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Exercise, Nutrition, Dental Health
Factors Relating to Healthy Aging and Preservation of Cognitive Function
Nutrition Factors
Nutrition is important for overall health in older adults, providing the fuel to maintain health of all body parts, including the brain. While there is no conclusive evidence that any nutrients can prevent the onset of dementia, there is evidence that some nutrients may show a correlation to cognitive function. It should be noted, however, that even though there may be a correlation between levels of certain nutrients and onset of dementia or cognitive decline, that does not necessarily indicate that there is a nutrient deficiency. Nutrition interactions are incredibly complicated and the reasons for an association can range from poor absorption, changing metabolism from nutrient imbalances, or even an alteration caused by the disease that results in changing levels of a nutrient.
Before discussing specific nutrients, it is important to note that one of the best things a person can do nutrition wise to avoid problems of aging, including onset of dementia, is to maintain a healthy weight and consume an overall healthy diet. Abdominal fat is being linked to dementia, and poor heart health (which, as most people know, involves diet as a risk factor) is also correlated with Alzheimer's and other types of dementia. Of course, exercise also helps in this area - see the article below for more information.
In regards to specific nutrients, antioxidants, omega-3 fatty acids, and folate, vitamin B12 and other B vitamins are some of the nutrients being investigated for their contribution to cognition and prevention of dementia in older adults, but study results have been inconclusive, with no evidence that concretely show delay or prevention of dementia for most nutrients studied. Some studies with folate have shown interesting results, however, with some research showing that if individuals with low folate levels increase their intake of this nutrient, there may be improvement on some cognitive tests.
Individuals should remember that folate intake should be considered as part of a balanced diet. It is recommended that a diet provide a wide variety of healthy foods for optimal nutritional efficiency. A diet containing high levels of vegetables and fruits, along with adequate amounts of whole grains, low fat dairy products, lean protein choices, and healthy fats is recommended. The recommended dietary allowance for folate for adults is 400micrograms per day. Some foods high in folate include beans, spinach and other greens, romaine lettuce, tomatoes, oranges, and other fruits and vegetables, and folic acid ( a form of folate) fortified foods
It should also be noted that folate has interrelationships with vitamin B12, found in animal foods. If a person chooses to supplement folate to high levels while having low intakes of vitamin B12, they can mask the B12 deficiency and make problems worse. Intake of folate should not exceed 1000 micrograms/day. Vegetarians or others who do not normally consume adequate amounts of meat, fish, poultry, milk, or eggs, should be sure to obtain adequate levels of B12 through supplementation.(The RDA for B12 for adults is 2.4 micrograms per day.)
For good information on general nutrition, look up the website www.mypyramid.gov. For information on specific nutrient values in food, the following website from the USDA is a valuable resource. www.nal.usda.gov/fnic/foodcomp/search/. This site is great for giving more detailed information than can be found on nutrition labels, and is helpful for determining the nutritive value of fresh foods that do not have nutrition labels.
While obtaining good nutrition through the diet is important, we realize that not everybody eats right all the time, and for older adults, absorption of some nutrients declines. If you feel that your diet may not always provide optimal nutrition, taking a multivitamin that provides the recommended dietary allowances for vitamins and minerals for your age group may be a good idea. Consuming high levels of individual nutrients may not be advised. If you have questions about your diet or about what supplements you should take, a talk to your health care provider or a registered dietitian may help. It may also be advised if you have special needs to inquire whether the professional you call is knowledgeable in that area.
For obtaining information on supplements and on vitamins and minerals in general, we recommend the website from the National Institutes of Health (NIH) - dietary-supplements.info.nih.gov/ They have excellent information about what supplements do (including information on the action of higher doses of vitamins and minerals), what levels are safe, and discussions on specific nutrition needs of older adults
References
The following are references for anyone interested in further information on the relation of folate to cognition and dementia development.
Durga, J. et al. (2007). Effect of 3-year folic acid supplementation on cognitive function in older adults in the FACIT trial: a randomized, double blind, controlled trial. Lancet 369, 208--216.
Middleton, L.E., Kirkland, S.A., Maxwell, C.J., Hogan, D.B., & Rockwood, K. (2007). Exercise: A potential contributing factor to the relationship between folate and dementia. Journal of the American Geriatrics Society 55, 1095-1098.
Morris, M.S., Jacques, P.F., Rosenberg, I.H., & Selhub, J. (2007). Folate and vitamin B-12 status in relation to anemia, macrocytosis, and cognitive impairment in older Americans in the age of folic acid fortification. American Journal of Clinical Nutrition 85, 193-200.
Exercise Factors
Research is ongoing regarding the role of exercise to cognition and delay of dementia in older adults, but some general results are showing up.
What about the APOE e4 gene?
The role of exercise may be particularly helpful for anyone carrying the APOE-e4 genotype. This gene is related to about 40 - 50% of Alzheimer's cases. If a person has a strong history of Alzheimer's in his or her family, he or she may particularly benefit from aerobic exercise.
It should be noted that many people with this gene never develop dementia, and it is generally not recommended to test for this gene since knowledge of it can cause undue alarm.
How does exercise work to preserve cognitive abilities?
