Oxidative Stress and Dietary Antioxidants in Neurological Diseases

Oxidative stress is an underlying feature of neurological diseases like Alzheimer’s, Parkinson’s, and multiple sclerosis.

Dietary antioxidants can help combat oxidative stress, providing valuable tools for helping protect the brain against aging and disease.

Currently, there is a divide between physicians and clinical workers, on the one hand, and nutritionists and dietitians, on the other.

Physicians understand the processes in neurological disease and associated conditions but are less knowledgeable about the science of nutrition and dietetics.

Nutritionists and dietitians on the other hand aren’t as familiar with the molecular and cell science of neurological disease.

This divide needs to be bridged so that medical science can advance, and preventive and treatment strategies can be devised.

The book Oxidative Stress and Dietary Antioxidants in Neurological Diseases aims to help bridge that gap.

It provides a comprehensive overview of the role of oxidative stress in neurological diseases. Then it goes on to discuss the therapeutic use of antioxidants via diet and supplementation, to combat oxidative stress.

This evidence-based book brings together leading experts in this area to showcase cutting-edge research. It is sure to be an invaluable text for professionals working in the field, as well as for individuals who seek to take proactive steps for their health.

Here, Life Extension® highlights some of the key concepts from the book, that bring together both the basic processes involved in neurological disease—and nutrient strategies that aim to combat it.

Oxidative Stress and Neurological Diseases

Part I: Oxidative Stress and Neurological Diseases, covers the basic processes of oxidative imbalance, including topics such as molecular biology, blood-brain barrier, neuroinflammation, aging, neuroprotection, and other areas.

The body produces reactive, unstable agents known as free radicals during normal metabolism, and following exposure to environmental toxins. Antioxidants serve as natural antidotes to these free radicals. While internally produced antioxidants are abundant in youth, their levels decline with age.

The imbalance between free radicals and the antioxidants needed to inactivate, or “quench” them, leads to a generalized state of oxidative stress that can damage lipids, proteins, DNA, and mitochondria throughout the body.

The brain is particularly susceptible to oxidative damage because of its high rate of oxygen consumption. Numerous chapters in the book delve into studies showing that oxidative stress plays a critical role in the initiation and progression of neurodegenerative diseases such as Alzheimer’s, Parkinson’s, and Huntington’s, which are characterized by a slow, progressive loss of neurons.¹

Data from people with mild cognitive impairment provide evidence that oxidative stress usually precedes the development of Alzheimer’s disease.² Furthermore, alterations in the levels of antioxidants and antioxidant enzyme activities has been reported in Alzheimer’s disease and other neurodegenerative disorders.³

The book also details the impact of oxidative stress on the blood-brain barrier, the protective barrier that regulates the transport of molecules between the brain and the circulation.

Evidence has indicated that the breakdown of the blood-brain barrier is involved in the pathogenesis of neurodegenerative diseases like Parkinson’s disease, Alzheimer’s disease, ALS (amyotrophic lateral sclerosis), and MS (multiple sclerosis), as well as neurovascular disorders like stroke and vascular dementia.⁴

Oxidative stress in the brain also triggers neuroinflammation, another damaging factor often present during neurological disorders. In addition, aging itself is associated with a chronic state of inflammation known as inflammaging that has been associated with age-related neurological diseases.

The body has a natural signaling ability to ward off oxidative stress and neuroinflammation. But in neurological disease, pathways such as the endogenous antioxidant response pathway, and uncoupling pathway, are altered, preventing proper control of oxidative stress and neuroinflammation.

Antioxidant Therapy in Neurological Disorders

Part II: Antioxidants and Neurological Diseases, covers numerous antioxidants found in plants, vitamins, and various compounds that have been found to have therapeutic potential for various aspects of neurological disorders.

Antioxidants are beneficial because they delay or prevent oxidation. Because oxidative stress is well documented as a factor in the initiation and progression of neurological diseases and neurodegenerative disorders, it is rational to consider the use of antioxidants to help alleviate the negative effects of oxidative stress.

Antioxidant properties are found in dietary compounds such as polyphenols (flavonoids), beta-carotene, vitamin C, and vitamin E (alpha-tocopherol).

