DEAR DR. BLONZ: I am wondering if I get the same benefits from drinking iced tea as hot tea. Also, does the decaffeination process change the tea's beneficial characteristics? -- D.D., San Jose, California
DEAR D.D.: Assuming they are made from the same tea leaves brewed in the same way, there should be no significant difference in the health benefits between iced tea and hot.
The decaffeination process, however, is a mixed bag; there is the possibility of losing some of the tea's beneficial phytochemicals, depending on how the tea is processed. Some companies use steam, while others remove caffeine through the use of solvents.
One animal study checked the effects of black and green teas -- both regular and decaffeinated -- against the development of skin cancer. It found that regular black tea was most effective, followed by the green tea, then the decaffeinated black, then the decaffeinated green tea. They all had beneficial effects; it was just a matter of degree.
Of interest here is the fact that the caffeine itself might have some anti-cancer properties. There have been studies that have found that adding caffeine back to the decaffeinated tea "restored" much of its anti-cancer abilities. Indeed, even caffeine was found to have an ability to prevent certain cancers on its own.
Don't take this as an endorsement of caffeine as an anti-cancer agent, but more to highlight the difficulties in understanding how complex substances work in the body. Also consider that these were specialized research studies where relatively large amounts of tea extracts or solids were given for a short period of time. It is unclear how much we can generalize from the studies. The takeaway should be that tea is a healthful beverage to be enjoyed any way you like it.
DEAR DR. BLONZ: I hope you can help me with an embarrassing problem I have with the back of my hands. It seems all I have to do is tap them with my finger or hit them by mistake, and they bleed under the skin, causing a very ugly bruise. Are there any supplements I can take? -- J.D., New York City
DEAR J.D.: The blood-clotting mechanism is a complex series of biochemical reactions, the end result of which is the creation of an insoluble plug that prevents blood cells from leaking out of the vessels. In the case of a bruise, the bleeding takes place under the skin.
As we age, our skin tends to become thinner. So, too, can the walls of our blood vessels. A weakness in our blood vessel walls can contribute to an increased tendency to bruise. This can occur in good health, but a number of health conditions, medications and dietary issues can also play a role.
Discuss your bruising tendency with your physician to verify that there isn't any underlying condition or medication that may be to blame. From a dietary standpoint, I would aim for at least five servings of fruits and vegetables a day. Vitamin C and the other nutrients found in many of these foods are involved with the formation of collagen, a substance used to form blood vessels. Until you have additional information about possible underlying mechanisms and factors to consider, it's best to keep your focus on foods -- not supplements.
Send questions to: "On Nutrition," Ed Blonz, c/o Universal Uclick, 1130 Walnut St., Kansas City, MO, 64106. Send email inquiries to firstname.lastname@example.org. Due to the volume of mail, personal replies cannot be provided.