Nutritional Implications of Rheumatoid Arthritis

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Nutritional Implications of Rheumatoid Arthritis

Agricultural Research

07/18/2004

Originally Published:20040701.

For some people, the benefits of eating a healthy diet are hard to detect on

a daily basis. But for others-such as those with rheumatoid arthritis-the

effects are often much more palpable.

Rheumatoid arthritis, or RA, is a chronic inflammatory disease with three

diet-associated aspects. One is elevated resting energy a expenditure.

Another is elevated whole-body protein catabolisma destructive form of

muscle metabolism that translates to muscle wasting. And yet another is low

body cell mass, which leads to increased fat mass.

Nutritionist B. , rheumatologist Ronenn Roubenoff, and

colleagues have conducted a study that solves the puzzle as to whether folks

with RA should increase their caloric intake to make up for their increased

resting energy expenditure. is director of the Energy Metabolism

Laboratory at the Mayer USDA Human Nutrition Research Center on Aging

at Tufts University in Boston, Massachusetts. Roubenoff has a visiting

appointment with the center.

People with RA tend to be less active than people withoutthe stiffness and

swelling caused by inflammation naturally prompt them to pursue less

physical, more sedentary lifestyles. Such habits lead in turn to overall

gains in fat mass. The combination of high fat mass and low muscle mass

contributes to an increased risk of disability.

Researchers at the center had previously shown that those who develop RA

also develop an increased metabolic rate; they simply burn more calories

while at rest. But they did not know what effect the elevated resting energy

expenditure has on daily total energy expenditure and thus on dietary energy

requirements.

Twenty healthy women and 20 women with RA, all of similar weight and size,

were studied. Their total energy expenditure and their energy expended

during rest and during exercise were measured or estimated. These three

measures make up the major components of the energy balance equation.

The researchers found that in the women with RA, low energy expenditure from

physical activity was directly linked to lower total energy expenditure.

" Even though their basal metabolism is revved up, people with rheumatoid

arthritis tend to be less active than people without-which reduces their

caloric needs, " says . This finding helped solve the puzzle of

whether women with RA need to eat more to make up for the fact that they

burn I more calories while at rest. They don't.

The researchers concluded that those with RA should consume nutrient-rich

diets and incorporate physical activity throughout the day to boost their

total energy expenditure. " Such a regimen will help them improve their

physical function and quality of life and maintain a healthy weight, " says

Roubenoff.

The study was published in the American Journal 9 of Clinical Nutrition.-By

lie n Bliss, ARS.

To reach scientists mentioned in this article, contact lie Bliss,

USDA-ARS Information Staff, 5601 Sunnyside Ave., Beltsville, MD 20705-5129;

phone (301) 504-4318, fax (301) 504-1641, e-mail rbliss@ ars.usda.gov.