Overview 

Erectile dysfunction (ED) may not be life-threatening, but it can be a life-changing issue for many men. In addition to contributing to a sense of inadequacy, the psychological impact of being unable to achieve or maintain an erection may affect personal relationships and even performance at work. The situation is often further complicated by being too embarrassed to discuss the problem with a medical professional. 

While ED primarily affects middle-aged men, this condition can occur at any age for a variety of reasons, including injury, medications, and medical conditions, such as heart disease. However, prior to public awareness of the subject (due in part to the appearance of drugs such as sildenafil citrate, better known as Viagra®), ED was generally thought to be purely psychological in nature. Today, the medical profession recognizes ED as being the result of a disruption somewhere in the integrative processes that allows an erection to occur—a combination of emotional response, hormones, nerve impulses and blood vessels. For most men, this imbalance usually stems from an underlying medical issue or the side effects of medication. Another movement that has occurred in recent years is to refrain from referring to this condition by the outdate term of impotence. 

How an Erection Occurs 

Obtaining an erection is a complex event. To understand how an erection can fail it is necessary to understand how it occurs in the first place. Aside from being driven by emotional, chemical and physical stimuli, the penis is actually being regulated by the brain, which is hard at work sending signals to penile endothelial cells and specialized neurons to release nitric oxide, an event that sets off a chain of biological actions. First, the release of nitric oxide triggers an enzyme called guanylate cyclase to become active, which then produces cyclic guanosine monophosphate (cGMP) to promote relaxation of the smooth muscles of the penis. This permits blood to flow into and expand the spongy tissue of the dual columns of the corpus cavernosum, while restricting the return of blood from the veins at the same time. In effect, this traps blood in the penis and an erection is achieved. As long as sexual excitement is maintained, blood flow and containment continues and the penis remains erect or, to use the medical term, in a state of tumescence. 

After ejaculation, or when sexual stimulation ceases, blood flow returns to normal and the penis returns to a flaccid state. This happens when phosphodiesterase type 5 enzymes (PDE5) become active to degrade cGMP. The brain responds by triggering the release of norepinephrine to the genitals to restrict blood flow in the penis. Herein lie a few different mechanisms by which an approach to treating ED may be taken—increasing nitric oxide utilization and inhibiting norepinephrine and PDE5. Prescription drugs such as Viagra® or Cialis® effectively take the latter course, but present certain side effects and risks. In addition, these medications don’t always work or are not appropriate for all men. For instance, men who must take blood thinners or nitrate drugs due to high blood pressure or heart disease, or those who may be at risk for prostate cancer, are not suitable candidates for these medications. 

Causes and Risk Factors 

One reason that many men may become unable to maintain an erection is the decrease in the availability of testosterone as he ages. As testosterone levels fall off, the activity of certain enzymes, such as aromatase and 5-alpha reductase, increase and promote the conversion of testosterone into androgens of a different type—namely, estrogen and dihydrotestosterone, respectively. However, this conversion cannot always be blamed as a cause of ED since some men with normal levels of testosterone also experience this condition. Therefore, a physical cause may be suspect. 

Common Physical Causes of ED 

Atherosclerosis (hardening of the arteries)

Heart disease

High blood pressure

Metabolic disorders (such as diabetes)

Obesity

Disease (such as Parkinson’s, Multiple Sclerosis, etc.)

Injury to the groin area

In addition, a man’s mental and emotional status may play a role in his being susceptible to ED, including the presence of: 

Chronic stress

Depression

Anxiety disorders

Relationship difficulties (frequent arguing, lack of communication, etc)

Finally, certain medications or mood-altering substances may promote ED, including: 

Excessive alcohol consumption

Smoking

Drug abuse

Prescription medications (including some prostate cancer treatments) 

Diagnosis 

Most men will experience an inability to produce or sustain an erection on occasion and this is perfectly normal. Clinical ED, however, is defined by an inability to maintain an erection during sexual relations 25% or more of the time. 

During screening for ED, the physician will no doubt inquire about your medical history, alcohol consumption and, possibly, the quality of the relationship with your partner. In addition, the physician will likely pursue a range of other diagnostic tools, including: 

Blood tests to measure testosterone levels and rule out other underlying conditions, such as diabetes. 

Dynamic infusion cavernosometry and cavernosography or DICC, which is a test usually administered by a urologist using local anesthesia to simulate blood flow in and out of the penis by injecting a dye into penile blood vessels. 

Nerve tests to ascertain of there is any nerve damage in the genital region. 

Ultrasound to detect possible difficulties with penile blood flow. 