Epidemiological and clinical studies have demonstrated that polyphenols and flavonoids exert a protective effect against neurodegenerative diseases.⁵ And numerous studies have shown that diets that include fruitsand vegetables rich in antioxidants (such as carrots, blueberries, strawberries, and spinach) can produce a beneficial effect against age-related decline in cognitive functions in old rats.

The book features in-depth information on the following nutrients and compounds:

• Mediterranean oils like argan oil, olive oil, and milk thistle seed oil
• Aspidosperma pyrifolium Mart.
• Carnosic acid and carnosol
• Curcumin
• Ginkgo biloba
• Morinda citrifolia Linn. (Noni) fruit
• Naringin and naringenin
• Nigella sativa L. and thymoquinone
• Resveratrol
• Saffron
• Sulforaphane

Here, we will expound on two key nutrients discussed in the book: curcumin and ginkgo biloba.

Curcumin

Curcumin, the main, biologically active component of the spice turmeric, has well-documented antioxidant and anti-inflammatory properties.⁶

Studies have demonstrated that curcumin exerts antioxidant effects by scavenging free radicals, alleviating lipid peroxidation, modulating antioxidant defense systems such as catalase and SOD, activating the Nrf2 pathway, and more.

In one in vitro study, curcumin protected glial cells (important brain cells that make up the white matter in your brain) against oxidative stress and inflammation caused by numerous damaging toxins.⁷

Curcumin could also be a key agent in the treatment of Alzheimer’s disease.⁸ Both in vitro and in vivo studies have shown that curcumin improves cognitive decline and synaptic functions and restores synaptic plasticity.⁹

Through its antioxidant effect, curcumin therapy has been proven to have beneficial effects in additional neurodegenerative disorders such as Parkinson’s, Huntington’s, and multiple sclerosis.

In addition, studies have shown that curcumin can help:

• Alleviate anxiety and depression,¹⁰
• Improve cerebral ischemic injury,¹¹
• Protect the brain during traumatic brain injury,¹²
• Treat neuropathic pain,¹³ and
• Enhance memory and learning.¹⁴

Ginkgo Biloba

Ginkgo biloba extract is known to have antioxidant properties, making it ideal for combating the oxidative stress that contributes to neurotoxicity and dysfunction in the brain.

Ginkgo biloba contains natural flavonoids (such as quercetin) that are free-radical scavengers, and metal chelators, and that enhance cellular antioxidant systems.

Ginkgo biloba has been shown to exert its neuroprotective effects through mechanisms such as combating inflammation,¹⁵ improving blood flow, inhibiting amyloid-beta aggregation, regulating neurotransmitters, and improving mitochondrial function.

Mitochondria help turn energy from food into energy your cells can use. These cells are particularly vulnerable to attack by reactive oxygen species (ROS), which leads to mitochondrial dysfunction.

These mitochondrial changes in the brain can contribute to the impairment of synaptic function and neuronal loss that manifests as cognitive deficits in oxidative stress-related neurodegenerative diseases such as Alzheimer’s disease.

Studies show that ginkgo biloba extract exerts protective effects against mitochondrial oxidative injury, helping maintain mitochondrial function.¹⁶

Summary

Oxidative stress is a feature of neurological disease and other associated conditions. It can arise due to molecular and cellular processes, or as a result of nutritional imbalances, either before the onset of disease or during its development.

Oxidative Stress and Dietary Antioxidants in Neurological Diseases provides a comprehensive overview of oxidative stress in neurological diseases, as well as the potentially therapeutic uses of natural antioxidants such as curcumin, ginkgo biloba, and others.

Since diseases are often multifactorial, the book does not describe oxidative stress in isolation, but in concert with other processes such as apoptosis, cell signaling, receptor-mediated responses, and others.

In the forward to the book, Professor Una Macleod, Dean of the Hull York Medical School and Professor of Primary Care Medicine, in the United Kingdom, writes, “Oxidative stress, antioxidant status and function, and the impact of dietary antioxidants within the context of neurological disease represent an exciting area of research which may ultimately contribute to improved quality of life in those experiencing neurological disease, particularly as the area matures and penetrates direct clinical care more extensively than at present.”

