Q: My mother is suffering from osteoporosis. Her doctor has asked her to increase her fluoride intake. Can you suggest foods rich in fluoride that she must take?

JK, Haldia

Rich sources of fluorine are atta (whole-wheat flour), rice, Bengal gram flour, spinach, a variety of fish such as Bombay Duck, pomfret and, vegetables such as brinjal, cucumber and carrots. Tea is also a good source of fluoride.

Q: Is it advisable to take raw egg? Which is better for health ? a quarter-boiled egg or a hard-boiled one?

HR, Calcutta

Egg albumin contains an anti-digestive factor, a protein called Avidin which is found in combination with Biotin, a B-complex vitamin. This Avidin-Biotin complex is not absorbed by the intestine. However, Avidin is destroyed by heat. So in a properly cooked egg, this combination breaks down and Biotin is released for absorption. Biotin deficiency has been reported in people consuming raw or undercooked eggs, as the Avidin is not destroyed and the undigested albumin is excreted from the body resulting in unavailability of Biotin.

Eating uncooked eggs (often used in egg-nog and desserts) is also not advisable, as they may be a potent source of infection. This is due to the prevalence of the pathogen Salmonella. A well-cooked egg is a better choice by far than an under-cooked or raw one.

Q: I am anaemic and a tea-drinker. Recently a friend told me that tea is contra-indicated in anaemia. Is it true?

DS, Calcutta

Tea is not contra-indicated in anaemic people. However you must be cautious about the time of intake. Although tea is rich in antioxidants and has many health-promoting elements, it must be remembered that it also has certain inhibitory factors. Tea is known to hinder the absorption of iron. Since anaemic people are advised to increase their iron intake, care must be taken to ensure that tea is not consumed immediately before, after or accompanied by foods rich in iron as it can impair iron absorption.