Written by Jessica Patella, ND. Supplementation with vitamin C after diagnosis of breast cancer is associated with a 19% reduction in mortality.
Breast cancer is the most common cancer among women. It is the leading cause of death from cancer in Hispanic women and the second leading cause of death among all other races (2). There are currently 2.8 million women in the United States who have undergone treatment for breast cancer (3). Of these women, 75-87% of breast cancer survivors report using multivitamins and supplements (4). Vitamin C is one of the most commonly consumed supplements (1,5) and a recent analysis of research studies found that supplementing with vitamin C after a diagnosis of breast cancer reduced the risk of death from breast cancer and all causes (1).
The analysis of research examined 10 different studies of vitamin C supplementation (n=6) and/or dietary intake (n=7) and included a total of 17,696 breast cancer cases (1). Of the studies that examined vitamin C supplementation, a 19% reduction in total cause of death and death from breast cancer was observed in women who supplemented with vitamin C after a diagnosis of breast cancer (RR 0.81, 95% CI 0.72-0.91; RR 0.85, 95% CI 0.74-0.99, respectively ) compared to those who did not use supplements (1).
In the studies that examined dietary intake of vitamin C, similar results were also observed. An increase in vitamin C intake of 100 mg per day was associated with a reduction in all causes of death (95% CI 0.59-0.89) and a higher intake of vitamin C was associated with a 20% reduced risk in all causes of death compared to low intakes of vitamin C (95% CI 0.69-0.92). Similar results were observed with a vitamin C intake of 100 mg per day reducing the risk of death from breast cancer (95% CI 0.64-0.94), with a 23% reduced risk of death in higher intakes of vitamin C compared to lower intakes (95% CI 0.61-0.98) (1).
The researchers proposed that because vitamin C is a strong antioxidant it could protect the body from free radical damage, which increases the progression of cancers (1,6). Amounts of supplemented vitamin C in the combined studies ranged from 400 mg per day to 1000 mg per day, with 1000 mg per day being the most common dosage (1).
This is the first meta-analysis to examine the effects of vitamin C intake on breast cancer survival. Therefore, more research needs to be conducted to determine if there is an optimal amount of vitamin C supplementation to see these benefits. It is also possible that women who supplemented with or increased dietary vitamin C levels were more health conscious, which could affect the results (1).
In conclusion, supplementing with vitamin C or increasing dietary intake of vitamin C after a diagnosis of breast cancer decreased the risk of death from breast cancer and the risk of death in general (1).
Jessica Patella, ND, is a naturopathic physician specializing in nutrition and homeopathic medicine and offers a holistic approach to health. She earned her ND from Southwest College of Naturopathic Medicine in Tempe, AZ, and is a member of the North Carolina Association of Naturopathic Physicians. Visit her website at www.awarenesswellness.com.
Source: Harris, Holly R., Nicola Orsini, and Alicja Wolk. “Vitamin C and survival among women with breast cancer: a meta-analysis.” European journal of cancer 50.7 (2014): 1223-1231.
© 2014 Elsevier Ltd. All rights reserved
Posted May 8, 2014.
References:
- Harris H, et al. Vitamin C and survival among women with breast cancer: A Meta-Analysis. Eur J Cancer (2014). doi: 10.106/j.ejca.2014.02.013
- Centers for Disease Control and Prevention. Breast Cancer Statistics.
- Breast Cancer Organization. U.S. Breast Cancer Statistics.
- Velicer CM, Ulrich CM. Vitamin and mineral supplement use among US adults after cancer diagnosis: a systematic review. J Clin Oncol 2008;26(4):665–73.
- Radimer K, et al. Dietary supplement use by US adults: data from the National Health and Nutrition Examination Survey, 1999–2000. Am J Epidemiol 2004;160(4):339–49.
- Willcox JK, et al. Antioxidants and prevention of chronic disease. Crit Rev Food Sci Nutr 2004;44(4):275–95.
