Does vitamin C really help fight breast cancer?

A new study aims to prove the effectiveness of vitamin C treatment for breast cancer patients. Photo / iStock

Vitamin C infusions have become a common part of breast cancer treatment - with benefits claimed by some patients. But its use has also been controversial due to a lack of clinical evidence around its effectiveness.

Now a new study aims to end the debate.

Led by Otago University vitamin C expert Professor Margreet Vissers, who featured in a documentary by TVNZ's Sunday last year, the project will determine the vitamin's ability to slow the growth and spread of cancer.

The $84,000 study will see Professor Vissers' team analyse breast cancer tumour tissue from the Christchurch tissue bank - an essential first step before progressing to clinical trials which require a sound rationale for enlisting patients.

Similar analysis have been conducted by Visser with bowel cancer and endometrial cancer tissue and the findings revealed patients with higher levels of vitamin C in their tumours have extended disease-free survival.

"If vitamin C works, we need to know how it works and for which tumours," she said.

"If this study shows that breast cancer responds to vitamin C in the same way as bowel cancer we'll be able to include breast cancer patients in our upcoming clinical studies."

Van Henderson, chief executive of the New Zealand Breast Cancer Foundation, which is funding the work alongside the Canterbury Medical Research Foundation (CMRF), said she was excited by the new research.

"We know that many women with advanced breast cancer will try intravenous vitamin C, but it's much harder to know if and how it's working," she said.

"The science behind Margreet's study makes a lot of sense; this might be a real chance to understand if vitamin C really can play a role in breast cancer. From there, we can figure out how it should be used, and when it's most effective."

CMRF chief executive Kate Russell said Professor Visser was highly regarded in her field and had already demonstrated that the more vitamin C there is in a tumour, the slower it will grow.

"This study is an important next step and could lead to a trial in patients in the near future."