Sexual performance

Figure 6. Regression analyses of the relationship between male bilateral symmetry and five measures of male sexual performance in the Manchester whole-ejaculate and Calahonda field studies.

Yohimbe bark improves sexual performance in males... 

When it comes to love, mature women have their own aces to play. Many men have learned that a young woman may enhance their sexual performance temporarily, but in a long-term relationship they often lose more than they gain. Of course, some men will not discover this unless they are fortunate enough to meet women their age who have confidence and finesse. 

Much has been said about the positive effects of vitamin E (a-tocopherol) on sexual performance and ability in humans. Unfortunately, there is little scientific rationale to substantiate such claims. The primary reasons for attributing a positive role in sexual performance to vitamin E come from experiments on vitamin E deficiency in laboratory animals. In such experiments the principal manifestation of this deficiency is infertility, although the reasons for this condition differ in males and females. In female rats there is no loss in ability to produce apparently healthy ova, nor is there any defect in the placenta or uterus. However, fetal death occurs shortly after the first week of embryonic life, and fetuses are reabsorbed. This situation can be prevented if vitamin E is administered any time up to day 5 or 6 of embryonic life. In the male rat the earliest observable effect of vitamin E deficiency is immobility of spermatozoa, with subsequent degeneration of the germinal epithelium. Secondary sex organs are not altered and sexual vigor is not diminished, but vigor may decrease if the deficiency continues. 

Because of experimental results such as these, vitamin E has been conjectured to restore potency or to preserve fertility, sexual interest, and endurance in humans. No evidence supports these contentions, but because sexual performance is often influenced by mental attitude, a person who believes vitamin E may improve sexual prowess may actually find improvement. The only established therapeutic use for vitamin E is for the prevention or treatment of vitamin E deficiency, a condition that is rare in humans. 

Damiana (Turnera aphrodisiaca) — Found throughout Mexico, Central America, and the Caribbean, the Latin name of this herb suggests its use as an aphrodisiac. Orexis is advertised to increase sexual performance immediately and effectively. 

Methaqualone also affects involuntary body functions that are controlled by the autonomic nervous system, lowering blood pressure, breathing rate, and pulse and bringing about a state of deep relaxation. Though thought to be an aphrodisiac because it lowers inhibitions, methaqualone, as a CNS depressant, usually impairs sexual performance, inhibiting arousal and climax. 

Organic nitrites (amyl nitrite and isobutyl nitrite) cause dizziness, giddiness, rapid heart rate, lowered blood pressure, "speeding," and flushing of the skin. These effects last only a few minutes and can readily be repeated. The main effect of the drug on sexual performance is probably to enhance or prolong erection through the release of nitric oxide in the corpora cavernosa (see Chapter 19 Nitric Oxide, Donors, Inhibitors). 

Reports of the effects of amfetamine on sexual behavior refer variously to unchanged, reduced, mixed, and heightened sexual performance, but long-term abusers often have sexual dysfunction (SED-9, 9). 

Some believe that topical application of cocaine to the glans penis enhances sexual performance. However, such use can cause complications, including superficial penile necrosis (217). 

Another example of the deceptive nature of alcohol is its sexual effect. Many people who drink to enhance sex claim that alcohol increases desire, removes inhibitions, and promotes relaxation, In men, however, its depression of the nervous system can prevent erection and drastically interfere with sexual performance. Writers as far back as Shakespeare have noted this property... 

As well as the concerns about sexual performance in treated hypertensives there may be concerns about fitness per se to attempt intercourse. The real possibility that it is hazardous is compounded often by their age and concurrent coronary artery disease. 

Two men developed prolonged epistaxis a few hours after taking sildenafil 50 mg to enhance their sexual performance (before the nose bleeding started) both had well-controlled hypertension (12). Epistaxis is not an unusual problem in elderly people with hypertension, and venous engorgement is thought to be the main causative factor. Whether this is amplified by sildenafil (and/or by sexual activity) is an open question. 

Although there are still some discrepancies in the hterature regarding zinc levels in dialysis patients, most studies have found decreased levels of the element in serum [64,65] and muscles whereas the levels in bone [63] and other tissues seem to be normal or even increased suggesting translocation of the element in uremia. The dialysis treatment itself seems to have little or no effect on the serum zinc concentrations. Zinc deficiency in uremic patients has been associated with anorexia, disturbances in taste and sexual performance [66] whereas decreased plasma zinc seem to correlate with erythrocyte superoxide dismutase levels [67]. As evaluated by Tiirk et al. [68], zinc supplementation did not have any effect on the restoration of immune parameters or enhancement of the antibody response to multivalent influenza vaccine in hemodialysis patients. On the ofher hand however, has zinc supplementation been reported an effective means of improving serum levels of zinc and cholesterol in the hemodialysis patient [69]. 

Alcohol and sexual response in men and women has been a favorite subject of writers for thousands of years. Much of the writing has been like Shakespeare s comments, based on informal personal observations. Witli regard to male sexual re.sponse, the folklore leads to dose-dependent conclusions. Alcohol has been thought to be an aphrodisiac in men at lower doses but an impediment to sexual performance at higher doses. An example is a quote of the Greek poet Euenas, from the 5th century b.c. (in Abel, 1985) ... 

---