Prostate cancer: aggression increases if few antioxidants are consumed
Prostate cancer: antioxidant deficiency worsens the disease
Poor consumption of foods and supplements rich in antioxidant compounds is associated with more aggressive prostate cancer. In contrast, the risk of developing severe forms is reduced by about 70 percent in men with the disease whose consumption of carotenoids, vitamins C and E, flavonoids, and isoflavones is very high. It can be hypothesized that in the future, proper nutrition and the use of antioxidant supplements may be a strategy to counter the aggravation of this widespread cancer.
This was reported in a study published last February in the journal Nutrition and Cancer and carried out by scientists at the University of Connecticut (USA).
Cancer and antioxidant capacity
Prostate cancer is one of the most common and is the second leading cause of cancer-related mortality among men in the United States. In Italy, according to estimates for the year 2015, there would be 35,000 new cases each year. Although the specific causes of prostate cancer are not yet determined, several risk factors for the disease have been identified: family history, age, race, but also diet. According to some studies, the level of antioxidant molecules consumed from foods and supplements may be associated with prostate cancer risk.
In fact, antioxidants are able to counteract oxidative stress, which is that condition that occurs in the body when there is excessive production of so-called reactive oxygen species (ROS), or free radicals, which can oxidize molecules needed by the body, especially lipids. Oxidative stress, along with inflammation, is implicated in the onset of various diseases such as cardiovascular and cancer. Men with prostate cancer usually show lower blood levels of certain antioxidant vitamins, E and C, and lower amounts of enzymes such as glutathione peroxidase and superoxide dismutase, all signs that reflect the presence of oxidative stress.
Estimating antioxidants in an individual's diet is complicated by the variety and synergistic effect of compounds. A reliable method for measuring antioxidants consumed from food is the study of total antioxidant capacity (TAC). TAC quantifies antioxidant compounds that reduce the formation of potentially harmful free radicals and is thus a cumulative index of antioxidant intake. Higher TAC has been found in some studies to be associated with lower plasma concentrations of C-reactive protein, a molecule that indicates the presence of inflammation and a reduced risk of mortality from any cause.
Higher CT scan is associated with lower tumor aggressiveness
The Terrence M. Vance-directed study, from the University of Connecticut, is the first to investigate the relationship between prostate cancer aggressiveness and CT in African American and European American populations, with the aim of determining whether antioxidant intake is able to influence the risk and aggressiveness of the disease and any differences in different ethnicities.
Results of the study showed that high total antioxidant capacity due to diet and supplement use was associated with a 69% lower risk of very aggressive prostate cancer, in all subjects. Among African Americans, those who had a higher TAC value due to diet possessed a 72% lower risk of developing aggressive cancer, compared with those whose values were lower. For European Americans, the risk of having a very serious cancer in the group with higher CT was 64 percent lower than those with lower CT. However, the researchers identified low blood levels of dietary antioxidants, decreased activity of antioxidant enzymes, and increased levels of lipid oxidation in the patients, signs that could indicate either increased oxidative stress, resulting in antioxidant depletion, or decreased levels of antioxidants with logical increases in free radicals and lipid oxidation.
Some information about the method of the study
Dr. Vance and his collaborators analyzed data from 855 African-American men and 945 European Americans, all from North Carolina-Louisiana, with prostate cancer. The subjects included were men who had been diagnosed with cancer as of July 1, 2004. Each individual answered a questionnaire designed to understand dietary habits in order to assess the amount of antioxidants from foods and supplements.
LA TAC was calculated by considering the contribution of carotenoids, vitamins C and E, flavonoids, isoflavones, and proanthocyanidins, and then adjusted for energy intake. Prostate cancers were classified into low-, medium-, or high-aggression cancer according to clinical stage, and levels were assessed at diagnosis of PSA, an enzyme normally produced by the prostate that is used for early detection of cancer, a condition in which it is produced in excess.
Antioxidant molecules to reduce the severity of prostate cancer
According to the researchers who conducted the study, these results demonstrate the need to determine whether antioxidant intake is able to influence the risk aggressive forms of the disease,an important step in identifying modifiable factors, such as diet and supplement use, that can reduce prostate cancer severity and mortality due to it. Further studies in other populations are needed, however, to confirm these findings and determine whether dietary components influence the development and progression of prostate cancer and by what mechanisms.
Source: Vance TM, Wang Y, Su LJ, Fontham ET, Steck SE, Arab L, Bensen JT, Mohler JL, Chen MH, Chun OK. Dietary Total Antioxidant Capacity is Inversely Associated with Prostate Cancer Aggressiveness in a Population-Based Study. Nutr Cancer. 2016 Feb-Mar;68(2):214-24. Epub 2016 Feb 4.
