Hong Kong people's immunity to influenza has lowered as shown by a growing number of them catching the disease frequently, otorhinolaryngology specialist Dr Simon Wong said yesterday.

He classified children/students and office workers as the most risky groups for they easily get infected in a crowded environment.

To guard against influenza, he advised people to maintain a balanced diet with regular intakes of Vitamin C and zinc that can enhance immunity, and have enough sleep and exercise, while the elderly and chronic patients should also receive vaccinations.

In January and February this year, Reader's Digest surveyed 607 people to find out their knowledge of influenza prevention.

As revealed, over 75 percent have had a cold or influenza as much as four times over the past year.

Among them, 27 percent of the female below 29 had influenza more than eight times during the period, while men from the 30-39 age group had influenza more frequently than the other age groups.

Most people (77 percent) choose to eat more vegetables and fruits to enhance their immunity and 63 percent prefer to work out for a longer time everyday, but many do not know zinc can also enhance immunity.

Dr Wong said the figures have shown that people's immunity has weakened.

Men aged 30-39 should be in the prime of their lives but the majority of those who have had influenza eight times or more in the past 12 months were from that age group.

Meanwhile, the number of children getting sick has increased and they are sick for a comparatively longer period.

At the same time, he noted that 55 percent consumed vitamin C when they were sick and 38.7 percent consumed vitamin C supplements when they had influenza.

Vitamin C is not a medicine and cannot cure diseases, he said, but it may be consumed daily because it carries no side effects.

Nutritionist Phoebe Ng said absorption of vitamin C prevents oxidation and damage of cells, while zinc intake improves immunity.

People can absorb zinc from such food as seafood, red meat, beans, sweet potatoes and tomatoes. They can be consumed together with citrons, strawberries, tomatoes, and guavas that contain abundant quantities of vitamin C, she advised.

(HK Edition 04/02/2008 page1)