Erectile dysfunction (ED) and health
The canary in the coal mine
ED (consistent inability to have an erection satisfactory for sexual intercourse) should always be a warning sign for underlying cardiovascular disease (CVD) and poor lifestyle choices, but particularly when it occurs before age 60 or in men with diabetes or hypertension. ED and CVD and poor general health are so closely linked because all are due in part to an impaired nitric oxide (NO) level in those tissues, due largely to poor lifestyle choices. ED and decreased NO are associated with physical inactivity, abdominal obesity, diabetes, hypertension, smoking, high fat/sugar intake and decreased antioxidant defenses, all of which reduce NO production. We analogized the connection in a paper in the American Journal of Cardiology entitled: The Link Between Erectile and Cardiovascular Health: The Canary in the Coal Mine” (Meldrum, 2011). Workers used to carry a canary with them into the mines because it would fall off its perch before any build-up of gases could incapacitate the miner. New ED in men age 40-49 predicted a 50-fold increase in CVD, including sudden death, over the following 10 years. The predictive value markedly tapered with only a 2.2% prediction at 50-59 and 1.3% for men over age 70 (Feldman, 1994). Men with new ED should have evaluation by their primary care physician. Be reassured that this discussion does not apply to men experiencing lesser reductions of erectile performance commonly accompanying aging.
ED is associated with a reduction of vascular NO of more than one-third, reduced levels of major cellular and circulating antioxidant systems that enhance vascular NO, reduced HDL cholesterol (a blood lipid protecting against CVD), and increased C-reactive protein, a commonly measured marker of systemic inflammation (Meldrum, 2012). All of these are predictive of CVD. ED itself is predictive of CVD. Men with angiographically proven CVD had onset of ED an average of 39 months earlier (Montorsi, 2003). Below we will discuss ED-associated factors decreasing and enhancing health.
Physical inactivity – the single most important cause of ED
Lack of regular exercise is highly predictive of ED. Sedentary men are 2-3 times more likely to have ED using a strong indicator of inactivity (daily hours of TV viewing) (Selvin, 2007). Sedentary men are 10-fold more likely to have some degree of reduced erectile quality (Agostini, 2011). In men with CVD, systems responsible for vascular NO levels were increased 2 to 3-fold by exercise. We suggest daily exercise because animal studies have shown that while acute exercise increases NO levels for 48 hours, daily exercise increases NO levels 4-fold, lasting for a week (Yang, 2006). In men, moderate exercise decreased ED by two-thirds and high physical activity by 80% (Akkus,2002). The increased blood flow due to exercise triggers vascular NO activity by physically deforming the vascular lining (“shear stress”) (Cheng, 2005). It also decreases oxidative stress, which keeps NO from quickly vanishing because its stability depends on extensive antioxidant protection.
Abdominal obesity – the “beer belly”
Fat within the abdomen, due largely to too much carbs and alcohol, causes resistance to the action of insulin, a prime stimulator of NO , and thereby an increased chance of having ED. Insulin resistance is also the main cause of adult onset diabetes, which causes CVD, renal disease, eye disease that can lead to blindness, poor circulation and nerve damage in the lower extremities, and many other health issues. Obesity also increases knee problems due to the excess load and increases the chance of developing several types of cancer. For a detailed discussion of obesity and many suggestions for weight control, you can download (for free) a paper we published on the obesity pandemic (Meldrum, 2017).
In diabetic men, ED is increased 3-fold. Increased circulating glucose causes oxidative stress and suppresses about two-thirds of the marked NO production by blood vessels induced by chocolate, a potent antioxidant. (Faridi, 2008). Physical activity and better control of blood sugar levels are associated with less ED. In diabetics, ED predicts cardiac events even without having evidence of CVD, and severe cardiac events with established CVD (Gazzaruso, 2008).
Hypertension (elevated blood pressure)
Men with hypertension are 2-3 times more likely to have ED and the chance of having ED increases the longer a man has an elevated blood pressure (Doumas, 2006). ED predicts a doubling of heart attacks and death from heart disease in hypertensive men. Unfortunately, treatments for the elevated blood pressure worsen ED with the prominent exception of short-acting angiotensin receptor blockers (ARB's). Valsartan increased coital frequency in hypertensive men without ED, and Irbesartan improved erectile function in hypertensive men with ED and metabolic syndrome (at least 3 of: abdominal obesity, hypertension, high triglycerides, low HDL cholesterol and elevated fasting blood sugar) (Baumhakel, 2008). Both early treatment and the choice of treatment of elevated blood pressure can greatly affect ED and its severity.
Smoking causes severe oxidative stress, and antioxidants have been shown to increase vascular NO from very low to above the level in non-smokers (Peluffo, 2009). If a man just can’t stop, he should make every effort to increase antioxidant intake.
Excess intake of fat and sugar
A high fat meal causes oxidative stress and decreases vascular NO, although not in physically active adults. It also increases inflammatory markers and adhesion molecules , and those changes were blocked by giving antioxidants (Meldrum, 2012). A high fat diet can also, over time, change gut bacteria into an inflammatory pattern (Meldrum, 2017). In mice, high fat intake increased calorie absorption and appetite via inflammation and other complex mechanisms (Meldrum, 2017). That of course would make weight control even more difficult. A high fat diet may also cause an abnormal blood lipid profile. All of these changes contribute to atherosclerosis (hardening of the arteries).
High sugar intake results in higher blood sugar levels, oxidative stress, reduced NO, and the future development of diabetes. Elevated sugar levels increase inflammation, again being blocked by antioxidant (Esposito, 2002).
The best advice is to not indulge in high fat or high sugar intake. However, if one must yield to those temptations, as with smoking, attention should be placed on maximizing antioxidant intake. Taking a strong antioxidant such as dark chocolate along with a high fat or sugar load would be the best plan.
Decreased antioxidant defenses
Unfortunately, in the face of increased oxidative stress that many men with ED have, the average levels of Pon-1, a major circulating antioxidant and of glutathione, a major tissue antioxidant are decreased. Glutathione levels also decrease with age, which was reversed by a strong antioxidant (Suh, 2004). It is interesting that a high dose of the PDE-5 inhibitor, Tatadafil (Cialis) was shown to decrease oxidative stress, possibly by enhancing another of the body’s natural antioxidant defenses (Verit, 2010).