Antioxidants

This section was compiled by Frank M. Painter, D.C.
Send all comments or additions to:   Frankp@chiro.org

If there are terms in these articles you don't understand, you can get a definition from the Merriam Webster Medical Dictionary.   If you want information about a specific disease, you can access the Merck Manual.   You can also search Pub Med for more abstracts on this, or any other health topic.

Antioxidants are substances (nutrients) in our foods which prevent or slow down oxidative damage within the body. When our cells use oxygen, they naturally produce “free radicals” (by-products) which cause damage to our DNA, cell membranes and cellular organelles. When a free radical attacks a molecule, it becomes a free radical itself, causing a chain reaction that can result in severe damage to a cell. What makes antioxidants so important is that they have the ability to neutralize free radicals without becoming one themselves. Antioxidants act as “free radical scavengers”, preventing and repairing damage. Health problems such as heart disease, macular degeneration, diabetes, cancer, and numerous other degenerative processes are all exacerbated by oxidative damage. The first recognized antioxidants were vitamin C and vitamin E, but other substances that have powerful antioxidant properties have also been recognized: Selenium, Carotenoids ( Beta-carotene, Lutein, Lycopene, Sulforaphane, Zeaxanthin, and Astaxanthin), Bioflavonoids (Anthocyanins, Proanthocyanidins, Quercetin, and Apigenin), Coenzyme – Q10 (Co–Q10), Soy Isoflavones (Genistein and Daidzein), and many other less well-known compounds found in fruits and vegetables.

