Cancer
Vitamin C SagaPart I :Vitamin C and Cancer
What is Cancer?
In the human body, cells normally have a defined lifespan and proliferation habit. Some times the normal habit of some cells may be altered. The abnormal cells may proliferate abnormally and generate Cancer. For a better description, let's watch a brief but useful video description of Cancer from "Canadian Cancer Society” :
What Causes Cancer?
There are many factors may cause Cancer. According to the "Canadian Cancer Society" there are some risk factors may cause cancer: getting older, smoking, not protecting from the sun, being overweight or obese, not having a healthy diet, not getting enough physical activity, drinking alcohol, coming into contact with harmful chemicals at home or at work, and having certain types of infections.
What is common in all above mentioned risk factors?
Changes in Genetic material!
The genome has all information of a cell metabolism, living, senescence, and dying. If there was an important change in an important part of genome, the normal cell metabolism may change and there may be a chance of rise of cancer. Risk factors may increase the chance of these unwanted and harmful alterations. By smoking, a person takes thousands of hazardous materials by him/herself and so increases the chance of genome changes by his/herself!
Ultraviolet rays of sunlight may have a similar effect on skin cells genome. Ultraviolet rays could make some chemical reactions between the structural molecules of genome and rise of mutations. The mutations may change normal cells to cancerous cells.
Can Cancer be Prevented?
People could choose a healthy life style and decrease the chance of Cancer as low as possible. Eating healthy foods and drinks and having physical activities play a great role in cancer prevention. You can find useful suggestions and comments on "Canada's Food Guides"
You may need also to take some food supplements and vitamins to complete the needed nutrients. The food supplements and Vitamins help your body to have a normal metabolism.
Indeed, some supplements and vitamins have more important role in cancer prevention. These type of supplements are called Antioxidants.
How Antioxidants may Help Cancer Prevention?
One of the most important risk factors of Cancer, are Free Radicals and agents could oxidize other molecules. Free radicals are very active and invasive molecules. They may attack entire molecules in the cell, e.g. DNA, RNA, proteins, lipids, and carbohydrates.
Attack to DNA can cause changes in genome structure and function and may cause Cancer!
Antioxidants can react with free radicals and protect cell's vital molecules from invasion and alteration.
Vitamin C: an Anti-Cancer Warrior
Vitamin C is a potent antioxidant. It could react with free radicals and help cells to have their normal metabolism. And so, Vitamin C could be considered as a potent anti cancer warrior. It protects cell from free radicals invasion by scarifying itself!
Attention!
NOAH Vitamin C as other Nutritional supplements is NOT
for prevention, treatment or diagnosis of diseases.
Can Vitamin C prevent Cancer?
There are so many scientific claims supporting Vitamin C benefits against Cancer, in the other hand there are lots of scientific studies showing that Vitamin C can not have any benefit in the case of Cancer.
What is truth? Is Vitamin C a magic bullet against cancer? or it is just like a lollipop?
The fact is that we should have real expectation. This is a scientific believe that Vitamin C is a potent and safe antioxidant, on the other hand, free radicals play an important role in cancer, so it could be concluded that Vitamin C could help preventing Cancer.
For a better view, we should include another important factor: The time! Free radicals are produced during normal metabolism in human body. The cancer prevention program with antioxidants could not be a short term plan like vaccination. It is a long term plan, may be for the rest of the life! Human needs taking Vitamin C in a daily basis, because it could not be stored in the body. If someone takes an excess amounts of Vitamin C, he will need taking Vitamin C the next day as well. The conclusion is: Vitamin C can help reducing the chance of Cancer, but it is a long term plan. You can compare it with Sunscreen creams, scientifically, Sunscreen creams can prevent ultraviolet rays reaching skin cells, and so they could help preventing skin cancer, but you need to apply it every time you may be in the exposure of the sun.
In the other words, protocols for prevention of Cancer, are long term plans. You should have healthy diet and life style to decrease the chance of Cancer. Having healthy life style is not limited to one week, one month, one year, or even one decade, it is for the rest of your life. Taking Vitamin C in a daily basis is one of the must does in a healthy life style.
