Pistachio Diet Improves Erectile Function Parameters and Serum Lipid Profiles in Patients with Erectile Dysfunction
We investigated the effects of Antep pistachio on International Index of Erectile Function (IIEF) scores, penile color Doppler ultrasound (PCDU) parameters and serum lipid levels in patients with ED. A total of 17 married male patients with ED for at least 12 months were included in this prospective study. Patients were put on a 100 g pistachio nuts diet for 3 weeks. IIEF and PCDU were evaluated before and after the pistachio diet. In addition, plasma total cholesterol (TC), low-density lipoprotein (LDL), high-density lipoprotein (HDL) and triglyceride were measured before and after dietary modifications from all subjects. Mean IIEF-15 score was 36±7.5 before the diet and 54.2±4.9 after the diet (P=0.001). Similarly, an increase in all five domains of IIEF was observed after the diet (P<0.05). Mean peak systolic velocity values before and after the pistachio diet were 35.5±15.2 and 43.3±12.4 cm s–1, respectively (P=0.018). After the pistachio diet, TC and LDL levels decreased significantly, whereas HDL level increased (P=0.008, 0.007 and 0.001, respectively). We demonstrated that a pistachio diet improved IIEF scores and PCDU parameters without any associated side effects in patients with ED. Furthermore, the lipid parameters showed statistically significant improvements after this diet.
Penile erection is a hemodynamic process involving increased arterial inflow and restricted venous outflow, coordinated with corpus cavernosum and penile arterial smooth muscle relaxation. Any problem in this mechanism results in ED, and its etiology is generally multifactorial. Diabetes, hypertension, high serum cholesterol level, peripheral vascular disease and cardiac problems are significantly found together with ED. However, vascular reasons predominate in the etiology of ED and it frequently appears along with atherosclerosis. It is known that atherosclerotic lesions prevent blood flow into cavernosal tissues resulting in ED.
Pistachio (Pistacia vera L.), a member of the Anacardiaceae family, is a native of the arid zones of Central and West Asia and distributed throughout the Mediterranean basin. In Turkey, the pistachio is grown mainly in the city of Gaziantep. Pistachio nuts are rich sources of plant proteins, dietary fibers and especially antioxidant substances (for example, antioxidant vitamins), besides being high in unsaturated fatty acids and low in saturated fatty acids (Table 1), which may also have cardioprotective effects.[5,6] Endothelial dysfunction, characterized by impaired nitric oxide bioavailability, precedes the development of atherosclerotic lesions and has been suggested as an important link between ED and cardiovascular disease.[7,8]
Epidemiological studies have demonstrated an association between nut consumption and coronary heart disease. Compared with people who ate nuts less than one time per week, those who ate them 1–4 times per week had a 25% reduced risk of dying from coronary heart disease; people who ate nuts at least 5 times per week showed a 50% reduction in risk. The American Heart Association recommends up to 20% of calories from monounsaturated fat and substituting unsaturated fat from vegetables and nuts.
Although various studies exist regarding the positive effects of pistachio nuts on serum lipid profiles, to the best of knowledge, its effect on ED has not been investigated yet. In our study, we investigated the effects of pistachio nuts on International Index of Erectile Function (IIEF) scores, penile color Doppler ultrasound (PCDU) and serum lipid levels in patients with ED.