrations of n-3 FA’s in sows and in their offspring, and the passive immune status of piglets would be improved. Performance data was collected throughout P1 and P2 on 150 sows (n = 30/diet). Sow and piglet serum, colostrum and milk were analyzed for FA profiles, and colostrum and piglet serum were analyzed for immunoglobulin (Ig) A and IgG. In P1, birth weights were unaffected by diet (P > 0.05). Average piglet weaning weights (P = 0.02) and ADG (P = 0.01) however, were highest for piglets born to sows consuming the 9:1P and 5:1P diets. During P2, 5:1F sows consumed 10% less feed (P = 0.04), their piglets had reduced birth weights (P = 0.05), and average weaning weight was reduced by 0.8 kg (P = 0.04) relative to control or 5:1P sows. Colostral and piglet plasma IgA and IgG were unaffected by diet (P > 0.05). Colostrum FA profile patterns were similar to that of the sow diets. Serum n-3 FA’s were greatest in sows (P < 0.01) and piglets (P < 0.01) consuming 1:1P or 5:1F diets. Serum α-linolenic acid (ALA) was highest in the 1:1P sows and eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) were highest in the 5:1F sows. In piglet serum obtained prior to suckling, ALA and DHA did not differ among treatments (P > 0.05) but EPA was 2.5 times greater in the 1:1P group and 4 times greater in the fish group (P < 0.01) compared to those from the control diet. In post-suckle samples, ALA was highest in serum from 1:1P diet piglets (P < 0.01), and EPA and DHA were highest in piglet serum from the 5:1F sows (P < 0.01). Omega-3 FA’s can perturb lipid metabolism, specifically increasing the lipolytic activity of adipose tissue and thus the second experiment tested the hypothesis that high producing sows, consuming reduced n-6:n-3 ratios would have increased body fat mobilization. Twenty sows per diet, farrowing ≥ 11 piglets and nursing ≥ 10 piglets during P3, were used. Performance data on sows and piglets (such as weights, numbers, backfat changes) was collected throughout lactation and milk samples obtained on d 4 and d 16 of lactation. Jugular catheters were inserted into 8 sows from each of the 9:1P and 1:1P groups on d 5 of lactation and sows were challenged with a single injection of epinephrine followed by serial blood collections. Feed intake was highest for sows consuming the control (8.4 kg/d) and 5:1P (8.2 kg/d) diets and lowest for the sows fed the 1:1P (7.4 kg/d) and 5:1F (7.7 kg/d) diets (P = 0.05). Altering the n-6:n-3 FA ratio did not affect sow BW, piglet ADG, milk DM and N content or the total output of milk (P > 0.2). Sows consuming the 1:1P diet had greater backfat thickness (P < 0.05) and numerically higher plasma NEFA at baseline compared with the 9:1P sows (240 vs 93 uM; P = 0.16). When given epinephrine, 9:1P fed sows tended to have lower net incremental area under the curve (niAUC) glucose (P = 0.08) and numerically higher niAUC NEFA (P = 0.17) and glycerol (P = 0.15). A third experiment was conducted to test the hypothesis that piglets raised by sows consuming reduced n-6:n-3 ratios would have reduced inflammatory responses post-weaning. Piglets (n = 20/diet) raised by sows consuming the treatment diets described above for 2 gestation/lactation cycles (P2) were selected at weaning. Within diet group, pigs were randomized to either a challenge control group (saline injected) or to a lipopolysaccharide (LPS) injected group (n=10/challenge•diet-1). Piglets were fed a common starter diet for 6 days followed by saline or LPS injections on d 7. Rectal temperatures were recorded for 24 hrs and blood samples were collected at 0, 2, 6 and 12 hrs post injection for pro-inflammatory cytokine and blood urea nitrogen (BUN) analysis. Injecting LPS caused decreased feed intake and reduced ADG (P < 0.01), and increased temperature and cytokine production (P < 0.05). Piglets raised by sows consuming the 1:1P diet had elevated temperatures (P = 0.01; diet x challenge P > 0.05). Overall, circulating plasma ALA and EPA were increased in sows and piglets when sows were fed a 1:1 plant based ratio compared to the control or high n-6:n-3 ratio groups. Sows fed a ratio of 1:1 mobilized more body fat relative to those consuming the 9:1 ratio; there were no treatment effects on piglet growth. Reducing maternal n-6:n-3 FA ratios below 5:1 increased piglet body temperature prior to and during an LPS induced inflammatory challenge,. Reducing the sow dietary n-6:n-3 FA ratio below 5:1 may have detrimental effects on piglets due to over-stimulation of inflammatory responses.

