That tell-tale paunchy belly, decreased strength, energy and sexual drive all describe the classic middle-aged male. Once thought to be from declining testosterone levels the symptoms and signs of male aging may be more of a consequence of declining estrogen levels than researchers had previously thought.

Estrogen and male aging, what do you know? T or F?

1. Estrogen is required for strong libido.

2. Males do not manufacture estrogen.

3. Only low testosterone levels decrease libido.

Commercials for low testosterone testing and treatment centers are everywhere in newspapers, Internet, television and radio. Get your testosterone levels checked, get diagnosed with viola, no more feeling middle-aged anymore. Sounds quick, easy and simple. But not so fast, say researchers from Harvard, University of Washington, Penn and other research schools. We have forgotten a key ingredient in the recipe for maintaining muscle mass, energy and libido. That ingredient is estrogen. Traditionally thought of as the female hormone, estrogen is increasingly the focus of research into how men age and how best to address symptoms. Smearing testosterone gel from head to toe may not bring the desired results when estrogen is forgotten.

Testosterone is produced primarily in the testes and production declines with aging. Estrogen is generated from testosterone. When male testosterone levels decrease so do those of estrogen. Both hormones work together to maintain normal sexual desire.

Normal testosterone levels are about 550 nanograms per deciliter of blood serum. Below 300 and there may be consideration for prescribing testosterone gel. In the study published in The New England Journal of Medicine, lead author Joel Finkelstein, M.D., noted that the role of estrogen in libido, energy and fat accumulation. The tell-tale middle age paunch emerges like an alien when testosterone levels dip between 300-350. That is when, Dr. Finkelstein explains, estrogen levels fall to a point where fat accumulation and distribution changes. Love handles grow. Testosterone levels below 200 affect muscle mass and strength.

Testosterone alone cannot sustain libido. However, there are no current recommendations for estrogen replacement in men. Research is scant and there can be significant side effects from estrogen including enlarged breasts.

We are only now learning about estrogen and testosterone replacement in men. Does hormone replacement therapy in men affect risk for prostate cancer or cardiovascular disease? We simply do not know at this time. Maybe HRT lowers the risk for heart attacks. Men have been long neglected in the study of aging and hormones. There are major studies set to begin this year to help us get answers. Who knows – in the near future men may be prescribed both testosterone and estrogen. Also, look for tighter recommendations for the diagnosis and treatment of "low T."

We humans begin our lives, males and females, with the same body habitus except for genitals. As we enter puberty our maleness and femaleness emerges. Then as we enter our 50s and 60s we start to morph into looking like each other again. An unscientific poll conducted in my office and home revealed this to be overwhelmingly unsettling to both genders.  Maybe research will allow us to preserve our dignity without placing us at risk for cancers and cardiovascular diseases. 

Answers: 1. T; 2. F; 3. F.

Dr. Lori Boyajian-O’Neill can be contacted at