皮肤越黑越容易晒黑？是真的！

近日，“皮肤越黑越容易晒黑”这一话题登上热搜，引发网友广泛讨论。

打开评论区，一大批“黑皮星人”深感共鸣。虽然不愿意承认，但“皮肤越黑越容易晒黑”，这一说法的确有科学依据。

A recent online discussion about whether people with darker skin are more likely to tan has attracted widespread attention. Although some may find the idea hard to accept, experts say there is scientific evidence behind it.

肤色越深越容易晒黑

越容易晒黑

当紫外线照射皮肤时，皮肤为了自我保护，基底层的黑色素细胞会生成大量的黑色素“撑起”防护罩，吸收紫外线。

肤色深的人，皮肤生成黑色素的能力相对更强，生成速度也更快，当黑色素生成能力超过黑色素降解代谢的速度时，就容易导致皮肤色素沉着。

When skin is exposed to ultraviolet (UV) rays, the body produces melanin to help protect itself. People with darker skin naturally produce melanin faster and in larger amounts. As a result, their skin is more likely to darken after sun exposure when melanin production exceeds the body's ability to break it down.

皮肤越黑，在日光暴晒下抵抗紫外线晒伤的能力越强，但因为黑色素生成速度更快、量更大，也更容易陷入“黑皮—晒黑—皮肤更黑—继续晒黑—皮肤更更黑”的无限循环中（当然，停止暴晒后皮肤会逐渐代谢掉多余黑色素，不会真的无限变黑）。

肤色越深越不容易晒伤

虽说肤色越深越容易晒黑，但并非毫无优势。相比白皮肤的人来说，肤色越深的人越不容易晒伤。

紫外线除了会破坏皮肤屏障，晒红、晒伤肌肤外，还会破坏皮肤的胶原蛋白和弹力蛋白。一旦失去这些重要蛋白的支撑，我们的皮肤就会失去弹性和韧性，肉眼可见地松弛下垂，法令纹、抬头纹等皱纹纹路也会更明显。

At the same time, darker skin also has certain advantages. Higher melanin levels help reduce the risk of sunburn by blocking more UV radiation from penetrating deep into the skin. This may also help slow some signs of photoaging, such as wrinkles and loss of skin elasticity caused by UV damage to collagen and elastic fibers.

肤色深的人，因为表皮基底层的黑色素合成快，可以快速阻挡紫外线进入皮肤深层，因此，除了不易晒伤之外，他们皮肤真皮层中的胶原蛋白和弹性纤维所受到的损伤也相对较少，从而降低了因日晒而形成皱纹的可能性。

People with darker skin have faster melanin synthesis in the epidermal basal layer, which allows them to quickly block ultraviolet radiation from penetrating into the deeper layers of the skin. As a result, in addition to being less prone to sunburn, they also experience relatively less damage to the dermal collagen and elastic fibers, making them less likely to develop wrinkles from sun exposure.

防晒对任何肤色都是必修课

日常生活中，无论肤色深浅，都应做好充分的防晒，这不仅是呵护皮肤的关键，也是维护健康的必要举措。以下三个防晒要点，快收好！

① 不同人群应选用不同防晒霜

标有SPF标志的防晒霜，主要是用来衡量对UVB（晒红、晒伤）的防护能力，SPF指数越高，对UVB的防护能力越强；标有PA标志的防晒霜，主要是用来衡量对UVA（晒黑、光老化）的防护能力，PA后的＋号越多，对UVA的防护时效越长。

正常情况下，所有肤色都需要广谱防晒，即同时覆盖UVB和UVA，但SPF和PA的倍数还应根据具体肤色、场景和皮肤状况做调整：浅肤色/户外场景优先选择高倍（SPF50+/PA++++），深肤色/日常场景无需盲目追求最高倍数，选择SPF30+/PA+++即可满足需求。

Still, sun protection is important for everyone, regardless of skin tone. Broad–spectrum sunscreen that protects against both UVA and UVB rays is generally recommended. People with fair skin or those spending long hours outdoors may need stronger protection, such as SPF50+ and PA++++, while SPF30+ and PA+++ are usually sufficient for darker skin in daily settings.

② 防晒霜的涂抹方法有讲究

防晒霜不是出门的时候才涂，而是应该在出门前提前15~20分钟涂抹。如果持续在户外活动，还应每隔两三个小时补抹一次。

Proper sunscreen use also matters. Sunscreen should be applied 15 to 20 minutes before going outside and reapplied every two to three hours during extended outdoor activities.

唇部、眼部建议使用专门的防晒霜。

面部脸颊两侧和前额各涂抹一枚一元硬币大小的防晒霜，且不能忽略耳朵和脖子前后。

肩部若裸露在外，应左右两肩各涂一枚一元硬币大小防晒霜。

四肢涂抹防晒霜时，每条手臂或腿均涂抹两枚一元硬币大小防晒霜。

③ 物理防晒

对于皮肤敏感、容易过敏长湿疹、皮肤屏障受损的人群来说，建议选择物理防晒，比如穿防晒衣、戴帽子、撑遮阳伞等。

织纱密度越高、颜色越深或有防晒涂层的防晒衣，其紫外线吸收能力越强，防晒效果越好。需提醒，防晒帽最好选择帽檐宽度在7.5厘米以上，且能遮挡脸颊和脖子的款式才有较好的防晒效果。

此外，一把合格的遮阳伞或防紫外线伞，对UVB的阻隔率要达到93%左右，对UVA的阻隔率要达到95%左右。

For people with sensitive or damaged skin, material sun protection may be a better option. Wearing UV–protective clothing, wide–brimmed hats, and UV–blocking umbrellas can help reduce direct exposure to harmful rays. In general, darker and more tightly woven fabrics provide better protection against the sun.

好啦！以上这些防晒小技巧，快同步转给你身边黑皮的朋友，一起做好防晒，美美迎接这个夏天吧！

来源：外研社UNIPUS

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