来自医学博士Lawrence E. Gibson的回答。
 
防晒霜的保质期长达三年。这意味着您可以把当年剩下的防晒霜使用到下一年。

一些防晒霜上有失效日期，显示它们什么时候不再有效。丢弃过保质期的防晒霜。如果您买的防晒霜上没有失效日期，把购买日期写在瓶子。丢弃那些超过3年、已经暴露在高温或颜色或黏稠度有明显变化的防晒霜。

然而，请记住，如果您大量和频繁地使用防晒霜，一瓶防晒霜一般撑不过一年。一般来说，1盎司(30毫升)就是大量使用——有一口杯大小——可以覆盖所有身体的暴露部位。如果您有一个瓶4盎司(118毫升)的防晒霜，您每一次要用四分之一左右。

为了防护最大化，使用一个SPF至少为15的广谱防晒霜。美国皮肤病学会推荐使用SPF为30或更大的广谱防晒霜。出门前20到30分钟充分涂抹防晒霜，并且大约每两小时重复涂抹一次，如果您经常游泳或出汗的话需要涂抹的更频繁。一定要涂好防晒霜。

中文翻译：梦乐媛
本文地址：http://www.wjbb.com/know/1086
原文出处：http://www.mayoclinic.org/healthy-lifestyle/adult-health/expert-answers/sunscreen-expire/faq-20057957 收起阅读 »

来自医学博士Lawrence E. Gibson的回答。
 
关于食物与皮肤健康的研究不多，但富含抗氧化剂的食物似乎对皮肤有保护作用。

以下食物对皮肤有益:

• 胡萝卜、杏、及其他黄色和橙色的水果和蔬菜；
• 菠菜和其他绿叶蔬菜；
• 西红柿；
• 蓝莓；
• 黄豆、豌豆和扁豆；
• 鲑鱼、鲭鱼和其他多脂鱼；
• 坚果。

另一方面，有些食物似乎对皮肤有害。例如，有研究表明，富含深加工或精制碳水化合物、不健康脂肪的饮食习惯会促进皮肤老化。

在此提醒您，许多利于皮肤健康的食物也能促进身体健康。与其关注有利于肌肤健康的特定食物，不如集中精力在健康饮食上。多吃水果和蔬菜；选择低脂或无脂的奶制品；在您最喜欢的食物中加入坚果、种子和豆类；选择全麦的面包和面食；限制甜食；并注意食物的多样性。

 
中文翻译：栀子花开
本文地址：http://www.wjbb.com/know/1085
原文出处：http://www.mayoclinic.org/healthy-lifestyle/adult-health/expert-answers/healthy-skin/faq-20058184 收起阅读 »

 
来自医学博士Lawrence E. Gibson的回答。
 
虽然适当的水合作用对身体健康很重要，但是目前尚不清楚健康的人饮用过量的水是否会影响皮肤的水合作用。

皮肤的结构有三层，分别是：表皮（皮肤最外层），真皮（位于表皮之下）和皮下脂肪组织。如果表皮的最外层缺水，皮肤会变得松弛、粗糙。尽管如此，尚缺少能够证实多补水对皮肤的水合作用或者皮肤表面有影响的相关研究。
 
如果您想保持水嫩的皮肤，您可以按照以下步骤试试：

• 避免皮肤暴露在干燥的环境里
• 避免皮肤长时间接触热水或者经氯消毒过的水
• 使用柔和的清洁剂，不用肥皂
• 避免使用含有酒精的护肤品
• 洗浴后立刻给皮肤做保湿护理，平日也要规律性地对皮肤做保湿护理
• 使用加湿器
• 冷天外出时围上围巾，戴上手套

如果您想了解皮肤干燥问题，请联系您的健康护理人员，或者皮肤科医生。  

中文翻译：乐山乐水
本文地址：http://www.wjbb.com/know/1084
原文出处：http://www.mayoclinic.org/healthy-lifestyle/adult-health/expert-answers/hydrated-skin/faq-20058067 收起阅读 »

 
来自医学博士Lawrence E. Gibson的回答。
 
Yes. The medication bimatoprost — marketed under the brand name Latisse — is approved by the Food and Drug Administration (FDA) to treat inadequate eyelashes (hypotrichosis). Bimatoprost is also marketed under the brand name Lumigan, which is used in prescription eyedrops to treat glaucoma. Eyelash growth was an unexpected side effect of Lumigan, which led to the creation and marketing of Latisse.

