The habit of eating a lot of meat and processed foods but little green vegetables, fruits, and whole grains is quite common and silently affects long-term health, including increasing the risk of cancer.
According to the World Cancer Research Fund (WCRF), there is strong evidence that a high-fiber diet reduces the risk of colorectal cancer – one of the most common types of cancer today. Conversely, a low-fiber diet increases the risk over time.
A meta-analysis published in the BMJ found that for every 10g of added fiber per day, the risk of colorectal cancer may decrease by about 10%. Those who consumed more whole grains – an important source of fiber – had a significantly lower risk of the disease compared to those who ate less.
Adding green vegetables, fruits, and whole grains to your daily diet is a simple change, but it can make a long-term difference in cancer prevention.
Photo: PH created from GM
The issue lies in the biological mechanism. Fiber doesn't just help with bowel movements as many people think. Once in the intestines, fiber acts as a natural "shield":
- Firstly, fiber helps increase stool volume and promotes bowel movements, thereby shortening the time harmful substances are in contact with the colon lining .
- Secondly, fiber is "food" for beneficial gut bacteria. When fermented, they produce short-chain fatty acids such as butyrate, which have anti-inflammatory effects, protect cells, and inhibit the growth of cancer cells .
- Thirdly, a high-fiber diet also helps control weight, blood sugar, and insulin—factors closely linked to cancer risk.
The gut microbiome plays a crucial role in regulating immunity and inflammation. A lack of fiber can disrupt the balance of this microbiome, creating a favorable environment for chronic inflammation—a underlying factor in many cancers, according to the TH Chan School of Public Health at Harvard University.
It's worth noting that this habit is easily overlooked. A "satisfying" meal of white rice, meat, and a few vegetables is common, but it doesn't provide enough fiber (typically around 25-30g/day for adults). A prolonged deficiency may not cause immediate symptoms, but the risk accumulates over the years.
Avoiding unhealthy foods isn't enough. Sometimes, it's the lack of what your body needs—like fiber—that poses a significant risk . Adding green vegetables, fruits, and whole grains to your daily diet is a simple change, but it can make a lasting difference in cancer prevention.
Common foods rich in fiber
- Green vegetables : Water spinach, mustard greens, broccoli, jute mallow
- Fruits : Bananas, apples, guavas, pears (eating them with the peel is even better)
- Beans and seeds : Black beans, red beans, green beans, chia seeds, almonds
- Whole grains : Oats, brown rice, whole-wheat bread
Prioritize fresh, minimally processed foods to retain the maximum amount of fiber.