According to a Nobel-winning scientist, there is no valid proof that a healthy diet can prevent people from developing cancer.

Sir Tim Hunt, a principal scientist with Cancer Research UK said that consumption of healthy foods could only provide a modest reduction in the risk of developing the disease.

He said that the two "most terrible" cancer-causing poisons in the surroundings were air and water. If you stopped breathing, you will not get cancer, but you have to breathe to live.

The scientist made these remarks in an important address at the Association for International Cancer Research (AICR) conference in Fife.

He agreed with recent study that discovered that eating the suggested "five-a-day" will only offer partial protection in avoiding the disease.

He indicated that anything that harms chromosomes or assaults DNA can cause cancer.

It is the air and not any toxins in it, and water that are continually assaulting our DNA.

But he cautioned that prevention is obviously better than cure when it comes to the health hazards linked with tobacco use.

He said that lung cancer was a very uncommon disease before people took to smoking.

In the lecture titled, ‘The Truth About Cancer’, Sir Tim also affirmed that there are still "very basic things" that are not understood regarding cancer.