The truth behind “cancer-fighting” foods

By Dr Shafinah Ahmad Suhaimi

As a cancer researcher, I am often the designated recipient of “miracle cure” articles shared by friends and relatives. Every few weeks, someone sends me a headline claiming that a particular fruit, herb or traditional remedy can kill cancer cells.

The question that follows is always the same: “Is this true?” And my answer often surprises people: “Yes and no.”

Many of these claims are based on genuine scientific studies. However, what is often left out is an important detail: most of the evidence comes from laboratory experiments, not from actual patients. Behind every exciting headline lies a much longer scientific journey.

In cancer research laboratories, scientists routinely grow cancer cells in small plastic dishes. These cells are then exposed to different substances, including plant extracts, natural compounds and newly developed drugs.

Sometimes the results are remarkable. Cancer cells stop growing or even die completely. This is usually the point where a headline appears online declaring that a certain plant “cures cancer”. But killing cancer cells in a laboratory dish is only the first step.

In fact, it is often the easiest step. Cancer cells growing in a dish are isolated and defenceless. They do not have to contend with the complexities of the human body. A compound can directly reach them at a high concentration and produce dramatic effects.

The real challenge is determining whether the same compound can work safely and effectively inside a living person. When we consume food or herbal products, the active compounds must survive a difficult journey. They encounter stomach acid, digestive enzymes and the liver’s filtering system before entering the bloodstream. By the time they reach the target tissue, only a tiny fraction may remain.

Scientists refer to this as bioavailability: the amount of a substance that actually reaches the body’s tissues and can exert its effects. A compound that performs exceptionally well in a laboratory dish may be far less effective when consumed as food.

Does this mean natural products are useless? Not at all. Nature has been one of medicine’s greatest sources of inspiration. Many modern medicines originated from plants, fungi and other natural sources. Researchers estimate that more than half of approved cancer drugs are linked, directly or indirectly, to natural compounds.

One famous example is paclitaxel, a chemotherapy drug widely used to treat breast, ovarian and lung cancers. It was originally discovered in the bark of the Pacific yew tree. However, this does not mean a patient can cure cancer by consuming tree bark.

The amount required to achieve a therapeutic effect would be unrealistic and potentially dangerous. Instead, scientists isolate, purify and modify the active compound so that it can be delivered safely and effectively as a medicine.

This distinction is crucial. A promising natural compound is not the same as a proven treatment. Another common misconception is that cancer is a single disease with a single cure waiting to be discovered.

The reality is far more complicated. Cancer is actually a collection of hundreds of diseases. Even two patients diagnosed with the same type of cancer may have tumours driven by completely different genetic and molecular changes.

For example, some breast cancers depend on hormones such as estrogen to grow, while others are fuelled by entirely different biological pathways. Some tumours spread to the bones, while others are more likely to spread to the lungs or brain.

Because of these differences, treatments that work for one patient may not work for another. This is why modern cancer care is moving towards personalised medicine, where treatments are selected based on the unique characteristics of an individual’s tumour.

Natural compounds may play an important role in this future, but only after rigorous scientific testing. In our laboratory, we investigate how natural products affect both cancerous and healthy cells. When a promising result emerges, it generates many new questions.

How does the compound work? Which molecular pathways are involved? Is it toxic to healthy tissues? What dose is safe? Can it reach the tumour in sufficient amounts? Answering these questions requires years of careful research involving laboratory studies, animal experiments and eventually clinical trials in humans.

Many promising compounds fail somewhere along this journey. That is not failure. It is science doing exactly what it is supposed to do which is separating hope from evidence.

So the next time you encounter a headline claiming that a particular food “kills cancer”, approach it with curiosity but also caution. The science behind the claim may be real, but it is often only the beginning of the story.

Can you eat your way out of cancer? Probably not. But maintaining a balanced diet rich in fruits, vegetables and other nutritious foods remains one of the best ways to support overall health and reduce the risk of many chronic diseases, including some cancers. The truth may not be as sensational as a miracle cure, but it is far more valuable.