Vitamin E: A New Perspective in Nutrition and Health

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Vitamin E capsules

Introduction

Vitamin E consists of a family of eight different compounds, four tocopherols and four tocotrienols (designated as alpha, beta, gamma and delta). Tocopherols and tocotrienols have similarities and differences in their molecules. The tocopherols consist of a head (chroman ring) and a tail (phytyl). The chroman ring carries the active antioxidant group. Each tocotrienol has an identical chroman ring as the corresponding tocopherol. Tocotrienols differ from tocopherols on their tail; the tocotrienols have three unsaturated sites while tocopherols have none. Our food contains all eight compounds. In many countries, including the United States, the typical diet supplies higher levels of non alpha tocopherols, especially gamma-tocopherol. In the past vitamin E became synonymous with only alpha-tocopherol and, as a result, alpha-tocopherol is the most commonly form used in food fortification, supplements and, most important, in the human clinical trials.

Natural vs. synthetic. alpha-Tocopherol is available commercially in the naturally occurring and the synthetic forms. For most vitamins, the synthetic forms are identical to the natural and have identical function in the body. Not so for alpha-tocopherol. All molecules in the naturally occurring d-alpha-tocopherol are identical. In contrast, the synthetic dl-alpha-tocopherol is a mixture of eight different molecular entities known as stereoisomers. Of these eight, only one is identical to the natural form. The other seven do not exist in nature. The potency advantage of the natural d-alpha-tocopherol is officially recognized by the Food and Drug Administration (FDA), the World Health Organization (WHO) and the United States Pharmacopoeia (USP). The natural form was recognized as 36 percent more potent than the synthetic. Studies in humans using powerful new techniques confirmed that the natural d-alpha-tocopherol is twice as bioavailable than of the synthetic. Based on extensive research, the Food and Nutrition Board of the National Academy of Sciences recommended that the biopotency of the natural d-alpha-tocopherol is twice as that of the synthetic dl form.

The recent controversy. Human blood and tissue contain much more alpha-tocopherol than any of the other tocopherols and tocotrienols as results of a specific transfer mechanism. At the heart of this mechanism is the alpha-tocopherol transfer protein which recognizes the alpha-tocopherol and preferentially puts more of it in the blood. Conclusive evidence showed that supplementation with alpha-tocopherol, especially at high levels, causes depletion of gamma-tocopherol and probably of the other tocopherols in the blood and the tissues. The major significance of this depletion on the efficacy of vitamin E received increased attention following results of major human clinical studies such as the Selenium and Vitamin E Cancer Prevention Trial (SELECT) and the Heart Outcomes Prevention Evaluation (HOPE) Study and several metaanalyses. As a result the efficacy and even the safety of supplemental vitamin E as alpha-tocopherol were questioned. These results, coupled with increasing, research based, understanding of the role of the other tocopherols and the tocotrienols in nutrition and health, contributed to the emerging perspective on vitamin E.

Emerging research

Significant ongoing research shows that tocopherols and tocotrienols and probably their bioactive metabolites, exhibit individually and in combination, responses that are different that those of alpha-tocopherol. These responses, which include inflammation, cell signaling and gene expression, and tumor cell specific toxicity and apoptosis, support the emerging perspective that only the complete family of tocopherols and tocotrienols provides the full potential of vitamin E to produce nutritional and health benefits.

Below is a brief summary of significant findings on the role of gamma-tocopherol and the tocotrienols.

gamma-Tocopherol

The research team of Dr. Bruce Ames at Berkeley University reported that gamma-tocopherol is more effective than alpha in quenching nitrogen radicals which contribute to inflammation and chronic disease. gamma-Tocopherol but not alpha increased cNOS protein expression. gamma-Tocopherol and its major metabolite reduced synthesis of the inflammatory prostaglandin E2 (PGE2) in both lipopolysaccharide-stimulated macrophages and IL-1b-treated human epithelial cells. In contrast, alpha-tocopherol reduced slightly PGE2 formation in macrophages, but had no effect in epithelial cells. The corresponding metabolite of alpha-tocopherol was not active. Our research indicated that gamma-tocopherol, added to a semi-purified diet, was more effective than alpha-tocopherol in reducing ras-p21 oncogenes in the colonocyte of rats. Phase I clinical studies are evaluating the role of gamma-tocopherol on colon and prostate cancer.

The anti-inflammatory properties of gamma-tocopherol were evaluated further in a collaborative research by the University of North Carolina, Michigan State, Berkeley and Purdue Universities and funded by the National Institutes of Heath. They conducted studies with mice and humans and evaluated a number of inflammatory markers associates. The results showed that gamma-tocopherol reduced systemic oxidative stress and inhibited important inflammatory pathways associated with allergic rhinitis and asthma. These included eosinophil infiltration, pulmonary production of PGE2, leukotriene B4 receptor (LTB4) and cysteinyl leukotrienes, and nasal expression of interleukins IL-4, -5, -13 and Interferon-gamma (IFN-γ). The researchers suggested that their results support therapeutic efficacy of gamma-tocopherol to inhibit ozone exacerbation of allergic airway responses.

