Australian scientists have found out a cause of healthy older men having poor memory. This research is the first of its kind and it is about elevated levels of a particular sex hormone.

The pituitary gland produces a hormone called luteinising hormone (LH), this in men controls the release of testosterone. It was seen that men who had higher levels of LH performed poorer on memory tests.

Lead researcher Zoe Hyde states that due to this finding search for a treatment for Alzheimer's disease has been felt.

Hyde, from the Western Australian Centre for Health and Ageing said, "We know that testosterone acts on the brain in a number of ways but LH was thought to have no direct effect. This study provides new insight into how hormones affect the brain and reveals a potential target for Alzheimer's disease drug therapies.

In women LH is also believed to control the release of oestrogen.

Hyde's research followed about 12, 000 men who were 65 years and older and this research was conducted as part of the major Health in Men Study since 1996.

In Australia Hyde’s research is the largest study of ageing men which was funded by the National Health and Medical Research Council of Australia (NHMRC).