Fatty acid profiling provides information on dietary intakes and an understanding of lipid metabolism. High throughput techniques such as fingertip prick (FTP) sampling has gained popularity in recent years as a simplified method for basic research, and could be further used to assess disease risk in the population, and other similar high-throughput techniques have the potential to assist in the monitoring and labeling of fatty acids in the food supply. With the advancement of high-throughput sample analysis techniques, a more complete understanding of storage stability is required as a larger volume of samples are produced with equal amounts of time to analyze them. Energy-assisted analysis techniques have the potential to help ameliorate some of these issues. Presently, FTP blood, whole blood and salmon storage stability is assessed under various storage conditions, and both microwave-assisted direct transesterification and indirect ultrasound-assisted extraction techniques are assessed. It is determined that storage of FTP blood and whole blood samples at -20°C results in significant and nearly complete highly unsaturated fatty acid (HUFA) degradation compared to all other temperatures examined. This degradation is determined to be the result of hemolysis and subsequent iron release from erythrocytes initiating fatty acid peroxidation reactions. Direct transesterification of FTP blood is reduced from as long as three hours to one minute with microwave-assisted energy and fatty acid extraction from ground flaxseed is reduced to 40 minutes from as long as 24 hours without compromising fatty acid profiles. Results of the current study provides insight into the storage stability of food sample and blood samples collected via high-throughput techniques, and provides support for the utilization of further high-throughput energy-assisted analytical methods that can help to minimize the potentially detrimental effects that long-term storage can have on fatty acid profiles.

Thesis (M. Med. Sc.)--University of Hong Kong, 2009. / Includes bibliographical references (p. 47-49).

Revised; Originally published: 05/2008 / The article provides information about different types of dietary fats and promotes consumption of healthy fats in moderation as part of a balanced diet. The prevalence of fat-free products in grocery stores may give some health-conscious consumers the perception that all dietary fats are unhealthy. However, fats are absolutely vital for proper physiological functioning, and it is imperative that fats are included in a healthy diet. Fats are classified as saturated, monounsaturated, or polyunsaturated. Both types of unsaturated fats, when consumed in moderation, can help lower cholesterol and decrease the risk of heart disease, especially when they replace saturated and trans fats. We provide tips for selecting healthier fats, along with a guide for consuming appropriate portions of fat.

Docosahexaenoic acid (DHA) is an omega-3 polyunsaturated fatty acid (n-3 PUFA) required for fetal neurodevelopment. Increased DHA levels are associated with 17β-estradiol levels, as DHA is higher in women relative to men and in pregnant relative to non-pregnant women, suggesting a maternal adaptation to supply DHA to the fetus. DHA can be synthesized in the body from shorter n-3 PUFA through sequential elongation-desaturation, with Δ6-desaturase being the rate-limiting enzyme. The goal of the present thesis was to characterize the mechanism underlying higher DHA in situations of altered 17β-estradiol status by examining the expression of DHA synthesis enzymes in rodent models. Fatty acid composition of several lipid classes was measured by gas chromatography and enzyme expression was measured by RT-qPCR and immunoblotting. Hepatic Δ6-desaturase and phospholipid DHA was higher in female relative to male, and in pregnant relative to non-pregnant rats. Similarly, 17β-estradiol supplementation of ovariectomized rats resulted in increased hepatic Δ6-desaturase expression and DHA content, while ovariectomy itself had no effects on DHA levels despite controlling for hyperphagia. Mice deficient in the DNA binding activity of estrogen receptor α (ERα) had no differences in hepatic Δ6-desaturase or DHA levels. These results suggest that 17β-estradiol mediates the higher DHA levels in females and during pregnancy through increasing hepatic Δ6-desaturase expression, although the effects of removing 17β-estradiol signalling through ovariectomy or ERα disruption are less clear. This work helps to explain findings of altered DHA status in response to changes in 17β-estradiol concentrations, possibly resulting in more appropriately tailored dietary DHA recommendations. Also, increased understanding of the regulation of DHA synthesis may improve DHA yields in agri/aquaculture and enable increased content of DHA in the food supply.

Chemical, physical and sensory properties of omega-3 fatty acid enriched chicken frankfurters developed with flax oil and microencapsulated fish oil at 1.2%, 2.4% and 3.6% were evaluated. Four replicate batches of frankfurters were produced for texture profile analysis and TBARS for assessment of lipid oxidation over four weeks of refrigerated storage. Gas chromatograph analysis indicated that omega-3 fatty acid levels increased (p<0.05) with flax and fish oils treatments resulting in a shift in omega-6/omega-3 with no increase in lipid oxidation over the storage period. The two highest levels of fish oil resulted in increased redness, hardness, gumminess and chewiness (p<0.05) with the highest fish oil having the lowest rating for acceptability. 1.2 and 2.4% flax oil and 1.2% fish oil samples were softer and juicier than commercial frankfurters. Addition of oils high in omega-3 fatty acids to chicken-based frankfurters can result in product resistant to oxidation and acceptable to consumers.

The objectives of this study were to evaluate the effect of rumen-protected fish oil (RPFO) and rumen-protected marine algae (RPMA) supplements on ovarian function of lactating dairy cows on pasture or in confinement during the estrus and ovulation synchronization period. Thirty-six Holstein cows were assigned to one of the two feeding systems and fed with lipid supplements from 30d before to 100d after calving. The resumption of cyclicity and onset of estrus were not influenced by LS. Mean daily number of the large follicles was similar across the treatments. During the Ovsynch period, RPFO treated cows had larger follicles (?10mm; P<0.05). Ovulation was delayed in RPFO and RPMA group but the number of ovulation was not altered. The number and diameter of CL were greater in the RPMA group. Progesterone concentrations were greater in the RPMA group on pasture (P<0.05). These findings indicate that RPMA supplementation improves the ovarian function.