With regular applications along the lash line of the upper eyelid, Latisse gradually encourages growth of longer, thicker and darker eyelashes. Latisse isn't meant to be applied to the lower eyelid. For full results, you must use the medication daily for at least two months. Eyelash improvements remain as long as you continue to use the medication. When you stop using Latisse, your eyelashes will eventually return to their original appearance.

Potential side effects of Latisse include:

• Itchy, red eyes
• Dry eyes
• Darkened eyelids
• Darkened brown pigmentation in the colored part of the eye (iris)
• Hair growth around the eyes if the medication regularly runs or drips off the eyelids

Although darkened eyelids might fade when the medication is stopped, any changes in iris color are likely to be permanent.In one small study of people who have eyelash loss due to alopecia areata — a medical condition that causes temporary hair loss — Latisse triggered moderate eyelash growth for more than 40 percent of participants. Research isn't conclusive, however. In another small study of people who have alopecia areata, Latisse wasn't an effective treatment for eyelash growth.If you're concerned about the appearance of your eyelashes, talk to your doctor. He or she can help you weigh the pros and cons of using an eyelash-growing medication.Answers from Lawrence E. Gibson, M.D.Yes. The medication bimatoprost — marketed under the brand name Latisse — is approved by the Food and Drug Administration (FDA) to treat inadequate eyelashes (hypotrichosis). Bimatoprost is also marketed under the brand name Lumigan, which is used in prescription eyedrops to treat glaucoma. Eyelash growth was an unexpected side effect of Lumigan, which led to the creation and marketing of Latisse.With regular applications along the lash line of the upper eyelid, Latisse gradually encourages growth of longer, thicker and darker eyelashes. Latisse isn't meant to be applied to the lower eyelid. For full results, you must use the medication daily for at least two months. Eyelash improvements remain as long as you continue to use the medication. When you stop using Latisse, your eyelashes will eventually return to their original appearance.Potential side effects of Latisse include:

• Itchy, red eyes
• Dry eyes
• Darkened eyelids
• Darkened brown pigmentation in the colored part of the eye (iris)
• Hair growth around the eyes if the medication regularly runs or drips off the eyelids

Although darkened eyelids might fade when the medication is stopped, any changes in iris color are likely to be permanent.

In one small study of people who have eyelash loss due to alopecia areata — a medical condition that causes temporary hair loss — Latisse triggered moderate eyelash growth for more than 40 percent of participants. Research isn't conclusive, however. In another small study of people who have alopecia areata, Latisse wasn't an effective treatment for eyelash growth.

If you're concerned about the appearance of your eyelashes, talk to your doctor. He or she can help you weigh the pros and cons of using an eyelash-growing medication.
 
中文翻译：
本文地址：http://www.wjbb.com/know/1083
原文出处：http://www.mayoclinic.org/healthy-lifestyle/adult-health/expert-answers/latisse/faq-20058367 收起阅读 »

来自医学博士Lawrence E. Gibson的回答。
 
答案是否定的。剃体毛并不能改变体毛的厚度、颜色或者生长速度。

面部或者身体的毛发被剃掉后顶部会变钝。当毛发刚长出来时，变钝的顶部摸起来好像更粗更硬。在这个阶段，毛发看起来就更明显而且可能表现得更黑或更厚，但这只是假象。

如果您注意到自己面部或者身体的毛发突然增加，请咨询医生。这可能是某种药物的副作用或者潜在疾病的征兆。医生可能会给您提供建议并且告诉您多种去除毛发的技巧。

中文翻译：Kseniya
本文地址：http://www.wjbb.com/know/1082
原文出处：http://www.mayoclinic.org/healthy-lifestyle/adult-health/expert-answers/hair-removal/faq-20058427 收起阅读 »

来自医学博士Lawrence E. Gibson的回答。
 
Tanning beds don't offer a safe alternative to natural sunlight.

