On Thursday, two World Health Organization agencies released their findings on aspartame, the artificial sweetener found in thousands of sugar-free products like diet sodas, chewing gums, yogurts and energy drinks.

週四，世界衛生組織的兩個機構公布了他們對阿斯巴甜的研究結果，這是一種人工甜味劑，被用於成千上萬的無糖產品中，如無糖汽水、口香糖、酸奶和能量飲料。

The organization’s International Agency for Research on Cancer classified aspartame as possibly carcinogenic to humans. A separate group, the Joint Expert Committee on Food Additives, said that there was not convincing evidence of a link between aspartame and cancer in humans and that people could still safely consume the sweetener in moderate amounts.

世衛組織下屬的國際癌症研究機構將阿斯巴甜列為可能對人類致癌的物質。另一個組織食品添加劑聯合專家委員會表示，沒有令人信服的證據表明阿斯巴甜與人類癌症之間存在聯繫，人們仍然可以安全地適量攝入這種甜味劑。

The announcement does not mean that aspartame definitively causes cancer, W.H.O. experts said in a news conference; instead, it is a call for additional research into its health effects.

世衛組織專家在新聞發布會上表示，這一聲明並不意味著阿斯巴甜一定會導致癌症，而是呼籲對其健康影響進行更多研究。

The W.H.O. is not advising companies to withdraw products that contain aspartame or urging people to stop consuming it altogether, said Dr. Francesco Branca, director of the Department of Nutrition and Food Safety at the agency. “We’re just advising for a bit of moderation,” he said.

世界衛生組織營養與食品安全部門主任弗朗西斯科·布蘭卡博士表示，世界衛生組織並不建議公司撤下含有阿斯巴甜的產品，也不會敦促人們完全停止食用阿斯巴甜。「我們只是建議攝入要適度，」他說。

According to the W.H.O., it is safe to consume up to 40 milligrams of aspartame per kilogram of body weight per day. Using diet soda as a measure, the limit means that, by some estimates, a 150-pound person would need to drink more than a dozen cans each day to surpass it.

根據世界衛生組織的數據，每天每公斤體重最多攝入40毫克阿斯巴甜是安全的。以無糖汽水為衡量標準，根據估算，這意味著一個體重68公斤的人每天需要喝十幾罐才能超過這個限量。

The Food and Drug Administration is slightly more permissive with its daily safety limit. It states that people can have up to 50 milligrams of aspartame per kilogram of body weight each day.

美國食品和藥物管理局（簡稱FDA）的每日安全限量則稍微寬鬆一些。它指出人們每天每公斤體重最多可攝入50毫克阿斯巴甜。

An F.D.A. official said agency scientists did not have concerns about the safety of aspartame when the sweetener is used “under the approved conditions.”

一名FDA官員表示，該機構的科學家並不擔心「在滿足批准的條件下」使用阿斯巴甜的安全性。

“Aspartame being labeled by I.A.R.C. as ‘possibly carcinogenic to humans’ does not mean that aspartame is actually linked to cancer,” the official wrote.

這位官員寫道：「國際癌症研究機構將阿斯巴甜標記為『可能對人類致癌』，並不意味著阿斯巴甜實際上與癌症有關。」

Given the vast quantities of sweetener under discussion, several experts said that consumers should not necessarily worry about the cancer risk of their aspartame consumption. Reaching that upper daily level of aspartame intake “isn’t casual consumption,” said Dr. Dale Shepard, a medical oncologist at the Cleveland Clinic. “This is making a project out of trying to get aspartame.”

鑒於所議甜味劑的使用量之廣，幾位專家表示，消費者不必擔心食用阿斯巴甜的癌症風險。克利夫蘭診所的腫瘤內科醫生戴爾·謝潑德博士說，「日常攝入並不會」達到每日阿斯巴甜攝入量上限。「要獲取那麼多阿斯巴甜沒那麼容易。」

The International Agency for Research on Cancer labeled aspartame as “possibly carcinogenic to humans,” a category that includes more than 300 viruses, chemicals, occupational exposures and more. Certain pickled vegetables, engine exhaust, some types of human papillomavirus and working in dry-cleaning all fall into the same I.A.R.C. category.

國際癌症研究機構將阿斯巴甜標記為「可能對人類致癌」，該類別包括300多種病毒、化學物質、職業暴露等。某些醃製蔬菜、發動機廢氣、某些類型的人乳頭瘤病毒以及從事乾洗工作都屬於這一類別。

The new classification for aspartame is based on limited evidence that has linked the artificial sweetener to liver cancer in humans. There is inadequate evidence to show that it can cause other types of cancer, and experts don’t know exactly how the sweetener might contribute to cancer. The group also found limited evidence that aspartame was associated with cancer in animals.