Here you can find some scientific researcher supporting Vitamin C preventing role against cancer:
• Effectiveness of 205 mg/day Vitamin C on the lowering the risk of breast cancer (1). It is also shown that The sensitivity to Vitamin C in cancer cells is related to the expression of sodium-dependent vitamin C transporter-2 (SVCT-2) which is shown to be over-expressed in nine different breast cancer cell lines (2).
• Vitamin C has ability to inhibits the formation of carcinogenic compounds like N-nitroso which is known as a cause of stomach cancer (2). High level of H.pylori infection (as a main cause of stomach cancer) is also observed in patients with low plasma level of Vitamin C. Vitamin C can inactivate Urease enzyme which is essential for H.pylori to survive at the low pH of stomach (3, 4).
• Total intake of vitamin C is associated with a considerable reduced risk of colon cancer (5).
• It is observed that supplementation with anti-oxidant (vitamins C and E and selenium) can reduce the 131I
causes oxidative stress in patients with thyroid carcinoma (6).
Attention!
NOAH Vitamin C as other Nutritional supplements is NOT
for prevention, treatment or diagnosis of diseases.
References:
1. Zhang S, Hunter DJ, Forman MR, et al. Dietary carotenoids and vitamins A, C, and E and risk of breast cancer. J Natl Cancer Inst. 1999;91(6):547-556.
2. Hong SW, Lee SH, Moon JH, et al. SVCT-2 in breast cancer acts as an indicator for L-ascorbate treatment. Oncogene. 2013;32(12):1508-1517
3. Liu C, Russell RM. Nutrition and gastric cancer risk: an update. Nutr Rev. 2008;66(5):237-249.
4. Jenab M, Riboli E, Ferrari P, et al. Plasma and dietary vitamin C levels and risk of gastric cancer in the European Prospective Investigation into Cancer and Nutrition (EPIC-EURGAST). Carcinogenesis. 2006;27(11):2250-2257.
5. Park Y, Spiegelman D, Hunter DJ, et al. Intakes of vitamins A, C, and E and use of multiple vitamin supplements and risk of colon cancer: a pooled analysis of prospective cohort studies. Cancer Causes Control. 2010;21(11):1745-1757.
6. Rosário PW, Batista KC, Calsolari MR. Radioiodine-induced oxidative stress in patients with differentiated thyroid carcinoma and effect of supplementation with vitamins C and E and selenium (antioxidants). Arch Endocrinol Metab. 2016 Aug;60(4):328-32.
Can Vitamin C treat Cancer?
There are some studies showing Vitamin C could help treatment of cancer. However, much more scientific studies do not supporting this claim and even there are some controversial results discussing Vitamin C even can make problem in treatment procedure, because some of the chemotherapy or radiotherapy protocols are fighting cancer by producing oxidizing agents and free radicals and so, Vitamin C may neutralize or decrease the treatment potency. And so, it is highly recommended to obey physicians orders and prescriptions to get best results against cancer.
Vitamin C and its Chemo-preventive and Chemo-therapeutic Effects in Cancer
Despite many progresses in both conventional and novel approaches for the treatment of different cancers, but this global health issue still remained challenging. Nutrition plays an important role in human health and also in the course of several diseases (1). Warburg which has a wonderful theory in cancer micro-environment (about acidity and oxygen content of cancer) believed that cancer is not an unresolved problem, rather this is a nutritional problem and usually emerges in people who ate poorly, or not natural diet. In the United States of America, 1,735,350 new cancer cases were diagnosed and 609,640 cancer deaths were happened during 2018 (2). Different nutritional supplements have been used into aiding the therapeutic intervention in cancer patients or for reducing the side effects of conventional therapies (3). On the other hand, anti-oxidant elements are known as the most familiar nutritional factors which have chemo-preventive effects on cancer. This is well accepted that cancer emerges as a result of DNA damage in the presence of free radicals (4). Free radicals could be produced during the normal metabolisms of the cells. The human body always needs scavengers to sweep up free radicals. Anti-oxidants like Vitamin C are the best scavengers for human body (5). But the effect of Vitamin C as a powerful anti-oxidant is not limited to scavenging free radicals. In fact, Vitamin C confers its benefits for cancer patients through multi ways. Warburg suggested that the rate of glucose metabolism in tumor cells is approximately ten-folds more than normal tissues. In aerobic conditions, glucose is converted to lactic acid in cancer cells (6). This high glucose consumption even in the presence of oxygen will result in lactic acid and lower the tumor micro-environment pH (Warburg Effect). In fact, cancer cell metabolism and its range of diversity is considered as its superiority in comparison to normal cell. According to the results of tumor micro-environment researches, in the acidic pH in tumor, the expression of some oncogenes will be facilitated (7).
