Derek Burnett
Derek Burnett is a Contributing Writer at Bottom Line Personal, where he writes frequently on health and wellness. He is also a contributing editor with Reader’s Digest magazine.
Benign Prostatic Hyperplasia (BPH, or just “enlarged prostate” to most people) is an oversized prostate gland whose excessive cell growth is non-cancerous. The prostate is a male sex gland located between the rectum and the bladder. It is normally about the size of a walnut, but with BPH, the gland increases in size, sometimes quite dramatically. Because of its anatomical positioning, an enlarged prostate can pinch off the urethra (the tube that carries urine out of the bladder), leading to urinary issues and, potentially, kidney damage and bladder stones.
Most men who reach full life expectancy will develop BPH at some point, although not all will develop symptoms. We still can’t say exactly what causes an enlarged prostate, but researchers are gathering more and more evidence about its drivers and risk factors.
Research into the causes of BPH has led investigators to look more closely at a male sex hormone called dihydrotestosterone (DHT). This fascinating substance plays an important set of roles at various stages in a male’s life. In the womb, it blocks development of female sex organs and promotes the formation of the penis, testicles, and prostate. During puberty, it promotes the growth of hair on the face, body, and pubic area, and it continues spurring prostate growth. When a man reaches adulthood, the primary effects of DHT are male-pattern baldness and enlargement of the prostate.
DHT is not to be confused with regular testosterone. The prostate converts some of a man’s testosterone into DHT, and DHT does not play the same kind of role in maintaining male physiology that testosterone does.
The exact role of DHT in the development of BPH remains murky. Researchers know that some cells in the prostate begin to proliferate when exposed to high levels of DHT…yet for two men with the exact same DHT levels, one might develop BPH and one might not. Further research is necessary to understand exactly how DHT levels contribute to the condition.
Without question, age is the single-greatest risk factor for BPH. The condition is rare among younger men, but around 50% of those between ages 51 and 60 develop BPH (many of them without symptoms)…and the numbers continue to climb with age. During their 60s, seven out of 10 men will have an enlarged prostate, as will roughly 80% of men over age 70.
Researchers still aren’t certain why age is so closely associated with the development of BPH, but it very likely involves hormonal changes in middle age. Although testosterone production drops off, the body converts testosterone into DHT at higher levels than it once did. And with decreased testosterone levels, the ratio of testosterone to estrogen changes (since estrogen levels in men do not fall as they age). One or both of these factors may help explain why BPH becomes so much more common as men get older.
The evidence regarding a connection between BPH and physical activity is mixed. Some studies find no such association, while others do. A major 2014 study found that if you sit for seven or more hours per day, you’re at significantly greater risk for developing BPH. That’s the bad news. The good news, according to the study, is that to lower your risk, you don’t need to run a marathon, or even go to the gym. You just need to stand up and move instead of sitting.
In 2021, the journal BMC Urology published research showing that being overweight or obese late in life—even among men who earlier had normal body size—was significantly linked to the development of BPH. That paper came on the heels of numerous other studies that have pointed a finger at obesity, which may contribute to BPH by increasing abdominal pressure, causing hormone changes, increasing insulin resistance, and triggering inflammation.
Although it has never been said that high blood pressure causes BPH, the two conditions appear together often enough to raise suspicion. In fact, nearly 30% of all men age 60 or older have BPH and high blood pressure together. It may be that the two conditions share an underlying mechanism, such as increased activity of the sympathetic nervous system.
As with high blood pressure, diabetes often exists alongside BPH, especially in older men. The relationship between the two conditions may be bidirectional, with each increasing risk for the other. To the extent that diabetes drives up BPH risk, it’s likely due to insulin resistance, systemic inflammation, and hormonal imbalances.
A team of Italian researchers performed a review of studies regarding diet and BPH which covered the period from 1964 to 2021. They found convincing evidence that adhering to an eating pattern similar to the Mediterranean diet, high in vegetables, fruits, nuts, legumes, and fish, was linked to a decreased likelihood of developing BPH and to an improvement in symptoms among men who already had the condition.
A 2023 study found strong evidence that insufficient sleep may be a driver of BPH. Previous studies had seen associations between poor sleep and BPH, but it had been unclear whether insufficient sleep caused BPH, or BPH caused insufficient sleep since one of the symptoms is having to get up during the night to pee. But thanks to the design of the 2023 study, its authors conclude that the sleep-BPH relationship is causal and unidirectional.
Although researchers have yet to identify a specific gene that controls whether or not a man develops BPH, we have known for decades that the condition appears to run in families. In fact, a 1994 study found that male relatives of men who had undergone surgery for BPH were four times more likely to also require treatment. Among brothers, the increased risk was sixfold.
