Nutrition And Parkinson

PARKINSON’S DISEASE AND A PLANT-BASED DIET
Kathrynne Holden, MS, RD
Summer 2000
The nature of Parkinson’s disease
Parkinson’s disease (PD) afflicts about one to one and one-half million people in the United States (Tanner 1992). PD is a progressive neurological disorder that results in the death of dopamine-producing cells in the brain. Loss of dopamine affects movement, both of skeletalmuscle and the smooth muscle of the gastrointestinal (GI) tract. This can result in slow, shuffling gait, resting tremor, and/or slowed peristalsis. Individuals with PD may experience frequent falls (Dolinis et al., 1997; Northrid ge et al., 1996), d ifficulty handling cooking and eating utensils, and such GI-related problems as slow stomach emptying, gastroesophageal reflux, and chronic constipation(Jost WH, 1997; Edwards et al, 1993; Edwards et al., 1994; Byrne et al., 1994).
Nutrition-related problems
Individuals with PD have been found to have a higher incidence of bone thinning and fractures than age-matched control groups (Ishizaki et al., 1993; Kao et al., 1994; Taggart, et al., 1995; Revilla et al., 1996; Koller et al., 1989; Johnell et al., 1992, Sato et al., 1997). Loss of theolfactory sense and sense of taste are frequently present (Huttenbrink, 1995; Hawkes et al., 1997), along with xerostomia (dry mouth) (Clifford and Finnerty, 1995), and sometimes loss of appetite (Starkstein SE, 1990). These, along with other factors, may contribute to the high rate of unplanned weight loss in this population (Markus et al., 1993; Davies et al., 1994; Beyer et al., 1995).
There arealso indications that B vitamin deficiencies may be of concern, although the causes are not clearly understood. In 1979, Bender et al. reported the possibility that users of levodopa-carbidopa (Sinemet, Sinemet CR, a medication used to treat the symptoms of PD) could be at risk for both niacin and vitamin B6 deficiencies. Long-time users of levodopa-carbidopa have since been found to haveincreased levels of serum homocysteine (Kuhn et al., 1998, Muller et al., 1999), implicating vitamins B6, folate, and B12. In attempts to determine the etiology of PD, Hellenbrand et al. compared the dietary habits of patients vs. a control group; patients were found to have consumed significantly less niacin than controls (Hellenbrand et al. 1996). In a more recent Swedish study researchers note thatconsumption of niacin-containing foods appeared to reduce risk for PD (Fall et al., 1999). Finally, in an unpublished study, pellagra was discovered in several patients using levodopa-carbidopa (Iacono et al.). Thus, patients could have increased risk for vascular disease, pellagra, and other conditions resulting from deficiencies of B vitamins.
Constipation is very common due to the disease and/orto the medications used to treat PD (Jost, 1997; Jost and Schrank, 1998; McIntosh and Holden, 1999). Chronic constipation can raise the risk for fecal impaction (Sonnenberg et al., 1994) and colon cancer (Jacobs and White, 1998; Will et al., 1998), therefore, safe methods of controlling constipation are desirable.
Furthermore, PD brings with it a food-medication interaction that has beengenerally under-addressed by dietetics professionals. Levodopa, the primary medication used to treat PD, competes with the five large neutral amino acids for carriers, both in the gut and at the blood-brain barrier (Lieberman, 1992). Thus, levodopa absorption is effectively blocked if taken with meals.
How can a vegetarian or plant-based diet be of help to people with PD?
While research has failed toconclusively show a link between diet and PD, nevertheless, fiber, nutrients found particularly in plants, and protein, are excellent reasons to choose among the various vegetarian and plant-based eating plans. Animal foods are often high in protein and lack fiber. Plants in general have a high proportion of carbohydrate, with moderate amounts of protein. Plants also contain fiber and many...