Results of a recent study showed that the tumor suppression effect of Vitamin C is linked to Ras oncogene metabolomic alterations. In this regard, it is observed that high-dose vitamin C is selectively toxic to human colorectal cancer cells carrying either K-Ras or B-Raf mutations (8). Mutation in K-Ras or B-Raf triggers downstream MAPK pathway, which leads to the up-regulation of GLUT1, a glucose transporter by which Vitamin C can enter to the cancer cells in the form of Dehydro ascorbate.
Dehydro ascorbate in the cells could be reduced back to Vitamin C through oxidization of glutathione. This metabolic pathway results in the depletion of glutathione which is needed for bearing the high levels of intracellular ROS in cancer cells. Therefore, cancer cells will be killed as a result of their own metabolism (9). Regarding to this fact, Vitamin C not only can confer its chemo-preventive role in cancer prophylaxis by free radical scavenger role, but also can impressed the cancer cells with metabolic alteration and make these cells sensitive to their own metabolomics and confer its chemotherapeutic role.
Attention!
NOAH Vitamin C as other Nutritional supplements is NOT
for prevention, treatment or diagnosis of diseases.
References:
1- Nagaraja TG, Galyean ML, Cole NA. Nutrition and disease. Vet Clin North Am Food Anim Pract. 1998 Jul;14(2):257-77.
2- https://www.cancer.org/research/cancer-facts-statistics/all-cancer-facts-figures/cancer-facts-figures-2018.html
3- Michael S Donaldson. Nutrition and cancer: A review of the evidence for an anti-cancer diet. Published online 2004 Oct 20. doi: 10.1186/1475-2891-3-19.
4- Dreher D, Junod AF. Role of oxygen free radicals in cancer development. Eur J Cancer. 1996 Jan;32A (1):30-8.
5- Valko M, Leibfritz D, Moncol J, et al. Free radicals and antioxidants in normal physiological functions and human disease. International Journal of Biochemistry & Cell Biology 2007; 39(1):44-84.
6- Otto Warburg's contributions to current concepts of cancer metabolism. Koppenol WH, Bounds PL, Dang CV Nat Rev Cancer. 2011 May; 11(5):325-37.
7- Wong TS, Liu XB, Chung-Wai Ho A, Po-Wing Yuen A, Wai-Man Ng R, Ignace Wei Identification of pyruvate kinase type M2 as potential oncoprotein in squamous cell carcinoma of tongue through microRNA profiling. Int J Cancer. 2008 Jul 15; 123(2):251-257.
8- Yun J, Mullarky E, Lu C, Bosch KN, Kavalier A, Rivera K, Roper J, Chio II, Giannopoulou EG, Rago C, Muley A, Asara JM, Paik J, Elemento O, Chen Z, Pappin DJ, Dow LE, Papadopoulos N, Gross SS, Cantley LC. Vitamin C selectively kills KRAS and BRAF mutant colorectal cancer cells by targeting GAPDH. Science. 2015 Dec 11; 350(6266):1391-6.
9- Seyeon Park, Seunghyun Ahn, Yujeong Shin, Yoonjung Yang, and Chang H. Yeom. Vitamin C in Cancer: A Metabolomics Perspective. doi: 10.3389/fphys.2018.00762