Q. I read about the person who got relief from psoriasis by bathing in the Dead Sea. I had almost the same experience at the Blue Lagoon in Iceland.
I had a bout of scalp psoriasis and dunked my head several times in the water. I didn’t have any more flare-ups again for nearly four months.
On the way back to the United States on the plane, we met a woman who flies to Iceland every three months just to go to the Blue Lagoon to treat her eczema. Now I buy the Blue Lagoon shampoo and conditioner online, and my scalp psoriasis has not recurred for nearly three years.
A. The Blue Lagoon is a popular resort spa in Iceland. The water comes from a geothermal power plant that supplies electricity for the city of Reykjavik. It is rich in sulfate and minerals such as silica, sodium and potassium.
Researchers at the University of Iceland have studied the effect of exposure to the geothermal seawater together with exposure to narrowband ultraviolet B light (Photodermatology, Photoimmunology and Photomedicine, February 2014). Although narrowband UVB exposure is a standard treatment for psoriasis, they found that bathing in the Blue Lagoon in addition to light exposure worked faster and produced longer-lasting remissions than UVB exposure alone.
Q. I have found a wonderful sleep aid. I am 94 and was having sleep problems until I found something that really works for me.
I drink about a half-cup of pure tart cherry juice every night before bedtime. Even after getting up to visit the bathroom, I go right back to sleep.
A. Thanks for the testimonial. Drinking tart cherry juice has been shown to improve sleep quality, perhaps because Montmorency cherries contain melatonin (European Journal of Nutrition, December 2012).
We would worry about someone your age taking melatonin pills because they can increase the risk for fracture (Age and Aging, November 2016). Tart cherry juice seems unlikely to cause dizziness or grogginess, however, because the dose of melatonin is low. You might have hit upon the best sleep aid for you.
Readers who are interested in tart cherry juice and other natural approaches to overcoming insomnia may wish to consult our newly revised Guide to Getting a Good Night’s Sleep. This online resource is available in the store at PeoplesPharmacy.com.
Q. You have written that some people stop a migraine by eating Chinese hot-and-sour soup. You implied that the benefit might be from capsaicin, the compound that gives hot peppers their kick.
While hot-and-sour soup does a great job at clearing the head and sinuses, it does not normally contain chili peppers. The “hot” in this soup comes from rice vinegar and white pepper.
Some American-style Chinese restaurants may use dried chilies or black pepper, but the standard is white pepper.
Chilies and white and black pepper come from different species. It may not matter so long as it works, but we should know the difference.
A. You are right: Chili peppers, white pepper and black pepper are different, but they all stimulate the same TRP (transient receptor potential) channels. This might explain why both hot-and-sour soup and hot gumbo with chili peppers work to control migraines (Journal of Headache and Pain online, Aug. 13, 2013).
In their column, Joe and Teresa Graedon answer letters from readers. Write to them in care of this newspaper or email them via their Web site: PeoplesPharmacy.com. Their newest book is “Top Screwups Doctors Make and How to Avoid Them.”