阿斯巴甜，它安全嗎？關於阿斯巴甜我們有什麼不知道的事情？
現在在網絡上有許多的爭論有關阿斯巴甜，以及有關阿斯巴甜在FDA的安全認證，阿斯巴甜被使用到很多消費食品之中作為代糖添加劑。從生化角度進行分析，在大多數人的所遵循的一般的飲食習慣之中阿斯巴甜是一種非常重要的成分。阿斯巴甜在攝入后非常容易水解，在腸道內會被分解為三種化合物。
-L 天冬氨酸
L-苯丙氨酸
甲醇
大多數人都擔心上述化合物的安全問題，但他們往往忽略了一個事實，即這些化合物在很多天然食品中也是十分常見的，甚至是在做過專門處理后仍會如此。而事實上，除了甲醇以外，天冬氨酸和苯丙氨酸這兩種氨基酸是人體所必須需求的兩種氨基酸。每個人都需要攝取足夠的這兩類氨基酸，否則就可能產生身體疾病，除了甲醇是不被需要的。
總之，人體代謝和吸收阿斯巴甜的過程中，身體沒有任何已知的酶排斥反應。在有關阿斯巴甜引發的和藥物在體內發生排斥反應中，有關對阿斯巴甜的控訴是非常不合理的，因為阿斯巴甜會在進入血液前就會被腸胃分解為三種物質。所以，有關和藥物在體內發生排斥反應的唯一可能性，就是藥物與阿斯巴甜所產生的三種化合物之間產生了化學反應。然而，上面所提到的這些化合物在諸多天然食品中都是其中的組成成分之一。因此，在實際上無論是化學合成的合成物還是天然食品所含有的化學物質，他們給人體帶來的效果是相同的，並不存在任何差異。
天冬氨酸，是最常見的在人體內部的20種氨基酸之一。天冬氨酸有兩種不同的化學結構，被分為L型天冬氨酸和天門冬氨酸，這兩種氨基酸都是非常常見的，在天然食品中如牛肉，大馬哈魚，蝦，雞蛋，豆芽菜，豆類，大多數堅果，鱷梨和蘆筍中都含有大量的這種物質。天冬氨酸在人體中扮演著一個非常重要的角色，它可以幫助人體進行物質生產。
苯丙氨酸，是一種人體所必須的氨基酸，在哺乳類動物的乳汁中非常常見，包括人類的母乳。這種化合物負責為許多其他的身體所需的化學物質、激素等提供原料，包括酪氨酸（一種重要的非必須氨基酸），多巴胺（一種激素和神經遞質），腎上腺素（一種重要的化學介質傳輸神經物質，為人體的衝動性現象負責并保持人體的自主神經系統正常）和黑色素（皮膚色素，保護人體免受紫外線傷害）。
甲醇，是一種常見的有毒化合物，是阿斯巴甜在體內分解代謝過程中所產生的唯一一種有害物質。阿斯巴甜在分解后還可能會產生甲酸，這是一種神經毒素，可能引起腦損傷，大多數人對此表示擔心，但這完全是杞人憂天的。人的腸道內含有大量的甲醛物質，這些甲醛物質會在幾秒內在腸道內與大量的甲醇產生化學反應，而隨著阿斯巴甜的攝入，甲醛的分泌量也會增加，只要體內的阿斯巴甜含量不超過標準定額的10%，阿斯巴甜所產生的甲醇就會被體內甲醛自然分解排出。
阿斯巴甜是否有害，一切都取決於劑量的攝取問題。在這三種化合物之中的任何一個，包括甲醇，都非常容易在天然食品中找到。現在我們可以將這些化合物，以劑量檢查分析的角度來對這些化合物進行檢測。以典型的軟飲料為例，每升飲料中大約含有224毫升的阿斯巴甜，至多560毫升，因為阿斯巴甜的甜度是蔗糖的200倍。
天冬氨酸
苯丙氨酸
甲醇
含有阿斯巴甜的飲料
224毫克/升
280毫克/升
56毫克/升
天然食品
蘆筍:
5500 毫克/公斤
雞蛋:
5000毫克/公斤
大頭魚:6500毫克/公斤
火腿(豬肉):
7459毫克/公斤
雞:
8800毫克/公斤
西紅柿汁:680 毫克 / 升
蘋果汁:
2000毫克/升
當然在正常飲食中，這種案例是不可能成為現實的，一個人不可能消耗1公斤的竹筍，雞蛋或肉類。一些嗜好軟飲料的人，對其成癮的人，也許每天會消耗高達一升的飲料，并攝取相應含量的阿斯巴甜如上述列表，但是我們可以從上述列表中得以證明阿斯巴甜並非是有害的。無論是天然來源的還是化學合成來源的，是否有害的關鍵是這種物質攝取量的少或多？我們身體變得更好或更差是與此相關的。
有關阿斯巴甜的爭議是如此之久，似乎沒有人注意到上述這點。。。是人們沒有注意到，其實糖農也是由國際巨頭操縱和經營，所以也出絕辦法去攻擊阿斯巴甜生產商。我們可以由此判斷，是因為阿斯巴甜的誕生奪去了製糖企業每年數十億美元的利潤，才出現了那麼多聳人聽聞的陰謀論！
每一種討論往往都會有兩種不同的對立的力量所支持的論點，大多時候，正是利益集團促使這些研究變了味，扭曲而不再告知人們真實的情況與利弊。
附：原文，作者@宙英 ，文章地址http://blog.sina.com.cn/s/blog_71a871150102uyo4.html
原文：
Aspartame, is it safe? Is there something they don’t want us to know?
