Why Do Some People Get Cancer Even Without Smoking or Drinking? Chest and Critical Care Specialist Dr. Ooi Hean (黃軒) explains that many cancer patients are puzzled when they develop cancer despite avoiding tobacco and alcohol. In a recent post on his Facebook page, Dr. Ooi shared that cancer isn’t always caused by “bad habits” but often by seemingly harmless daily routines that quietly increase risk over time.
He cited a 40-year-old male patient who neither smoked nor drank, and considered his diet light and healthy, yet developed early-stage colorectal cancer. Dr. Ooi identified four common lifestyle behaviors that may silently promote cancer growth:
1. Sugar: The problem isn’t sugar itself, but the speed at which blood sugar rises. Highly refined sugars, white flour, and sweetened beverages spike blood sugar, prompting insulin surges that can encourage cancer cell growth.
2. Oil/Fried Foods: Fried chicken, fries, sausages, hot dogs, and doughnuts can trigger chronic inflammation. Each indulgence forces the immune system into “firefighting mode,” gradually weakening it so that it struggles to fight tumors or infections.
3. Staying Up Late: Consistently sleeping at 3 a.m. or later increases stress, free radicals, and cellular damage, accelerating aging and creating conditions favorable for cancer cells to emerge.
4. Gut Microbiome Imbalance: The gut hosts roughly 70% of the immune system. Modern diets high in oily, low-fiber, and poorly fermented foods disrupt the balance of good and bad bacteria, compromising immunity and overall defense against cancer.
Dr. Ooi emphasized that preventing cancer doesn’t require consuming ten different “superfoods” or supplements daily. Instead, minimizing sugar, fried foods, and late nights while maintaining a healthy gut microbiome allows the body to repair, rebalance, and significantly reduce cancer risk.
