Physical activity reduces osteoporosis

Regular sports or other physical activities reduce the risk of fractures in men at a later stage in life. One of the hazards of old age is that the bones become less dense, and therefore weaker, often leading to broken bones when an elderly person falls. As many as half of all women and a quarter of men older than 50 years will break a bone because of this, and the consequences can be serious, particularly if the hip is broken. The thinning of bones, known as osteoporosis, does affect all people as they age, but the degree to which it occurs varies greatly between individuals. Osteoporosis develops over many years, and in most people bone density starts to decline after the age of about 30 years. Preventive action should therefore begin early. However, data from previous studies is inconsistent, and therefore it is uncertain whether and to what extent leisure physical activity affects the risk of osteoporotic fractures in men. Researchers at the University Hospital, Uppsala, Sweden, surveyed more than 2000 men, 49-51 years of age, who were asked about their amount of physical activity outside working hours. They were asked the same questions again when they were aged 60, 70, 77, and 82. A record was also kept of the number of fractures these men had suffered during the 35 years of the study. Although, some of the men died before the end of the study, about half were still alive at the end. On the basis of the answers to the questions on physical activity at the start of the study, the men were divided into three categories: those whose lifestyle was considered to be ''sedentary,'' those whose leisure activities included some walking and cycling, and those who participated in sports for at least 3 hours a week. These were referred to as the low, medium, and high-activity groups. Over the 35 years, 428 men had at least one fracture and 134 broke a hip, but there were big differences between the groups-20% of the low-activity men had fractures, compared with 13% of those with medium activity and only 8% of those in the high-activity group. In particular, the chance of having a hip fracture was reduced by increased activity. The results showed that exercise reduces the risk of osteoporotic fractures in men. Participating in sports seems to be particularly effective; one-third of the fractures could be prevented if men could be persuaded to take part in sports regularly.