教你如何选择最好的防晒霜

你会依照说明大量地进行使用的防晒霜便是最好的防晒霜。本文帮助你了解防晒霜的成分，防晒霜的类型及其他更多的知识。

By Mayo Clinic staff

文：梅奥诊所（Mayo Clinic） 员工

Have conflicting media reports left you confused about the best sunscreen? Or wondering whether you should use sunscreen at all? 

你是否曾为互相矛盾的媒体报道而困扰，不知道哪种防晒霜最好？或者怀疑压根就不该使用防晒霜？

Lawrence Gibson, M.D., a dermatologist at Mayo Clinic, Rochester, Minn., says that people are asking tough questions about sunscreens and raising controversial issues about the best sunscreen. He offers the following guidance. 

明尼苏达州罗切斯特市梅奥诊所（Mayo Clinic）的皮肤科专家劳伦斯•吉普森（Lawrence Gibson）指出，人们对防晒霜提出了很多尖锐的问题，关于什么是最好的防晒霜也引起了不少的争议。他本人给出了如下指导：

What's the best way to sort through the details on sunscreens?

如何整理一大堆关于防晒霜的信息？

Start by looking beyond the topic of best sunscreen. Get back to the bigger picture, which is protecting yourself from the sun. Here are three main things to keep in mind: 

让我们从最好的防晒霜这个话题之外说起。回到更高的一个层面来，是什么在保护你免于日晒？以下三条建议要牢记于心：

Avoid the sun during peak hours. Generally, this is between 10 a.m. and 4 p.m. — regardless of season. These are prime hours for exposure to skin-damaging ultraviolet (UV) radiation from the sun, even on overcast days. 

Wear protective clothing. This includes pants, shirts with long sleeves, and sunglasses. Top it off with a wide-brimmed hat. In addition, consider investing in special sun-protective clothing for golf, gardening, walking, running — even swimming.

 Use sunscreen. Liberal use of sunscreen is a key part of any program to protect yourself from the sun. What does the term 'broad spectrum' mean when applied to sunscreens?

在一天之中的高峰时段避免日晒。通常，这个时段是指上午10点至下午4点之间——无论在哪个季节均是如此。这段时间是皮肤受到太阳紫外线照射伤害的主要时段，即使是阴天也是如此。

注意穿有保护作用的衣物。包括裤子，长袖的裙子和太阳镜，最后再加一顶宽檐的帽子。此外，在打高尔夫球、做园艺工作，散步，跑步乃至游泳时，要考虑买一件专门的防晒服。

使用防晒霜。大量地使用防晒霜是所有防晒措施的主要部分。当“广谱（broad spectrum）”用于指防晒霜时，是什么意思呢？

There are two types of UV light that can harm your skin — UVA and UVB. A broad-spectrum, or full-spectrum, sunscreen is designed to protect you from both. 

太阳光线中有两种紫外线会对你的皮肤造成伤害，即UVA和UVB。广谱（broad-spectrum）或全谱（full-spectrum）的防晒霜可以防止这两种紫外线造成的伤害。

UVA rays can penetrate deeply into your skin and suppress your immune system. This increases the risk of wrinkling and age spots. UVB rays can burn your skin. Too much exposure to both UVA and UVB rays raises your risk of skin tumors, including a form of cancer called squamous cell carcinoma. The best sunscreen offers protection from all UV light. 

UVA能穿透你的皮肤，使免疫系统的功能下降，这就增加了长皱纹和老年斑的危险。UVB会灼伤你的皮肤。过多地暴露在UVA和UVB下会增加患皮肤瘤的危险，包括患鳞状细胞癌的危险。最好的防晒霜应该保护皮肤不受到所有紫外线的伤害。

Does the best sunscreen also have the highest SPF?

最好的防晒霜应该有最高的SPF吗？

SPF stands for sun protection factor. This is a measure of how well the sunscreen deflects UVB rays. Currently, there's no standard for measuring UVA protection. 

SPF是sun protection factor(防晒系数)的缩写。用来计算防晒霜防护紫外线UVB能力的高低。现在，还没有能够测量UVA防护的标准。

Manufacturers calculate SPF based on how long it takes to sunburn skin that's been treated with the sunscreen as compared with skin that hasn't been treated with sunscreen. Theoretically, the best sunscreen has the highest SPF number. Many dermatologists recommend using a product with an SPF of 30 or more. However, no one really agrees on a "good" SPF number. A sunscreen with an SPF of 60 might be better than one with an SPF of 30, but not necessarily — and the SPF 60 product isn't likely to be twice as effective as the SPF 30 product. 

