Custom «Antioxidant Supplements and Cancer» Essay Paper Sample

It has long been argued that Antioxidants like carotene, lutein, lycopene, vitamins C and E, and other Antioxidants substances plays a part in preventing diseases like macular degeneration, Alzheimer's disease, cancer, and cardiovascular disease (Ladas and Kelly). These Antioxidants are said to have the capability of neutralizing free radicals, thus helping to detoxify the natural cell metabolism by-products (USA Today Magazine, 4-5). However, some studies done recently suggests that although the supplements containing the mentioned antioxidants are by and large considered safe, taking higher doses of supplements may actually be harmful (Lerner 227).

This report thoroughly examines why antioxidants might be supportive to cancer patients, and then evaluate the research done so far to establish whether these conclusions are supported by the results.  It provides an in-depth evaluation of the research on the use of antioxidants and its effect on cancer patients.  The review reveal that despite all of these hundreds of studies spread over more than 30 years, there is little or no holistic evidence that antioxidants, when taken as supplements, afford any significant long-term protection against any major chronic disease or increase life expectancy. The study recommends foods that may present wide range of health benefits as well as antioxidants, such as those with protein, high in fiber, minerals and other vitamins.

For many years, researchers have suggested that there is a relationship between radicals and cancer. These free radicals, which are by-products of normal cell process that produces energy, called oxidation can wreck havoc within the cell. Free radicals damage has been implicated in up to 80 percent of all human diseases including cancer (Challem 7).  Although the body is equipped with mechanisms to counter the side effects of oxidation, some researchers assert that food high in antioxidants or antioxidant supplements helps to reduce their harmful effects. Evidence for the benefits of ingesting antioxidants comes from epidemiological studies. Many studies suggests that humans with diets high in antioxidants or who have higher antioxidant levels in their blood have reduced risk of some diseases and may even live longer (Challem 33).  

However, the studies on the effect of antioxidants on disease risk are confusing. Some studies suggest that people who ingest supplements have a lower risk of illness, but the problem is that the type of people who choose to take vitamins supplements are more health-conscious and healthier than those who do not choose to take vitamins. There have been numerous trials with human subjects that have been used to suggest that to suggest that antioxidant supplements have beneficial effects (Ladas & Kelly, 2010). Other studies have tested whether particular antioxidants can prevent the onset of chemically induced cancers in short-term studies or have looked at the effects on the growth of isolated human cancer cells in culture. Other studies have looked at the ability of these compounds to inhibit mutagenicity in bacteria which is used as an indicator of anticancer potential (Total Health 22). However, despite all these many studies, there is still little holistic evidence that antioxidants, when taken as supplements, afford any significant long-term protection against any major chronic disease or increase life expectancy in affluent well nourished population (Tufts University Health & Nutrition Letter, 1-2). No randomized trial on antioxidant supplementation has shown a decreased illness or death (Bendich and Deckelbaum 234). And some studies have shown a decreased illness rates. 

This wide-ranging search offers an adequate published literature review to sustain a comprehensive review of the efficacy the antioxidants supplements for cancer prevention and treatment. The review reveals that while free radicals have been associated with  over 100 ailments in human, this insinuation should not be taken wholly as a proof of their role in formation of these human ailments or that preventing the function or formation of these free radicals can cure or prevent these diseases (Tufts University Health & Nutrition Letter, 2).

This report's objective was to carry out a search and a review of the published literature on research the use of antioxidants supplements, coenzyme Q10, vitamin E, and vitamin C, for the prevention and treatment of cancer. Based on this search, the study evaluated the evidence for the value of these forms of antioxidants.

The aim of this study was to perform a meta-analysis by combining the results of appropriate literature on studies that focused on evaluation of the research on the use of antioxidants and its effect on cancer patients and testing whether particular antioxidants can prevent the onset of cancers.

Various biomedical databases were searched. These databases include MEDLINE, Elsevier Biobase, CINAHL, Cochrane Library, NLM databases, and TGG Health & Wellness DB. 

