Media Claim on ‘Vitamin C’ gives chemotherapy a boost’

The headline ‘Vitamin C’ gives chemotherapy a boost’ suggested by a US scientist was a misleading and inaccurate statement as the study was looking specific at late stage ovarian cancer. From the study, scientists did not find high dosage of vitamin C help with cancer survival nor reducing the risk of cancer (Ma and Chapman et al., 2014). Yet, the study did show that there was a slight chance of reducing minor chemotherapy side effect. Therefore, the study has been oversimplified and misinterprets results and statements which can lead to assumptions from general public misunderstanding this article resulting in toxicity of vitamin C when overdosed. Overdose of vitamin C can lead to other problems and health disease such as indigestion, diarrhea and iron poisoning which only occurs in people who have rare iron overload disorders – hemochromatosis (Zobel, 1976), lack of vitamin C in the diet can also cause scurvy (Naidu,2003).

‘Vitamin C’ gives chemotherapy a boost’ was published in BBC Health website on 9^th February 2014, written by Helen Briggs and science editor. Comments were from Dr Jeanne Drisko, lead researcher Qi Chen and Dr Kat Arnet – science communications manager for Cancer Research UK. The claim is based on a study that was carried out by researchers from University of Kansas in the US and world cancer research fund (WCRF) and American Institute for cancer research (AICR). The article itself was published in the peer-reviewed journal, Science Translation Medicine.

Cancer is a condition where specific cells in parts of the body grow and reproduce uncontrollably and forming tumours. Cancer cells can invade and destroy surrounding healthy tissue and organs (King and Rotter et al., 1992). Cancer may also spread to more distant parts of the body through the lymphatic system or bloodstream (Mendelsohn, 2008). Many factors have been identified which can increase risk of cancer such as tobacco use, dietary intake, certain infections, environmental radiation, lack of physical exercise, obesity and genetics which potentially can damage genes and causes mutation in cells (Kushi and Byers et al., 2006). Many researchers have found that there are over 200 different types of cancer cells (Schram and Ng, 2012). However, according to Jemal and Bray et al., 2011, many cancers can be prevented by living healthier life styles, one of the factors is reducing excess smoking which can preclude the risk of getting lungs cancer, plus eating plenty of fresh vegetable and fruits, and reducing the intake of meat and carbohydrates can prevent other health factors such as obesity.

Ovarian cancer is where cancer cells are found in ovaries. However, the exact causes of cancer still remain unknown (Hunn and Rodriguez, 2012). Women who have had menopause and have not had any children would have a higher chance of developing ovarian cancer (Vo and Carney, 2007). However, ovarian cancer can affect all ages. There are three types of ovarian cancer – epithelial ovarian cancer; germ cell tumours and stromal tumours (Bandera and Era, 2005). The best and effective treatment for ovarian cancer are the combination of surgery and chemotherapy, all treatments are depending on the stages of cancer (Ehrlich and Teitelbaum et al., 2007).

Vitamin C also known as ascorbic acid acts as an antioxidant; an oxidative stress; an enzyme cofactor for the biosynthesis, also most importantly vitamin C acts an electron donor for enzymes (Vobecky and Shapcott et al., 1975). Acting as an antioxidant prevents free radicals during oxidation reaction to form chain reactions in cells which can damage or kill cells. Instead, antioxidant interacts with those chain reactions by removing free radicals and inhibits other oxidation reactions in the cells, protecting against lip peroxidation, reducing nitrates and stimulating the immune system (Bender, 1993). Vitamin C has also shown to inhibit formation of carcinogens and protects DNA from mutagenic attack and most vitamin C is found in critic fruits (Combs, 2012).

Furthermore, Ma and Chapman et al., 2014 stated that the study was looking if vitamin C could potentially be a cancer treatment and the study was mainly looking into women who are in their late stage ovarian cancer. BBC’s report on this study was miscellaneous as there were some bias comments towards the study, but BBC did include some accurate quotes from the study such as the sample size – only 22 patients were participated which showed that the study was not reliable as the sample size was too small to prove whether vitamin C helped to kill cancer cells or increase survival rate (Park, 2013). Moreover, the title ‘Vitamin C’ gives chemotherapy a boost’ was misleading as the study found no supportive evidences that vitamin C can prevent cancer, only can inhibit some mechanisms and reduce the risk of cancer development (Ma and Chapman et al., 2014). However, the study did show that vitamin C may reduce side effects from treatment for women, yet, the sample size was too small which was unable to support the outcome. However, the expert from the study quoted that in order to find out if high-dose vitamin C has an effect on cancer cells, further studies and large clinical trials are needed to ensure safety and effectiveness (Ma and Chapman et al., 2014).

Additionally, BBC may have been over analysed the press release from the University itself, as it claimed that ‘Researchers establish benefits of high-dose vitamin C for ovarian cancer patients’. This statement was supported via Park, 1985‘s research which stated that ‘vitamin c is involved in the mechanism of action of the intracellular oxidation state changes which is an identification of genes or protein synthesis.’. This suggested that vitamin C has the ability to regulate specific cellular phenotypes which potentially could improve the efficacy of cancer therapies. Nevertheless, the report stated that the vitamin C treatment worked along with standard chemotherapy drugs which slow down tumour growth in mouse studies, not human. Therefore, the benefits of high-dose vitamin C for cancer cells cannot be taken into account due to the fact that human and mouse have different types of genes and intracellular mechanism (Park, 1985). As a result, there are not any beneficial effects on human, but there are beneficial effects on mouse.

In addition, within the small group of patients that were tested on, they have found fewer side-effects when vitamin C was given out along with the chemotherapy. According to WCRF and AICR‘s report on diet and ovarian cancers, it showed that vitamin C has no effect on ovarian cancer which do not decrease nor increase the risk of cancer. However, according to Part 2 evidence and judgements and Part three Recommendations chapter twelve- public health goals and personal recommendations from WCRF and AICR, it suggested that the population should consumption an average of non-starchy vegetables and of fruits to be at least 600g (21 oz) daily. This is because there are evidences that diets high in vegetable and fruits could protect against oesophagus cancer not ovarian cancer (Mikirova and Casciari et al., 2012).

According to BBC, the researcher’s injected vitamin C into human ovarian cancer cells as well as mice in the laboratory conditions. BBC stated that ‘researchers found ovarian cancer cells were to be sensitive to vitamin C treatment, but normal cells were unharmed (De Laurenzi and Melino et al., 1995). High dosage of vitamin C could prevent cancer was originally suggested by chemist and double Nobel Prize winner Linus Pauling in 1970s in which the clinical trial was abandoned due to failed to replicate the expected results to the theory behind vitamin C and cancer (Cameron and Pauling, 1979). The method used in the study was by injecting vitamin C straight into the bloodstream as it is safer, can be effective, low-cost (Head, 1998). The rate at which human body excrete vitamin C through oral ingestion is a lot faster than by injection through bloodstream (Cameron and Pauling, 1979). Furthermore, patients were not completely blind tested as most of them knew what they were given – vitamin C and placebo, therefore, many physiological effects have been taken into account toward the analysis of results.

In conclusion, due to lack of supportive evidences, vitamin C has no significant back story in supporting the evidence of beneficial effect on ovarian cancer even though from the study some beneficial effects did show on mice. Furthermore, the clinical trial was tested unfairly as participants knew about the comparison test with placebo, which might have had effected the results, in which the results are not accurate and reliable as the sample size was consisting of 22 participants. Nevertheless, the study did find moderate result from patients who have taken parts in the vitamin C trials; as a result, vitamin C might reduce the side effects of chemotherapy.

References

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