DEAR DR. BLONZ: What are the facts about goji fruit? I have heard people say that it can boost the immune system, contribute to longevity and cure cancer. -- B.B., via email
DEAR B.B.: Goji fruit is a type of berry known also as the wolfberry (Lycium barbarum). It is a native of China and is actually a member of the tomato family. Goji is a fruit that matures in the sun and, like all such fruits, it contains nutrients and antioxidant phytochemicals. This is a general theme in nature: Fruits, berries, vegetables and even some grains that grow and mature in the sun need to possess an arsenal of protectants for the plant to survive.
There's no scientific evidence that goji, or products made from it, can cure cancer, boost the immune system, increase longevity or improve other bodily functions. It is simply a fruit, a type of food we should be having every day.
When something is new and "exotic," there tend to be promotions laced with overstatement. These are usually promotional statements put forth by people who stand to benefit from the sale of the products. (It is interesting that in some cases, such products have unpleasant flavors and must be enhanced with apple juice or other natural sweeteners.)
We are open to persuasion by marketing techniques that target health situations that affect our lives. Rather than being skeptical and objective and asking "Why?" we get cajoled into asking, "Why not?" When you want to believe something because you hope it'll help you or someone you love, you become an easy target.
Please understand, I am not saying that such foods have no value. But there's no evidence that, by eating them, you'd be doing anything extra that couldn't be accomplished by having widely available berries or other types of healthful fruits.
DEAR DR. BLONZ: I am concerned about the BPA lining of metal cans. Is it more beneficial to eat tuna that is packed in glass than metal? -- R.B., Walnut Creek, California
DEAR R.B.: No problem with glass, but no need, either -- there are several companies that use BPA-free cans. Trader Joe's is one of them. Others are Wild Planet, Crown Prince, Vital Choice and Whole Foods brand (check individual cans of any of these brands before purchasing, just to be sure). And tuna is also sold in BPA-free pouches. Look for tuna caught pole-and-line or by trolling, as these methods result in fish with a lower risk of mercury. If you eat a lot of tuna, do some research at tinyurl.com/q3gojw2. Learn more about BPA at tinyurl.com/ngpzoks.
DEAR DR. BLONZ: I used to take niacin pills when my doctor recommended them to lower my blood pressure. I often experienced the "niacin flush" you described. I usually took the pills in the morning. One afternoon, on the way home from work, my ankles and lower legs began itching incredibly. When I got home I had rashes on my legs (which sounds like the experience your reader N.L. had). My doctor said I had an allergic reaction to the niacin and should stop taking the pills immediately. I never had the experience again. I realize this doesn't prove a direct connection between the niacin and my skin's reaction; however, my doctor's prognosis and your statement regarding allergic reaction would seem to be in conflict. -- D.M., via email
DEAR D.M.: Niacin is an essential nutrient that is integral to our metabolism -- we can't do without it. The niacin "flush" reaction to elevated doses is not an allergic reaction. The "allergy" terminology might have been used by your doctor for the sake of simplification.
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.