Tocotrienols

Radioprotection. Dr. Sree Kumar of the Armed Forces Radiobiology Research Institute, Uniformed Services University of the Health Sciences and Martin Hauer-Jensen MD of the Winthrop P Rockefeller Cancer Institute at the University of Arkansas for Medical Sciences reported that gamma-tocotrienol exhibits major protection to radiation exposure. It functions as an inhibitor of HMG-CoA reductase (the key enzyme in LDL cholesterol synthesis), which prevents the depletion of the nitric oxide synthase (NOS) cofactor BH4. Impaired function of NOS produces excessive free radicals which damage the tissue. Additional research showed that both gamma and delta tocotrienols reduce injury to bone marrow and hematopoietic system and stimulate hematopoiesis. These findings have major implications not only in protection to major radiation exposure to nuclear accident or attack but also in radiation therapy and wound healing.

Cancer. Several researcher groups reported effects of tocotrienols on mechanisms carcinogenesis. Significant effects, primarily of gamma and delta tocotrienols on breast, prostate, colon and pancreatic cancers included caspase dependent and independent apoptosis, angiogenesis, inflammation and signal transduction mechanisms. A human clinical study is evaluating the role of delta-tocotrienol in pancreatic cancer.

Neuroprotection. The research team of Dr. Chandan Sen of the Ohio State University Medical Center reported that alpha-tocotrienol inhibits glutamate-induced activation of phospholipase A2 which results in neuroprotection with major implications for neurodegenetative diseases and stroke. Dr. Sen is conducting a Phase I clinical trial on the human tissue distribution of orally supplemented natural vitamin e tocotrienol, which will provide data for additional clinical studies.

Cardiovascular. The function of gamma-tocopherol as an inhibitor of HMG-CoA reductase (the key enzyme in LDL cholesterol synthesis) and its relationship to the nitric oxide synthase (NOS) cofactor BH4 and inflammation support observations on cardiovascular benefits of tocotrienols. A Phase II Double Blind Placebo Controlled Study is currently evaluating the neuroprotective and anti-atherogenic effects of palm tocotrienol rich fraction

Wound healing, burn injury and surgical scars. The protective effects of tocotrienols on radiation injury and other mechanisms of action suggest benefits in wound healing, burn injury and surgical scars. A clinical study at Ohio State University is evaluating the efficacy of tocotrienols on the treatment of surgical scars.

Summary and Conclusions

The emerging research on the unique individual effects of tocopherols and tocotrienols, coupled with the strong evidence of synergistic effects and epidemiological and other data suggesting health benefits of vitamin E especially from diet indicate that:

  1. The use of alpha-tocopherol and often the synthetic dl-form contributed to the absence of clinical benefit in major clinical studies by:
    1. Providing the form that may not be the most beneficial for the specific application.
    2. Causing the depletion of the other tocopherols and tocotrienols from the blood and the tissue thus causing an adverse imbalance and eliminating their benefits and synergies.
  2. The proven synergistic effects of tocopherols and tocotrienols and their unique individual effects indicate that vitamin E supplements should contain the complete family of tocopherols plus tocotrienols. Additional tocotrienols and/or non-alpha tocopherols may be appropriate for people with special needs and at high risk for certain disease conditions.
  3. The development of nutritional and health guidelines and products such as dietary supplements and health products specific for specific diseases or health conditions must consider all vitamin E homologs and bioactive metabolites, and their individual and combined effects in relation to their absorption, metabolism and tissue uptake.

Recommendations

The emerging scientific consensus and perspective on vitamin E indicates that only products that contain the complete vitamin E family – of tocopherols plus tocotrienols in their natural form provide the full spectrum of benefits.

Specially formulated products rich on the specific active homologs can play a significant role in health programs for major disease conditions such as neurodegenerative, immune / inflammatory, some cancers and cardiovascular.

The protection of gamma and delta-tocotrienols against radiation injury and associated mechanisms of actions and research, support benefits in skin heath, wound healing, burn injury and surgical cars. The antioxidant properties of tocopherols and tocotrienols, couples with the unique functions reviewed above suggest a major role in anti-aging programs.

Unique E Mixed Tocopherols, Unique E Tocotrienols, Unique Omega E+

A. C. Grace Company has 50+ years of history providing pure vitamin E products to the market and was the first company to introduce a high gamma-tocopherol mixed tocopherols (in 1962) when most companies were offering alpha-tocopherols only products.

Five decades later, this premier E product is still considered the best in the industry by tens-of-thousands of healthcare professionals, scientists and health-conscious consumers.

UNIQUE E® Mixed Tocopherols Concentrate – the highest concentration of the complete Vitamin E tocopherol complex – HIGH-gamma-tocopherol, with alpha, beta and delta isomers – completely void of fillers or additives that can turn rancid. The proprietary formula of concentrated tocopherols is specifically designed to provide the highest biological activity and maximum synergistic benefits of the all-natural complex. (In softgel form and 1-ounce pump liquid form.)

