It would appear that scientists at the Atatürk Teaching and Research Hospital in Ankara, Turkey have found a tasty alternative to Viagra. According to their study conducted on 17 married male patients, who have suffered from erectile disfunction (ED) for at least 12 months, a diet of 100 g of pistachio nuts daily, which corresponds to 20% of the daily calorie intake, for 3 weeks improved all five domains of International Index of Erectile Function (IIEF) scores. The five domains are EF, erectile function; IS, sexual intercourse satisfaction; OF, orgasmic function; OS, overall satisfaction; SD, sexual desire. After the 3-week pistachio diet the mean IIEF-15 score jumped very significantly from 36±7.5 to 54.2±4.9.

Pistachio nuts are high in unsaturated fatty acids, low in saturated fatty acids and are a rich source of plant proteins (particularly high in nonessential amino acid arginine), dietary fibers, antioxidants (resveratrol and anthocyanins) and phytosterols (β-sitosterol). As such they have the ability to lower cholesterol, improve endothelium-dependent vasodilation and protect the blood vessels from oxidative damage which can lead to atherosclerosis and stiffening of the arteries.

This effect was confirmed in previous studies where people who ate nuts (any nuts, not just pistachio) 1–4 times per week had a 25% reduced risk of dying from coronary heart disease, compared to people who ate them less than once per week; those who ate nuts at least 5 times per week showed a 50% reduction in risk. This was the first study however to take a look at the effect of nut consumption on erectile disfunction.

Penile erection is a complex hemodynamic process involving increased arterial inflow and restricted venous outflow, coordinated with corpus cavernosum and penile arterial smooth muscle relaxation. A problem at any of these stages can result in ED. Many previous studies have shown a link between ED and cardiovascular disease, but this study specifically showed that eating pistachio nuts can significantly lower many well recognised cardiovascular risk factors such as cholesterol (HDL, high-density lipoprotein; LDL, low-density lipoprotein; TC, total cholesterol), TC (from 179.5 to 148.3 mg/dl), LDL (from 106.1 to 84.8 mg/dl), TC/HDL (from 4.3 to 2.4), LDL/HDL (from 2.6 to 1.4), and increase HDL (from 42 to 62.1 mg/dl). Although statistically not significant, a decrease in triglyceride (TG) levels was also found. In addition, TG/HDL ratio (from 4 to 2.1) was significantly decreased.

On the other hand testosterone levels were reduced from 452.1±163.4 to 379.1±95 ng/dl, which can be attributed to significant amounts of phytosterols found in pistachio nuts, with serum prolactin levels remaining unaffected. In addition blood platelet counts showed a significant decrease after the diet from 305.6 to 242.4 (P=0.028), which could explain the improvement in blood flow and PCDU parameters.

The study found improvements in blood vessel relaxation and endothelium-dependent vasodilatation by measuring significantly increased peak systolic velocity (PSV) values using penile color Doppler ultrasound (PCDU). End diastolic velocity (EDV) values also showed an improvement, however it was not statistically significant.

The findings of this study will come as little surprise to Austrians, who have long been claiming that their Pumpkin Seed Oil is an aphrodisiac. They were even producing chocolate coated pumpkin seeds and marketing them as Styriagra, until Viagra maker Pfizer decided to put an end to their rather cheeky insinuation with a lawsuit.

Perhaps the Turkish scientists should be taking a closer look at pumpkin seeds next, as they have long been used to alleviate the symptoms of benign prostatic hyperplasia (BPH) or enlarged prostate. They contain high amounts of essential minerals such as zinc, which can help prevent testosterone deficiency and is also essential for the production of sperm. There are even claims that zinc prevents the build up of dihydrotestosterone, which is responsible for male pattern baldness and apparently pumpkin seeds can also boost female sexual function and enable better sexual lubrication.

L.G.