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Thursday, October 1, 2009

Improving and Protecting Memory

Memory is a complicated neurological process and our understanding has progressed rapidly over the last thirty years. Studies have shown associations between environmental factors and the brain’s ability to encode, store and retrieve information. Experts now understand how sleep, exercise, diet, botanical medicine and stress management can improve and protect memory.

Sleep

Sufficient sleep before and after learning is an essential element in committing new information to memory. In 2007, Harvard researchers examined the effects of sleep deprivation after new experiences. The study compared people who got enough sleep the night before learning new information to those who got insufficient sleep. Individuals who didn’t sleep enough had a compromised ability to remember the information they had learned. Even a single night of sleep deprivation caused impairment in the hippocampus, part of the brain’s limbic system that is responsible for encoding information to form new memories.

Physical Exercise

During physical activity, the movement of muscles increases circulation throughout the body. Regular aerobic exercise improves blood flow to the brain and strengthens the cardiovascular system, reducing the risk of deficits in memory and stroke (loss of neurological function following blood loss to the brain).

All physical activity can support a healthy memory, so the best exercise is one that you enjoy and practice often. However, some activities offer benefits besides better memory. Researchers at the McGill University in Montreal studied the health effects of tango dancing on thirty adults between the ages of 68 and 99 years. Half the participants joined a walking program and the other half took lessons for tango, a dance involving a series of complex movements. Both groups improved their scores on memory tests, but the tango dancers also experienced improved self-esteem, balance, coordination and multi-tasking ability.

Mental Exercise

When it comes to memory, mental exercise is as important as physical exercise. Older adults who read, play games, solve puzzles, take classes and learn new things have better memories than those who do not. The more you use your memory, the longer you will enjoy it, so spend at least 10 to 15 minutes every day exercising your brain.

Nutrition

Crucial constituents of brain cells, omega-3 fats like docosahexaenoic acid (DHA) are one of the most important nutrients for memory. Researchers have found that fish, the best source of DHA, is especially good at reducing risk of Alzheimer’s disease and slowing age-related cognitive decline. Many fish are contaminated with mercury and other hazardous pollutants, but in general, species with the lowest levels of toxins and the highest concentrations of DHA include wild salmon, herring, sardines and anchovies. To find the best choices in your area, search the Monterey Bay Aquarium’s Seafood Watch website: www.montereybayaquarium.org/cr/seafoodwatch.aspx. Raw nuts and seeds, including ground flax seed and borage oil, are good sources of omega-3 fats, but they do not contain DHA.

Other nutrients also play key roles in preserving memory. Antioxidants like vitamins C and E protect brain cells against damage from free radicals (reactive oxygen molecules). Studies have shown that flavonoids and polyphenols found in berries can prevent and reverse age-related cognitive decline. B vitamins are necessary for the production of neurotransmitters (chemical messengers in the brain) and myelin (a sheath around brain cells that facilitates cell-to-cell communication). B vitamins are also required for the to body eliminate homocysteine. This amino acid has been linked to Alzheimer’s disease and stroke (common causes of memory loss), as well as heart attack.

Colorful fruits and vegetables are the best source of these necessary nutrients. Choices that are especially good for brain health include blueberries, blackberries, black currants, strawberries, beans, peas, citrus fruit, spinach, kale, and dark green leafy vegetables like dandelion, mustard, beet, collard and turnip greens.

Botanical Medicine

Ginkgo biloba has been used as a medicine for thousands of years and studies have confirmed its cardiovascular benefits. In individuals with compromised circulation, it can improve memory by increasing blood flow to the brain. Evidence has shown that it can also slow certain types of dementia involving memory loss. In 2005, researchers in Poland studied twenty-seven adults with dementia related to Alzheimer’s disease, vascular dementia, or both. They were given Ginkgo extract for six months. The herb was well-tolerated and none of the participants showed loss of cognitive function.

Gingko biloba can increase the risk of bleeding, interfere with some medications, and at high doses, cause side effects like gastrointestinal upset and headaches. Individuals interested in taking Ginkgo should seek guidance from a doctor trained in botanical medicine.

Stress Management

Stress can have a negative affect on memory. Elevated levels of adrenal stress hormones called glucocorticoids can damage the memory center of the brain, the hippocampus. All cells need glucose to function, including brain cells responsible for memory. Glucocorticoids can inhibit the transport of glucose into hippocampal memory neurons. In 1991, researchers at Stanford University found that memory can be affected when stress hormones are elevated for four hours or longer.

Some acute stress is good, like preparing for an important speech or running a race. But when stress is chronic, it increases the risk of high blood pressure and cardiovascular disease, conditions that can lead to stoke and memory loss. Managing stress can be an important part of preserving memory and several effective options exist: exercise, yoga, meditation, breathing exercises, progressive muscle relaxation, and qi gong, among others.

Other Factors

While memory loss may be a normal part of aging, it may also be related to other factors, like Alzheimer’s disease, stroke, infection, head trauma or alcoholism. Individuals affected by these conditions, and those who suspect they may be, should talk to their doctors about treatment. These underlying causes of illness must be addressed before memory loss can improve.

REFERENCES

Bidzan L et al. [Preliminary assessment of ginkgo biloba (Ginkofar) in patients with dementia]. Psychiatr Pol. 2005 May-Jun;39(3):559-66.

Farooqui T and Farooqui AA. Aging: an important factor for the pathogenesis of neurodegenerative diseases. Mech Ageing Dev. 2009 Apr;130(4):203-15. Epub 2008 Nov 21.

McKinley P et al. Effect of a community-based Argentine tango dance program on functional balance and confidence in older adults. J Aging Phys Act. 2008 Oct;16(4):435-53.

Virgin CE Jr et al. Glucocorticoids inhibit glucose transport and glutamate uptake in hippocampal astrocytes: implications for glucocorticoid neurotoxicity. J Neurochem. 1991 Oct;57(4):1422-8.

Yoo SS et al. A deficit in the ability to form new human memories without sleep. Nat Neurosci. 2007 Mar;10(3):385-92. Epub 2007 Feb 11.