Tufts Researchers Update Their Food Guide Pyramid for Older Adults
BOSTON — Tufts University researchers have updated their Food Guide Pyramid for Older Adults to correspond with the USDA food pyramid, now known as MyPyramid. The Tufts version is specifically designed for older adults and has changed in appearance and content. The Modified MyPyramid for Older Adults continues to emphasize nutrient-dense food choices and the importance of fluid balance, but has added additional guidance about forms of foods that could best meet the unique needs of older adults and about the importance of regular physical activity.
"Adults over the age of 70 have unique dietary needs," says first author Alice H. Lichtenstein, D.Sc., director of the Cardiovascular Nutrition Laboratory at the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts (USDA HNRCA). "Older adults tend to need fewer calories as they age because they are not as physically active as they once were and their metabolic rates slow down. Nevertheless, their bodies still require the same or higher levels of nutrients for optimal health outcomes. The Modified MyPyramid for Older Adults is intended to be used for general guidance in print form or as a supplement to the MyPyramid computer-based program."
In 2005, the USDA debuted MyPyramid, an Internet-based program capable of dispensing individualized dietary guidance based on sex, age, height, weight, and exercise habits. Lichtenstein and colleagues were concerned about computer use among older adults and the adaptability of MyPyramid to print form. The Modified MyPyramid for Older Adults is available as a graphic print-out with icons representing foods in the following categories, and fluid and physical activity:
- Whole, enriched, and fortified grains and cereals such as brown rice and 100% whole wheat bread.
- Bright-colored vegetables such as carrots and broccoli.
- Deep-colored fruit such as berries and melon.
- Low- and non-fat dairy products such as yogurt and low-lactose milk.
- Dry beans and nuts, fish, poultry, lean meat, and eggs.
- Liquid vegetable oils and soft spreads low in saturated and trans fat.
- Fluid intake.
- Physical activity such as walking, house work, and yard work.
The Modified MyPyramid for Older Adults appears in the January 2008 issue of the Journal of Nutrition. Added to the new pyramid is a foundation depicting physical activities characteristic of older adults, such as walking, yard work, and swimming. "Regular physical activity is linked to reduced risk of chronic disease and lower body weights. Government statistics indicate that obesity in adults 70 years and older has been increasing, physical activity is one way to avoid weight gain in later years and its adverse consequences," says Lichtenstein, also the Stanley N. Gershoff Professor at Tufts University's Friedman School of Nutrition Science and Policy. "In addition, regular physical activity can improve quality of life for older adults."
Emphasized in the Modified MyPyramid for Older Adults are icons depicting packaged fruits and vegetables in addition to fresh examples, forms that for a number of reasons may be more appropriate for older adults. These include, for example, bags of frozen pre-cut vegetables that can be resealed or single-serve portions of canned fruit. "These choices are easier to prepare and have a longer shelf life, minimizing waste. Such factors are important to consider when arthritis kicks in or dark, cold days mean it is less likely someone will go out to replenish their refrigerator stores," Lichtenstein says.
"We continue to emphasize the importance of consuming adequate amounts of fiber-rich foods, which means choosing mainly whole grain products rather than highly refined forms, and whole fruits and vegetables rather than juices. The Modified MyPyramid for Older Adults is replete in good examples," Lichtenstein says. "Fresh, frozen, canned and dried fruits and vegetables are excellent sources of fiber, as well as a whole host of other nutrients. The increased availability of whole grain products lowers the barrier on making those choices."
The Modified MyPyramid for Older Adults stresses the importance of consuming fluids by having a row of glasses as its foundation. "As we age there can be a disassociation between how hydrated our bodies are and how thirsty we feel, this can be particularly of concern in the summer months," Lichtenstein says. The authors note food and beverages with high water content, such as lettuce, vegetable juice and soups, are important contributors of fluid in an older person's diet.