The process of reviewing the literature and publications on antioxidants and its effect on cancer was broken down into four stages. First was actual searching for relevant sources. This involved careful searching to find materials that were useful by discriminating between the various literature types. Secondly, a management system to store and catalogue all the sources found was set up. Thirdly, there was the need to decide which of the many sources found were relevant, making judgments about which papers that will be used and why. Finally, the selected material will be used to develop the research focus and argue the rationale.

The output was Limited the to human studies and the search was done using the terms antioxidants, coenzyme Q110, vitamin C, and vitamin E, and their accompanying pharmacological synonyms, study design, meta-analyses, and systematic reviews of the condition of interest (cancer)

Selection Criteria

The literature reviewed includes articles that investigate the value of antioxidants and the integral part it plays to various body functions. The investigation included trials that evidenced the use of the antioxidants as supplements for the prevention or treatment of cancer and the applicability of coenzyme Q10, vitamins C and Vitamin E during conventional treatment of cancer patients. For background information about antioxidants supplements, systematic reviews, meta-analysis and reviews of the past clinical trials on the use of antioxidants and its effect on cancer patients was essential.

Reporting the Evidence

Literature searches yielded numerous articles, of which 15 were selected for screening based on selection criteria. This selected articles included clinical trials reports, medical journal reviews, and publications that provided supplemental information on antioxidant supplements. Twelve peer reviewed articles were reviewed. Eight of these articles thoroughly examines why antioxidants might be supportive to cancer patients, and then evaluate the research done so far to establish whether these conclusions are supported by the results. The remaining articles describe the use of the antioxidants during conventional treatment of cancer patients as one of the most contentious subject in oncology.

Data Collection and Analysis

All selected publications, articles and journals, were reviewed independently and information about study design, state of the disease, patient demographics, medical intervention, and outcomes was collected.

The study identified 15 articles relevant to the study of antioxidants supplement effect in preventing and treating various forms of cancer. Most of these studies presented data on corresponding to various exclusive trials, while others presented the same trial.

Most of the publications thoroughly examines why antioxidants might be supportive to cancer patients, and then evaluate the research done so far to establish whether these conclusions are supported by the results.   The articles states that studies have revealed a relationship between diets rich in antioxidants, especially vitamin C, and a reduced cancer risks.  These studies have tested whether particular antioxidants can prevent the onset of chemically induced cancers in short term studies with laboratory animals or have looked at the effects on the growth of isolated human cancer cells in culture.

Many articles reported association of supplemental vitamin c with cancer incidence or mortality. Four studies examined all cancer sites combined, and none found either large or statistically significant associations. The studies for stomach cancer found consistent inverse associations with Vitamin C.

Numerous observational studies have examined association of supplemental Vitamin E with cancer incidence or mortality. Only four studies report associations with all cancer research publications combined; two found statistically significant 60 percent reductions in risk, and one found a 20 % association. One of these studies was a randomized controlled trial that combined Vitamin E with beta-ceraton and selenium.

Other studies have looked at the ability of antioxidants to inhibit mutagenicity in bacteria which is used as an indicator of anti-cancer potential. 

A number of the systematic reviewed literature however reveal that despite all of these hundreds of studies spread over more than 30 years, there is little or no holistic evidence that antioxidants, when taken as supplements, afford any significant long-term protection against any major chronic disease or increase life expectancy.

Most of the data supporting the use of antioxidants in the oncology setting are derived from cellular and animal research. Observational researches have been conducted in adults and children with cancer. Few case studies have been reported among adults with cancer. Observational trials have consistently reported decreased levels of antioxidants in patients receiving cytotoxic therapy.

The following observations based on the analyses were noted:

This in-depth evaluation of the published literature on efficacy of antioxidants, vitamin C and vitamin E does not support the hypothesis that they help in prevention or treatment of cancer.

Randomized, controlled clinical trials investigating the use of antioxidants in the ecology setting have been conducted among individuals with cancer. These clinical trials have not verified the benefits of antioxidant supplements but have yielded mixed reports. Several studies found that people with low dietary intakes or blood levels of antioxidants have a higher risk of cancers of stomach, esophagus, pancreas, breasts, lung, colon, cervix, prostate, and ovaries. Nutritional Aspect of Development of Cancer report by COMA concluded that high intakes of the antioxidant vitamins are associated with reduced cancer risks. The Agency for Health care Research and Quality (AHRQ) however indicate that there is insufficient evidence to reach any conclusion about the relationship (Tufts University Health & Nutrition Letter 1-2).