將阿斯巴甜新劃入此類別的有限證據顯示，這種人工甜味劑與人類肝癌有關。沒有足夠證據表明它會導致其他癌症，專家也不清楚這種甜味劑的致癌原理。該組織還發現，阿斯巴甜與動物癌症有關的證據是有限的。

By contrast, alcoholic beverages fall into the most extreme classification: “carcinogenic to humans.” The I.A.R.C. also classifies air pollution, tobacco and processed meats as carcinogenic to humans.

相較之下，酒精飲料屬於最嚴重的一類，即「人類致癌物」。國際癌症研究機構還將空氣污染、煙草和加工肉類列為人類致癌物。

“The larger challenge is that with aspartame, like other additives, there’s just not enough science to say definitively, ‘Yes, this causes cancer’ or ‘No, it doesn’t,’” said Dr. Dariush Mozaffarian, a cardiologist and professor of nutrition at the Friedman School of Nutrition Science and Policy at Tufts University.

「更大的難點在於，和其他添加劑一樣，沒有足夠的科學證據能確定阿斯巴甜『的確致癌』或者『不會致癌』，」塔夫茨大學營養科學與政策學院營養學教授、心臟病專家達裡什·莫扎法裡安表示。

In terms of lowering cancer risk, people should first think about other factors that may make them more susceptible, like obesity as well as alcohol and cigarette use, said Dr. Neil M. Iyengar, a medical oncologist and physician scientist at Memorial Sloan Kettering Cancer Center in New York City.

紐約市紀念斯隆·凱特琳癌症中心臨床科學家兼醫學腫瘤學家尼爾·艾揚格表示，在降低癌症風險的問題上，人們應該首先考慮其他可能更容易致癌的因素，比如肥胖、飲酒和吸煙。

There is an array of artificial sweeteners on the market, with varying chemical structures. Data on their long-term health effects is lacking.

市面上人工甜味劑種類繁多，其化學結構也各不相同。關於這些甜味劑對健康長期影響的數據並不多。

There’s no clear “winner” that is the best for you, said Joanne Slavin, a professor of food science and nutrition at the University of Minnesota-Twin Cities.

明尼蘇達大學雙城分校的食品科學與營養學教授喬安妮·斯萊文表示，關於哪一種對人「最有益」，並沒有明確的結果。

In the spring, the W.H.O. said that artificial sweeteners like aspartame, stevia, sucralose and saccharin may not help people lose body fat and that consuming them might be associated with a greater risk of cardiovascular disease, diabetes and overall mortality. Erythritol, a zero-calorie sugar substitute, has recently come under scrutiny for its potential links to cardiovascular issues, although that evidence is inconclusive.

世衛組織今年春天表示，阿斯巴甜、甜菊糖、三氯蔗糖和糖精鈉等人工甜味劑可能無法帶來減脂效果，食用之後還可能增加心血管疾病、糖尿病和總體死亡率的風險。不含卡路里的代糖赤蘚糖醇最近因其與心血管疾病的可能聯繫引發關注，儘管相關證據尚無定論。

Some health experts recommend phasing out artificial sweeteners from your diet altogether, as challenging as that may be. “If they don’t do any good, and they’re not required in the diet, and there’s no real advantage — why bother with them?” said Marion Nestle, a professor of nutrition, food studies and public health at New York University.

一些健康專家建議，雖然難度可能很高，但應該在飲食中逐步剔除人工甜味劑。「如果它們沒有任何好處，在飲食中也不是必需品，不會帶來真正的益處，那為什麼還要攝入呢？」 紐約大學營養、影片研究和公共衛生學教授瑪麗昂·內斯特爾表示。

But sugar comes with concerns, too. Anything that consistently spikes your blood sugar can be a problem, especially if you have diabetes or another metabolic disorder. The Centers for Disease Control and Prevention has linked the frequent consumption of sugar-sweetened beverages, like regular sodas, with Type 2 diabetes, cardiovascular disease, kidney diseases, obesity and other health concerns.

但糖類本身也有健康隱患。任何持續升高血糖的食品都可能帶來問題，尤其是在你已經患有糖尿病或其他代謝紊亂疾病的情況下。美國疾控中心認為，經常含糖飲料（如普通汽水）與2型糖尿病、心血管疾病、腎臟疾病、肥胖和其他健康問題都有關係。

“There’s always risk,” Dr. Slavin said. “In the end, if you can stand the calories, maybe a little bit of sugar in lemonade is better than an alternative sweetener. That’s your call, depending on your health status and what you want to do.”

「風險總是存在的，」斯萊文表示。「最後的辦法，就是假如能接受卡路里的話，也許在檸檬水裡加一點糖會比攝入其他甜味劑更安全。這要看你怎麼想，取決於你的健康狀況和你想要怎麼做。」