New research into the best diets for Parkinson’s disease reveals the Mediterranean and MIND diets may be associated with later-age of onset of PD

There are not many aspects of life that a person feels are under his or her control – especially if that person happens to have Parkinson’s disease (PD).  But diet – the foods that we eat – is one of those elements that we do have control over. It is not surprising therefore, that people with PD are constantly searching for diets and foods that will maximize their quality of life and allow them to live their best life with this disease. Inquiries into the best diet for Parkinson’s is one of the most frequently asked questions I receive. I gave some guidance on this issue and some of the popular diets people ask about in these previous blog posts:

• What We Know About Avoiding Particular Foods & Supplements for Parkinson’s
• What We Know (And Don’t Know) About Taking Particular Foods & Supplements
• The Role of Certain Diets for People with Parkinson’s Disease

A recent study has given us some more insight into this subject. This study asked people with PD to record details of their diet and then scored their answers for adherence to two different diets: the Mediterranean diet and the MIND diet. It then correlated their diets to the age of onset of their PD and found that stricter adherence to both of these diets was associated with later age of onset of PD. There was a difference of up to 17.4 years in age of onset between those that most strictly kept to the diets and those that least maintained these diets. This suggests that following these diets before PD is diagnosed may delay the onset of PD symptoms.

What constitutes a Mediterranean diet?

The following constitutes the Mediterranean diet:

• • Vegetables
  • Fruits
  • Whole grains
  • Legumes such as beans, peas and lentils
  • Nuts
  • Low-fat proteins, such as fish and poultry
  • Olive oil

The Mediterranean diet has been formally studied over the years and in a large systemic review, was shown to be associated with reduced rates of cancer, cardiovascular disease, Alzheimer’s disease, and PD.

What constitutes a MIND diet?

Another diet, known as the Dietary Approaches to Stop Hypertension (DASH) diet was designed to help treat and prevent high blood pressure. The DASH diet emphasizes many of the same principles as the Mediterranean diet.

More recently, experts suggested a combination of the Mediterranean and DASH diet, meant to maximize cognitive benefits. It is entitled the Mediterranean-DASH Intervention for Neurodegenerative Delay or MIND diet. Past studies have investigated the cognitive benefits of this diet including one study which found that those who followed the MIND diet showed a slower decline in cognitive scores, and functioned cognitively as if they were 7.5 years younger than their counterparts who did not adhere to the diet.

The following constitutes the MIND diet:

• • Green, leafy vegetables
  • All other vegetables
  • Berries
  • Whole grains
  • Beans
  • Nuts
  • Poultry
  • Fish
  • Olive oil
  • Wine

The following should be avoided in the MIND diet:

• • Red meat
  • Butter and stick margarine
  • Cheese

The principles of the MIND diet are very similar to the Mediterranean diet, with some notable additions. The MIND diet recommends green leafy vegetables such as spinach and kale as the first choice over other vegetables. Berries (such as blueberries) are specifically promoted, as opposed to fruit in general. A small amount of red wine daily is also encouraged. (Of note, for people with mild PD symptoms, red wine may be a safe addition to their diet. However, for people who have more advanced PD symptoms, such as difficulty with balance, this element of the diet may need to be skipped. Please discuss this with your neurologist.)

In the current study, each person’s diet was calculated based on an extensive, validated, food-frequency questionnaire. The methods used in this study for scoring these questionnaires have been rigorously established.

Drawbacks to the study

The study did not answer a number of other questions: Is there a benefit to the person with PD if the diets are only started once PD is already diagnosed? And if so, what elements of PD may improve? (e.g. movement symptoms? cognition? longevity?)  It seems likely that the diets would offer benefit even after symptoms are manifest, but this question is not answered directly in the current study.

Another aspect to note is that the study relies on people filling out questionnaires about what they eat. People may not be accurate in their accounting and may record a “better” diet than they actually ingest. However, this tendency to over-report good dietary habits should be equivalent for everyone in the study and may therefore not affect the results substantially.

Since these diets focus on healthy and nutritious foods, even though the study does not provide all of the answers, there is minimal risk, and considerable potential benefit to incorporating them into your life.

Why do these diets work?

The scientific underpinnings as to why these diets affect brain health are not fully understood and likely consist of a combination of different positive benefits – some of which have been established and others that have not. It is possible that the established heart benefits of the diets drive some of the brain health benefits. That is, the diets promote healthy hearts and clean blood vessels and therefore support excellent blood flow to the brain. It is well established, that vascular disease in the brain can contribute to cognitive decline as well as the motor symptoms of parkinsonism. Therefore, ensuring that the brain achieves good blood flow has positive benefits on brain health for everyone, especially those who have another disease such as PD.

In addition, specific components of the foods that are encouraged in these diets may work on the cellular level to protect neurons from cell death or decrease neuro-inflammation. But knowing which elements are conferring the benefit is not straightforward. Whereas individual compounds found in foods may show benefit in cell culture or in animal models of PD in the lab, none of these compounds have been shown to confer a meaningful benefit on the quality of life, symptom management, or disease progression when tested in people with PD. In fact, to date, researchers have not been able to identify a specific nutritional supplement that achieved the type of benefits in clinical trial demonstrated in this diet study. Currently, therefore, the best way to ingest the nutrients that protect the brain is through a comprehensive diet plan and not by taking a defined group of supplements.

Tips and Takeaways

• A new study has demonstrated that the MIND and Mediterranean diets are associated with a delay in onset of PD symptoms
• Both of these diets emphasize vegetables, fruits, whole grains, legumes, nuts and olive oil
• The MIND diet adds green leafy vegetables and berries as important elements
• Even though these diets focus on healthy and nutritious foods, as always you should discuss any changes that you make with your neurologist