Reference
Aldemir M, Okulu E, Neselioglu S, Erel O, Kayigil O. Pistachio diet improves erectile function parameters and serum lipid profiles in patients with erectile dysfunction. Int J Impot Res. 2011;23(1):32-38.
Design
An uncontrolled prospective intervention trial
Study Participants
17 married men with complaints of erectile dysfunction for a minimum of 12 months
Intervention and Design
Participants consumed 100 grams/day of pistachio nuts (Pistacia vera L.) for 3 weeks. International Index of Erectile Function (IIEF) scores and penile color Doppler ultrasound (PCDU) were tested before and after the pistachio diet. Total cholesterol (TC), low-density lipoprotein (LDL), high-density lipoprotein (HDL), and triglycerides were also measured before and after dietary intervention.
Key Findings
IIEF score increased by 151% after the diet. TC and LDL levels decreased significantly, whereas HDL level increased.
Practice Implications
Although the effect of nut and particularly pistachio consumption on lipid levels is well established (see NMJ Review on Pistachios, 2010), the reported benefit in erectile dysfunction may be unique only to pistachios.
In April 2010, Sari et al reported that a diet high in pistachios improved blood glucose levels, endothelial function, and some indices of inflammation and oxidative status in healthy young men. The 32 participants in the Sari study followed a Mediterranean style diet for 4 weeks prior to instituting the pistachio phase. After the month of eating pistachios, low-density lipoprotein had dropped by 23% and total cholesterol by 21%. The pistachio diet significantly improved endothelium-dependent vasodilation (P=0.002, 30% relative increase), decreased serum interleukin-6, total oxidant status, lipid hydroperoxide, and malondialdehyde and increased superoxide dismutase.1
Given these collected data, we should feel confident at encouraging pistachio consumption for patients with undesirable cardiovascular risk factors, and we should now entertain the same prescription for those with erectile dysfunction.
A July 2010 paper suggested that the Mediterranean diet in itself could improve erectile function.2 Thus the fact that Sari’s paper used a 4-week run-in with participants following the Mediterranean diet makes their results seem more significant.
A June 2010 paper by Li et al compared pistachios against pretzels as a snack food eaten during a weight loss program. Despite the common belief that high-fat snacks will lead to weight gain, eating pistachios as an afternoon snack led to more significant decreases in body mass than did eating pretzels. Triglyceride levels in the pistachio consumers were 39% lower than in the pretzel group.1
Two other papers on pistachio consumption and CVD risk factors, Kay et al and Gebauer et al, published 2008 and 2010 respectively, were reviewed in the May 2010 issue of this journal. To briefly summarize, Kay reported in 2008 that eating 2 servings of pistachios per day dropped cholesterol by 8%, LDL by 11% and the non-HDL cholesterol/HDL cholesterol ratio by 10%.3 In 2010, analyzing blood samples retained from Kay’s initial 2008 study, Gebauer reported that eating pistachios had had a significant impact on reducing levels of oxidized LDL.4
Given these collected data, we should feel confident at encouraging pistachio consumption for patients with undesirable cardiovascular risk factors, and we should now entertain the same prescription for those with erectile dysfunction.