Also included as an integral part of the Modified MyPyramid for Older Adults is a flag at the top suggesting that older adults may need certain supplemental nutrients. "The need for calcium, vitamin D and vitamin B12 can increase as we age and some people find it difficult to get adequate amounts from food alone, especially when calorie needs go down," Lichtenstein says. "The flag at the top of the Modified MyPyramid for Older Adults serves as a reminder that some people may need to discuss this potential need with their health care providers. However, we continue to emphasize that the majority, if not all, of nutrients an older adult consumes should come from food rather than supplements."
The original Food Guide Pyramid for Older Adults, published by Tufts researchers in 1999, is widely used as an illustration in textbooks and manuals, featured in newsletters for older Americans, and in informational material prepared by the Departments of Elder Affairs in a number of states. Now that the USDA's Food Guide Pyramid has been redesigned to be computer based, the Tufts researchers felt it was important to update their version.
This study was supported by a grant from the Ross Initiative on Aging at Tufts University and the US Department of Agriculture (USDA).
Lichtenstein, AH, Rasmussen, H,Yu, WW, Epstein, S, Russell, RM. Journal of Nutrition. 2008 (January); 138 (1): 78-82. "Modified MyPyramid for Older Adults."
Elderly at Risk for Physical Disabilities Exercise, Improve Physical Function
BOSTON — Elderly adults at risk for physical disabilities are able to adhere to a regular program of moderate exercise for one year, a recent study of 213 men and women suggests. Led by corresponding author Roger Fielding, Ph.D., of the Jean Mayer USDA Human Nutrition Research Center on Aging (USDA HNRCA), the authors observed that improvement in physical function was related to the participants' ability to adhere to the physical activity regimen.
"At the beginning, middle and end of the study the participants were tested on their walking speed, strength, flexibility and balance to gauge their physical function," said Fielding, director of the Nutrition, Exercise Physiology and Sarcopenia Laboratory at the USDA HNRCA. "We saw a greater improvement in physical function in the participants who reported exercising 150 minutes or more per week."
The study, published in the November 2007 issue of Medicine & Science in Sports & Exercise, analyzed data from the physical intervention arm of the Lifestyle Intervention and Independence for Elders Pilot (Life-P). The participants ranged in age from 70 to 89 years-old, were sedentary when they enrolled, had health problems, such as cardiovascular disease and osteoporosis, and some physical limitations such as difficulty walking or climbing stairs. They followed a moderate exercise program that consisted of walking, strength, flexibility, and balance training.
For the first six months of the study, the participants exercised under supervision at one of four university centers and at home. Center visits were optional during the second six months. The participants filled out surveys to track their adherence to the physical activity regimen during the center visits and at home. The authors observed that physical activity adherence was consistent with earlier studies that followed older adults for shorter durations.
A future randomized trial would study a larger population of elderly for a longer period of time. "Larger studies are needed to confirm that exercise can improve physical function in elderly at high risk for physical disabilities," said Fielding, who is also a professor at the Friedman School of Nutrition Science and Policy and Tufts University School of Medicine. "What we found, however, is that this group can commit to a regular program of physical activity in a long-term randomized trial and the better their adherence to a program of physical activity, the greater their improvements in physical functioning."
This study was supported by the United States Department of Agriculture (USDA) and the National Institute on Aging, part of the National Institutes of Health.
Fielding, RA, Katula, J, Miller, ME, Abbott-Pillola, K, Jordan, A, Glynn, NW, Goodpaster, B, Walkup, MP, King, AC, Rejeski, WJ, and for the Life Study Investigators. Medicine & Science in Sports & Exercise. 2007 (November); 39 (11): 1997-2004. "Activity Adherence and Physical Function in Older Adults with Functional Limitations."
Vitamin B12 Function May Be Diminished by Excessive Folate
BOSTON — In a study of adults aged 20 and over, researchers at Tufts University showed that homocysteine and methylmalonic acid are at much higher levels in individuals who have a combination of vitamin B12 deficiency and high blood folate levels than in individuals who are also vitamin B12 deficient but have normal folate levels.
