## 1 Introduction  
Ischemic heart disease (IHD) can present as a chronic coronary syndrome (CCS), which is a form of stable disease, or as an acute coronary syndrome (ACS) [1]. Despite different treatment options, IHD has been the leading cause of death worldwide in the last 20 years [2]. The best-known risk factors for the development of IHD are arterial hypertension, dyslipidemia, physical inactivity, obesity, diabetes mellitus, and smoking, as the aforementioned risk factors contribute to the development of atherosclerosis, which underlies IHD [3]. A healthy lifestyle, which includes smoking cessation, physical activity, a healthy diet, and the maintenance of an optimal weight, reduces the risk of subsequent cardiovascular events and mortality [4]. The fact that diet in particular can affect cardiovascular risk was previously recognized in the Seven Countries Study, which showed that the Mediterranean diet significantly reduced the risk of IHD. The Mediterranean diet is a high-fat/low-glycemic diet in which 40% of calories come from fat; however, the fat is mainly unsaturated oils, such as olive and canola oil. In the Seven Countries Study, the coronary risk in Crete (i.e., consumption of Mediterranean diet) was only 1/15 of that in Finland, where most of the consumed fat is saturated fat (along with cholesterol), and 40% of the risk in Japan, where a low-fat diet emphasizing fish is practiced [5]. N-3 polyunsaturated fatty acids (n-3 PUFAs), but also some other nutrients, for example, selenium as a trace element, vitamin E, and the carotenoid lutein, have health-promoting effects and reduce cardiovascular risk, as shown in numerous studies [4; 6; 7; 8]. The Mediterranean diet, rich in n-3 PUFAs, can modulate endothelial function and contribute to better vascular homeostasis balance in IHD patients, even if severe endothelial dysfunction is present. Replacing saturated fats with unsaturated fats, especially PUFAs, also reduces the risk of IHD [4]. This idea is supported by the fact that a lower risk of coronary artery disease (CAD) is linked with the consumption of fish (known for being rich in n-3 PUFAs) at least once a week [6]. N-6 PUFAs are considered proinflammatory, while n-3 PUFAs are considered anti-inflammatory; when there is a higher ratio of n-6/n-3 PUFAs, there are more mediators, such as prostaglandin series 2 (PGI2), leukotriene series 4 (LTB4), and thromboxane B series 2 (TXB2), that act as vasoconstristors, activate platelets, and are proinflammatory. When the n-3 PUFA concentration is higher and the n-6/n-3 PUFA ratio is lower, then the production of anti-inflammatory and vasodilator mediators such as PGI3, LTB5, and TXA3 dominates. Therefore, an unbalanced n-6/n-3 PUFA ratio in favor of n-6 PUFAs has a orthrombolic and proinflammatory effect, which contributes to the development of atherosclerosis [9; 10]. In addition, some micronutrients have been shown to be beneficial in maintaining health. One of them is selenium. Selenium is essential for the function of many enzymes involved in the regulation of the inflammatory response, the proliferation and differentiation of immune cells, and the migration and adhesion of leukocytes. Moreover, selenium is a part of antioxidant mechanisms; selenium increases the antioxidant capacity and affects nuclear factor kappa B (NF-kB) signaling pathways, reducing the production of tumor necrosis factor alpha (TNF-\(\alpha\)) and proinflammatory interleukins [11]. Lutein has anti-inflammatory and atheroprotective effects in patients with CAD. Serum lutein levels are inversely proportional to the levels of proinflammatory cytokines (e.g., TNF-\(\alpha\), interleukin 6 (IL-6)) and oxidized low-density lipoprotein cholesterol (OxLDL) [8]. Overall, functional foods rich in these nutrients could play a role in the prevention and treatment of various cardiovascular diseases.