While the exact mechanism of exercise related to cognition is unknown, there are three particular areas that are of interest. Exercise increases cerebral blood flow, and it is known that carriers of the APOE-4e gene tend to have lower cerebral blood flow than others. Exercise may also improve neural health and efficiency and may help regenerate neurons in an area of the hippocampus, a part of the brain associated with Alzheimer's. Finally, exercise increases release of neurotransmitters that may contribute to improved cognition.
What type of exercise helps memory and other cognitive functions?
The type of exercise that is most beneficial has yet to be determined, but it appears that aerobic exercise has the best benefit. The exercise does not have to be extremely strenuous; a brisk walk that causes a person to sweat and increases heart rate and breathing may be effective. Some research has shown that longer duration of exercise of an hour or more may be more beneficial than short sessions, and participation four times or more per week is advised. In general, the recommendations for heart health are similar to the recommendations for healthy aging of the brain.
What about nutrition and exercise?
There may also be an interrelationship between exercise and nutrition. The effect of exercise may increase levels of some nutrients in the body and may possibly improve absorption or metabolic action. It could be said that while nutrition provides the proper fuel for good health, exercise may provide the optimal delivery system for getting nutrients where they are needed.
Of course, exercise helps with weight control, aiding in particular by improving mobilization of fat stores for energy. Dieters who exercise as well as restrict Calories generally lose more of their weight from fat, whereas people who try to lose weight from restricted food intake alone may be end up losing as much as 40% of their weight loss from muscle rather than fat.
How should an older adult who has been inactive start an exercise program?
To get started with moderate physical activity, try taking a walk around the neighborhood, swimming at a local pool, getting on a bicycle for a gentle ride, taking a hike, or taking up social dancing - are all good aerobic activities that are fun as well. However, if you meet any of the criteria below, it is advised to obtain a doctor's clearance before beginning an exercise program.
The American College of Sports Medicine advises that men over the age of 45 and women over the age of 55, as well as anyone with heart disease, diabetes, high blood pressure, obesity, or other chronic health conditions, be evaluated with a cardiovascular stress test before undertaking a vigorous exercise program. These tests would be prescribed by a physician and the tests can often be obtained at a hospital or cardiac rehab center.
How do I find professional exercise help (personal trainer, physical therapist, exercise physiologist) to get me started correctly?
A person new to exercise may also want to elicit the help of an exercise professional. Using a professional for advice for even a few weeks can make a big difference in getting a good start. It is important that the person chosen has proper certification with knowledge and skill to work with any special needs. The American College of Sports Medicine (ACSM) personal trainer or group exercise instructor certification are certifications that are require a good knowledge of the field. A degree in exercise science or kinesiology also helps insure adequate knowledge. For anyone with medical problems, working with either a physical therapist or ACSM registered exercise physiologist or exercise specialist may be advised. A physician may give a referral for a physical therapist depending on personal health problems; exercise physiologists may be found through hospital wellness centers or cardiac rehabilitation centers.
For more information on getting started in exercise, the website of the American College of Sports Medicine, http://www.acsm.org//AM/Template.cfm?Section=Home_Page, is excellent.
References
Colcombe, S., Erickson, K., Raz, N., Webb, A,, Cohen, N., McAuley, E. et al. (2003). Aerobic fitness reduces brain tissue loss in aging humans. Journal of Gerontology 58A, 176-180.
Cotman, C. & Engesser-Cesar, C. (2001). Exercise enhances and protects brain function. Exercise and Sport Sciences Reviews 30, 75-79.
Larson, E.B., Wang, L., Bowen, J.D., McCormick, W.C., Teri, L., Crane, P. et al. (2006) Exercise is associated with reduced risk of incident dementia among persons 65 years of age and older. Annals of Internal Medicine 144, 73-81.
Schuit, A.., Feskens, E., Launer, L., & Kromhout, D. (2001). Physical activity and cognitive decline, the role of the Apo lipoprotein e4 allele. Medicine & Science in Sports & Exercise 33, 772-777.
Dental Health Factors
The role of dental health in relation to development of dementia in older adults shows an association between poor dental health and development of dementia, although much of the information is more theoretical in nature and is based on epidemiological research. There is a relation of periodontal disease to general health conditions, and the belief is that the inflammatory process that is associated with periodontal disease may affect other areas of the body.
One study that analyzed the dental health of nuns in a longitudinal study found that those individuals who had large numbers of teeth extracted, leaving nine or less teeth, had significantly higher incidences of Alzheimer's type dementia. There is no way to provide a specific explanation for why this could be, but as mentioned above, the inflammatory process may be increased in individuals who exhibit dental disease that necessitates tooth extractions.
While there is only an associative link between dental health and development of dementia related conditions, it is prudent for an individual concerned about his or her healthy aging to consider dental care to be a high priority. Dental care, both at home and at the dental office, improves quality of life at any age, and can help older adults stay healthy throughout life.
For information on dental health as related to general health, and for dental information for older adults, visit the website of the American dental Association - www.ada.org/
Reference
Sparks, P. S., Desrosiers, M., Donegan,S. J., Yepes, J. F., & Kryscio, R.J. (2007). Tooth loss, dementia and neuropathology in the Nun Study. Journal of the American Dental Association 138, 1315-1322.