The science of sunscreen

 Image: © wragg/Getty Images If you've ever searched online for information about sunscreen, what you found may have made you feel less than sunny about slathering on these lotions and creams. Sunscreen is designed to protect your skin from the sun's damaging rays, but some of the claims made about it suggest it could do more harm than good. Assertions include everything from statements that sunscreen is ineffective to warnings that it's outright dangerous. Some writers even go as far as to state that sunscreen may cause skin cancer, thanks to a purported harmful cocktail of toxic ingredients. That's enough to darken your day. More »

Is poison ivy contagious?

Q. I'm very allergic to poison ivy. My spouse currently has a bad poison ivy rash that he got while trimming some bushes in our yard. I'm afraid I'm going to get a rash from him. Is it contagious? A. Good news: poison ivy rashes are not contagious. You will get a rash from poison ivy only if you come into contact with urushiol oil, which is the plant oil in poison ivy that triggers the rash. In addition, a poison ivy rash, even one with open blisters, won't spread to other areas of the body. The rash only occurs on parts of the body that were actually exposed to the plant oil. Poison ivy rashes can appear to spread if urushiol oil is trapped under your fingernails and you scratch an itch. While you can't get a rash from coming from your spouse, you can get it from clothing or other items that have the plant oil on them. For example, the clothes your spouse was wearing that came into contact with the poison ivy plant. Poison ivy oil can cling to garden tools or even pet fur. The oil from poison ivy is known to linger. According to the FDA, it can stick around on surfaces, sometimes for years, until it is washed away using water or rubbing alcohol. So be certain that all surfaces that are potentially contaminated are cleaned thoroughly to reduce your risk. — by Hope Ricciotti, M.D., and Hye-Chun Hur, M.D., M.P.H.Editors in Chief, Harvard Women's Health Watch More »

Avoiding the pain of kidney stones

The pain associated with kidney stones has been described by some as more excruciating than childbirth. Kidney stones are small, hard stones, formed when high levels of minerals in your urine start to crystallize in your kidneys, forming a pebble-like mass. The pain comes when these stones migrate from your kidneys through the ureters, which are the narrow tubes that carry urine from your kidneys into your bladder. "Kidney stone pain is not subtle," says Dr. Gary Curhan, a professor of epidemiology at the Harvard T.H. Chan School of Public Health. It typically starts in the flank, at the side of the lower back. Sometimes if the stone moves, the pain migrates to the front of the body. Occasionally a stone gets stuck as it enters the bladder and causes symptoms — such as a feeling of urgency or frequent urination — that can be mistaken for a urinary tract infection or bladder irritation. More »

Fermented foods can add depth to your diet

Fermented foods, which are preserved using an age-old method, can provide health benefits if eaten regularly. Fermented foods containing live active cultures can help support a healthy gut microbiome, which helps to ensure that the lining of the intestines is strong and doesn’t allow digested material to leak out of the intestinal tract. This condition, called leaky gut syndrome, has been linked to a number of chronic diseases and health conditions. (Locked) More »

Small tricks to help you shed pounds and keep them off

 Image: © Wand_Prapan/Getty Images If you're struggling to lose weight, you probably feel like the odds are stacked against you. You're not necessarily wrong. "There is so much great-tasting food, and it's abundant and in your face all the time. To me it's kind of a miracle that people aren't even heavier than they are," says Dr. Meir Stampfer, a professor of epidemiology and nutrition at the Harvard T.H. Chan School of Public Health. In addition to an abundance of food, most people today also have a far more sedentary lifestyle than past generations. "Even active people who exercise a lot aren't expending the calories their ancestors did," says Dr. Stampfer. More »