In the last year, a series of studies from Italy, Baltimore and the Oxford Project to Investigate Memory and Ageing (Optima) has shown that men with Alzheimer's have lower testosterone levels than is normal for their age - and that these low levels predate the development of their disease.Researchers are so far cautious about promoting androgen therapy in middle age. Abuse by athletes of testosterone-based anabolic steroids at up to 20 times the therapeutic dose hasn't helped its reputation. But a series of recent studies, including one of 1,500 men by members of the Andropause Society, suggests not only that low testosterone is a problem in up to 80 per cent of men, but that treating the deficiency is good for their hearts, boosts libido, strengthens bones and helps to prevent depression and Alzheimer's disease.It was believed that, because women suffer fewer heart attacks than men before the menopause, testosterone encourages cardiovascular disease. Yet researchers have now shown that low testosterone levels raise the risk of heart disease - and that testosterone replacement therapy appears to lessen thickening of the arteries, thereby helping to prevent stroke, angina, heart disease and high blood pressure. Ever since then, he has taken daily testosterone supplements, in the form of capsules, implants, patches and, most recently and successfully, a cream he rubs into the skin of his scrotum. Almost from day one, he says, he's been a new man: nicer to be with, more relaxed, more energetic and both healthier and sexier.His story is one to which doctors should pay urgent attention, according to Dr Malcolm Carruthers, chairman of the Andropause Society and author of Androgen Deficiency in the Adult Male, with which he aims to "equip the medical profession with the information needed to diagnose and treat androgen deficiency".About one in 10 men between the ages of 40 and 60 are thought to have subnormal testosterone levels as a result of normal ageing, physical illnesses such as mumps, or other problems including stress, too much alcohol and even tight jeans. Typical symptoms are irritability and hostility - "often, literally, an impotent rage," says Dr Carruthers.Until now, the medical consensus has been that hormonal changes in men are a myth and that taking testosterone - available therapeutically since it was first isolated in 1935 - simply turns on aggression, promiscuous sexuality and big muscles.

Well on the way to a collapsed marriage and a failing career, he had "the great good fortune", as he says, to consult a specialist in what was then called the male menopause, now known as the andropause.A simple blood test revealed him to be in urgent need of extra testosterone, at an earlier age than normal (50-plus), probably because he had mumps in his twenties. He doesn't get irritated at supermarket checkouts, or snarl at his family. He used to - but not because he had too much testosterone, as you might expect. Collom's own experience, increasingly backed up by clinical evidence, suggests that such grumpy-old-man behaviour is a giveaway sign of someone with dangerously low levels of male hormones. Back in 1989, Collom, then 43, was surly to his wife and stepson, anxious, depressed, and lacking in energy and sex drive. Bernard Collom doesn't do road rage. Australia: Tries Tuqiri, Mortlock, Smith; Conversions Giteau 2.SOUTH AFRICA: P Montgomery; B Paulse, M Joubert, D Barry, J de Villiers; J van der Westhuyzen, B Conradie (F du Preez 40); O du Randt (H Shimange 79), J Smit (capt), E Andrews (CJ van der Linde 67), B Botha, V Matfield, S Burger (J Cronje 36-40), J van Niekerk, AJ Venter (G Britz 64).AUSTRALIA: C Latham; C Rathbone (W Sailor 64), S Mortlock (M Burke 74), M Giteau, L Tuqiri; S Larkham, G Gregan (capt); B Young (M Dunning 67), B Cannon (J Paul 64), A Baxter, J Harrison, N Sharpe (D Vickerman 56), G Smith (J Roe 23-28), D Lyons (Roe 69), P Waugh.Referee: P O'Brien (New Zealand).

They lack a strong tighthead prop to strengthen the scrum, and some of their decision-making can be perilous, to say the least.But tries by the excellent Victor Matfield and Joe van Niekerk, plus Percy Montgomery's two conversions and second-half brace of penalties were enough, in the end, to win the title for the Springboks.South Africa: Tries Matfield, Van Niekerk; Conversions Montgomery 2 Penalties Montgomery 3. Substitutes used: Burrow, Bailey, Jones-Buchanan, McDermott.Bradford: Reardon, Withers, Pryce, Hape, Vainikolo, Paris, Beacon, Fielden, Paul, Parker, Peacock, Swann, Radford. Substitutes used: Pratt, Johnson, Langley, Moore.Referee: K Kirkpatrick (Warrington).. They wobbled like jellies, managed only a single penalty goal in 40 minutes, missed tackles late on and had two players sent to the sin-bin. But when Stirling Mortlock and George Smith scored tries in the final 10 minutes to add to Lote Tuqiri's first-half score, a nation's heartbeat all but halted.All South Africa celebrated the win, but Jake White's team still has many weaknesses. The irrepressible McKenna then sent McGuire racing 60 yards, to touch down again, before Sinfield's long pass gave McKenna the chance for his second.Marcus Bai got in on the act with a wonderful solo effort soon after the break, before Bradford finally broke down the Leeds defence for their first try from Logan Swann.Then with Leon Pryce in the sin-bin, Jamie Jones-Buchanan added another for Leeds before Harris got a late and hollow consolation for the Bulls.Leeds: Mathers, Walker, McKenna, Senior, Bai, Sinfield, McGuire, Ward, Biskin, McDonald, Adamson, Lauiti'iti, Poching.