Exposure to ultraviolet (UV) radiation damages your skin, whether the exposure comes from tanning beds or natural sunlight. This damage increases the risk of skin cancer and premature skin aging. In fact, tanning beds emit UVA rays — which might increase the risk of melanoma, the deadliest form of skin cancer.

If you'd like the golden glow of a tan without exposure to damaging UV radiation, consider using a sunless tanning product. Avoid tanning beds, and use a broad-spectrum sunscreen whenever you're outdoors.
 
中文翻译：
本文地址：http://www.wjbb.com/know/1081
原文出处：http://www.mayoclinic.org/healthy-lifestyle/adult-health/expert-answers/tanning/faq-20057884 收起阅读 »

来自医学博士Lawrence E. Gibson的回答。
 
没有证据表明去除纹身膏的效果。最好的情况是，纹身去除膏可能会褪色或减轻纹身。然而，纹身仍将依然可见，并且还可能伴随皮肤刺激和其他反应。
 
记住，纹身是永久的。因为墨水被放置在皮肤表层之下，完全去除纹身是困难的。如果你想去除纹身，不要尝试自行去除纹身。向皮肤科医生询问激光手术或其他去除纹身的方法。

中文翻译：豌豆爸爸
本文地址：http://www.wjbb.com/know/1080
原文出处：http://www.mayoclinic.org/healthy-lifestyle/adult-health/expert-answers/tattoo-removal-cream/faq-20058090 收起阅读 »

来自医学博士Lawrence E. Gibson的回答。
 
在老年人群中，脆弱的或薄皮肤容易开裂是一个常见的问题。衰老、阳光照射和遗传学在皮肤变薄的过程中都起作用。长期使用某些药物，如口服或外用糖皮质激素，也会削弱皮肤和皮肤下的血管。

皮肤薄不一定是有严重的潜在疾病的迹象。但是您可能要去看医生，他可以评估您的皮肤并确定皮肤为什么如此脆弱。

保护薄的皮肤并防止开裂和切口：
 
穿长袖衬衫，长裤和宽边帽子。做庭院劳动或园艺时，可以考虑戴两层保护前臂区域防止皮肤小伤。您也可以尝试戴管状或轧制的纱布绷带。
 
避免长时间的阳光照射。
 
如果必须在室外阳光下，请使用SPF最小为15的广谱防晒霜。大量的涂抹防晒霜，并且两个小时重复一次——如果您经常游泳或出汗，就要更加频繁。
 
可以使用良好的保湿霜保持皮肤充满水分，如薇霓肌本、药妆推荐或丝塔芙。

和您的医生讨论服用维生素A（视黄醇）治疗皮肤，它可改善皮肤承受伤害的能力。

中文翻译：梦乐媛
本文地址：http://www.wjbb.com/know/1079
原文出处：http://www.mayoclinic.org/healthy-lifestyle/healthy-aging/expert-answers/thin-skin/faq-20057753 收起阅读 »

Canadian CHILD Study sheds new light on childhood risk of developing allergies

New research from the Canadian Healthy Infant Longitudinal Development (CHILD) study shows that exposure to outdoor air pollution during the first year of life increases the risk of developing allergies to food, mould, pets and pests.

The study, published in the journal Environmental Health Perspectives, showed that the sensitivity to allergens was associated with exposure to traffic-related air pollution during infancy.