	Association of Serum Antioxidant Vitamins and Carotenoids With Incident Alzheimer Disease and All-Cause Dementia Among US Adults Neurology 2022 (May 4); [EPUB] Incident all-cause dementia was inversely associated with serum lutein+zeaxanthin and β-cryptoxanthin levels. Further studies with time-dependent exposures and randomized trials are needed to test neuroprotective effects of supplementing the diet with select carotenoids.
	Oxidative Stress Biomarker Monitoring in Elite Women Volleyball Athletes During a 6-Week Training Period J Strength Cond Res. 2011 (May); 25 (5): 1360–1367 Reactive oxygen metabolites (ROM) were measured in 16 elite female athletes receiving supplemental vitamin C, E, zinc, and selenium, and compared to 12 controls during a 6-week training period. ROM and other markers of oxidative stress were reduced in athletes receiving supplements compare to controls. Antioxidant supplements may help to prevent the depletion of antioxidant defenses in athletes.
	Effect of Long-term Treatment with Antioxidants (Vitamin C, Vitamin E, Coenzyme Q10 and Selenium) on Arterial Compliance, Humoral Factors and Inflammatory Markers in Patients with Multiple Cardiovascular Risk Factors Nutrition & Metabolism 2010 (Jul 6); 7: 55 ~ FULL TEXT This relatively short study (6 months) clearly demonstrated that even modest intake of 4 supplements that provide significant antioxidant properties made a significant improvement in the elesticity of both small and large blood vessels, while also reducing blood pressure, and also improving blood lipid composition (increased HDL-cholesterol levels and modest decreases in triglycerides).
	Resveratrol ~ Is Red Wine a Youth Potion? Functional Foods & Nutraceuticals ~ February 2004 Man’s pursuit of long life, the so-called fountain of youth, edged closer to fruition with the recent announcement that a dietary component may increase the human lifespan to the point where it would be common to live 125 years. This red-coloured youth potion can be obtained from a bottle of vino, and perhaps as a dietary supplement. Lead researcher David Sinclair, PhD, assistant professor of pathology at Harvard University Medical School, says the lifespan of all life forms tested so far—yeast cells, fruit flies, worms and mice—has been dramatically lengthened by minute amounts of a red wine extract, resveratrol. You may also enjoy this Newsweek article by Dr. David Sinclair, titled: Can We Slow Aging?.
	Natural Medicine and Nutritional Therapy as an Alternative Treatment in Systemic Lupus Erythematosus Alternative Medicine Review 2001 (Oct); 6 (5): 460–471 ~ FULL TEXT Systemic lupus erythematosus (SLE) is a multisystem autoimmune disorder without a known cure. Conventional medicine typically approaches the disease with a treatment plan that includes the use of corticosteroids, non-steroidal anti-inflammatory drugs (NSAIDS), antimalarial drugs, and chemotherapeutic agents. The results vary and safety is questionable. Conservative treatment methods, such as the use of vitamins, minerals, and fatty acids, have been shown to have an impact on the activity of the disease.
	Effects of Multinutrient Supplementation on Antioxidant Defense Systems in Healthy Human Beings J Nutr Biochem 2001 (Jul); 12 (7): 388–395 Oxidative damage is involved in the pathogenesis of many diseases, such as cardiovascular disease, cancer and diabetes. The antioxidant defense system plays an important role in protecting the body from oxidative damage. Numerous studies have been shown that a single vitamin or mineral supplementation has the beneficial effect on the antioxidant defense system. However, the overall combined effect of multinutrient supplementation on antioxidant defense system remains to be clarified...until now. Read on!
	Effect of Antioxidants on the Occurrence of Pre-Eclampsia in Women at Increased Risk: a Randomized Trial Lancet 1999 (Sep 4); 354 (9181): 810–816 Supplementation with vitamins C and E may be beneficial in the prevention of pre-eclampsia in women at increased risk of the disease.
	Antioxidants Resolve Radiation Side Effects Nutrition Science News ~ September 2001 Radiation proctitis, characterized by rectal pain, bleeding, diarrhea, and incontinence, is a common side effect of radiation therapy for cervical or prostate cancers. Radiation generates large numbers of free radicals that harm nearby normal cells. Researchers asked 20 men and women with radiation proctitis to take a combination of 400 IU vitamin E and 500 mg vitamin C twice a day. All of the patients' symptoms, except pain, were reduced during the eight-week study, and some of the symptoms were completely resolved.
	Sustaining The Brain With Antioxidant Protection Functional Foods & Nutraceuticals ~ November 2003 The end of the 1990s marked the completion of the so-called Decade of the Brain, a title bestowed upon this period by researchers and clinicians in the neurosciences. Their intent was both to enhance awareness of the various neurodegenerative diseases and to encourage research into the diverse genetic, infectious, environmental, traumatic and lifestyle influences on their development. But despite the commendable advances in our understanding of the causes of these maladies, lack of significant progress from a therapeutic perspective may mean that we will leave the Decade of the Brain to usher in the Century of Brain Dysfunction.
	Parkinson's Defense Nutrition Science News ~ May 2001 While the underlying causes of PD remain unknown, three factors are proposed. Genetics probably plays a role in PD development because 15 to 20 percent of PD patients have had a close relative with the disorder. [ 3 ] Environmental toxins such as pesticides are also considered a cause. A population-based case-control study of 608 men and women older than 50 at the Henry Ford Health System in Detroit revealed an association between PD and occupational exposure to herbicides and insecticides. [ 4 ] Animal studies show that pesticides that produce free radicals damage cellular mitochondria, selectively destroy dopamine-producing neurons, and produce PD-like behavioral symptoms. [ 5 ] These studies also support the third potential cause, and the most common theory, which is that PD stems from free radical-mediated degeneration of dopamine-producing cells and oxidative destruction of dopamine.
	Antioxidants Quell Sickle-Cell Nutrition Science News ~ April 2001 Researchers at the Philadelphia Biomedical Research Institute asked 10 patients with sickle-cell anemia to take a combination of 6 g aged garlic extract, 6 g vitamin C, 1,200 IU vitamin E, and 1,000 mcg folic acid per day for six months. Twin siblings took only folic acid. Patients taking the antioxidants had one-third as many as painful sickle-cell episodes and also reported higher energy levels.
	Aging Gracefully With Antioxidants Nutrition Science News Living well includes getting enough relaxation, exercise, community spirit and nutritious foods. It may also include taking vitamins. An avalanche of research data suggests that high intakes of antioxidant-rich fruits, vegetables and supplements lowers the risk of old-age diseases. [1]
	Anthocyanins Nutrition Science News ~ December 2001 Eaten in large amounts by primitive humans, anthocyanins are antioxidant flavonoids that protect many body systems. They have some of the strongest physiological effects of any plant compounds, and they are also things of beauty: anthocyanins provide pigment for pansies, petunias, and plums.
	Antioxidant Vitamins Block Homocysteine's Acute Toxic Effects Nutrition Science News ~ December 2000 About one-fourth of all American adults have excessively high blood levels of homocysteine. This amino acid is formed from methionine, which is taken into the body via animal-derived foods. High levels of homocysteine translate into a significant increase in hardening of the arteries known as arteriosclerosis. In that way, homocysteine is similar to cholesterol because prolonged, elevated levels of it gradually damage the inner linings of blood vessels, causing atherosclerotic plaque and narrowing of the arteries. However, for a catastrophic end result of this process to occur — a heart attack or a stroke — it typically takes more than just narrow arteries: It requires the blood within the artery to congeal into a clot, suddenly causing an obstruction.