There are many controversies around aspartame since its approval by FDA and being introduced into many consumer products. It is important to analyse the issue from a biochemical perspective as well as the general diet that most people follow.
Aspartame, upon ingestion and readily hydrolyzed in the small intestines, will break down into 3 compounds.
- Aspartic Acid
- Phenlyalanine
- Methanol
Most people concerned about the safety issue of the above compounds, ignored the fact that they are VERY COMMON in many natural food, even before processing. Except methanol, the two amino acids are in fact, essential for human. Except methanol(甲醇), the two amino acids are in fact, essential for human.
Before the body can metabolize and absorb aspartame, no known body enzymes will react with it, therefore, the claim of drug contradiction is highly unlikely since aspartame cannot enter the blood stream before being metabolized. So the only possible drug interaction is coming from the release of the three compounds. However, as mentioned above, these compounds are vastly available in many natural food, and a chemical compound is just a chemical compound, regardless of whether it is from natural source or synthesized, they bring the same effect to human body.
Aspartic acid, is among the most common 20 proteins used by human body, there are two different chemical structures, L-Aspartic acid and D-Aspartic acid, both are common and are readily found in large quantity in beef, salmon, shrimp, egg, sprouting seeds, legumes, most nuts, avocados andasparagus. Aspartic acid plays an important role in synthesizing several proteins in human body.
Phenylalanine, also classified as essential amino acid, is common found in mammal’s breast milk, including human breast milk. This compound is responsible as a precursor for numerous other important chemicals inside human body, including tyrosine (another precursor of protein), dopamine (a hormone and neurotransmitter), adrenaline (an important chemical mediators for transmitting nerve impulses and also keep the autonomic system of human to function properly) and melanin (skin pigment that protect human from UV-B damage).
Methanol, a commonly known toxic compound, is the only harmful substance that is released by aspartame upon metabolization. At the end of the metabolism pathway, formic acid is produced, which is a neurotoxin that can cause brain damage as most people worry, this is the consent among alarmists and the science community. Formaldehyde, which is another chemical product within the pathway, is metabolized within seconds, and other biochemical activities within the body produce a thousand times more formaldehyde then aspartame intake. About 10% by weight of aspartame will break down to methanol inside the body.
To define whether they are harmful or not, it all depends on dosage. And for each of them, including methanol, can be readily found in natural food. To put it into perspective, each of these compounds will be examined on a dosage based analysis. Typical soft drinks only contains 560mg of aspartame per litre due to the fact that it is 200 times sweeter than sugar.
Aspartic acid
Phenylalanine
Methanol
Aspartame in soft drinks
224 mg/L
280 mg/L
56mg/L
Natural Source
Asparagus:
5500 mg/kg
Egg: 5000 mg/kg
Pout (Fish) : 6500mg/kg
Ham (Pork):
7459mg/kg
Chicken:
8800mg/kg
Tomato Juice : 680mg/L
Apple Juice :
2000mg/L
Certainly, in normal diet, it is very unlikely for a person to consume 1 kg of egg or asparagus or some other meat products. Some soft drinks addicts really consume a litre of it per day, but from the table above it is very clear that Aspartame is not harmful at normal dosage since most natural food in our daily diet introduce a lot more of the chemicals concerned into our body system, for better and the worse.
The aspartame controversy has a long history, and nobody seems to notice that sugar farmers are not traditional farmers, but owned and operated by large international corporates, so does the manufacturer of aspartame. It is totally logical for the sugar corporate to launch attack on aspartame since it has taken away billions of profit from them.
Every good argument has two opposing forces in play, and most of the time, backed by huge interest groups. |