“With the increasing rates of allergies amongst children in Canada and elsewhere, we were interested in determining if air pollution from traffic might be partially responsible,” said Michael Brauer, the study’s senior author and a professor in the School of Population and Public Health at the University of British Columbia. “This is the first study to find a link between air pollution and measured allergic sensitization during the first year.”

While infants exposed to air pollution were at greater risk, researchers did not find a link between mothers exposed to air pollution during pregnancy and allergy risk in their children. Vancouver had the largest proportion of children to develop sensitivity to allergens (23.5 per cent), compared to Toronto and Edmonton (17 per cent each), and Manitoba (9 per cent). The study also found that children who live with furry pets and no attached garage were more likely to have no sensitivity to allergens.

“Understanding which environmental exposures in early life affect the development of allergies can help tailor preventative measures for children,” said Hind Sbihi, a PhD candidate at UBC and first author of the study. “We also found that children who attended daycare or with older siblings in the household were less likely to develop allergic sensitization, suggesting that exposure to other children can be protective.”

BACKGROUND

The CHILD Study, funded by AllerGen NCE and the Canadian Institutes of Health Research (CIHR), involves more than 3,500 families and their infants across Canada who are being closely monitored to determine how genetic and a wide range of environmental factors contribute to health outcomes, especially with regard to allergies and asthma.

The researchers used data from 2,477 children and assessed the children with skin allergy testing at approximately one year of age. They were tested for sensitivity to ten allergens, including cat, dog, dust mites, cockroach, fungus, milk, egg, soy and peanut. Of the participants, 16 per cent of infants were sensitive to at least one of the tested allergens; 12.5 per cent were sensitive to a food allergen; and 5.3 per cent were sensitive to an inhalant allergen.

Exposure to traffic-related air pollution was assessed by estimating nitrogen dioxide levels at each child’s home address. The researchers also evaluated the time each child spent away from home, including daycare attendance, and the use/type of the home’s ventilation system.
 
中文翻译：
本文地址：http://www.wjbb.com/know/1078
原文出处：http://news.ubc.ca/2015/05/04/exposure-to-air-pollution-in-the-first-year-of-life-increases-risk-for-allergies/
文献下载：http://ehp.niehs.nih.gov/wp-content/uploads/advpub/2015/3/ehp.1408700.acco.pdf 收起阅读 »

来自医学博士Brent A. Bauer的回答。
 
The hormone melatonin plays a role in your natural sleep-wake cycle. Natural levels of melatonin in the blood are highest at night. Some research suggests that melatonin supplements taken at the right time might be helpful in treating jet lag or other sleep disorders that involve poor alignment of your natural biological clock with the night-day pattern around you. Melatonin might also reduce the time it takes to fall asleep — although this effect is typically mild.

Melatonin might be more effective for other types of sleep issues, such as delayed sleep disorder or other sleep disorders affecting circadian rhythm.

The most common melatonin side effects include:

• Daytime sleepiness
• Headaches
• Dizziness

Other, less common melatonin side effects might include abdominal discomfort, mild anxiety, irritability, confusion and short-lasting feelings of depression.In addition, melatonin supplements can interact with various medications, including:

• Blood-thinning medications (anticoagulants)
• Medications that suppress the immune system (immunosuppressants)
• Diabetes medications
• Birth control pills

If you're considering taking melatonin supplements, check with your doctor first — especially if you have any health conditions. He or she can help you determine the correct dose, which depends on the intended use.

If you take melatonin, choose commercial supplements produced in a lab. Melatonin supplements made from animal sources might contain contaminants. Avoid activities that require alertness — such as driving or operating heavy machinery — for four to five hours after taking melatonin. Also, melatonin is generally recommended only for short-term use — up to two months. Some research indicates that longer term use might be appropriate in certain cases, however.
 
中文翻译：
本文地址：http://www.wjbb.com/know/1077
原文出处：http://www.mayoclinic.org/healthy-lifestyle/adult-health/expert-answers/melatonin-side-effects/faq-20057874 收起阅读 »