Sugar, Insulin Resistance and Parkinson's Disease

Research is also connecting the impact of various sugars on the microbiome and the potential impact on memory and cognition (source ). 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 bacteria in your gut can balance and improve your blood sugar levels.

Cardiologists are focused on the heart and don’t look for neurological issues other than cardiac related neuropathy. Our system ignores the fact that all of these diseases begin with metabolic disease. Something in the system isn’t functioning properly and that often goes back to the metabolism of sugars in the microbiome.

• Insulin is an anabolic (muscle building) hormone secreted by b cells in the pancreas that regulates glucose homeostasis in cells major ones being liver, skeletal muscle and fat cells
• Insulin signals the cells in the body to absorb the sugar from your blood where it is used for energy or in the case of fat, stored for later use to produce energy
• Insulin controls switch between fasting (use of energy stores) and feeding (storage of sugars - glucose/fructose in fat)
• Insulin is now known to have a much broader role in the body
• Insulin-like signaling regulates processes such as reproduction and lifespan
• Insulin signalling is involved in brain plasticity, learning and memory
• Insulin can modulate the expression of neuropeptides involved in the regulation of food intake within the central nervous system

• Poor diet is the number one contributor
• Diets high in processed foods
• Vegetable and seed oil consumption
• added sugars, especially high fructose corn syrup
• high carbohydrate diets - white rice, white potatoes, highly processed white flour
• 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
• Chronic stress may also contribute to insulin resistance as stress hormones interfere with insulin signals
• Medications
• Fluorquinolone antibiotics
• Beta blockers for blood pressure
• Anti-psychotics
• Immunosuppressants
• Glucocorticoids
• PD medication Levodopa-Carbidopa

There are an increasing number of studies suggesting that insulin resistance impacts dopamine function in the brain and muscles.

A study from researchers at Harvard Medical School showed that insulin resistance increased dopamine turnover in the dopaminergic neurons in the brain. Both Type1 and Type 2 diabetes are associated with age-related cognitive impairment. The Harvard study in neurons showed that changes in key molecular pathways were the consequence of loss of insulin signalling. Stress is a known contributor to Parkinson’s disease and stress hormones like cortisol and adrenaline can interfere with insulin signalling. Insulin resistance in the brain induces mitochondrial dysfunction and impacts dopamine in the brain.

This is particularly interesting given the data indicating that Levodopa-Carbodopa causes insulin resistance based upon this research in muscle tissue and animal model (reference ). Glucose transport in to the muscles is stimulated by insulin in skeletal muscles. Skeletal muscle is the predominant insulin response tissue. This study from 2004, showed that levodopa-carbidopa decrease insulin-stimulated glucose transport, glycogen accumulation (glucose stored in fat) and glycogen synthase activity in skeletal muscle. This provides some insight to the descriptions from Parkinson’s patients about how their legs feel when they are not working properly. Lack of glucose in the muscles would, of course, make the legs feel heavy and unresponsive.

Separate research has shown that MAO inhibitors, drugs often used in the treatment of Parkinson's, can impact glucose levels in the blood, indicating that these drugs can improve glucose tolerance and insulin sensitivity.

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. Glycogen storage is the primary mechanism for managing glucose homeostasis in the body. 1% of glycogen is stored in the muscles, with the rest stored in the liver. Glycogen stored in the liver is converted back in to glucose when needed to maintain glucose homeostasis. Given the potential impact on glycogen storage from the primary Parkinson’s medication, it is more likely that people with Parkinson’s will have trouble maintaining glucose homeostasis. 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.

The primary focus of a healthy ketogenic diet should be restoring metabolic flexibility through a focus on whole, organic foods, healthy fats, fish and pasture raised meats and non-starchy vegetables. The ketogenic diet is not a license to eat a pound of bacon for breakfast or a tub of sour cream and cheese for lunch. I recommend the bookKeto Flex by Ben Azadi if you are interested in exploring a ketogenic lifestyle in the healthiest way possible. Ben is especially knowledgeable about diabetes from his own personal story of losing his father to diabetes.

Diet is the biggest predictor for a healthy microbiome and balanced blood sugar. The Western diet, unfortunately, is not the optimal diet for your best health. The Western diet is high in processed foods, seed oils (canola and soybean), high fructose corn syrup, soft drinks, emulsifiers, preservatives and trans fats. You can change the bacteria in your gut in under thirty days by changing your diet . The best diet is one that is nutrient dense and includes lots of fresh, organic colorful vegetables, herbs and spices, organic blueberries, oily fish like salmon, pasture-raised meats and eggs, and incorporates oils like coconut and olive instead of the seed oils. A diet high in fresh vegetables and organic legumes (properly soaked and prepared) will increase the amount of fiber in your diet and reduce the simple carbohydrates. This will feed a population of healthy bacteria and reduce the growth of pathogens that prefer simple carbohydrates and sugar. A source of great help in lowering blood sugar is taking the right probiotic .

When I first formulated ourSugar Shift probiotic for my husband, John, my focus was on making mannitol in the gut because of research I had read about the ability of mannitol to stop the aggregation of the proteins. When I started to study mannitol chemistry, I learned how certain probiotic organisms can convert glucose and fructose into mannitol which humans don’t use but bacteria do. In a way, this mimics fasting to some degree because it converts the excess sugars in the upper GI tract. When I first made the product I was just thinking of mannitol production. I didn’t understand all of the research and implications of impaired glucose metabolism in Parkinson’s disease. 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 makethe Shift . We start a clinical trial in diabetes and pre-diabetes beginning April 1, 2022. We are excited to see the results later this year.