Researchers from Massachusetts General Hospital in Boston have found that glucose ingestion was associated with a significant decrease in the male hormone testosterone.

The study, published in the journal Clinical Endocrinology, shows that 75g of sugar intake causes a 25 per cent drop in testosterone levels for up to two hours after consumption.

In order to investigate the physiological impact of glucose on testosterone levels, researchers randomized 74 men from 19 to 74 years of age.

All participants underwent a 75g glucose tolerance blood test at baseline, as well as 30, 60, 90 and 120 minutes later.

A number of biomarkers were measured, including levels of sex hormone binding globulin (SHBG), which is used to evaluate men for low testosterone.

Among the test subjects, 57 per cent of men had normal glucose tolerance, 30 per cent had impaired glucose tolerance and 13 per cent had newly diagnosed type 2 diabetes.

Upon analysing the results, the researchers noticed that glucose consumption was associated with a 25 per cent decrease in testosterone levels, which remained suppressed at 120 min compared with baseline.

At least 10 of the 66 men with normal circulating testosterone at the start of the experiment experienced a reduction in the sex hormone levels below the hypogonadal range (low testosterone range).

Male hypogonadism is the failure of the gonads in the testes to produce sufficient androgens like testosterone and which sometimes warrants hormone replacement.

The findings also revealed that the effect of glucose on testosterone levels is independent of the glucose tolerance threshold for each participant or their body mass index (BMI).

The research findings suggest that glucose intake induces an important reduction in total testosterone levels in men, which appears to be similar across the spectrum of glucose tolerance responses.