The nervous system is a complex system that regulates and coordinates body functions, including the coordination of muscles, the senses, speech, memory, thought and emotion. Nervous system health, especially brain health, becomes a common concern as we age. As we get older, physical changes occur in the brain that can lead to cognitive decline, including a decrease in levels of neurotransmitters such as acetylcholine, which plays a large role in memory and learning.1 Other factors that can adversely affect cognitive health include alcohol abuse, chronic inflammation, vascular diseases and stress.1
It is estimated that up to one-third of adults will suffer from mild cognitive impairment, a gradual decline in cognitive function characterized by slow thinking and a reduced ability to learn as they age.1 Dementia is a type of cognitive impairment that decreases the ability to carry out everyday activities. Alzheimer’s disease is the most common cause of dementia among people age 65 and older.2 It is characterized by a progressive impairment of memory that results in serious loss of memory, thinking and language skills and behavioral changes that can prevent a person from living independently.2 It is believed that Alzheimer’s is caused by an accumulation of beta-amyloid protein in the brain, which damages nerve cells.3
Memory loss and forgetfulness can be a normal part of aging. However, scientists have discovered that healthy older people can do as well as younger people on memory and learning tests.4 Studies show that a lack of certain dietary nutrients can contribute to the development of mental disorders.5 Good nutrition and dietary supplements can support mental and nervous system health.
Lecithin is a rich source of phospholipids, including phosphatidylserine, phosphatidylcholine, phsphatidylethanolamine and phosphatidylinositol.6 Phospholipids help maintain healthy nerve cell membranes.7 Research has found that people with Alzheimer’s and age-related memory impairment have altered phospholipid compositions in the brain, and that the changes in neurotransmitter functioning in people with cognitive dysfunction may be attributed to these low levels of brain phosphlipids.6,7,8 Phosphatidylserine is the most abundant phospholipid in the human brain.6 Research indicates that phosphatidylserine levels in the brain may decrease with age.6 Studies show that supplementing with phosphatidylserine can improve cognitive function.6
Essential fatty acids such as those found in fish oil, krill oil, flaxseed oil (omega-3 fatty acids) and in evening primrose oil and borage oil (omega-6 fatty acids) play a key role in nervous system health and normal brain function.9 DHA (docosahexaenoic acid), an essential omega-3 fatty acid found in fish oil is highly concentrated in the brain (30% of brain gray matter is DHA).6 DHA also appears to promote the accumulation of phosphatidylserine in cell membranes.6 Alzheimer’s patients have lower cellular levels of DHA than control groups.10 Overall, lower levels of brain DHA is associated with cognitive impairment.10
Studies indicate that huperzine A (derived from Chinese club moss) may be beneficial for cognitive dysfunction and memory impairment.6 Huperzine A has been found to inhibit the enzyme acetylcholinesterase (AChE, which is responsible for breaking down acetylcholine. Acetylcholine is a neurotransmitter that is believed to be involved in learning, memory and mood. Alzheimer’s disease has been associated with low levels of acetylcholine in the brain.11 By inhibiting AChE, huperzine A increases levels of acetylcholine in the brain.12
B vitamins are important for healthy nervous system function. For example, vitamin B6 is required for the body to make neurotransmitters including dopamine, serotonin and norepinephrine.9 Vitamin B12 is vital for maintaining healthy nerve cells.13 Deficiencies of B vitamins can cause dementia if not corrected.14 Elevated levels of homocysteine have been associated with increased risk of developing Alzheimer’s disease and vascular dementia.15 It has been discovered that folic acid, vitamin B12 and B6 help to lower homocysteine levels.6
Animal studies have suggested that diets high in antioxidants can delay age-related memory loss.16 Alpha lipoic acid is a potent antioxidant and has been found to protect nerve cells.12 It has been approved in Germany for the treatment of neuropathy.12 Alpha lipoic acid is fat-soluble and can cross the blood–brain barrier.12 There is some evidence that alpha lipoic acid may be helpful for certain neurodegenerative conditions.12
According to many studies, supplementing with ginkgo biloba may improve cognitive function and memory.6 Ginkgo flavonoids have antioxidant actions and have been found in studies to protect nerve cells from oxidative damage.6 Ginkgo’s positive effects on cognitive function may also be attributed to ginkgo’s ability to improve circulation throughout the body, including in the central nervous system.6
1. Life Extension Foundation. Mild Cognitive Impairment. 1995-2010. Available at: http://www.lef.org/protocols/neurological/mild_cognitive_impairment_01.htm
2. Alzheimer’s Foundation of America. About Alzheimer’s. 2010. Available at: http://www.alzfdn.org/AboutAlzheimers/definition.html
3. MedicineNet.com. Alzheimer’s Disease. 1996-2010. Available at: http://www.medicinenet.com/alzheimers_disease/article.htm
4. National Institute on Aging. Forgetfulness: Knowing When to Ask For Help. 2010. Available at: http://www.nia.nih.gov/HealthInformation/Publications/forgetfulness.htm
5. Lakhan S.E., Vieira K.F. Nutrition Journal. Nutritional Therapies for Mental Disorders. 2008. Available at: http://www.nutritionj.com/content/7/1/2 Accessed October 26, 2009.
6. Jellin JM, Gregory PJ, Batz F, Hitchens K, et al. Pharmacist’s Letter/Prescriber’s Letter Natural Medicines Comprehensive Database. Stockton, CA: Therapeutic Research Faculty; 2010. [Online Database)
7. Wells K, Farooqui AA, Liss L, Horrocks LA. Neural membrane phospholipids in Alzheimer’s disease. Neurochem Res. 1995 Nov;20(11):1329-33. Available at: http://www.ncbi.nlm.nih.gov/pubmed/8786819
8. Prasad MR, Lovell MA, Yatin M, Dhillon H, Markesbery WR. Regional membrane phospholipid alterations in Alzheimer's disease. Neurochem Res. 1998 Jan;23(1):81-8. Available at: http://www.ncbi.nlm.nih.gov/pubmed/9482271
9. University of Maryland Medical Center. Attention Deficit Hyperactivity Disorder. 2009. Available at: http://www.umm.edu/altmed/articles/attention-deficit-000017.htm Accessed October 14, 2009.
10. Lipids. 2000 Dec;35(12):1305-12.
11. Linus Pauling Institute. Micronutrient Information Center: Choline. 2000-2010. Available at: http://lpi.oregonstate.edu/infocenter/othernuts/choline/
12. Hendler SS Ph.D., M.D., Rorvik D M.S. PDR for Nutritional Supplements. 1st ed. New Jersey: Medical Economics Company, Inc.; 2001.
13. University of Maryland Medical Center. Vitamin B12 (cobalamin). 2009. Available at: http://www.umm.edu/altmed/articles/vitamin-b12-000332.htm Accessed October 14, 2009.
14. WebMD:EMedicineHealth. Dementia Overview. 2010. Available at: http://www.emedicinehealth.com/dementia_overview/page2_em.htm
15. MedicineNet.com. Dementia. 1996-2010. Available at: http://www.medicinenet.com/dementia/page9.htm
16. Nutrition, brain aging, and neurodegeneration. Joseph J, Cole G, Head E, Ingram D. J Neurosci. 2009 Oct 14;29(41):12795-801. Available at: http://www.ncbi.nlm.nih.gov/pubmed/19828791 and http://www.jneurosci.org/cgi/content/full/29/41/12795