Q. We have been hearing about the benefits of lycopene. Is it true that...
Q. We have been hearing about the benefits of lycopene. Is it true that red and yellow tomatoes have different types of lycopene, and that the type in yellow tomatoes is more easily absorbed by the human body?…
Q. My mother has severe age-related macular degeneration (AMD) and it was recommended she...
A.Touted as the strongest natural antioxidant found to date and also promoted for anti-inflammatory benefits, astaxanthin is a naturally occurring plant pigment. Like many such compounds, its a type of carotenoid. When microalgae containing astaxanthin are eaten by salmon or shellfish, the compound turns their flesh pink; the same effect is seen in the feathers of flamingos who consume astaxanthin via algae. Supplement producers seeking to cash in on recent publicity for astaxanthin, including the…
Q. Im thinking about taking a vitamin A supplement, but am confused by the...
If youre eating a balanced diet and have no special health concerns, you probably dont need extra vitamin A of any kind. According to the Office of Dietary Supplements of the National Institutes of Health, Vitamin A is available in multivitamins and as a stand-alone supplement, often in the form of retinyl acetate or retinyl palmitate [preformed vitamin A].
Q. You continue to sing the praises of salmon as a source of omega-3....
Q. You continue to sing the praises of salmon as a source of omega-3. Im not a fan of salmon (or other fish, for that matter). How much omega-3 in capsule form should I take to approximate the benefit of one serving of salmon?
Q. You recently covered a new green tea study that focused on protecting brain...
A.Jeffrey Blumberg, PhD, director of Tufts HNRCA Antioxidants Research Laboratory, responds: It is not possible to determine the green tea cups/day equivalent in that particular study because the authors disclosed the dose only as 0.05% standardized green tea extract without describing the standard. However, two observational studies of green tea and cognitive performance, published in the American Journal of Clinical Nutrition in 2006 and 2008, identified those drinking two or more cups per day and…
Q. The dietary coach at my gym recommended that I go on the Paleo...
A.Susan B. Roberts, PhD, director of Tufts HNRCA Energy Metabolism Laboratory, replies, We do not recommend the Paleo diet. It has a very strange (non-scientific) view of what Paleolithic man ate, and does not provide a balanced, healthy diet. For somebody who is not overweight, the USDAs MyPlate is good general dietary advice.…
Q. You recently wrote that certain fibers can bind essential minerals and lessen their...
A.Robert M. Russell, MD, emeritus professor at Tufts Friedman School, answers: It is known that many foods that are high in fiber (particularly cereals) can inhibit the absorption of iron and zinc from the gastrointestinal tract. However, cereals that are high in fiber are also high in a substance known as phytate, which also has an inhibitory effect on these minerals absorption. So it is hard to pick apart how much of the inhibition of…
Q. Raisins are my favorite snack. Is this a good choice? If grapes are...
A.Diane L. McKay, PhD, an assistant professor in Tufts Friedman School and a scientist in its HNRCA Antioxidants Laboratory, notes that a supplement in the June 2013 issue of the Journal of Food Science was all about raisins. While this was sponsored by the California Raisin Board, it nonetheless presented some valuable studies. Basically, she says, the findings were: …
Q. I am unable to eat chocolate or drink coffee or tea with caffeine,...
ADiane McKay, PhD, a scientist in Tufts HNRCA Antioxidant Nutrition Laboratory, answers: Since carob and chicory are plant-based, they both contribute to our daily intake of phytochemicals. Chicory (Cichorium intybus) is one of the richest dietary sources of caffeic acid (not to be confused with caffeine), while carob (Ceratonia siliqua) is high in tannins, as well as the minerals calcium and potassium. …
Q. Does the magnesium content of frozen spinach differ from that of fresh?
A. Adela Hruby, PhD, MS, MPH, who recently completed an American Heart Association Predoctoral Fellowship at Tufts Friedman School, responds: According to the USDA Nutrient Database, per gram, both raw spinach and frozen spinach (unprepared or prepared by boiling and draining), contain around the same amount of magnesium (about 75-82 milligrams per 100 grams of spinach). However, if you go by a typical serving of one cup, rather than by weight, then frozen spinach, because its…