Life Extension Magazine October 2007
The Intimate Link Between Erectile Dysfunction and Heart Disease
By William Davis, MD
Natural Remedies to Enhance Erectile Function
In addition to testosterone, a number of nutritional supplements may either accentuate the effects of testosterone or enhance the artery-dilating effects of nitric oxide.
The path to a healthy erection involves multiple steps, so the “recipe” for success varies among individuals and may involve some trial and error. It’s always worth discussing your erectile function with your doctor, who may need to consider pathological causes of erectile dysfunction. A doctor’s assistance is also necessary if you are considering one of the erection-promoting drugs.
Coming back to the powerful benefits of nitric oxide, one may wonder if it can be taken as a supplement. Unfortunately, the fleeting nature of this molecule makes that impossible. But the body manufactures nitric oxide directly from L-arginine, an amino acid in the diet. The average American generally ingests up to 5.4 grams (5,400 mg) of L-arginine per day through foods, as it is naturally contained in many proteins, especially meat, nuts, and dairy products.29 This amount is generally more than adequate to serve as a substrate for nitric oxide synthesis.
L-arginine also has modest erection-promoting effects in those patients not consuming adequate amounts of L-arginine in the diet. My clinic recommends 3,000–6,000 mg, twice a day, preferably on an empty stomach. Full erection-enhancing benefit may develop slowly and may require up to three months, although some individuals do experience more immediate effects. My clinic has used L-arginine in combination with prescription drugs for erectile dysfunction without complications (e.g. abnormally sustained erections, called “priapism”), but this should be discussed with your doctor. It may be prudent to take a reduced dose of L-arginine when initiating prescription therapy for erectile dysfunction, reserving the full dose of L-arginine only as needed.
Adverse effects of L-arginine are few, such as loose stools at higher doses. Simply cut back on the dose and build up gradually if you experience this. If you have any active gastrointestinal conditions associated with diarrhea or frequent loose stools, such as ulcerative colitis, Crohn’s disease, or malabsorption, first discuss the use of L-arginine with your doctor.30
Another way of increasing nitric oxide in the body is to prevent its rapid degradation by oxygen radicals. Pomegranate and a superoxide dismutase (SOD)-enhancing nutrient called GliSODin® have been shown to favorably affect nitric oxide activity31-34 and to reverse clinical measurements associated with endothelial dysfunction in humans.35,36 In the animal model, pomegranate has been shown to increase penile blood flow and improve erectile response to stimulation.37 In a preliminary study, men with mild-to-moderate erectile dysfunction experienced modest improvements after only four weeks of consuming pomegranate juice each day.38 Pomegranate juice has been reported to mildly inhibit an enzyme pathway that degrades certain medications, though this effect is dramatically less pronounced than that produced by the common beverage grapefruit juice.39
Achieving optimal nitric oxide levels may help:40-44
Carnitine supplements may enhance erections as effectively as testosterone, according to an Italian study. Taking two forms of carnitine, propionyl-L-carnitine, 2,000 mg/day, and acetyl-L-carnitine, 2,000 mg/day, improved erectile function, modestly exceeding the benefit seen with oral testosterone. Interestingly, both testosterone and carnitine also yielded equal improvements in mood and energy.45 Another study revealed that propionyl-L-carnitine, 2,000 mg/day, when added to drug treatment with Viagra® increased the likelihood of successful erections in men who were initially unresponsive to the drug alone. Measurably improved erections increased from 23% with Viagra® alone to 68% when the supplement was added.46 Carnitine is generally considered safe and well tolerated, mild gastrointestinal symptoms being the only notable side effect.47
A deficiency of the adrenal hormone, dehydroepiandrosterone (DHEA) is also believed to play a role in erectile dysfunction. Over a decade ago, the Massachusetts Male Aging Study revealed blood levels of DHEA-sulfate (the major form of DHEA in the blood) to be closely correlated with erectile ability.2 Since then, several small trials, including one comparing DHEA, 50 mg/day, with placebo, have uncovered a significantly better erectile response in those taking DHEA.48 Individuals with hormone-dependent cancers should consult a physician before taking DHEA.
