Cholesterol-lowering potential in human subjects of fat from pigs fed rapeseed oil

The future is bright: Biofortification of common foods can improve vitamin D status

Vitamin D deficiency is a global concern, linked to suboptimal musculoskeletal health and immune function, with status inadequacies owing to variations in UV dependent cutaneous synthesis and limited natural dietary sources. Endogenous biofortification, alongside traditional fortification and supplement usage is urgently needed to address this deficit. Evidence reviewed in the current article clearly demonstrates that feed modification and UV radiation, either independently or used in combination, effectively increases vitamin D content of primary produce or ingredients, albeit in the limited range of food vehicles tested to date (beef/pork/chicken/eggs/fish/bread/mushrooms). Fewer human trials have confirmed that consumption of these biofortified foods can increase circulating 25-hydroxyvitamin D [25(OH)D] concentrations (n = 10), which is of particular importance to avoid vitamin D status declining to nadir during wintertime. Meat is an unexplored yet plausible food vehicle for vitamin D biofortification, owing, at least in part, to its ubiquitous consumption pattern. Consumption of PUFA-enriched meat in human trials demonstrates efficacy (n = 4), lighting the way for exploration of vitamin D-biofortified meats to enhance consumer vitamin D status. Response to vitamin D-biofortified foods varies by food matrix, with vitamin D₃-enriched animal-based foods observing the greatest effect in maintaining or elevating 25(OH)D concentrations. Generally, the efficacy of biofortification appears to vary dependent upon vitamer selected for animal feed supplementation (vitamin D₂ or D₃, or 25(OH)D), baseline participant status and the bioaccessibility from the food matrix. Further research in the form of robust human clinical trials are required to explore the contribution of biofortified foods to vitamin D status.

Effect of dietary lard containing higher alpha-linolenic acid on plasma triacylglycerol in rats

It is well known that the consumption of n-3 polyunsaturated fatty acid (PUFA) decreases the plasma triacylglycerol (TAG) level. The technology of elevating the content of n-3 PUFAs in pig meat has already reached a practical level. In this study, the effects of dietary lard containing higher alpha-linolenic acid (LNA) on plasma TAG were compared with those of normal lard in rats. The rats were fed a diet containing either 10% normal lard or a high linolenic lard for 4 weeks. The plasma and liver TAG levels in the high linolenic lard group were significantly lower than those in the normal lard group. The activity of the fatty acid synthase (FAS) of the liver in the high linolenic lard group was significantly lower than that in the normal lard group. The contents of n-3 PUFAs in hepatic total lipid, TAG fraction, and the phospholipids (PLs) fraction increased in the high linolenic lard group. The results indicate that the high linolenic lard suppressed hepatic FAS activity compared with the control lard, resulting in a lower concentration of plasma TAG. These results also suggest that pig meat containing high LNA may be more nourishing than normal pig meat.

Pork meat: a good source of selenium?

The knowledge about Se bioavailability from animal food is sparse. This study was therefore initiated in order to evaluate the bioavailability of Se from pork meat in humans. Twelve male volunteers (age 21-30 years) participated in a randomised crossover study with strictly controlled diet containing 170 g pig meat/10 MJ per day and 106 +/- 13 microg Se/d for 3 x 3 weeks. Complete faecal and urinary collections were made during the last week of each period. Bioavailability was evaluated from absorption and retention of Se and changes in plasma Se concentration and blood glutathione peroxidase (GSHPx) activity. The apparent absorption of Se was 94 +/- 2% (100 +/- 13 microg/d). Faecal and urinary excretion were 7 +/- 1 microg/d and 39 +/- 21 microg/d, respectively, resulting in a retention of 61 +/- 24 microg/d. The diet intervention did not affect plasma Se concentration and GSHPx activity. Absorption and retention of Se from pig meat were high suggesting a high availability. However, the availability of pig meat Se for blood Se protein appears to be low.

Can human micronutrient status be improved by supplementing domestic animals?

Micronutrient deficiencies are a major problem throughout the world and hundreds of millions of the world's population are affected by micronutrient deficiency disorders. In Europe the prevalence of clinical micronutrient deficiency disorders is less than that in the Third World. However, marginal deficiency of some of the micronutrients might be involved in the aetiology of many of the so-called lifestyle diseases, e.g. cancer, cardiovascular diseases, diabetes, osteoporosis. Supplementing domestic animals with micronutrients in excess of their needs could be one strategy to increase the intake and, thereby, status of micronutrients in the human population. This approach should, however, be considered carefully, in relation to both animal and human welfare. Many micronutrients that may accumulate in animal foods are toxic in high doses. It would also be unethical to expose animals to doses that might have deleterious effects on their health, and concentrations in animal products that might have adverse effects when consumed by man should be avoided. Furthermore, food quality should not be impaired by the supplement. On the other hand, to be relevant in relation to human nutrition, the given micronutrient should accumulate in animal tissue in concentrations that make an important contribution to total intake. Finally, the micronutrient should be incorporated in a way and in a form that is bioavailable to man, i.e. is well absorbed and utilized.

Effects of dietary conjugated linoleic acid on fatty acid composition and cholesterol content of hen egg yolks

The main objectives of the present study were to determine the effect of dietary conjugated linoleic acid (CLA) isomers on the fatty acid composition and cholesterol content of egg-yolk lipids. Forty-five 25-week-old laying hens were randomly distributed into five groups of nine hens each and maintained in individual laying cages, throughout 12 weeks of the experiment. They were assigned to the five treatments that consisted of commercial layer diets containing 0, 5, 10, 15 or 20 g pure CLA/kg. Feed intake of hens varied little and insignificantly. Egg mass was uniformly lower (P<0.05) in the hens fed the CLA-enriched diets. Feed conversion efficiency, when expressed per kg eggs, was impaired (P<0.05), although without obvious relation to the dietary CLA concentration. Feeding the CLA-enriched diets resulted in gradually increasing deposition of CLA isomers (P<0.01) in egg-yolk lipids. Saturated fatty acids were increased (P<0.01) and monounsaturated fatty acids decreased (P<0.01). Polyunsaturated fatty acids (PUFA), when expressed as non-CLA PUFA, were also significantly decreased (P<0.01). The most striking effects (P<0.01) were observed for palmitic (16 : 0) and stearic (18 : 0) acids, which increased from 23.6 to 34 % and from 7.8 to 18 %, respectively. On the other hand, oleic acid (18 : 1n-9) decreased from 45.8 to 24.3 %. Among non-CLA PUFA, linoleic (18 : 2n-6) and alpha-linolenic (18 : 3n-3) acids were strongly (P<0.01) decreased, from 14.2 to 7.7 % and from 1.3 to 0.3 %, respectively. The same was true for arachidonic (20:4n-6) and docosahexaenoic (22 : 6n-3) acids. The cholesterol content of egg yolks, when expressed in mg/g yolk, was not affected by the dietary CLA concentrations. In conclusion, unless the adverse effects of CLA feeding to laying hens on the fatty acid profile of egg yolks are eliminated, the CLA-enriched eggs cannot be considered functional food products.