The 7:1 Diet For Parkinson's Disease: A Nutritionist's View
It has been well established by the medical community that diet, particularly protein, has a direct impact on the effectiveness of Parkinson’s disease medications. Levodopa, the active ingredient in most P.D. drugs (such as Sinemet) must be transported across the blood/brain barrier into the brain for conversion to dopamine. Only then can it alleviate the symptoms of P.D. However, the digestion of dietary protein results in certain amino acids, (large neutral amino acids-LNAAs) which compete with levodopa for transport into the brain.
The result is that the amount of protein you eat has a direct impact on the amount of levodopa reaching your brain, and subsequently, on your symptoms of P.D. Dietary carbohydrate also plays a part, lowering blood levels of LNAAs by triggering the release of insulin.
Balancing carbohydrate and protein, specifically in a ratio of 7:1 (7 parts carbohydrate to 1 part protein) results in the most stable blood levels of LNAAs- the goal of dietary management. This allows for a consistent and more predictable response to Sinemet. Studies show an optimal response to levodopa with a 7:1 diet, as compared to either a higher carbohydrate intake (30:1) or lower carbohydrate intake (1.5:1).
The 7:1 balance, therefore, is the goal of dietary modification to enhance the effect of your Sinemet.
Until now, for Parkinsonians with on-off syndrome, the best dietary advice was to follow a Protein Redistribution Diet (PRD). The PRD allowed for the Recommended Dietary Allowance of protein , 0.8 grams of protein per kilogram body weight, approximately 45-55 grams for an average weight female or male. The catch was that it limited the total daytime protein intake to only 7 grams. That’s the amount of protein in less than one cup of milk or one slice of deli meat. The remaining protein allowance was to be consumed in the evening meal.
There are several drawbacks to the PRD. It is very difficult to plan and to follow. Daytime meals would contain mostly fruits and vegetables, but omit dairy products, eggs and meats. Costly low protein products, such as breads and pastas are essential as is a good repertoire of low protein recipes. High motivation is essential to adhere to this rigid plan.
Furthermore, once protein intake increases in the evening, patients typically “turn off”. The logical solution is to self restrict protein, resulting in an inadequate total protein intake and potentially malnutrition. In addition to a protein deficiency, patients are more at risk for inadequate calcium, riboflavin, vitamin D and iron, the consequence of reducing dairy products and meats.
In contrast, the 7:1 diet allows for normal daytime meals.
The 7:1 diet balances carbohydrate and protein, allowing for 7 parts carbohydrate for one part protein. Each meal and snack is planned in this ratio for best results. The total number of grams of protein from each of the food items to be eaten at the meal is calculated. This is determined by reading the food labels or consulting lists of protein content of foods. Based on the amount of protein at that meal, the number of grams of carbohydrate needed is calculated. For example, if 10 grams of protein is included at breakfast, 7 times that amount (7×10) or 70 grams of carbohydrate needs to be included at breakfast as well.
Protein is found in a wide variety of foods. Foods highest in protein include milk and other dairy products and meats ( including fish and poultry). But even starchy foods such as breads, dried beans or peas, grains and cereals have protein which needs to be accounted for. They are, however, relatively high in carbohydrate.
Foods high in carbohydrate and low in protein include fruits and juices, sugar and syrups, sorbet and sherberts, soda and other sweetened beverages. These can be added to your meals to help shift the balance to 7:1. A rule of thumb is to keep meat and dairy portions small and fruit/juice and starch servings large to help improve your ratio.
A Registered Dietitian can evaluate your dietary needs and create an individualized meal plan to meet the 7:1 ratio. Adequacy of protein, calories, vitamins and minerals will also need to be assessed. Supplements may be recommended, particularly to help meet the calcium RDA.
A typical day may be planned as follows:
- 2 slices of bread with jelly
1 poached or fried egg
1 piece of fruit
8 oz of juice
- 1 cup of minnestrone soup
2 slices of bread
garden salad with oil and vinegar dressing
1 cup fruit salad
- 2 cups microwave popcorn
8 oz juice
- 1 cup pasta
1/2 cup jarred meat sauce
2 Tbsp. grated parmesan cheese
1 cup cooked broccoli and carrots
As you can see, the 7:1 diet allows for greater flexibility in meal planning than the PRD. Adjustment for breakfast, lunch and snacks tend to be quite manageable.
The drawbacks? Unless you are a practicing vegetarian, the 7:1 is most difficult to follow for dinner. It is achievable, for example using pasta dinners along with a high juice or fruit intake to boost the total carbohydrate and offset the protein, but requires more planning. One solution is to shift intake to closer to a 7:1. The average American’s dinner is quite high in protein, approximating a 1.5:1 ratio! Liberalizing protein intake at dinner, the time when mobility is less critical, is certainly an option. But be aware that with increased protein may come increased symptoms. Even a reduction in the portions of high protein foods will shift the balance closer to 7:1 and may improve your response to Sinemet.
Another alternative is to utilize formulated products developed for Parkinsonians in the 7:1 ratio. This eliminates the difficulty of preparing foods, for some a challenging activity.
The other drawback is that it is not possible, with table foods alone, to achieve a 7:1 diet with a total calorie intake of less than 1800-1900 calories, since carbohydrate at seven times the protein intake needs to be included, and a palatable dinner would also include a small amount of fat. This is primarily an issue for overweight Parkinsonians and many women. Most Parkinsonians, however, have an increased calorie requirement and may need additional calories to stabilize their weight or regain to a healthy level.
The 7:1 diet, under your doctor’s supervision may be what you need to better manage your Parkinson’s Disease. Be aware that dietary changes may necessitate modification in your Parkinson’s Disease medication. In addition, if you have diabetes, increasing your carbohydrate may require an adjustment in your oral agent or insulin.
While this article has focused on the cutting edge of medical nutrition therapy for Parkinson’s disease, other nutritional issues are worthy of discussion.
The “big C ” to Parkinsonians is not cancer, but constipation. Constipation, the chief complaint of many PD patients, may result from the disease process itself, causing a decrease in muscle movements affecting the bowels, and difficulty passing stools. Constipation may also result from the P.D. medications, a decrease in fluid or fiber intake, and physical activity. Increasing fluid and fiber intake, along with physical activity, is essential. An increase in fiber without the fluids can worsen the situation, resulting in gas, cramping and distension.
To increase fiber, include whole grains and cereals (such as 100% whole wheat breads, bran cereals, brown versus white rice). Whole fresh fruits and vegetables, as well as dried fruit are also valuable sources of fiber. Naturally, you need to consider your ability to chew and swallow these foods, and adjust the texture to meet your tolerance. For instance, if chewing is difficult, a baked apple with the skin on, cut up, or apple sauce may be more practical than a fresh whole apple. Fiber content can be enhance by adding some high fiber cereals (such as all-bran, bran buds) as a topping.
For assistance with modifying your diet, including planning a 7:1 diet, increasing fiber content, or addressing texture tolerance, request a referral to a qualified registered dietitian. Patients able to travel to the Boston area can schedule appointments with me by contacting me by phone or by email (see the contact information on our home page).
For More Information
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