是時候介紹抗氧化劑2.0版了

抗氧化劑一詞在消費者中有很高的認知度，因此被廣泛使用來吸引消費者的注意力是很自然的。但是，如果不采取某種措施來衡量生物活性，我們就有可能把所有東西都貼上抗氧化劑的標簽，而沒有任何意義。這對一個如此努力提高消費者意識的行業構成了非常現實的威脅。現在正視這種情況並引入新的2.0版本係統可以防止它成為真正的問題。膳食或補充劑中額外的抗氧化劑有助於平衡由於衰老、暴露於汙染、吸煙和過度運動等因素而向促氧化劑傾斜的天平。抗氧化劑一詞包羅萬象，包含了數量驚人的植物化學物質，以及更廣為人知的維生素。健康聲明法規將防止輕率地宣稱潛在的健康益處，但在2010年引入這些法規之前，抗氧化劑“品牌”(如果我可以這麼稱呼它的話)對消費者具有如此大的吸引力，以至於能夠宣稱“是(豐富的)抗氧化劑來源”似乎很有誘惑力。目前還沒有任何規章製度來阻止人們在標簽上印上諸如“抗氧化劑含量高”或“抗氧化劑來源豐富”之類的說明。但“高”或“富”的定義是什麼呢?似乎沒有一個分界點。 This will of course change when the health claims legislation comes into play because the statement "contains antioxidants" implies a health benefit. But for the moment, we're going through a period of transition, and that means things can be fuzzy. We have already started to see a backlash of sorts. In October, the UK's Innocent was rapped on the knuckles for making a health claim about its smoothie having a high antioxidant content and detoxifying effect. The Advertising Standards Authority (ASA) said an advert by the firm, which claimed its fruit juice contained more antioxidants than the "five-a-day" portion, was not truthful or substantiated. A week earlier, and the UK Tea Council was criticised for exaggerating the benefits of tea, and banned from making further claims about the drinks' antioxidant potential after running a series of adverts. The message is clear: It is time for a spring-clean of the antioxidant house. But how should we go about doing this? I don't pretend to have the answers, but I do have a couple of suggestions. How about we settle on a definitive way of classifying antioxidant activity, and levels that could be classed as low, medium, or high in terms of antioxidants levels? Moreover, we need to link antioxidant content to an endpoint - for example, the dose of antioxidant needed to reduce a certain biological marker linked to the risk of a specific disease, like tomato extracts and prostate specific antigen (PSA) levels in relation to prostate cancer. Not convinced? Only last week, Ming Hu from the University of Houston issued a "call to arms" in an editorial in the journal分子藥物更多關於抗氧化劑，特別是多酚類物質的研究。在他的專家觀點中，缺乏關於這些化合物的生物利用度和利用的數據。有趣的是，胡指出，一種典型的多酚的生物利用度隻有10%左右。換句話說，原來的食物或補充劑可能含有大量的多酚，但隻有十分之一會被腸道吸收。目前，抗氧化活性是基於實驗室分析，但這能讓我們真正認識到其潛力嗎生理好處呢?有許多量化抗氧化活性的方法，但這些隻是增加了混亂。我們經常看到新的抗氧化劑排行榜，有這樣那樣的水果或漿果名列前茅。但是，在ORAC或FRAP測試中的良好表現對特定的健康益處究竟意味著什麼呢?所選化合物的抗氧化活性已通過一係列基於實驗室的測定方法進行了測定，包括血漿鐵還原能力(FRAP)測定、氧自由基吸收能力(ORAC)和Trolox等效抗氧化能力(TEAC)。關於哪種方法是最好的，有相當多的爭論。ORAC測試的門徒可以發現FRAP的錯誤，而FRAP可以發現ORAC的錯誤。我們不能忽視這樣一個事實:這些試驗是在試管中進行的。就在最近，康奈爾大學的科學家們提出了一種新的抗氧化活性測量方法，稱為細胞抗氧化活性(CAA)測定法，並將其稱為量化抗氧化活性的“下一步”。據報道，新的測定方法將抗氧化活性的量化從試管轉移到測量細胞內的生物活性。 However, I have already received emails highlighting potential 'issues' with this new method, and anticipate other cellular-based assays to follow. We have a plethora of data now, each proposing a measure of antioxidant activity. It is all getting a bit confusing. The time for action is now, before more companies get their knuckles rapped for overstating or misrepresenting the antioxidant issue. It is all well and good tapping into kudos attached to the term, but only by using it responsibly will we all benefit.斯蒂芬·丹尼爾斯是nutra配料網和FoodNavigator.com的科學編輯。他擁有貝爾法斯特女王大學的化學博士學位，曾在荷蘭和法國從事研究工作。如果你想對這篇文章發表評論，請發郵件給stephen.daniells'at'decisionnews.com