Supplements with Antioxidant Properties

	Bioflavonoids This section includes abstracts about the research supporting Bioflavanoid supplementation.
	Blueberry Extract This section includes abstracts about the research supporting Blueberry Extract supplementation.
	Carotenoids This section includes abstracts about the research supporting Carotenoid supplementation.
	Chardonnay Grape Seed This section includes abstracts about the research supporting Chardonnay Grape Seed extract supplementation.
	Coenzyme – Q10 This section includes abstracts about the research supporting CoQ 10 supplementation.
	Resveratrol This section includes abstracts about the research supporting Resveratrol supplementation.
	Vitamin C This section includes abstracts about the research supporting Vitamin C supplementation.
	Vitamin E This section includes abstracts about the research supporting Vitamin E supplementation..
	Selenium This section includes abstracts about the research supporting Selenium supplementation.
	Zinc This section includes abstracts about the research supporting Selenium supplementation.

Antioxidants and Cancer

	Should Antioxidants be Used in Cancer Therapy? Alternative Medicine Review 1999 (Oct); 4 (5): 303 ~ FULL TEXT In this issue of Alternative Medicine Review, Davis W. Lamson, ND, and Matthew D. Brignall, ND, do answer the above question with a detailed, well-referenced paper which examines evidence in the scientific literature regarding the use of antioxidants as sole cancer therapy, as well as their concurrent use in radiotherapy and chemotherapy. [2] They rely on in vitro, and animal and human in vivo studies to establish their point: that antioxidants have been shown, in many cases, to be anti-neoplastic themselves, to enhance the effectiveness of radiation and chemotherapy regimens, and to reduce the toxic - and sometimes deadly - side-effects of conventional cancer therapies.
	Natural Agents in the Prevention of Cancer Data exist in the scientific literature showing reduction in the risk of tumor occurrence achieved by the use of nutritional and other natural materials. However, many trials that have attempted to prevent cancer occurrence with nutritional supplementation have found no effect or even increased tumor incidence. Several factors appear to be responsible for these disparate data, including the forms of nutrients used and the types of cancer being studied.    Part I: Human Chemoprevention Trials Alternative Medicine Review 2001 (Feb); 6 (1): 7–19 ~ FULL TEXT The battle against cancer has been waged for several decades without resounding curative success from the use of chemotherapy or radiotherapy in most common solid tumors. (1) Much of the present day research directed against active malignancy has shifted toward identification of strategies affecting the growth rate or apoptosis of such cells so that life with cancer can be greatly extended without the deleterious effects of the more aggressive therapies.    Part II: Preclinical Data and Chemoprevention for Common Cancers Alternative Medicine Review 2001 (Apr); 6 (2): 167–187 ~ FULL TEXT This paper is the second of a series examining the use of nutritional supplements as chemopreventive agents. The first paper in the series examined the data from human chemoprevention trials. [1] In the present paper the mechanisms of action of promising treatments will be discussed. In vitro and animal data are presented in support of the agents as appropriate. The subject of chemoprevention with nutritional agents has been the subject of voluminous research, and this review should not be considered exhaustive. In cases where review articles already exist regarding a particular agent (e.g., vitamin A, beta-carotene), these papers should be consulted for a more complete summary.
	Antioxidants and Cancer Therapy Evidence reviewed here demonstrates exogenous antioxidants alone produce beneficial effects in various cancers, and except for a few specific cases, animal and human studies demonstrate no reduction of efficacy of chemotherapy or radiation when given with antioxidants. In fact, considerable data exists showing increased effectiveness of many cancer therapeutic agents, as well as a decrease in adverse effects, when given concurrently with antioxidants.    Part I: Their Actions and Interactions With Oncologic Therapies Alternative Medicine Review 1999 (Oct); 4 (5): 304–329 ~ FULL TEXT Dietary and endogenous antioxidants prevent cellular damage by reacting with and eliminating oxidizing free radicals. However, in cancer treatment, a mode of action of certain chemotherapeutic agents involves the generation of free radicals to cause cellular damage and necrosis of malignant cells. So a concern has logically developed as to whether exogenous antioxidant compounds taken concurrently during chemotherapy could reduce the beneficial effect of chemotherapy on malignant cells. The importance of this concern is underlined by a recent study which estimates 23 percent of cancer patients take antioxidants. [1]    Part II: Quick Reference Guide Alternative Medicine Review 2000 (Apr); 5 (2): 152–163 ~ FULL TEXT This guide is meant to be a companion to the previous review on effects of antioxidant supplementation during cancer therapy. [1] Widespread use of antioxidant compounds makes this an area of increasing interest to oncologists as well as other physicians; hence, the attempt to reduce the findings of a lengthy report to a manageable guide.    Part III: Quercetin Alternative Medicine Review 2000 (Jun); 5 (3): 196–204 ~ FULL TEXT Quercetin is the major bioflavonoid in the human diet. The estimated average daily dietary intake of quercetin by an individual in the United States is 25 mg. [3] Its reputation as an antioxidant stems from the reactivity of phenolic compounds with free radical species to form phenoxy radicals which are considerably less reactive. Additionally, one can envision a polyphenolic compound easily oxidizable to a quinoid form (similar to vitamin K) and participating in the redox chemistry of nature.
	The Effect of Dietary Levels of Selenium on Radiation Resistance and Radiation-induced Carcinogenesis Nutrition Research 1996; 16 (3): 505–516 Combined (internal plus external) radiation exposure of the population and emergency workers, as a result of the Chernobyl accident, increased the oncogenic risk, and to reduce it is a problem of the utmost importance. A long–term experiment in 400 rats exposed to radiation following the Chernobyl pattern showed that a selenium–enriched diet started after exposure caused a longer average lifespan and a 1.5 – 3.5 fold decrease of leukaemias and other malignancies, e.g. breast, thyroid and lung cancers, etc., at late times.

