Lipids in functional foods, nutraceuticals and supplements

In recent decades, there has been a growing interest in the concept of ‘functional foods’ within the food industry and from the consumers, but although many definitions exist for functional foods, an official, internationally accepted definition is still missing. The concept of functional foods derives from the awareness that specific components of the diet have beneficial effects on the health and well-being and have a potential role in reducing risks of disease. Some foods which are commonly consumed in the daily diet, such as fruits, vegetables, grains, fish and dairy products, are widely studied for their many natural components that contribute benefits beyond those of basic nutrition. An important group of compounds within unsaturated fatty acids are the long-chain (C16–C20), PUFA (LC-PUFAs). Humans can synthesize certain fatty acids, but are unable to desaturate long-chain fatty acids at either C3 or C6 from the methyl end, making them essential. Examples of foods rich in v-3 PUFA are anchovies, sardines, mackerels and other fatty fish. Plant sterols (or phytosterols), the formulations and effects of which have been recently reviewed in EJLST [1], are naturally contained in vegetables oils, cereals, tree nuts and legumes, represent another important group of fat components widely studied for their capacity of lowering serum concentrations of cholesterol. This effect occurs because plant sterols, being structurally similar to cholesterol, reduce its absorption from the gut. Functional foods can be traditional foods or foods in which one or several components have been modified, removed or reduced (e.g. a yoghurt with reduced fat), added (e.g. spread with added phytosterols), replaced or enhanced (e.g. a juice with enhanced antioxidant content) to improve the benefits. This can also be achieved through innovative technological approaches developed by the food industry. Results from epidemiologic and clinical studies have indicated that the consumption ofv-3 PUFAs, namely eicosapentaenoic acid (EPA) and docosaesaenoic acid (DHA), and of phytosterols (mainly b-sitosterol, campesterol and stigmasterol) have positive effects in decreasing risk factors of cardiovascular diseases. Several groups studied the incorporation of phytosterols in various foods rich in fats, such as margarine, salad dressing, cream-cheese, milk and yogurt [2–4]. In double-blind placebocontrolled randomized studies, it has been demonstrated that the consumption of phytosterolenriched fermented milk was associated with a significant decrease in plasma concentrations of low-density-lipoprotein cholesterol as compared with the consumption of placebo [5–7]. The lipid-lowering effect of milk enriched with v-3 PUFAs has also been investigated in various clinical trials [9]. Milk fat is considered an efficient vehicle to favour the adsorption of fat and lipid-soluble compounds (v-3 PUFAs, oleic acid, vitamin E, etc.), because of its dispersion in very small micelles [7, 8]. The formulations, sources and effects of v-3 PUFAs on human and animal health have been widely considered in studies published in EJLST [10–12]. This special issue on ‘Lipids in Functional Foods’ focuses on: (i) new sources for lipids with health beneficial properties to improve the value of low quality foods, and (ii) innovative technological approaches to enhance their analysis, extraction procedures or to enrich the nutritional profile of traditional foods. Caramia and colleagues [p. 375–388] reviewed current studies on extra virgin olive oil as a traditional ‘fat’ functional food, providing components of great interest for the reduction of risk factors for several pathological conditions. The antioxidant activities of the constituents of vegetable oils have been investigated by Nakbi et al. [p. 469–478] in adult rats. Murine models have been exploited by Xiao and colleagues [p. 461–468] to study the beneficial effects of coldpressed flaxseed oils, enriched with vitamin E, on lipid profile and antioxidant status. Triacylglycerols, the main components of edible oils, differ in the total length of acyl chains Cinzia Ballabio