Q: LIKE a lot of Chinese people, I enjoy eating all sorts of preserved vegetables, salted dry fish, fermented bean curd, shrimp paste and sauces. Do the Chinese delicacies really cause cancer? Is there really a connection between what we eat and getting cancer? Dr Rose writes: By comparing patterns of cancer in different countries, researchers have concluded that diet plays an important role in causing cancer. For example, a high intake of fat has been linked with cancer of the bowel and breast cancer; mouldy foods, such as the fungi eaten in Chinese food, are known to cause cancer of the oesophagus and liver. Similarly, stomach and nasopharyngeal cancer have been linked to the high consumption of dried and salted fish, pickled food, cured meats and salt in the Chinese diet. Nasopharyngeal cancer is so common among the Chinese that it is often called the Chinese cancer. The risk of contracting this cancer in southern China, Hong Kong and Singapore is 30 times greater than in the West. Nasopharyngeal cancer originates in the uppermost part of the throat, behind the nose, and usually spreads to the nasal cavity, nasal sinuses, the base of the skull and the lymph nodes in the neck. It is most common between the ages of 40 and 50, affecting twice as many men as women. Oesophageal cancer is also especially prevalent among the Chinese. Doctors examining the eating habits of a group of almost 2,000 Hong Kong Chinese, 4,000 of whom had been diagnosed with oesophageal cancer, concluded that eating pickled vegetables daily increases your risk of developing oesophageal cancer by 30 per cent. The pickled vegetables and preserved foods cause cancer because they contain sodium nitrite, a preservative which converts to cancer-causing nitrosomines, in a person's intestine. Although you do not need to give up all Chinese delicacies to avoid these cancers, you should eat them only in moderation. Many people die from cancer because their condition is diagnosed too late. Be aware of the early signs and symptoms of these cancers. The first signs of nasopharyngeal cancer are nosebleeds, a persistently runny nose and voice change. Difficulty swallowing, rapid weight loss and respiratory infections are the early signs of oesophageal cancer. Let your physician know if you are experiencing any of these symptoms. Q: MY wife and I are avid gardeners and we spend every free hour we have on our plants. We have two dogs. I know that some plants are quite toxic and dangerous for animals while others are completely safe. Can you provide a list of the dangerous ones? Dr Rose writes: Many plants have saps or juice which can cause pain, swelling and rash upon contact. Here is a list of safe plants and those which are harmful to animals: Safe: African Violet, Albizzia, Alyssum, Aralia, Japanese Baby Tears, Baby's Breath,Boston Fern, Bottle Brush, Bougainvillea, Calla Lily, Christmas Cactus, Dandelion, Fir, Forget-Me-Knot, Fuschia, Gloxinia, Hoya, Impatiens, Lilac, Magnolia, Stellata, Orchid, Palm, Rosary Vine, Sedum, Silk Tree, Yucca. Harmful to Animals: Agapanthus, Apricot Tree, Avocado, Black Acacia, Black Locust, Cherry Tree, Dracaena, Hyacinth, Heavenly Bamboo, Liquorice Plant, Lupine, Sweet Pea, Oak Tree, Spruce Tree. Q: LAST month, at my gynaecological check-up, my doctor recommended a hormonal injection, Depo Provera, for birth control. I had heard that this drug has serious side effects including cancer and I thought that it was banned in the United States because ofthe cancer risk. Wouldn't it be better for me to take something else? Dr Rose writes: You heard correctly. The United States Food and Drug Administration failed to approve the drug in 1978 because tests on animals suggested that it could cause breast cancer. However, the World Health Organisation recently concluded that the injectable female contraceptive Depo Provera does not increase the overall risk of breast cancer and found no link between it and cervical and ovarian cancer. Furthermore, researchers concluded that the drug has a protective effect against endometrical cancer. Finally, in January 1993, the FDA approved the drug for use in the United States. Depo Provera is a reversible birth control method lasting for three months and currently used by nine million women in 90 developing and developed countries. It has an extremely low failure rate (about one per cent) and is safe for use in women with epilepsy, diabetes and renal failure. The side effects are minimal and include temporary weight gain and bloating and intermittent vaginal bleeding. If you are still concerned about this method I suggest that you discuss alternative methods with your doctor. There are many other forms of birth control available and you should choose one that you feel comfortable with. Dr Rose Ong is a certified family physician licensed in the United States. She welcomes enquiries but cannot answer them individually. Specific questions should be addressed to your own physician. Additional enquiries: Peak Corporate Health Management, 525-6600, fax 525-8100.