It's the main ingredient in most beauty products and a crucial element of every skin care regimen ... but I still encounter lots of misconceptions when it comes to plain ol' water! 

    Yes, water is essential to all of our biological processes. When it comes to skin, H20 is necessary for the proper functioning of enzymes that enable skin to continually replace itself and slough off old, dead cells. And yes, if the body is severely dehydrated, you will see changes in your skin. But true dehydration is very different from the occasional need for a tall glass of water.

    In the vast majority of cases, then, dehydrated skin is not indicative of a dehydrated body - and drinking more water will not have a significant impact on your skin's hydration. Make no mistake: As a doctor (and a human being!), I'm a big fan of water and advocate drinking plenty of it. But if you're experiencing dry skin - and more of us will be as the weather turns cooler and humidity drops in many parts of the world - the only way to get relief is to strengthen your skin barrier.

    So, what's the skin barrier? That's the layer of skin - right in the middle of the epidermis - that's rich in lipids (a.k.a. fats) like fatty acids, cholesterol, and ceramides. When it's healthy, it is responsible for keeping moisture in your skin, and irritants out.

    But when this barrier is compromised, your skin loses water to the environment, resulting in dry skin, and is also more susceptible to allergic reactions and irritation. That's also why you may feel plagued by dull skin during the winter: When the skin barrier is disrupted, its lipids aren't holding your skin cells together effectively. As a result, cells' edges begin to curl up, resulting in dry skin's rough, lifeless appearance.

    The best way to tackle dry skin, then, is to help bolster the skin barrier so it can do its job and retain moisture. In fact, you can find the same lipids that are naturally present in your skin barrier in many moisturizers - fatty acids (like stearic acid), cholesterol, and ceramides are readily available in many creams and lotions. Glycerin, another rich moisturizer, is also easy to find. Best of all, these top-notch ingredients are affordable, and you'll find them in the aisles of your very own drugstore.

    My favorites? For your face, look for the Dove ProAge moisturizers. And if you're in the market for a bit of a splurge, Atopalm MLE Cream is a wonderful option for dry, sensitive skin. For the body, I love Cera Ve Moisturizing Cream, Dove ProAge Cream Oil Lotion, and Vaseline Intensive Rescue Moisture Locking Lotion.

    Wishing you great skin!

    水是多数美容用品的主要成分，是所有皮肤护理方案的关键要素。。。但说到纯粹的水，我还是遇到了不少错误的想法。

    不错，水对我们所有的生命活动都是至关重要的。说到皮肤，水对能促使皮肤不断新陈代谢的酶来说，是必不可少的。如果身体严重脱水，皮肤就会出现变化。但真正的脱水跟偶尔要来一大杯水的情况多有不同。

    绝大多数情况下，皮肤脱水不代表身体脱水----而且多喝水并不能明显润泽你的皮肤。可别犯错了：作为一个医生（作为人类！），我是挺爱喝水的，也提倡多喝。但如果你皮肤干燥----天气变冷湿气降临的时候全球大部分地区的大部分人都会如此----唯一的缓解方法是筑牢皮肤防线。

    那么，皮肤防线是什么呢？是夹在表皮层中间的一层皮，富含脂肪酸，胆固醇和神经酰胺等类脂物（也可以叫脂肪），在健康状态下负责锁住水份，使肌肤免受外界刺激。

    如果防线崩溃，皮肤就因失水而变得干燥，易过敏，易受刺激。这就是为什么你会在冬天因皮肤干燥而烦恼：皮肤防线瓦解，类脂物无法有效将皮肤细胞结为一体。因此，表皮细胞的边缘开始卷起，使得干燥皮肤看上去粗糙无生气。

    解决皮肤干燥问题的最好方法还是筑牢皮肤防线，使之能正常运作，锁住水分。实际上，许多润肤膏包含的类脂物与皮肤防线自有的没什么区别----脂肪酸（如硬脂酸），胆固醇和神经酰胺在很多洗面奶和化妆水里都有。另一种较贵的润肤霜甘油，也比较好找。最喜人的是，这些高级成分都是买得起的，你随便在哪个药房都可以找到。

    我的收藏？脸部护理用Dove ProAge润肤霜。如果你想在周围炫一下，Atopalm MLE Cream 是个好选择，专为干燥敏感皮肤而备。全身护理，我喜欢用Cera Ve 保湿霜, Dove ProAge Cream Oil Lotion, 和 Vaseline Intensive Rescue Moisture Locking Lotion

    愿你拥有美好肌肤！