生产商计算该系数是基于在涂抹了防晒霜和没抹防晒霜的这两种情况下，对皮肤晒红的时间进行的对比。理论上来说，最好的防晒霜的防晒系数也就最高。很多皮肤科的专家也推荐使用防晒系数为30及30以上的防晒产品。然而，关于“适当的”防晒系数值，大家都没有达成一致。防晒系数为60的防晒霜可能会比防晒系数只有30的要好，但这也没有必要，而且防晒系数为60的防晒产品所达到的效果并不是防晒系数为30的两倍。

To understand this, remember how sunscreen is typically used. It might not be applied thoroughly or thickly enough, and it might be perspired away or washed off while swimming. All this can make even the best sunscreen less effective than the SPF number on the bottle would lead you to believe. 

要明白这一点，要记住我们通常是如何使用防晒霜的。可能抹的不够彻底，也不够厚，还可能随着汗水流走，在游泳时被洗掉。所有的这一切都会使得最好的防晒霜的防晒效果低于它瓶子上标的防晒系数。

Are spray sunscreens better than other types of sunscreen?

喷雾型的防晒霜比其他类型的更好吗？

You can use sunscreen that comes in any form: spray, lotion, cream, wax stick or powder. Your choice is a matter of personal preference and which area of the body you're covering. If you have dry skin, you might prefer a cream — especially for your face. A gel might work better for areas covered with hair, such as the scalp. 

你可以使用任何形式的防晒品：防晒喷雾，防晒油，防晒霜，防晒棒或者防晒粉。这取决你个人的偏好，以及你将用于身体哪个部位的防晒。如果你是干性皮肤，你可能更喜欢霜，尤其用于脸上时。胶类产品更适合同于有毛发的地方，如头皮处。

Which sunscreen ingredients are best?

哪种防晒霜成分最好？

To ensure broad-spectrum protection, the American Academy of Dermatology (AAD) recommends sunscreens with any of the following ingredients: 

为了确保广谱防护，美国皮肤病协会（AAD）推荐使用含有以下任何成分的防晒产品。

Avobenzone 

Cinoxate 

Ecamsule 

Menthyl anthranilate 

Octyl methoxycinnamate 

Octyl salicylate 

Oxybenzone 

Sulisobenzone 

You might encounter warnings that sunscreens with oxybenzone can irritate your skin, especially if you're sensitive to skin care products. However, a recent analysis of 64 studies indicates that sunscreens with 1 to 6 percent oxybenzone don't pose a significant risk of skin sensitization or irritation for most people. 

阿伏苯宗

西诺沙酯 

依莰舒 

氨基苯甲酸胺 

紫外线吸收剂 

水阳酸盐 

氰笨甲酮 

舒利苯酮 

你可能受到过相关警告，含有氰笨甲酮的防晒霜可能会使你的皮肤过敏，尤其是如果你对皮肤护理品很敏感的话。然而，一份对于64份研究报告的分析表明，含有1%到6%的氰笨甲酮的防晒品并不会对大多数人的皮肤造成过敏或刺激。

In addition to sunscreens based on the chemicals listed above, you can now choose from a number of mineral-based sunscreens — sometimes referred to as "inorganic." Their main ingredients are zinc oxide and titanium dioxide. Neither one of these seems to penetrate the skin, and sunscreens based on these ingredients appear to be safe as well as effective. 

除了含有上述列举化学物质的防晒霜，你还可以选择含有一系列矿物的防晒霜，也指“无机物”，主要成分是氧化锌和氧化钛。这两种物质都不会穿透皮肤，基于这两种成分的防晒霜效果好，还安全。

Are some brands of sunscreen better than others?

各种防晒霜品牌的产品有无优劣之分？

Try several different brands to see which works best for you. Brand matters less than how you use the product. In general, look for water-resistant, broad-spectrum coverage with an appropriate SPF — at least 15. Check the expiration date, and follow the directions on the label. 

