Testosterone production typically starts to decrease by about 1% per year from the age of 30. However, the rate and severity with which testosterone levels drop in practice, is highly individual and can be affected by a range of external factors. Low testosterone is relatively common in the over 40 age group, affecting up to 12% of men aged 50 and over, and with prevalence increasing each year. Those more likely to suffer from testosterone deficiency are men with pre-existing health problems such as diabetes (up to 50% of men with type 2 diabetes have low testosterone levels), obesity, high blood pressure, raised cholesterol levels, heart disease, and chronic inflammatory conditions (such as asthma or arthritis). Some prescription medications will also lower testosterone production.
Symptoms of testosterone deficiency may include a decrease in libido, difficulty in achieving and maintaining an erection, tiredness, reduced muscle mass, increased body fat, mood swings, or just feeling like everything is that bit harder. Importantly, testosterone deficiency is not just a physical disorder; it can have a devastating impact on mental and emotional wellbeing.
The key factor is to decipher why the levels are low and then in some cases, testosterone levels can be restored by making lifestyle changes, for instance changing the way we exercise, improving diet, avoiding consuming large amounts of alcohol, and even reducing stress levels (this is because during anxiety or stress the body produces high levels of cortisol which directly suppresses testosterone production). Sleep is another important factor in testosterone production; although the ideal amount of sleep varies from person to person, one study found that sleeping only 5 hours per night was linked to a 15% reduction in testosterone levels. We should all be aiming for a minimum of 6-7 hours per night.