Impact of n-3 Docosapentaenoic Acid Supplementation on Fatty Acid Composition in Rat Differs Depending upon Tissues and Is Influenced by the Presence of Dairy Lipids in the Diet

Docosapentaenoic acid-rich oil lowers plasma glucose and lipids in a mouse model of diabetes and mild obesity

Many studies have investigated the beneficial effects of n-3 polyunsaturated fatty acids, such as their potential for lowering lipid levels and reducing diabetes risk. However, few studies have specifically examined docosapentaenoic acid (DPA), an n-3 polyunsaturated fatty acid with limited availability in its pure form. We hypothesized that DPA would have lipid-lowering effects and improve insulin resistance in KK/Ta mice. To test our hypothesis, 7-week-old KK/Ta mice were fed a high-fat diet for 12 weeks to induce obesity before being divided into 3 groups and fed an experimental diet for 10 weeks. The experimental diets were: LSO, using lard and safflower oil as fat sources; SO, in which lard in the LSO diet was replaced with safflower oil; and DPA, in which lard in the LSO diet was replaced with DPA oil. After 10 weeks, plasma triglyceride and total cholesterol concentrations were significantly decreased in the DPA group, but not in the SO group. Sterol regulatory element-binding protein-1 and stearoyl-CoA desaturase-1 gene expressions involved in fatty acid synthesis in the liver were significantly lower in the DPA group compared with the LSO group. Plasma glucose concentrations were significantly decreased in both the SO group and the DPA group compared with the LSO group, whereas plasma insulin concentrations were significantly decreased in the DPA group alone. These results indicate that DPA has plasma lipid-lowering and hypoglycemic effects, possibly from suppression of fatty acid synthesis in the liver.

Elevated plasma phospholipid n-3 docosapentaenoic acid concentrations during hibernation

Factors for initiating hibernation are unknown, but the condition shares some metabolic similarities with consciousness/sleep, which has been associated with n-3 fatty acids in humans. We investigated plasma phospholipid fatty acid profiles during hibernation and summer in free-ranging brown bears (Ursus arctos) and in captive garden dormice (Eliomys quercinus) contrasting in their hibernation patterns. The dormice received three different dietary fatty acid concentrations of linoleic acid (LA) (19%, 36% and 53%), with correspondingly decreased alpha-linolenic acid (ALA) (32%, 17% and 1.4%). Saturated and monounsaturated fatty acids showed small differences between summer and hibernation in both species. The dormice diet influenced n-6 fatty acids and eicosapentaenoic acid (EPA) concentrations in plasma phospholipids. Consistent differences between summer and hibernation in bears and dormice were decreased ALA and EPA and marked increase of n-3 docosapentaenoic acid and a minor increase of docosahexaenoic acid in parallel with several hundred percent increase of the activity index of elongase ELOVL2 transforming C20-22 fatty acids. The highest LA supply was unexpectantly associated with the highest transformation of the n-3 fatty acids. Similar fatty acid patterns in two contrasting hibernating species indicates a link to the hibernation phenotype and requires further studies in relation to consciousness and metabolism.

Organic versus Conventional Raw Cow Milk as Material for Processing

Milk, as one of the basic raw materials of animal origin, must be of adequate hygienic and physicochemical quality for processing. The aim of the article was to compare the quality of raw milk from three production systems, intensive, traditional (together referred to as conventional), and organic, as material for processing, as well as the quality of products made from it. Particular attention was focused on hygienic quality (somatic cell count and total bacterial count), physical characteristics (acidity), basic nutritional value (content of dry matter, total protein, casein, fat, and lactose), content of health-promoting substances (whey proteins, fatty acids, vitamins, and minerals), and technological parameters (rennet clotting time, heat stability, and protein-to-fat ratio). Research assessing the quality of organic milk and dairy products is significantly less extensive (if available at all) than for milk from conventional production (intensive and traditional). The available reports indicate that raw milk from organic farms is more valuable, especially in terms of the content of health-promoting compounds, including vitamins, fatty acids, whey proteins, and minerals. This applies to organic dairy products as well, mainly cheese and yoghurt. This is explained by the fact that organic farming requires that animals are kept in the pasture. However, the hygienic quality of the raw milk, and often the products as well, raises some concerns; for this reason, organic milk producers should be supported in this regard, e.g., through consultancy and training in Good Hygienic Practices. Importantly, milk production in the traditional and organic systems is in line with the concept of the European Green Deal.

The Future of Lipid-lowering Therapy

The recent introduction of inhibitors of proprotein convertase subtilisin/kexin 9 to lower low-density lipoprotein (LDL) cholesterol on top of statins or as monotherapy is rapidly changing the landscape of treatment of atherosclerotic cardiovascular disease (ASCVD). However, existing lipid-lowering drugs have little impact on lipoprotein(a) (Lp(a)) or plasma triglycerides, two other risk factors for ASCVD. This review summarizes the evidence and the rationale to target Lp(a) and triglycerides and provides an overview of currently tested strategies to lower Lp(a), apolipoprotein C-III and angiopoietin-like protein 3. In addition, it summarizes new findings on the use of omega-3 fatty acids (OM3FA) to fight ASCVD. With the exception of OM3FA supplementation, the promise of the experimental drugs discussed here depends on the long-term safety and efficacy of monoclonal antibodies and/or antisense oligonucleotides Clinical outcome trials will ultimately prove whether these new therapeutic modalities will reduce ASCVD risk.

Comparative effects of dietary n-3 docosapentaenoic acid (DPA), DHA and EPA on plasma lipid parameters, oxidative status and fatty acid tissue composition

The specific and shared physiologic and metabolic effects of eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and even more of n-3 docosapentaenoic acid (DPA) are poorly known. We investigated the physiological effects and the overall fatty acid tissue composition of a nutritional supplementation of DPA compared both to EPA and DHA in healthy adult rats. Rats (n=32) were fed with semisynthetic diets supplemented or not with 1% of total lipids as EPA, DPA or DHA in ethyl esters form from weaning for 6 weeks. Fatty acid tissue composition was determined by gas chromatography-mass spectrometry, and blood assays were performed. The DPA supplementation was the only one that led to a decrease in plasma triglycerides, total cholesterol, non-high-density lipoprotein (HDL)-cholesterol, cholesterol esters and total cholesterol/HDL-cholesterol ratio compared to the nonsupplemented control group. The three supplemented groups had increased plasma total antioxidant status and superoxide dismutase activity. In all supplemented groups, the n-3 polyunsaturated fatty acid level increased in all studied tissues (liver, heart, lung, spleen, kidney, red blood cells, splenocytes, peripheral mononucleated cells) except in the brain. We showed that the DPA supplementation affected the overall fatty acid composition and increased DPA, EPA and DHA tissue contents in a similar way than with EPA. However, liver and heart DHA contents increased in DPA-fed rats at the same levels than in DHA-fed rats. Moreover, a large part of DPA seemed to be retroconverted into EPA in the liver (38.5%) and in the kidney (68.6%). In addition, the digestibility of DPA was lower than that of DHA and EPA.