Scientists reveal how sugar fuels various forms of cancer growth

The findings are considered worrying because "as a culture, we are very addicted to sugar", says scientist Dr Jung-whan Kim. Photo / Getty

A sugar rich diet may be fuelling various forms of cancer, as new research confirms a long suspected belief.

Previous studies have suggested that tumours thrive off sugar, using it as energy to mutate and spread across the body.

According to the Daily Mail, now scientists have shown one type of cancer - which can be found in the lungs, head and neck, oesophagus and cervix - has more of a sweet tooth than others.

Squamous cell carcinoma (SqCC) was more dependent on sugar to grow, experts at the University of Texas at Dallas found.

This form of the disease used higher levels of a protein that carries glucose to cells to enable them to multiply, they discovered.

Lead author Dr Jung-whan Kim said: "It has been suspected that many cancer cells are heavily dependent on sugar as their energy supply.

"But it turns out that one specific type - squamous cell carcinoma - is remarkably more dependent.

"This type of cancer clearly consumes a lot of sugar. One of our next steps is to look at why this is the case."

Writing in the journal Nature Communications, he warned the findings were worrying because "as a culture, we are very addicted to sugar".

Health officials highlight the fact that all cells, not just cancerous ones, require energy, which is found in the form of glucose, to survive. Photo / Getty

He added: "Excessive sugar consumption is not only a problem that can lead to complications like diabetes, but also, based on our studies and others, the evidence is mounting that some cancers are also highly dependent on sugar.

"We'd like to know from a scientific standpoint whether we might be able to affect cancer progression with dietary changes."

Health officials across the world have stood firm on their stance towards sugar in recent years, despite growing evidence showing it to potentially fuel tumour growth.

Instead, they highlight the fact that all cells, not just cancerous ones, require energy, which is found in the form of glucose, to survive.

Without a sufficient supply of the sugar, each cell in the body would struggle to perform their duties.

Cancer Research UK make clear that cancerous cells aren't just dependent on sugar for their growth, as they rely on amino acids and fats also.

The new findings came after researchers looked into the differences between two major subtypes of non-small cell lung cancer - adenocarcinoma (ADC) and SqCC.

Studies have suggested that tumours actually thrive off sugar. Photo / 123rf

About one quarter of all lung cancers are SqCC, which has been difficult to treat with targeted therapies.

The study first tapped into The Cancer Genome Atlas, which maps information about 33 types of cancer gathered from more than 11,000 patients.

Based on that data, it found a protein responsible for transporting glucose into cells was present in significantly higher levels in lung SqCC than in lung ADC.

The protein, called glucose transporter 1, or GLUT1, takes up glucose into cells, where the sugar provides a fundamental energy source and fuels cell metabolism.

GLUT1 is also necessary for normal cell function, such as building cell membranes.

As high levels of GLUT1 was implicated in SqCC's appetite for sugar, the researchers examined human lung tissue, isolated lung cancer cells and animals to find evidence of the link.

Professor Kim added: "We looked at this from several different experimental angles, and consistently, GLUT1 was highly active in the squamous subtype of cancer.

"Adenocarcinoma is much less dependent on sugar.

"Our study is the first to show systematically that the metabolism of these two subtypes are indeed distinct and unique."

The study also investigated the effect of a GLUT1 inhibitor in isolated lung cancer cells and mice with both types of non-small cell lung cancer.

When the mice were given the inhibitors, their SqCC growth slowed down, but this was the opposite for the adenocarcinoma.

The findings indicate that GLUT1 could be a potential target for new lines of drug therapy, especially for SqCC.

The study also found GLUT1 levels were much higher in four other types of squamous cell cancer of the head and neck, oesophagus and cervix.

Dr Justine Alford, Cancer Research UK's senior science information officer, said: "This study in cells and mice did not look at the links between sugar in the diet and cancer risk.

"Instead, it reveals interesting differences in the way that two types of lung cancer take in and use sugar, which the researchers think could be used as a way to diagnose and target the disease in the future.

"All cells - both cancerous and healthy - use sugar, so there is no need to be alarmed by this study."