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据英国《每日邮报》10月30日报道，美国威斯康星州大学的一项研究显示，规律运动可预防老年性失明。

该研究共有4000多名43－86岁的受试者参与，主要观察规律运动对湿性老年性黄斑发病有无影响。黄斑是视网膜的一小部分，具有感光和精细视物功能。黄斑点退化导致黄斑变性，从而影响视力。湿性老年性黄斑变性是老年性黄斑变性中最严重的一种类型，可在确诊后数月内出现中心视力丧失，75岁以上老年人有过半深受其困扰。该病仅影响中央视力，而周边视力不受损害，可致盲或低视力。患者的中心视力逐渐模糊，阅读、驾驶和看电视等变得越来越困难。

该研究的主要调查指标有：受试者进行出汗运动（骑自行车、跳舞和慢跑）的出汗频率、每天爬多少层楼梯、走多少条街道。结果发现，爬楼梯对老年性黄斑变性无影响。而每周三次以上的出汗运动可使湿性老年性黄斑变性的发病率减少七成。很多温和的运动同样有效，如每天步行12条以上街道可将患病风险减少三分之一。

一项发表在《英国眼科学杂志》上的研究认为，饮食可能对眼健康起到很大作用。有资料显示，规律进食多油的鱼可减少老年性黄斑变性的发生。鱼中的脂肪酸，包括omega-3脂肪酸，对眼睛健康也很重要。

然而，规律运动最为关键，因为它可保持眼睛血管健康，使视力敏锐，从而防止老年性黄斑变性的发生。另外，从生物学角度来看，身材苗条的人要比那些惯于久坐的人年轻，这一点是很重要的，因为老年性黄斑变性的发病率会随着年龄的增长而逐渐增高。因此老年人要预防眼病，还须多些规律运动。

http://www.dailymail.co.uk/pages/live/articles/news/news.html?in_article_id=413532&in_page_id=1770

Regular exercise can help prevent blindness
By FIONA MACRAE
Last updated at 22:00pm on 30th October 2006

Regular exercise can prevent blindness in old age, research shows.

Those who break into a sweat during exercise at least three times a week are 70 per cent less likely to develop age-related macular degeneration, the most common cause of blindness in the elderly.

More gentle activity can also ward off the condition, with daily walks cutting the risk by 30 per cent.

It is thought exercise keeps vision sharp by keeping key blood vessels in the eye healthy into old age.

Caused by the deterioration of the macular - the tiny part of the retina responsible for picking up colour and fine detail - macular degeneration affects the vision of more than half of over-75s.

Sufferers find their central vision gradually deteriorates, making it increasingly difficult to carry out tasks such as reading, driving and watching TV.

While their peripheral vision is not affected, the damage to their central vision leads to many being registered as blind or partially sighted.

The US study looked at the effect of exercise on a version of the condition called wet age-related macular degeneration.

The most serious form of AMD, it can lead to loss of central vision within months of diagnosis.

More than 4,000 men and women aged between 43 and 86 years old were asked how often they exercised enough to cause them to sweat. Sweat-breaking activities could include cycling, dancing and jogging.

They were also asked how many flights of stairs and how many blocks or short sections of street they walked each day.

Climbing stairs did not affect the onset of AMD, the University of Wisconsin research showed.

Analysis of the results revealed that those who broke into a sweat from exercise at least three times a week were 70 per cent less likely to develop wet AMD.

More gentle exercise was also of benefit, with those who walked more than 12 blocks a day being a third less likely to be diagnosed with the condition than those who did little or no exercise.

The results held true even when weight, age, and other factors known to increase the risk of AMD were taken into account.

Writing in the British Journal of Ophthalmology, the researchers said it was possible that diet may play a role in eye health.

However, it is likely regular exercise is also key, with physical activity keeping eye blood vessels, thought to be involved in the development of AMD, healthy into old age.

Physically fit people are also likely to be 'biologically' younger than those with a sedentary lifestyle, which could be important as AMD becomes more common with age.

Other studies have shown that those who regularly eat oily fish are less likely to develop AMD.

It is thought that fatty acids found in the fish, including omega 3, are also vital for eye health.

http://www.dailymail.co.uk/pages/live/articles/news/news.html?in_article_id=413532&in_page_id=1770

编辑：蓝色幻想