Sugar, Insulin Resistance and Parkinson's Disease
People with Parkinson’s disease be mindful of their intake of carbohydrates and sugar. Studies suggest that having persistent high blood sugar, insulin resistance or type 2 diabetes, may accelerate disease progression. (source 1, source 2). It turns out that the microbiota in your gut is a key determinant of how readily sugar enters your blood after eating. (source) Therefore, having the right microbiota in your gut is linked to balancing your blood sugar levels. A source of great help in lowering blood sugar is taking the right probiotic.
In 2018, researchers from Cedar-Sinai Medical Center published a study in the Journal of Parkinson's disease, titled "High Prevalence of Undiagnosed Insulin Resistance in Non-Diabetic Subjects with Parkinson's disease" (Hogg et al, 2018). The study revealed that nearly 60% of the non-diabetic study participants had undiagnosed insulin resistance - despite having normal blood sugar levels.
A data analytics project I worked on about a decade ago provided access to a large set of hospital data, including over 40,000 Parkinson's patients. During the project we looked at de-identified Parkinson's patient data based on billing codes. Using these codes we were able to look for additional health issues (comorbidities) in the patients with a PD diagnosis. The two most prevalent comorbidities in Parkinson's were diabetes and cardiovascular disease. Sugar consumption affects all of these diseases.
Our current approach to science and medicine is very specialized. As a result, the connections across diseases are often missed. Neurologists don't look at blood chemistry routinely, so it's likely a neurologist would have no idea of this potential connection between diabetes, insulin resistance and Parkinson's.
Based on my many conversations with people with Parkinson's and their partners, I noticed a tendency toward sugar addiction. I often comment on this when I attend Parkinson's support group meetings or even research presentations at Universities where the tables are spread with donuts and candy - the very "foods" you should NOT be eating.
So what is insulin?
- Insulin is a hormone produced in the pancreas that regulates the amount of sugar in your blood
- Insulin signals the cells in your muscles, fat and liver to absorb the sugar in your blood where it is used for energy
- Insulin protects the body from having too much sugar in the blood
What is insulin resistance? Insulin resistance is when your cells become less sensitive to the hormone signals and do not respond. When this happens the cells require more and more insulin to take up the sugar in the blood.
What can happen when you become insulin resistant?
- Excess sugar can build up in the blood, damaging the blood vessels to your organs
- It can develop into diabetes
- Contributes to increased systemic inflammation
- Puts strain on the pancreas where insulin in made and is correlated with pancreatic cancer
What are potential causes or contributing factors to insulin resistance?
- Poor diet: Diets high in processed foods and added sugars, high carbohydrate diets
- Inflammation in the body from other causes, eg. infection, contributing to a vicious cycle
- Inactivity, reduced physical exercise
- Being overweight or obese or a state known as lean obesity where fat is localized in the belly but the rest of the body is thin
How does insulin resistance play a role in PD? There are an increasing number of studies suggesting that insulin resistance impacts dopamine function in the brain.
A study from researchers at Harvard Medical School showed that insulin resistance increased dopamine turnover in the dopaminergic neurons in the brain.
Separate research has shown that MAO inhibitors, drugs often used in the treatment of Parkinson's, can impact glucose levels in the blood after insulin, indicating that these drugs can improve glucose tolerance and insulin sensitivity.
Our relationship with sugar is complicated. Our brains depend on glucose as the main source of energy and tight regulation of glucose metabolism is critical for brain physiology. Disrupted glucose homeostasis affects cell death pathways and forms the basis for many brain disorders. The Texas Institute for Neurological Disorders reports that too much sugar/glucose can lead to memory deficits and a high sugar diet can lead to dopamine deficits as the brain becomes used to high levels of sugar. The brain can use glucose, lactate or ketones for energy. Recent research has shown that ketones are some of the best brain fuel.
When I first formulated our Sugar Shift probiotic for my husband, John, my focus was on making mannitol in the gut. The process of the probiotic bacteria making mannitol in our formula actually converts the excess sugars from the diet. Many of our customers now report that their blood glucose has improved and they no longer crave sugars. So many chronic diseases are fueled by sugar. Maybe we can help you make the Shift.