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Q.ÌýI'm 63, and I've begun to notice a decline in the quality of my fingernails. They have numerous up-and-down ridges, and at the tips, they're always splitting. I've heard you can tell a lot about a person's health from the condition of her nails. What does my split nails say about mine?

A.ÌýSome changes in nails can be a sign of an underlying health problem, but the lengthwise nail ridging you describe is usually not one. It's simply a common sign of normal aging. The growth of fingernails and toenails slows as we get older, and their appearance may change. Some nails become yellowed or dull and brittle, and some or all may develop tiny longitudinal ridges. Fingernails tend to become thinner and more fragile, while toenails usually become thicker and harder.

Research we're watching

If your hair has been thinning, an infusion of your body's own plasma may help grow it back, according to the American Academy of Dermatology.

A number of recent studies show that platelet-rich plasma (PRP) therapy is successfully regrowing lost hair. This includes a 2018 study in the International Journal of Women's Dermatology that found the technique was beneficial in treating androgenetic alopecia, a type of genetically and hormonally driven hair loss that affects as many as 35% of women by age 60.

There are lots of dubious claims and mysterious ingredients, but yes, by trapping water, moisturizing can help with dry skin.

Dry skin by itself isn't a medical worry, although serious cases can result in cracks and fissures that invite infection and inflammation. The real issue is discomfort � dry skin can be sore, tender to the touch, and often itchy (although not all itchy skin is dry). There's also the red, rough, scaly appearance lamented in many advertisements for moisturizers.

This is one problem that hasn't suffered from lack of attention: there are dozens of creams and lotions for dry skin. They are sold as moisturizers, which is more of a marketing term than a medical or scientific one. Indeed, routine skin care is a realm where there's little science to be found. Well-controlled studies of ingredients are few and far between. Companies keep information about ingredients proprietary and are careful to limit claims for what the products do to stay within FDA rules.

ARCHIVED CONTENT: As a service to our readers, Ì첩ÌåÓý Publishing provides access to our library of archived content. Please note the date each article was posted or last reviewed. No content on this site, regardless of date, should ever be used as a substitute for direct medical advice from your doctor or other qualified clinician.Ìý

Q.ÌýDoes the acne drug, isotretinoin (Accutane), cause depression and suicide, or are psychiatric risks from the Accutane side effects exaggerated?

In the journals

Zinc oxide (ZO) is one of the most effective ingredients in sunscreen, but previous studies have suggested it could potentially damage skin cells. Now, a small study in the February 2019 Journal of Investigative Dermatology has found that ZO nanoparticles don't penetrate the skin or damage skin on a cellular level even with repeated applications.

ZO is one of 17 active sunscreen ingredients approved by the FDA. ZO offers broad-spectrum protection and shields against both UVB rays, which cause sunburn, and UVA rays, which penetrate more deeply and are more likely to damage cell DNA and increase the risk of skin cancer.

Microneedling was once viewed with skepticism, but it can be an effective procedure to improve the skin.

If the idea of poking yourself in the face with tiny needles in hopes of improving your skin sounds a little bizarre to you, you're not alone. For years, the medical establishment looked at the practice, known as microneedling, with a leery side-eye.

"I didn't take it seriously until relatively recently," says Dr. Kenneth Arndt, medical editor of the Harvard Special Health Report Skin Care and Repair and a founding editorial board member of the Ì첩ÌåÓý Letter.

News briefs

ÌýImage: © agrobacter/Getty Images

For some people, it's tough to prevent flare-ups of rosacea, the reddened and sometimes bumpy skin that shows up on the cheeks, nose, and other areas of the face. Caffeine, heat and sun exposure, and a long list of foods (everything from spicy foods to yogurt) have been thought to trigger rosacea or make it worse. But a study published online Oct. 17, 2018, by JAMA Dermatology not only pokes a hole in the idea that caffeine is to blame, it also suggests that one major caffeine source � coffee � might even reduce the risk of rosacea. Researchers analyzed health and diet survey responses gathered every four years from nearly 83,000 women (most of whom were white) from 1991 to 2005. It turns out that women who drank four or more cups of caffeinated coffee per day were 23% less likely to report a diagnosis of rosacea during the study period, compared with women who drank less than one cup per month. Increased caffeine intake from tea, soda, and chocolate had no impact on the likelihood of developing rosacea. The study was only observational and can't prove cause and effect. But coffee has also been linked to many other health benefits, including lower blood pressure, a slower rate of weight gain with age, and reduced risks for developing type 2 diabetes or dying from cardiovascular disease or neurological diseases.