http://www.ettoday.com/2002/10/24/218-1367288.htm
味精害眼睛？日本研究；吃太多味精 视网膜会退化
2002/10/24 08:32
记者何瑞珠／编译
虽然味精有让清水变鸡汤的神奇调味功效，不过加太多味精却可能有害人体健康。
根据即将出刊的新科学人杂志的报导，吃太多味精可能会让人变成瞎子。
【新科学人】上的这篇论文是日本弘前大学的大黑教授所作的研究，大黑教授在六个月
内□食三组老鼠，一组吃过量味精，一组吃中量味精，还有一组完全不吃味精。
经过半年後，吃过量味精的老鼠百分之七十五出现视网膜退化迹象，有些老鼠甚至
连光线都无法感应，跟瞎了眼一样。其实以前就有研究指出，味精有害人体健康，
国人在加味精前实在要三思才行。
http://news.bbc.co.uk/1/hi/health/2352709.stm
"Food additives 'affect sight"
Wednesday, 23 October, 2002, 18:02 GMT 19:02 UK
Food additives 'affect sight'
The food additive MSG is found in Chinese food
Scientists are warning that a flavouring, commonly found in Chinese food,
could be linked to sight problems.
Tests in rats have shown that high levels of monosodium glutamate (MSG) can
damage the retina.
MSG is found in oriental and processed foods.
The research was carried out by scientists at Hirosaki University in Japan.
They found rats fed on diets high in MSG suffered vision loss and had
thinner retinas.
But UK eye experts said people would have to eat an exceptionally large
amount of MSG before they suffered problems, and eating a take-away once
a week would not cause problems.
The researchers theory of how MSG affects sight is that it binds to
receptors on retinal cells, destroying them.
This then triggers secondary reactions that reduce the ability of the
cells which are left to relay electrical signals.
Concentrations
The Japanese team fed rats three different diets for six months, with
either high or moderate amounts of MSG, or none.
MSG made up 20% of the diet of the rats given the highest amount.
In rats on the high MSG diet, some retinal nerve layers thinned by
as much as 75%.
They were also unable to see natural light as well.
Some damage was also seen in rats put on the moderate MSG diet.
Researchers also found high concentrations of MSG in the vitreous
fluid which bathes the retina.
The research was published in New Scientist magazine and the journal
Experimental Eye Research.
'Theoretically possible'
Lead researcher Hiroshi Ohguro said it was the first study to show
eating food containing MSG could cause danage to the eyes.
He told New Scientist high levels of MSG had been used in the tests.
But he added: "Lesser amounts should be OK, but the precise
borderline amount is still unknown."
He suggested the study could explain why there is a high level of
normal-tension glaucoma in eastern Asia.
Normal-tension glaucoma is a form of the disease which leads to
blindness without the usual increase in pressure inside the eyeball.
However, the higher rate could also be due to genetics.
Peng Tee Khaw, professor of glaucoma and wound healing at Moorfields
Eye Hospital in London, told BBC News Online the rats were fed a huge
amount of MSG.
He said they were given an amount equal to a salt cellar half their
size, so humans would have to eat an equivalent amount.
Professor Khaw said: "It's theoretically possible that if people ate
large amounts of this stuff, they would have a damaging effect.
"But once a week, it would be a miniscule amount in comparison with
what these researches are putting into these rats.
"If you have the odd take-away, I shouldn't worry."
He said if people should perhaps be careful if they did have extremely
high amounts of MSG in their diets, or had pre-existing retinal problems. \
日本的一些科学家警告说，味精（英文简写：MSG）可能对视力造成负面影响。
在中国等一些东方国家，味精的使用很普遍。
对老鼠试验後发现，大剂量味精对视网膜会有影响。
老鼠在食用一段时间味精含量高的食品後，视网膜会逐渐变薄，久而久之会失明。
但英国的眼科专家指出，人们只有在服用了大量的味精之後，才会有发生视力问题的
危险，每周从中餐外卖店那里买一次东西吃不会对健康产生影响。
关键在含量
日本的研究人员在六个月的时间里对三组老鼠进行试验，第一组天天食用高含量
味精食品；第二组食用低量味精食品；第三组食用无味精食品。
研究发现，在含量20%的味精饮食组中，有些老鼠的视网膜变薄了75%，有的甚至怕见日光。
研究小组的负责人说，虽然少量食用味精可能对身体不会构成危害，但是，就这项
研究而言是很有价值的，因为这是第一次通过实验证明了味精损坏视力。
有关研究发表在最新一期的《新科学家》杂志和《眼科试验研究》两分刊物上。
◆ 修改: 04/02/08 11:39:43 <61.30.36.229>