At best, studies of antioxidant supplements have produced disappointing results, and a few have raised the possibility that high doses of a single antioxidant may be harmful. The women's Health Study found that vitamin e supplements provide no protection against cancer. After long evaluation on various studies on antioxidants and risk in diseases, eminent scientist have come up with a 500-page report to be used to set new Recommended Dietary Allowances for antioxidants in the Institute of Medicine. In so doing, they have established that most Americans from the food they eat they get enough antioxidant vitamins and yet the disease remains prevalent in this society. Taking antioxidants in large doses is said to improve health or even prevent chronic diseases, although, no sufficient evidence has been established to support these statement. 

Researches evidently show that Vitamins E protects against cancer. Fifty-nine human studies analyzed by researcher and published in the article cancer causes and control found out that of all supplements studied, vitamin E supplements were the most strongly associated with a reduced cancer risk. Many studies also found that high level of vitamin E in the body are associated with a lower risk of cancer, whereas low levels are associated with a greater risk. These trends have been identified with cervical cancer, cancer of the breast, lung cancer, throat cancer, and colon cancer. However at this time, there is no research to indicate that vitamin E can reverse cancer in humans.

The study also demonstrates an indirect association (the study did not analyze vitamin C itself but intake of foods that contain high amounts of vitamin C,) between high intake of vitamin C and a lowered cancer risk, particularly the risk of stomach and esophagus cancer. Specifically, consumption of fresh fruit with high levels of vitamin C has been shown to reduce the risk of gastric cancer. An epidemiological study also showed that vitamin C consumption has a protective role against a premalignant condition that causes uterine cervical dysplasia. 83 percent of the case-controlled studies showed that vitamin C has a significant protective effect against cancer, while demonstrating a protective effect, particularly for esophagus cancers, larynx cancer, pancreas infections, oral cavity, rectum, stomach, and cervix cancers.  However, this is not conclusive because the people who choose to take vitamins supplements (vitamin c in this case) are more health-conscious and healthier than those who do not choose to take vitamins. The study also suggests that perhaps other than vitamin C, the other compounds found in vegetables and fruits may be responsible of exerting the protective effect, thus reduced cancer risks. It may also be that people who take large amounts of plant foods may thereby avoid excess of detrimental substances in fats and meats.

Overall, studies have not clearly defined cancer risks associated with low levels of antioxidants although most of the publications thoroughly examine why antioxidants might be supportive to cancer patients. Generally, the review describes the use of the antioxidants during conventional treatment of cancer patients as one of the most contentious subject in oncology.  Most publication states that studies have revealed a relationship between diets rich in antioxidants, especially vitamin C, and a reduced cancer risks.  These studies have tested whether particular antioxidants can prevent the onset of chemically induced cancers in short term studies with laboratory animals or have looked at the effects on the growth of isolated human cancer cells in culture. The review provides information about cancer prevention and points out that like carotene, lutein, lycopene, vitamins C and E, and other Antioxidants substances can play a part in preventing diseases like, macular degeneration, Alzheimer's disease, cardiovascular disease, and cancer. These antioxidants can neutralize free radicals which in the natural cell metabolism are toxic by-products that are why they are thought to help prevent these diseases.  Antioxidants supplements are usually considered safe, although studies shows that taking these supplements in large doses than it is recommended for some time can be dangerous and probably toxic.

The report thoroughly examines why antioxidants might be supportive to cancer patients, and then evaluate the research done so far to establish whether these conclusions are supported by the results.  It provides an in-depth evaluation of the research on the use of antioxidants and its effect on cancer patients.  The results from this study indicate that the association of dietry supplement use with cancer risk is complex and generally inconsistent.

Further Research

The in-depth evaluation of the published literature on efficacy of antioxidants, vitamin C and vitamin E does not support the hypothesis that they help in prevention or treatment of cancer. However, several intermediate studies reported positive outcomes. These isolated findings will require further investigation.