http://www.ettoday.com/2002/10/24/218-1367288.htm
味精害眼睛？日本研究；吃太多味精 視網膜會退化
2002/10/24 08:32
記者何瑞珠／編譯
雖然味精有讓清水變雞湯的神奇調味功效，不過加太多味精卻可能有害人體健康。
根據即將出刊的新科學人雜誌的報導，吃太多味精可能會讓人變成瞎子。
【新科學人】上的這篇論文是日本弘前大學的大黑教授所作的研究，大黑教授在六個月
內餵食三組老鼠，一組吃過量味精，一組吃中量味精，還有一組完全不吃味精。
經過半年後，吃過量味精的老鼠百分之七十五出現視網膜退化跡象，有些老鼠甚至
連光線都無法感應，跟瞎了眼一樣。其實以前就有研究指出，味精有害人體健康，
國人在加味精前實在要三思才行。
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. \
日本的一些科學家警告說，味精（英文簡寫：MSG）可能對視力造成負面影響。
在中國等一些東方國家，味精的使用很普遍。
對老鼠試驗後發現，大劑量味精對視網膜會有影響。
老鼠在食用一段時間味精含量高的食品後，視網膜會逐漸變薄，久而久之會失明。
但英國的眼科專家指出，人們只有在服用了大量的味精之後，才會有發生視力問題的
危險，每周從中餐外賣店那裡買一次東西吃不會對健康產生影響。
關鍵在含量
日本的研究人員在六個月的時間裡對三組老鼠進行試驗，第一組天天食用高含量
味精食品﹔第二組食用低量味精食品﹔第三組食用無味精食品。
研究發現，在含量20%的味精飲食組中，有些老鼠的視網膜變薄了75%，有的甚至怕見日光。
研究小組的負責人說，雖然少量食用味精可能對身體不會構成危害，但是，就這項
研究而言是很有價值的，因為這是第一次通過實驗證明瞭味精損壞視力。
有關研究發表在最新一期的《新科學家》雜誌和《眼科試驗研究》兩分刊物上。
◆ 修改: 04/02/08 11:39:43 <61.30.36.229>