Antioxidants and Cardiovascular Disease

	The Role of Chronic Inflammation in Cardiovascular Disease and its Regulation by Nutrients Alternative Medicine Review 2004 (Mar); 9 (1): 32–53 Nutrients such as arginine, antioxidants (vitamins C and E, lipoic acid, glutathione), and enzyme cofactors (vitamins B2 and B3, folate, and tetrahydrobiopterin) help to elevate nitric oxide levels and may play an important role in the management of cardiovascular disease. Other dietary components such as DHA/EPA from fish oil, tocotrienols, vitamins B6 and B12, and quercetin contribute further to mitigating the inflammatory process.
	Randomized Trials of Dietary Antioxidants in Cardiovascular Disease Prevention and Treatment J Cardiovasc Risk 1996 (Aug); 3 (4): 368–371 The hypothesis that antioxidant vitamins might reduce cardiovascular disease risk is based on a large body of basic and human epidemiologic research. Basic research provides a plausible mechanism by which antioxidants might reduce the risk of atherosclerosis. A large number of descriptive, case–control and cohort studies provide data suggesting that consumption of antioxidant vitamins is associated with reduced risks of cardiovascular disease. These data raise the question of a role of antioxidants, such as vitamins C and E, and beta–carotene, in the primary prevention of cardiovascular disease, but do not provide a definitive answer.
	Supplementation with Vitamins C and E Suppresses Leukocyte Oxygen Free Radical Production in Patients with Myocardial Infarction European Heart Journal 1995 (Aug); 16 (8): 1044–1049 Clinical studies suggest that neutrophil activation during acute myocardial infarction (MI) aggravates tissue injury. Activated neutrophils are an important source of oxygen free radicals (OFR), the injurious effects of which are counteracted by endogenous antioxidants. We have previously shown in healthy subjects that supplementation with antioxidant vitamins C and E suppresses OFR production by isolated neutrophils assayed by chemiluminescence (CL).

