Australasian Science: Australia's authority on science since 1938

It’s Not How Big It Is, Is It?

By Guy Nolch

A review has determined the average penis length in men, while those with erectile dysfunction may benefit from a treatment using a by-product of liposuction. Meanwhile, there is a link between corruption and antibiotic resistance.

Urban legend has it that men are somewhat preoccupied with the size of their penis. While penis length and girth can be the subject of much snickering, some men can become so distressed by feelings of inadequacy that they may even be diagnosed with body dysmorphic disorder.

Despite this there have been no formal systematic reviews of penis size measurements, and no attempts to graph the distribution of the size of a flaccid or erect penis. Until now.

A review of the medical literature published in BJU International by Dr David Veale of King's College London found 17 studies with up to 15,521 males who underwent penis size measurements by health professionals. Veale found that:

  • the average length of a flaccid penis was 9.16 cm;
  • the average length of a flaccid stretched penis was 13.24 cm;
  • the average length of an erect penis was 13.12 cm;
  • the average flaccid circumference was 9.31 cm;
  • the average erect circumference was 11.66 cm; and
  • there was a small correlation between erect length and height.

“We believe these graphs will help doctors reassure the large majority of men that the size of their penis is in the normal range,” Veale said. “We will also use the graphs to examine the discrepancy between what a man believes to be their position on the graph and their actual position or what they think they should be.”

While the results may comfort men whose bell-end is further along Veale’s bell curve than they had imagined, spare a thought for men dealing with erectile dysfunction – and the unromantic news that the by-products of liposuction may help treat them.

While stem cells derived from fat are easy to harvest and can divide and grow longer than those taken from bone marrow, they can sometimes form tumours. Now Korean researchers have tested whether the uncultured stromal vascular fraction (SVF) collected in liposuction procedures can restore erectile function in rats whose cavernous nerve has been injured. This nerve, which facilities erection, is sometimes injured during surgery to treat prostate cancer.

The researchers reported in STEM CELLS Translational Medicine that both sources of stem cells significantly improved the erectile function over a control group, with increased levels of a neuronal enzyme suggesting that they had stimulated nerve regeneration. However, the SVF cells produced a better muscle/collagen ratio and endothelial cell content in the blood vessel than the adipose-derived stem cells.

If the procedure reaches clinical use, one can only hope that the patients don’t swap the bigger problem of erectile dysfunction for the smaller problem of size.

Antibiotic Resistance Linked to Corruption

Antibiotic resistance has been linked to poor governance and corruption around the world and not a country’s wealth. “It is a finding that will be surprising to most people in the field of Medicine,” said Prof Peter Collignon of The Australian National University, who led the research published in PLOS ONE.

Co-author A/Prof Sanjaya Senanayake of The Australian National University said that countries with higher levels of corruption often had less rigorous and less transparent processes, with less effective controls over areas pertinent to antibiotic resistance. “These include factors that affect antibiotic usage and the ways antibiotic-resistant bacteria spread via water, foods and poor infection control,” he said.

“In countries with greater corruption, antibiotic usage may also be much higher than what is recorded. If governance and control of corruption can be improved, this can be an important factor in reversing high levels of antibiotic resistance.”

The team found that resistance levels were higher when healthcare was performed by the private sector. “This may be because clinicians in the private health system are subject to fewer controls when it comes to both the volumes and types of antibiotics used,” Senanayake said. “If more appropriate prescribing and better antimicrobial stewardship were to take place, that will likely result in lower levels of antibiotic resistance.”