For centuries, the herb Korean ginseng has been reported to enhance sexual function and desire. Recent studies have confirmed these effects, suggesting that compounds called ginsenosides may produce a nitric oxide-dependent, artery-relaxing effect. A study using Korean ginseng showed an increase in erectile firmness and sexual satisfaction of 60% in men taking ginseng, compared with 30% in those taking placebo.49 Another study also showed a 60% response rate in men taking Korean ginseng, 900 mg three times per day, with improvements in penetration and maintenance of erection.50 Similar findings were confirmed by a recent Brazilian study, which also revealed that testosterone levels remained unchanged during supplementation, suggesting that erection-enhancing effects may not be mediated by a change in testosterone.51 Korean ginseng should not be combined with anticoagulant drugs, such as warfarin, or with nonsteroidal anti-inflammatory drugs that can increase bleeding, such as naproxen or indomethacin. Korean ginseng may decrease blood sugar levels, so you should consult a physician before combining the herb with insulin or other antidiabetic medications.52
Ginkgo biloba has displayed variable effects in enhancing erections. In one study of antidepressant-induced sexual dysfunction, 76% of men experienced improved erections and orgasmic function when given 60–240 mg of ginkgo supplement per day. Interestingly, women participants experienced an even greater improvement in sexual function than men.53 Responses can be highly variable, however, with some men experiencing dramatic improvement, while others derive no benefit. Combining ginkgo with aspirin, anticoagulant drugs such as warfarin (Coumadin®), or thrombolytic (clot-dissolving) medications may increase the risk of bleeding. Individuals with a history of hemorrhagic stroke should not use ginkgo prior to discussion with their doctor.54
Some interesting possibilities for enhancing erectile function may lie in the world of flavonoids. Flavonoids from red wine (resveratrol and others) and green tea (epigallocatechin and other green tea catechins) are emerging as facilitators of the artery-relaxing effects of nitric oxide.55
Optimizing Erectile Function: A Rational Approach
Along with a nutritional program to support and optimize erectile health, it is important for your doctor to consider whether any of your current medications are contributing to erectile dysfunction. Common culprits include antidepressant and antihypertensive medications (especially beta blockers like atenolol and metoprolol; angiotensin-converting enzyme inhibitors like lisinopril and ramipril; and calcium channel blockers like diltiazem and amlodipine). Of course, speak to your doctor before stopping any medication.
As heart disease is so closely tied to erectile function, it is also wise to discuss the possibility of hidden heart disease with your doctor if you have erectile dysfunction. Struggles with erectile function usually precede the symptoms of heart disease by several years, so the time to act is now, when your preventive actions are more likely to result in success.8 My preferred method to screen for hidden heart disease is a computed tomography (CT) basic heart scan, which yields a heart scan “score.” A CT heart scan should not be confused with a CT coronary angiogram, commonly referred to as a 64-slice CT coronary angiogram. This is performed on the same CT-scanning device, but involves the use of an X-ray dye and far more radiation exposure than the modest amount required for a basic heart scan. A heart scan score greater than zero signifies the presence of coronary plaque—the disease process underlying a heart attack. The higher the score, the greater the plaque formation. In my opinion, a distant second choice is a stress test, though bear in mind this detects only advanced heart disease.
The formula for successful relief of erectile dysfunction will vary from one man to another, but a combination of useful agents, both non-prescription and prescription, can successfully enhance erectile health in the majority. Many of the same agents that support erectile health, including carnitine, pomegranate, and DHEA, may also yield benefits in the cardiac arena.
Dr. William Davis is a practicing cardiologist in Milwaukee, Wisconsin. He is the founder of the Track your Plaque program, a heart disease prevention program that shows how to use CT heart scans to control coronary plaque. He can be contacted through www.TrackYourPlaque.com.
If you have questions about the scientific content of this article, please call one of our Health Advisors at 1-800-226-2370.
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