The book was designed for nutritionists, dietitians, food scientists, physicians and clinical workers, neurologists, healthcare workers, and research scientists.

We believe informed Life Extension® readers will also benefit from this comprehensive look at neurological diseases, as it provides both the background knowledge and specific practical applications for protecting against brain aging and neurodegeneration.

If you have any questions on the scientific content of this article, please call a Life Extension Wellness Specialist at 1-866-864-3027.

References

1. Kim GH, Kim JE, Rhie SJ, Yoon S. The role of oxidative stress in neurodegenerative diseases. Exp Neurobiol 2015:24(4):325-40.
2. Tramutola A, Lanzillotta C, Perluigi M, Butterfield DA. Oxidative stress, protein modification and Alzheimer’s disease. Brain Res Bull 2017;133:88-96.
3. Wang X, Wang @, Li L, Perry G, Lee H-g, Zhu X. Oxidative stress and mitochondrial dysfunction in Alzheimer’s disease. Biochim Biophys Acta (BBA)—Mol Basis Dis 2014;1842(8):1240-7.
4. Tramutola A, Lanzillotta C, Perluigi M, Butterfield DA. Oxidative stress, protein modification and Alzheimer’s disease. Brain Res Bull 2017;133:88-96.
5. Samieri C. Epidemilogy and risk factors of Alzheimer’s disease: a focus on diet. In: Biomarkers for preclinical Alzheimer’s disease. Springer; 2018. p. 15-42.
6. Hewlings SJ, Kalman DS. Curcumin: a review of its effects on human health. Foods 2017;6(10):92.
7. Parada E, Buendia I, Navarro E, Avendano C, Egea J, Lopez MG. Microglial HO-1 induction by curcumin provides antioxidant, antineuroinflammatory, and glioprotective effects. Mol Nutr Food Res 2015;59(9):1690-700.
8. Mukhopadhyay C, Ruidas B, Chaudhury S. Role of curcumin in treatment of Alzheimer’s disease. Int J Neurorehabil 2017:4:3.
9. Brondino N, Fusar-Poli L, Panisi C, Politi P. Potential neuroprotective effects of curcumin against dementia. In: Neuroprotective effects of phytochemical in neurological disorders. Hoboken, New Jersey: John Wiley & Sons, Inc; 2017. P. 435-46.
10. Chimakurthy J, Talasila M. Effects of curcumin on pentylenetetrazole-induced anxiety-like behaviors and associated changes in cognition and monoamine levels. Psychol Neurosci 2010;3(2):267-76.
11. Huang L, Chen C, Zhang X, Li X, Chen Z, Yang C, et al. Neuroprotective effect of curcumin against cerebral ischemia-reperfusion via mediating autophagy and inflammation. J Mol Neurosci 2018:64(1):129-39.
12. Dai W, Wang H, Fang J, Zhu Y, Zhou J, Wang X, et al. Curcumin provides neuroprotection in model of traumatic brain injury via the Nrf2-ARE signaling pathway. Brain Res Bull 2018;346:28-36.
13. Zhu X, Li Q, Chang R, Yang D, Song Z, Guo Q, et al. Curcumin alleviates neuropathic pain by inhibiting p300/CBP histone acetyltransferase activity-regulated expression of BDNF and cox-2 in a rat model. PLoS One 2014;9.
14. Nam SM, Choi JH, Yoo DY, Kim W, Jung HY, Kim JW, et al. Effects of curcumin (Curcuma longa) on learning and spatial memory as well as cell proliferation and neuroblast differentiation in adult and aged mice by upregulating brain-derived neurotrophic factor and CREB signaling. J Med Food 2014;17:641-9.
15. Kim M-S, Bang JH, Lee J, Han J-S, Baik TG, Jeon WK. Ginkgo biloba L. extract protects against chronic cerebral hypoperfusion by modulating neuroinflammation and the cholinergic system. Phytomedicine 2016; 23(12):1356-64.
16. Sastre J, Millan A, de la Asuncion JG, et al. A Ginkgo biloba extract (EGb 761) prevents cmitochondrial aging by protecting against oxidative stress. Free Radic Biol Med 1998:24(2):298-304.