Nocturnal tumescence test, which is a simple matter of placing a band of perforated tape around the penis while the patient sleeps to determine if nocturnal erections occur, indicating that the cause of ED may not be physical. 

Recommended Supplements in the Treatment of Erectile Dysfunction 

The primary goal of treatment of ED is to increase testosterone and nitric oxide availability while inhibiting aromatase and 5-alpha reductase. In addition, a low fat diet and adequate exercise can help to keep other physical causes in check by helping to maintain stable blood glucose, blood pressure and a healthy weight. There are several nutrients that can help to achieve these goals. 

DHEA 

The progressive decline of available DHEA, or dehydroepiandrosterone, has also been linked to ED and some studies indicate that DHEA replacement therapy may improve symptoms in some men. While DHEA does not exhibit androgenic activity itself, certain enzymes found in the skin, muscles, bone and brain can convert DHEA into testosterone. In addition, there is evidence that adequate DHEA levels offer a protective effect against the development of diabetes type II and arteriosclerosis, as well as helping to lower serum triglycerides. 

Arginine 

Arginine is an amino acid involved with nitric oxide production in the body and may help to improve penile blood flow. Furthermore, arginine may provide additional benefits in terms of other factors related to nitric oxide metabolism, such as improved functioning of the endothelium and relaxing vascular smooth muscle, both of which contribute to reducing blood pressure and the risk of arteriosclerosis. 

Resveratrol 

Derived from red grapes, this natural antioxidant provides multiple benefits for men at risk for ED. For one thing, resveratrol inhibits aromatase, the enzyme responsible for converting testosterone into estrogen. For another, resveratrol provides protection from free radical damage, promotes healthy vascular functioning and improves insulin sensitivity, an important factor in the prevention and management of diabetes type II. 

Herbs Used in the Treatment of Erectile Dysfunction 

French Maritime Pine Bark 

Pycnogenol, obtained from the bark of French maritime pine, has been shown to be a natural nitric oxide enhancer. In fact, it mimics the enzyme that converts arginine into nitric oxide, making these two substances a dynamic pair when taken together. One study that combined pycnogenol and arginine therapy involving 40 men with ED resulted in more than 90% of the group experiencing full erections after three months of treatment.  

Horny Goat Weed 

Setting the humorous name aside, this herb has long been associated with improved sexual performance. Recently, researchers have uncovered the science behind the myth with the discovery of an agent known as icariin. Since then, several studies have shown that this substance works by improving nitric oxide availability, as well as improved pressure in the corpus cavernosum. 

Yohimbe 

Derived from the bark of an African evergreen, yohimbe has had a long reputation as an aphrodisiac, the merit of which has now been scientifically established. In fact, it has been used by various cultures as a treatment for ED and is a regulated medication in some countries. Its primary mechanism of action is to block norepinephrine at receptor sites. Researchers have also investigated the possibility of combining yohimbe with a nitric oxide inhibitor, specifically arginine. One recent study demonstrated that this combined therapy was significantly effective. At the same time, the researchers noted that this therapy did not present the risk of interacting with nitrate medications, unlike many conventional prescription drugs for ED currently on the market. 

Fenugreek 

Researchers have recently isolated and identified a compound found in fenugreek known as fenuside that shows promise as an effective and natural treatment for ED. It’s benefit is two-fold—it not only increases testosterone production, but also behaves in a manner similar to this hormone by binding to testosterone receptor sites and promoting testosterone-driven activity. A number of animal studies indicate that fenuside is comparable in efficacy to the popular prescription drug Viagra®. The results of more studies using human subjects are expected soon. 

Saw Palmetto 

Saw palmetto has been shown to inhibit 5-alpha reductase, as well as dihydrotestosterone at receptor sites. In fact, it has been studied fairly extensively for its benefit to men with prostate issues, including cancer. In addition, the herb also stimulates the relaxation of smooth muscles.

Safety Precautions 

DHEA 

Avoid DHEA if you have an estrogen-related cancer, such as breast, uterine or ovarian cancer. DHEA should also be avoided in the presence of prostate cancer. 

Do not take if you are pregnant or nursing. 

Arginine 

Arginine (L-arginine) can stimulate growth hormone and should not be taken if you have cancer. 

Arginine may encourage outbreaks of herpes simplex. 

Supplementation should be monitored if you have kidney disease. 

Yohimbe 

Do not take if you have an anxiety order. Yohimbe has been known to trigger panic attacks, for example. 

Do not take if you have kidney or liver disease, heart disease, high blood pressure, or ulcers. 

Saw Palmetto