UNIQUE E® Tocotrienols – High-Delta and Gamma Delta-Gold® Tocotrienols derived from the Annatto plant contain the highest concentrates of tocotrienols at 125 mg per softgel capsule. Unlike products derived from palm or rice bran oil, Annatto tocotrienols contain no alpha-tocopherol – which has been shown to inhibit assimilation of tocotrienols in the body.

UNIQUE OMEGA E+® – Unique, comprehensive approach to cardiovascular health and healthy blood pressure. Designed by leading nutrition and medical experts in collaboration with the Hypertension Institute of Nashville, UNIQUE OMEGA E+® provides a novel, strategic formulation of omega-3 fatty acids with natural, safe compounds that accentuate and expand its benefits. This unique formulation supplies:

  • Marine omega-3 fatty acids in their natural triglyceride form processed in state of the art facility for quality and purity.
  • Vitamin E as natural tocopherols rich in gamma-tocopherol plus tocotrienols.
  • CoQ10 specially formulated for enhanced absorption.
  • Vitamin D3 specially formulated for enhanced absorption.
  • Natural carotenoids rich in lycopene and astaxanthin.

UNIQUE OMEGA E+® is specially formulated for enhanced absorption and bioavailability. Balanced inflammatory responses, improved lipid profile, and strong wide-spectrum antioxidant protection support cardiovascular health and normal blood pressure.

For more information go to www.acgrace.com

Selected References

Papas, A. The Vitamin E Factor, HarperCollins Publishers, New York, 416 pages, 1999

Lippman SM, et al. Effect of selenium and vitamin E on risk of prostate cancer and other cancers: the Selenium and Vitamin E Cancer Prevention Trial (SELECT). JAMA. 2009;301:39-51.

Yusuf S, et al. Vitamin E supplementation and cardiovascular events in high-risk patients. The Heart Outcomes Prevention Evaluation Study Investigators. N Engl J Med 2000;342:154-60.

Cooney R, et al. Gamma-tocopherol detoxification of nitrogen dioxide: superiority to alpha-tocopherol. Proc Natl Acad Sci U S A 1993;90:1771-1775.

Jiang, et al. gamma-Tocopherol and its major metabolite, in contrast to alpha-tocopherol, inhibit cyclooxygenase activity in macrophages and epithelial cells. Proc Natl Acad Sci U S A. 2000;97:11494-11499.

Gao R, et al. The uptake of tocopherols by RAW 264.7 macrophages. Nutr J. 2002;1:2.

Campbell S, et al. Development of gamma (gamma)-tocopherol as a colorectal cancer chemopreventive agent. Crit Rev Oncol Hematol. 2003;47:249-59.

Sylvester PW, et al. The value of tocotrienols in the prevention and treatment of cancer. J Am Coll Nutr. 2010 (3 Suppl):324S-333S.

Ju J, et al. Cancer-preventive activities of tocopherols and tocotrienols. Carcinogenesis. 2010;31:533-42.

Constantinou C, et al. Induction of caspase-independent programmed cell death by vitamin E natural homologs and synthetic derivatives. Nutr Cancer. 2009;61:864-74.

Kumar KS, et al. Preferential radiation sensitization of prostate cancer in nude mice by nutraceutical antioxidant gamma-tocotrienol. Life Sci. 2006;78:2099-104.

Wagner JG, et al. Gamma-tocopherol attenuates ozone-induced exacerbation of allergic rhinosinusitis in rats. Toxicol Pathol. 2009;37:481-91.

Wiser J. In vivo gamma-tocopherol supplementation decreases systemic oxidative stress and cytokine responses of human monocytes in normal and asthmatic subjects. Free Radic Biol Med. 2008;45:40-9.

Wagner JG, et al. Gamma-tocopherol prevents airway eosinophilia and mucous cell hyperplasia in experimentally induced allergic rhinitis and asthma. Clin Exp Allergy. 2008;38:501-11.

Wagner JG, et al.Ozone enhancement of lower airway allergic inflammation is prevented by gamma-tocopherol. Free Radic Biol Med. 2007;43:1176-88.

Constantinou C, et al. induction of caspase-independent programmed cell death by vitamin E natural homologs and synthetic derivatives. Nutrition and Cancer 61, 864-874, 2009.

Kulkarni S, Gamma-tocotrienol protects hematopoietic stem and progenitor cells in mice after total-body irradiation. Radiat Res. 2010;173:738-47.

Berbée M, et al. gamma-Tocotrienol ameliorates intestinal radiation injury and reduces vascular oxidative stress after total-body irradiation by an HMG-CoA reductase-dependent mechanism. Radiat Res. 2009;171:596-605.

Khanna S, Molecular basis of vitamin E action: tocotrienol modulates 12-lipoxygenase, a key mediator of glutamate-induced neurodegeneration. J Biol Chem. 2003;278:43508-15.

Sen CK, et al. Tocotrienols in health and disease: the other half of the natural vitamin E family. Mol Aspects Med. 2007;28:692-728.

ClinicalTrials.gov Identifier NCT00700791. Efficacy of Natural Vitamin E Tocotrienol on the Treatment of Surgical Scars.

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