Antioxidants and Diabetes Mellitus

	Oxidative Stress and Diabetic Vascular Complications Diabetes Care 1996 (Mar); 19 (3): 257–267 Long–term vascular complications still represent the main cause of morbidity and mortality in diabetic patients. Although prospective randomized long–term clinical studies comparing the effects of conventional and intensive therapy have demonstrated a clear link between diabetic hyperglycemia and the development of secondary complications of diabetes, they have not defined the mechanism through which excess glucose results in tissue damage.
	Status of Antioxidants in Patients with Diabetes Mellitus with and Without Late Complications Aktuel. Ernahr. Ed. Klin. Prax 1994; 19 (3): 155–159 The role of antioxidative vitamins in the therapy of diabetes mellitus is of growing importance. The development of diabetic late complications (cataract, retinopathy, nephropathy and neuropathy and others) is associated with an increased presence of free radicals, and therefore, elevated oxidative stress of the human body. The aim of the present study was the evaluation of the vitamin and selenium status of diabetics.
	Diabetes Mellitus –– A Free Radical–associated Disease. Results of Adjuvant Antioxidant Supplementation Z Gesamte Inn Med 1993 (May); 48 (5): 223–32 Our investigations carried out in patients with diabetes mellitus revealed oxidative stress loads. The study presented here was to clarify whether a therapy with antioxidants can contribute to an improvement of prognosis. 80 patients affected with a long term diabetic late syndrome were randomised and arranged to 4 groups of n = 20 each.
	Rationales for Micronutrient Supplementation in Diabetes Med Hypotheses 1984 (Feb); 13 (2): 139–151 Available evidence– some well–documented, some only preliminary– suggests that properly–designed nutritional insurance supplementation may have particular value in diabetes. Comprehensive micronutrient supplementation providing ample doses of antioxidants, yeast–chromium, magnesium, zinc, pyridoxine, gamma–linolenic acid, and carnitine, may aid glucose tolerance, stimulate immune defenses, and promote wound healing, while reducing the risk and severity of some of the secondary complications of diabetes.

Antioxidants, Free Radicals, and Disease

	The Relation Between Antioxidants and Memory Performance in the Old and Very Old J Am Geriatr Soc 1997 (Jun); 45 (6): 718–24 Among people aged 65 and older, higher ascorbic acid and beta-carotene plasma level are associated with better memory performance. These results indicate the important role played by antioxidants in brain aging and may have implications for prevention of progressive cognitive impairments.
	The Role of Free Radicals in Disease Australian and New Zealand Journal of Ophthalmology 1995 (Feb); 23 (1): 3–7 The eye is an organ with intense AOS (activated oxygen species) activity, and it requires high levels of antioxidants to protect its unsaturated fatty acids. The human species is not genetically adapted to survive past middle age, and it appears that antioxidant supplementation of our diet is needed to ensure a more healthy elderly population.
	Antioxidant Vitamins and Disease – Risks of a Suboptimal Supply Ther. Umsch 1994 (Jul); 51 (7): 467–474 The treatment with multivitamin preparations containing vitamin C and E was associated with better transplant performance in kidney transplants in a recent study. In conclusion, 'optimal' plasma concentrations of essential antioxidants are a primary aim in the prevention of disease such as ischemic heart disease, stroke and cancer. This is achieved by intake of higher doses of dietary antioxidants (as compared with RDAs) or, if necessary, by vitamin supplements.
	Free Radicals and Neuroprotection B. J. Wilder, M. D., Professor Emeritus of Neurology U. Florida College of Medicine From the above, one can appreciate that the balance between cellular oxidation and free radical production is most important in maintaining homeostasis and preventing cellular damage and death. Elaborate systems have developed to accomplish this. However, a number of disease processes and defects in antioxidant mechanisms can lead to both progression and initiation of tissue injury and cell death.