Homocysteine and methylmalonic acid, compounds used by enzymes that contain vitamin B12, accumulate in the blood in patients who are vitamin B12 deficient. "Finding that the combination of high blood folate levels and low vitamin B12 status is associated with even higher levels of these compounds is a strong indication that the high folate is interfering with the action of these B12-containing enzymes, thus resulting in the exacerbation or worsening of the vitamin B12 deficiency," says corresponding author Jacob Selhub, Ph.D., director of the Vitamin Metabolism Laboratory at the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University (USDA HNRCA).
In an earlier study, Selhub and co-authors Martha Savaria Morris, Ph.D., and Paul Jacques, D.Sc, also of the USDA HNRCA, have shown that the prevalence of anemia and cognitive impairment among U.S. elderly who are vitamin B12 deficient is much worse if this B12 deficiency is also accompanied by high blood folate rather than normal blood folate. This indicates that the worsening of the vitamin B12 deficiency, as indicated by higher homocysteine and methylmalonic acid due to high blood folate, is also manifested clinically through higher prevalence of anemia and cognitive impairment.
Results of the present study are published in the December 11, 2007 issue of the Proceedings of the National Academy of Sciences. Selhub and colleagues analyzed data from 10,413 adults who participated in two National Health and Nutrition Examination Surveys (NHANES). Slightly less than half of the participants (4,940) took part in phase 2 of the NHANES III, which was conducted between 1991 and 1994. The remaining 5,473 adults took part in the NHANES conducted from 1999 to 2000 and from 2000 to 2002.
The authors intentionally used one NHANES survey conducted prior to 1998, the year the Food and Drug Administration required that all enriched cereal-grain products be fortified with folic acid, the synthetic form of folate, in order to help prevent birth defects in infants. "It is important to note that these adverse interactions between high folate blood levels and vitamin B12 deficiency were seen only in the study participants from the NHANES conducted between 1999 and 2002, after the fortification of flour and other cereals with folic acid," says Selhub, who is also a professor at the Friedman School of Nutrition Science and Policy at Tufts University.
Folic acid is a synthetic form of the vitamin, which requires specific processing by the body for incorporation into the folate pool of the body. Naturally occurring folates, found in leafy vegetables, legumes and in many other fruits and vegetables, can be readily incorporated into the body's folate pool and are believed to be beneficial even at higher intakes.
"There is no reason to avoid foods with naturally occurring folate and it is essential to consume B12 containing products such as eggs, meat, milk and poultry and even supplements if necessary," says Selhub. "The combination of high blood folate and normal vitamin B12 status is actually beneficial to health."
This study was supported by the Agricultural Research Service of the U.S. Department of Agriculture.
Selhub, J, Morris MS, Jacques PF. Proceedings of the National Academy of Sciences. 2007 (Dec. 11); 104 (50): 19995-2000. "In vitamin B12 deficiency, higher serum folate is associated with increased total homocysteine and methylmalonic acid concentrations."
If you are a member of the media interested in learning more about these topics, or in speaking with a faculty member at the Friedman School of Nutrition Science and Policy at Tufts University, or another Tufts health sciences researcher, Tufts University, or another Tufts health sciences researcher, please contact Andrea Grossman at 617-636-3728 or, via email, Andrea.Grossman@tufts.edu, or Christine Fennelly at 617-636-3707, or via email, Christine.Fennelly@tufts.edu.
Tufts research scientists work with federal agencies to establish the USDA Dietary Guidelines, the Dietary Reference Intakes, and other significant public policies. The Gerald J. and Dorothy R. Friedman School of Nutrition Science and Policy at Tufts University is the only independent school of nutrition in the United States. The school's eight centers, which focus on questions relating to famine, hunger, poverty, and communications, are renowned for the application of scientific research to national and international policy. For two decades, the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University has studied the relationship between good nutrition and good health in aging populations.
