Prostate Cancer: Aggressiveness Increases If You Consume Few Antioxidants

Prostate Cancer: Antioxidant Deficiency Worsens the Disease

Poor intake of antioxidant-rich foods and supplements is associated with increased aggressiveness of prostate cancer. Conversely, the risk of developing severe forms of the disease is reduced by about 70% in men with high consumption of carotenoids, vitamins C and E, flavonoids, and isoflavones. It is hypothesized that in the future, proper nutrition and the use of antioxidant supplements could represent a strategy to counteract the progression of this widespread cancer.

This was reported in a study published last February in the journal Nutrition and Cancer, conducted by scientists at the University of Connecticut (USA).

Cancer and Antioxidant Capacity

Prostate cancer is one of the most common cancers and represents the second leading cause of cancer-related death among men in the United States. In Italy, according to 2015 estimates, there are approximately 35,000 new cases annually. Although the specific causes of prostate cancer remain undetermined, several risk factors have been identified, including family history, age, race, and diet. Some studies suggest that the level of antioxidant molecules consumed through food and supplements may be associated with prostate cancer risk.

Antioxidants counteract oxidative stress, which occurs when the body produces excessive reactive oxygen species (ROS), or free radicals, capable of oxidizing molecules essential for the body, especially lipids. Oxidative stress, together with inflammation, is implicated in the development of various diseases, including cardiovascular diseases and cancer. Men with prostate cancer typically show lower blood levels of certain antioxidant vitamins, such as vitamins E and C, and reduced amounts of enzymes like glutathione peroxidase and superoxide dismutase, which reflect oxidative stress presence.

Estimating dietary antioxidants is complicated by the variety and synergistic effects of the compounds. A reliable method to measure antioxidants consumed with food is the study of Total Antioxidant Capacity (TAC). TAC quantifies antioxidant compounds that reduce the formation of potentially harmful free radicals and thus represents a cumulative index of antioxidant intake. Higher TAC levels have been associated in some studies with lower plasma concentrations of C-reactive protein, a marker of inflammation, and with reduced risk of all-cause mortality.

Higher TAC is Associated with Lower Prostate Cancer Aggressiveness

The study, led by Terrence M. Vance from the University of Connecticut, is the first to investigate the relationship between prostate cancer aggressiveness and TAC among African American and European American populations, aiming to determine whether antioxidant intake influences disease risk and aggressiveness and to assess ethnic differences.

Results showed that a high total antioxidant capacity from diet and supplements was associated with a 69% lower risk of highly aggressive prostate cancer in all subjects. Among African Americans, those with higher dietary TAC had a 72% lower risk of developing aggressive cancer compared to those with lower TAC. For European Americans, the risk of aggressive cancer was 64% lower in the higher TAC group. Researchers also identified low blood levels of dietary antioxidants, reduced antioxidant enzyme activity, and increased lipid oxidation levels in patients, indicating greater oxidative stress, antioxidant depletion, and increased free radical and lipid oxidation.

Study Methodology Details

Dr. Vance and colleagues analyzed data from 855 African American men and 945 European American men from North Carolina and Louisiana diagnosed with prostate cancer from July 1, 2004, onward. Participants completed dietary questionnaires to assess antioxidant intake from foods and supplements.

TAC was calculated considering the contributions of carotenoids, vitamins C and E, flavonoids, isoflavones, and proanthocyanidins, adjusted for energy intake. Prostate cancers were classified as low, intermediate, or high aggressiveness based on clinical stage, and PSA levels—a prostate-produced enzyme used for early cancer detection—were measured at diagnosis.

Antioxidant Molecules to Reduce Prostate Cancer Severity

According to the researchers, these findings highlight the need to determine whether antioxidant intake can influence the risk of aggressive prostate cancer forms—an important step toward identifying modifiable factors such as diet and supplements to reduce prostate cancer severity and mortality. Further studies in other populations are needed to confirm these results and clarify the dietary components’ role in prostate cancer development and progression, along with their 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.