Cancer remains the leading cause of death in Hong Kong, with lung, colorectal, and liver cancers claiming the most lives in 2021, according to the Hong Kong Cancer Registry. Now, a Taiwanese nephrologist has sounded the alarm on ten seemingly harmless daily habits that may significantly increase cancer risk—ranging from sleeping with the lights on to sipping piping hot beverages.
Dr. Hung Yung-hsiang, a renowned kidney specialist in Taiwan, recently took to social media to share a clinically observed ranking of carcinogenic behaviors, drawing on decades of patient cases and international research. His warning comes as Hong Kong confronts a sobering reality: cancer is not merely a matter of genetics but, for the vast majority, a consequence of lifestyle choices made over years or decades.
The Science Behind the Risk
Medical evidence confirms that only 5 to 10 percent of cancers are hereditary. The remaining 90 to 95 percent are linked to environmental factors, dietary patterns, and daily routines. Crucially, the transformation from a normal cell to a malignant tumor is not instantaneous. It typically spans 10 to 20 years, offering a critical window for intervention.
“During this latency period, consciously improving your habits—diet, exercise, and sleep—can strengthen your immune system and potentially reverse or halt the cancerous process,” Dr. Hung explained. “But if bad habits persist, malignant cells gradually take hold.”
A Tragic Case Study
To illustrate the stakes, Dr. Hung recounted the story of a 60-year-old woman who arrived at his clinic unable to swallow solid food. Over six months, she had lost eight kilograms, growing so weak she could barely stand. Her initial complaint: difficulty eating rice, which progressed to an inability to swallow even porridge. By the time she sought help, she was diagnosed with terminal esophageal cancer that had already metastasized to her lungs and liver. Doctors gave her less than six months to live.
The woman’s husband had passed away a decade earlier, and her children had moved out. Living alone, she spent her days watching television, sipping rice wine, snacking on pickled foods, reheating salty soups repeatedly, and drinking boiling-hot broth. Dr. Hung identified five of her habits as particularly dangerous.
The 10 Cancer-Causing Habits Ranked
Dr. Hung’s list, ranked from least to most harmful, highlights everyday behaviors many Hongkongers may overlook:
10. Drinking Scalding Beverages
The World Health Organization has classified any drink above 65 degrees Celsius as a probable carcinogen for esophageal cancer. Hot liquids damage the delicate lining of the mouth and throat over time.
Prevention tip: Let drinks cool before sipping.
9. Using Styrofoam Bowls for Instant Noodles
Pouring boiling water into a polystyrene container can cause the plastic to leach carcinogenic chemicals, especially when the bowl is covered to steam the noodles.
Prevention tip: Use ceramic or glass bowls instead.
8. Sleeping with the Lights On
Artificial light at night disrupts melatonin production, a hormone that suppresses tumor growth. Studies link nighttime light exposure to higher breast and prostate cancer risk.
Prevention tip: Use blackout curtains and avoid screens before bed.
7. Consuming Processed Meats
Bacon, sausages, and ham are classified as Group 1 carcinogens by the WHO. Preservatives like nitrates form cancer-causing compounds in the body.
Prevention tip: Limit intake and opt for fresh, unprocessed protein sources.
6. Reusing Cooking Oil
Heating oil repeatedly—common in deep-frying—creates trans fats and aldehydes, both linked to DNA damage and cancer.
Prevention tip: Use fresh oil for each frying session and avoid reusing leftovers.
5. Eating Overly Salty Foods
High sodium intake damages the stomach lining and increases risk of gastric cancer, particularly when combined with pickled or fermented items.
Prevention tip: Reduce salt and choose herbs or spices for flavor.
4. Skipping Breakfast Regularly
Prolonged fasting disrupts blood sugar regulation and increases inflammation, a known cancer promoter.
Prevention tip: Eat a balanced breakfast within two hours of waking.
3. Prolonged Sitting
Sedentary behavior is linked to higher rates of colorectal, breast, and endometrial cancers. Lack of movement impairs circulation and immune surveillance.
Prevention tip: Stand and stretch every 30 minutes; aim for 150 minutes of moderate exercise weekly.
2. Smoking and Secondhand Smoke
Tobacco remains the single largest preventable cause of cancer worldwide, responsible for lung, throat, bladder, and many other malignancies.
Prevention tip: Seek professional support to quit; avoid exposure to smoke in public spaces.
1. Excessive Alcohol Consumption
Alcohol is metabolized into acetaldehyde, a DNA-damaging compound. Even moderate drinking raises risk for breast, liver, esophageal, and colorectal cancers.
Prevention tip: Limit to one drink per day for women, two for men—or abstain entirely.
A Broader Health Warning: The Kidney Connection
In the same social media post, Dr. Hung also listed 10 kidney-damaging foods, noting that nearly one in nine Taiwanese adults suffers from chronic kidney failure. In Hong Kong, roughly 1,300 new kidney disease patients are diagnosed annually, and over 10,000 individuals with end-stage renal failure depend on dialysis or transplants.
“We are born with about 200,000 glomeruli—kidney filters—and they never regenerate,” Dr. Hung warned. “Protecting them through diet is non-negotiable.”
Among the worst offenders: sugary breakfast cereals, white bread, sausages, and deep-fried snacks. The top spot went to high-sugar, high-calorie beverages, which not only damage kidneys but also contribute to fatty liver, gout, diabetes, and hypertension.
What This Means for Hong Kong
With cancer rates climbing and an aging population, awareness is the first line of defense. Experts urge Hongkongers to adopt anti-cancer habits today:
- Switch from instant noodles in foam cups to homemade soup in ceramic bowls.
- Replace late-night screen time with a dark, cool bedroom.
- Swap processed snacks for fresh fruit or nuts.
- Make hydration a priority—drink water, not sugary or scalding drinks.
“Cancer doesn’t happen overnight,” Dr. Hung emphasized. “It’s a slow, preventable process. Every small change you make today can steer your body away from disease.”
For those seeking more guidance, Hong Kong’s Department of Health offers free cancer screening programs, dietary consultations, and smoking cessation services. Readers can also explore related articles on kidney health and anti-inflammatory eating at the Lolleroll Hong Kong food blog.
Take action now—your future self will thank you.