多试几种不同品牌的防晒霜，看看哪种最适合你。比起你如何使用它来说，品牌没那么重要。总体上，选择防水、适当的防晒系数（至少为15）的广谱防晒霜。记得查看有效期，并且按照标签上的说明来使用。

What about claims that sunscreen is ineffective?

如何看待防晒霜毫无用处的说法？

Even the best sunscreen isn't perfect. Many sunscreens especially fall down when it comes to UVA protection. In addition, sunscreen use alone isn't thought to prevent all skin cancers. Yet sunscreens are getting better, and using them is certainly better than using nothing at all. 

即便是最好的防晒霜也不会是十全十美的。很多防晒霜在UVA防护上根本不起作用。另外，单单使用防晒霜是不会防止各种皮肤癌的。使用防晒霜只是会更好一些，肯定比什么都不用好。

Is there any truth to the claim that sunscreen use can actually increase the risk of melanoma?

关于使用防晒霜会增加患黑素瘤的危险这种说法有没有事实依据？

Researchers don't understand why people develop melanoma — a serious form of skin cancer. There are several different types of melanoma, and not all types are equally linked to sun damage. Genetics plays a key role as well. Many factors are involved, which makes it hard to link sunscreen use with skin cancer. 

研究者不知道人们为什么会得黑素瘤，一种严重的皮肤癌。黑素瘤有好几种，并不是都和日晒有关，遗传因素也很重要。也还有很多其他的原因，因此很难说皮肤癌就和防晒霜有关。

If you have any risk factors for skin cancer — especially a family history of the disease — be sure to consult a dermatologist. Also remember this advice from the AAD: "Check your birthday suit on your birthday." If you notice any changes in your skin, such as growths or bleeding, consult a dermatologist right away. When detected early, most forms of skin cancer are quite treatable. 

如果你有患皮肤癌的危险，尤其是有这种病的家族遗传史，一定要去咨询皮肤科医生。同时也记住AAD的这条建议：“过生日那天一定要检查全身。”如果发现你皮肤上有任何变化，如肿瘤或流血，要马上看皮肤科医生。发现及时的话，大部分的皮肤癌是可以治愈的。

What else is it important to remember about using sunscreen?

使用防晒霜还有什么注意事项？

When you use sunscreen: 

涂抹防晒霜的注意事项：

Apply generous amounts of sunscreen to dry skin 30 minutes before you go outdoors. Use sunscreen on all skin surfaces that will be exposed to sun — especially your face, ears, hands, arms and lips. If you don't have much hair on your head, apply sunscreen to the top of your head or wear a hat. Coat your skin well and rub sunscreen in thoroughly. Reapply sunscreen every two hours — more often if you're perspiring. Reapply sunscreen immediately after swimming. Remember that sand, water and snow reflect sunlight and make it even more important to use sunscreen. Since UVA rays penetrate glass and clouds, use sunscreen even when it's cloudy or you're indoors but in rooms with lots of windows. You can apply sunscreen to children as young as age 6 months. Keep younger children in the shade as much as possible. 

要在出门前30分钟，在干燥的皮肤上大量地涂抹。

要在所有将暴露在太阳下的皮肤表面涂抹，尤其是你的脸，耳朵，手，胳膊和嘴唇。如果你的头发不太多，也可以在头顶上抹防晒霜，或者戴一顶帽子。

仔细地涂抹在皮肤上，并彻底擦匀。

每隔两个小时要再涂抹一次，如果你出汗了涂抹频次则要更高。

游完泳后马上抹防晒霜。

记住沙子、水和雪都会反射太阳光，这使得抹防晒霜更为重要。

由于UVA光线可以透过玻璃和云彩，因此即使在阴天或者在有很多窗户的室内也要用防晒霜。

6个月大的孩子就可以抹防晒霜了，同时要尽可能让你的孩子待在阴凉处。

What's the bottom line on sunscreen?

使用防晒霜的底线是什么？

Use sunscreen year-round, but don't let any product lull you into a false sense of security about exposure to the sun. A combination of shade, clothing, sunscreen and common sense is your best bet.

全年都要使用防晒霜，但是不要以为误以为用了防晒霜在太阳下就彻底安全了。只有将待在阴地，穿长袖衣服，使用防晒霜以及了解一些常识这几项结合起来，才是最好的防晒办法。