THEN, of course, women discovered that to survive in the male-dominated workplace they had to memorize a page from the masculinity handbook and many became more aggressive than men. Now comes the greatest endorsement for fundamentally forward behavior: It’s good for your health.

In a recent study, researchers from the University of Nebraska and Pennsylvania State University found that moderately aggressive men had higher levels of T lymphocytes and B lymphocytes, immune cells commonly called “helpers” and “suppressors,” than more reserved fellows. Both lymphocytes are involved in controlling immune response.

Loose translation: Real men don’t need flu shots.

The study, reported in Psychosomatic Medicine, was based on an analysis of 4,415 men between the ages of 30 and 48. To determine how aggressive they were, the researchers first asked the men a range of questions, from how often they skipped school when they were younger to whether they had ever fought with weapons. They then measured the men’s immune response by taking blood samples.

The researchers could find no association between higher testosterone levels and immunity, but that’s hardly surprising: Testosterone is a notoriously elusive target. In men it fluctuates on hourly, daily and seasonal bases. It spikes and dips depending on whether you feel like a winner or loser and climbs in response to just thinking about a hot date on Saturday night.

Many studies have documented a linkage between testosterone and aggressive behavior that now seems indisputable, and it seems well within the realm of scientific probability that the hormone can be credited with being involved in this latest good news, researchers say.

Yes, credited. Isn’t it nice to think of testosterone in this new, positive way?

STRONG CHIN, STRONG BODY?

The findings fit nicely with what’s known about the immune system and dominance — or at least the look of dominance. An analysis of the class of 1950 at West Point showed that the most reliable predictor of a soldier’s future rank was a formidable appearance — a muscular face, strong chin and brow, and good skeletal structure — “a gestalt kind of thing,” according to Allan Mazur, who did the study. Though the cadets’ resemblance to Stone Cold Steve Austin provided few clues as to how they’d do in mid-career, they accurately predicted who would eventually become generals.

The powerful look also predicted another Promethean quality: The generals, on average, fathered one more child than their pudgy-cheeked, weak-chinned classmates.

What does this have to do with immunity? In favoring Dick Tracy types, as they have long done, women are unconsciously choosing genetic resilience. The heavy lower face typical of the dominant male specimen is a visible record of the surge of androgens that helps morph a skinny lad with a weak chin into a meaty general.

EVOLUTIONARY INSIGHTS

Researchers theorize that the link between aggression and immunity dates to man’s early days, when guys who were best at finding food and protecting their kin were the most aggressive in the clan. In response to the injuries and infections that accompanied these high-risk behaviors, a healthy immune system evolved.

But not, as it turns out, as healthy as women’s. In the paper in Psychosomatic Medicine, Dr. Douglas Granger, who teaches biobehavioral health at Penn State, noted that in general women have stronger immune systems than men.

In studying that page from the masculinity handbook, they’ve apparently really done their homework.

JUST IN the past few months, surprising new research has highlighted the heart risks to both teenagers and young adult men.

A study reported in the American Heart Association journal Circulation is particularly alarming. Researchers from Louisiana State University examined the arteries of 760 teens and young adults who died as a result of an accident, suicide or murder and found that many were clogged badly enough to cause a heart attack.

They found that 2 percent of males aged 15 to 19 and 20 percent of men between 30 and 34 had advanced fat-laden plaques, the obstructions that can become dislodged and cause a heart attack or stroke. They found no advanced plaques in girls 15 to 19, but did find them in 8 percent of women in the 30 to 34 range.

The investigators admit that their research cohort may not be representative of the public at large — perhaps people at risk of an early death eat poorly or have other factors associated with heart disease, such as depression. “But if our results hold true for larger populations, one in five men between the ages of 30 and 34 has some significant damage to his heart arteries,” says Dr. Henry McGill of the Southwest Foundation for Biomedical Research in San Antonio, Texas, who led the study.

“That would indicate the need to tailor prevention messages to younger people.”

Not surprisingly, the researchers found that those who were obese or had high levels of low-density lipoproteins (often called the “bad” cholesterol) were 2.5 times more likely to have advanced plaque blockages. The results, says McGill, give strong support to the idea that nutritional guidelines for the prevention of heart disease should be recommended for children as well as adults.

Another study that followed about 82,000 men over 34 years uncovered some equally startling data. While men in their 20s and 30s may think it unnecessary to worry about their cholesterol levels, the study, reported in the Journal of the American Medical Association, indicates otherwise.

Younger men with high cholesterol face a greater long-term heart risk than men diagnosed with the condition in middle age for a simple reason: The longer high levels exist, the more damage they cause.

The JAMA report found that those with high levels of cholesterol were 3.5 times more likely to die of a heart disease-related death than men with healthful levels.

So what’s a strapping, invincible young man to do with this information? He should get a cholesterol test every five years beginning at age 20. If his level is above 240, he should try to bring it down through exercise, nutrition or, perhaps, medications.

And thus avoid the fate of many of the men in these two studies, as well as that of my father.

Both before and since then, several studies have reached similar conclusions. The herb is as effective as finasteride, the prescription medicine used to treat BPH, all investigations found.

But publication of the study in JAMA was especially significant. Reports in the journal of this and other herbal treatments signal that alternative therapies have entered into mainstream medicine.

BEYOND THE PLACEBO EFFECT

Since prescription drugs already effectively treat BPH, what’s the big deal? Why do we need an alternative?

“One reason is that herbal medications are less expensive and less toxic,” says Dr. William Fair, emeritus chairman of urology at the Memorial Sloan-Kettering Cancer Center in New York. “As with herbal supplements in general, there is still the problem of standardization. But the fact that there’s evidence that these substances provide something more than a placebo effect means the industry should work toward it.”

Fair, who has written extensively on the use of herbal supplements to complement conventional, or allopathic, medicine, notes that another herb, phygeum africana, has shown similar benefits to men with BPH.

Both substances, he says, have a significant effect on urinary flow rates. They have the added benefit of producing none of the side effects of finasteride.

NATURE’S PHARMACY?

Phygeum, however, may never see widespread use as a preventive treatment for BPH.

So far it’s been found only in Columbia, and appears to be on the edge of extinction. Its plight illustrates much about the future of potential natural treatments for disease: Only about 1.5 percent of the world’s plants have been identified. Who knows what other plants yet to be identified but on the verge of extinction might contain cures for deadly diseases?

What other natural treatments might benefit men with prostate problems? Perhaps the most exciting new agent introduced in the last year has been the herbal tea mixture PC-SPES, which has been shown to inhibit prostate cancer that is resistant to hormone therapy.

When prostate cancer spreads beyond the gland, doctors frequently attempt to block testosterone, which “feeds” the tumor. When hormones fail to do the job, the cancer spreads quickly. PC-SPES has been shown to have a phytoestrogenic effect — that is, it blocks testosterone.

Although it has not been subjected to the same randomized control studies as chemotherapy, it has been used by Chinese and other Asian cultures for more than 3,000 years.