Neurodegenarative Diseases

	Oxidative Stress in Diabetes and Alzheimer's Disease J Alzheimers Dis 2009 (Apr); 16 (4): 763–774 Oxidative stress plays a major role in diabetes as well as in Alzheimer's disease and other related neurological diseases. Intracellular oxidative stress arises due to the imbalance in the production of reactive oxygen/reactive nitrogen species and cellular antioxidant defense mechanisms. Oxidative stress also contributes to the production of advanced glycation end products through glycoxidation and lipid peroxidation. The advanced glycation end products and lipid peroxidation products are ubiquitous to diabetes and Alzheimer's disease and serve as markers of disease progression in both disorders. Antioxidants and advanced glycation end products inhibitors, either induced endogenously or exogenously introduced, may counteract with the deleterious effects of the reactive oxygen/reactive nitrogen species and thereby, in prevention or treatment paradigms, attenuate or substantially delay the onset of these devastating pathologies.
	Multiple Sclerosis, An Autoimmune Inflammatory Disease: Prospects for its Integrative Management Alternative Medicine Review 2001 (Dec); 6 (6): 540–566 ~ FULL TEXT No pharmaceutical or other therapies exist that confer prolonged remission on MS, and obvious interrelationships between toxic, infectious, and dietary factors make a persuasive case for integrative management. The time-proven MS diet meticulously keeps saturated fats low, includes three fish meals per week, and eliminates allergenic foods. Dietary supplementation for MS minimally requires potent vitamin supplementation, along with the thiol antioxidants, the anti-inflammatory omega-3 fatty acids, and adaptogenic phytonutrients. Gut malabsorption and dysbiosis can be corrected using digestive enzymes and probiotics. You may review other articles about the nutritional treatment of Multiple Sclerosis
	Parkinson's Disease as Multifactorial Oxidative Neurodegeneration: Implications for Integrative Management Alternative Medicine Review 2000 (Dec); 5 (6): 502–545 ~ FULL TEXT Parkinson's disease (PD) is the most common movement pathology, severely afflicting dopaminergic neurons within the substantia nigra (SN) along with non-dopaminergic, extra-nigral projection bundles that control circuits for sensory, associative, premotor, and motor pathways. Clinical, experimental, microanatomic, and biochemical evidence suggests PD involves multifactorial, oxidative neurodegeneration, and that levodopa therapy adds to the oxidative burden. Rational, integrative management of PD requires: (1) dietary revision, especially to lower calories; (2) rebalancing of essential fatty acid intake away from pro-inflammatory and toward anti-inflammatory prostaglandins; (3) aggressive repletion of glutathione and other nutrient antioxidants and cofactors; (4) energy nutrients acetyl L-carnitine, coenzyme Q10, NADH, and the membrane phospholipid phosphatidylserine (PS); (5) chelation as necessary for heavy metals; and (6) liver P450 detoxification support.
	Coenzyme Q10 Administration and its Potential for Treatment of Neurodegenerative Diseases Biofactors 1999; 9 (2–4): 261–266 Oral administration of CoQ10 significantly decreased elevated lactate levels in patients with Huntington's disease. These studies therefore raise the prospect that administration of CoQ10 may be useful for the treatment of neurodegenerative diseases.

Antioxidants and Vision

Dietary Intake of Antioxidants and Risk of Age-related Macular Degeneration JAMA 2005 (Dec 28); 294 (24): 3101–3107 In this study, a high dietary intake of beta carotene, vitamins C and E, and zinc was associated with a substantially reduced risk of AMD in elderly persons.

Natural Therapies for Ocular Disorders    Part I: Diseases of the Retina Alternative Medicine Review 1999 (Oct); 4 (5): 342–359 ~ FULL TEXT During the past few decades numerous studies have been published on the efficacy of nutritional and botanical medicines in the prevention and treatment of ocular diseases, including macular degeneration, diabetic retinopathy, retinitis pigmentosa, cataracts, glaucoma, and others. Part One of this review will explore the research on diseases of the retina, including macular degeneration, retinopathy, and retinitis pigmentosa.    Part II: Cataracts and Glaucoma Alternative Medicine Review 2001 (Apr); 6 (2): 141–166 ~ FULL TEXT Part one of this article was published in the October 1999 issue of Alternative Medicine Review and discussed nutritional and botanical approaches to conditions of the retina. This second part covers alternative treatments for nonretinal disorders: senile cataracts, diabetic cataracts, and chronic open-angle glaucoma.

Thanks to   Pub Med
for their quality MEDLINE search tool!

Return to the NUTRITION Section

Since 1–01–1998

Updated 5-16-2022