Causes of Enlarged Prostate (BPH)
Medically reviewed by Dr. J. Kellogg Parsons M.D
Experts don’t know for certain what all the causes of enlarged prostate are. One theory is that the prostate glands of older men response better to the male hormone testosterone and its directive to “grow.” Another theory is that a fluctuation in the ratio of testosterone to estrogen triggers the growth. Since men produce small amounts of the typically female hormone estrogen—or more specifically, a type of estrogen called estradiol—this is a possibility.
What Are the Risk Factors for an Enlarged Prostate?
Researchers have identified the most common risk factors for an enlarged prostate. They can be divided into two categories: those you can change and those you cannot.
Which Risk Factors or Causes of Enlarged Prostate Can’t You Change?
Age: The half-century mark seems to be the tipping point when it comes to greater risk of developing BPH. While slightly more than 20 percent of American men ages 40 to 49 have symptoms of BPH, this figure rises to about 35 percent among men 50 to 59, 58 percent in the 60 to 69 age group, and 84 percent in men age 70 and older. Factors that may contribute to the age-related risk of developing BPH include changes in hormone levels and damage to the blood vessels that supply the prostate and surrounding structures. When the prostate cells are deprived of enough blood, some experts speculate that this triggers the unwanted growth.
Family history: If you have a close male relative (father, grandfather, brother, son) who has or had an enlarged prostate, then you are at an increased risk of getting the disease. This is especially true if your relatives had symptoms severe enough to require treatment before the age of 60.
Ethnicity: Results of a large-scale study published in 2007 found that black and Hispanic men are more likely to develop an enlarged prostate than white and Asian men. However, other studies have not found much difference between ethnic groups.
Which Risk Factors for an Enlarged Prostate Can You Change?
It is possible to have a positive impact on each of the following risk factors by making some modifications to your lifestyle. The extent of that effect will vary depending on the degree of severity for each factor as well as how consistent you are with the changes you make.
Excessive DHT: DHT is the acronym for dihydrotestosterone, a substance that is the result of a conversion of testosterone by an enzyme called 5-alpha reductase. BPH is an androgen-dependent disease, which means it is influenced by the male hormone (androgen) testosterone. The prostate will not grow unless it is “directed” to do so by testosterone, which is made mainly by the testes. Boys who have their testicles removed before they reach puberty will never develop BPH, and removing them after puberty but before BPH develops dramatically reduces the chance of suffering from the disease. But testosterone alone is not the bad guy: it must be converted by 5-alpha-reductase into DHT, and the DHT is what promotes the prostate cells to grow. Experts believe DHT levels rise in many men as they age, even if testosterone levels decline, and that the buildup of DHT may be a factor in BPH. Certain lifestyle, diet, supplements, and other adjustments can influence your DHT and testosterone levels.
Elevated estradiol: It’s natural for you to have some of the female hormone estrogen (in the form of estradiol). Estradiol is produced as a byproduct of conversion of testosterone, among other means. The proper balance of estrogen-to-testosterone in men is important for a healthy sex drive, to enhance brain function, protect the heart, and strengthen the bones. When estradiol levels are too high, however, and the ratio is out of balance, you can experience fatigue, increased body fat, loss of libido and an enlarged prostate. An imbalance between estrogen and testosterone increases DHT activity, and thus encourages prostate cells to grow.
Overweight/Obesity: Being overweight, especially around the midsection, raises the risk of excessive prostate growth and is one of the causes of an enlarged prostate. A review study published in 2014 also noted a strong relationship between obesity and the development of BPH and lower urinary tract infections. The link between obesity and BPH may be related to the reduced testosterone levels seen in the obese. Also, a drop in testosterone means there’s an accompanying rise in estrogen levels, which can increase the activity of DHT and thus prostate growth. Obesity also affects insulin levels in the blood, which is another risk factor for BPH (see below).
Diabetes: Having diabetes increases the risk of developing BPH, perhaps significantly, and is one of the potential causes of BPH. In a 2015 study, researchers pointed out that components of type 2 diabetes—high glucose levels, insulin resistance, obesity—increase the progression of BPH. Research indicates relationship may be due to elevated insulin levels, which not only “corral” the blood sugar and usher it into the cells, but also stimulate growth. The diabetes-BPH link may also be related to the damage that diabetes does to blood vessels. If the vessels that service the prostate are damaged, an enlarged prostate may be the result.
High “Bad” Cholesterol: Researchers at the UCSD School of Medicine reported that among men with diabetes, those who had higher levels of the notorious “bad” cholesterol, low-density lipoprotein (LDL), were more likely to develop BPH than men who had normal LDL levels. When the researchers divided the men into three groups (high, medium, low), those with “high” LDL levels were four times more likely to have BPH than those in the “low” group. (The levels of total cholesterol and triglycerides, which are commonly called blood fats, were not linked to BPH in this study.) More recent research, however, has questioned whether higher LDL truly is a risk factor for BPH.
Metabolic syndrome: In a 2016 study conducted in the UK, investigators reported that men with BPH were significantly more likely to have metabolic syndrome than men without the prostate condition. More specifically, having BPH was associated with a 37 percent increased odds of having metabolic syndrome.
Also referred to as “Syndrome X,” metabolic syndrome is a cluster of disorders that increase the risk of developing cardiovascular disease.
These disorders include obesity, elevated blood pressure, glucose intolerance or insulin resistance (the inability of normal amounts of insulin to transport blood sugar into cells on command), a pro-inflammatory state (elevated C-reactive protein in the blood), and a prothrombotic state (high fibrinogen or plasminogen activator inhibitor-1 in the blood). Researchers discovered that these factors also increased the risk of developing BPH.
Atherosclerosis: If you have atherosclerosis–the hardening and thickening of artery walls caused by the accumulation of plaque—you may be at increased risk for BPH, according to at least one study which looked at the causes of BPH.
Sedentary lifestyle: A lack of exercise may increase your chances of developing BPH, possibly because exercise helps fight obesity, reduces inflammation, type 2 diabetes risk, insulin resistance, and other risk factors associated with BPH. A 2015 study found that exercise was especially associated with nighttime urination (nocturia): men who were physically active for at least one hour per week were 34 percent less likely to have severe nocturia when compared with men who had no exercise.
Poor diet: If you want to reduce your risk of developing an enlarged prostate, focus on eating lots of vegetables and less red meat and unhealthy fats.
For example, a study showed that eating a high-fat diet raised the odds of developing BPH by 31 percent, while eating red meat daily increased the chances by 38 percent.
However, if you consume at least four servings of vegetables daily, you can reduce your risk by 32 percent. The exact role that fat plays in causing the prostate to grow is not understood, although researchers have some ideas. Fat has the ability to increase the levels of testosterone, estrogen, and other hormones, which have been linked with BPH. Fat is also associated with chronic inflammation, which can cause prostate enlargement and play a role in prostate cancer.
Weak immune system: Exercise, poor diet, stress and poor lifestyle can all compromise and weaken the immune system leading to disease and inflammation and an increased risk of prostate disease.