6.3: Nutrition and Chronic Neurological Illnesses
By the end of this section, you should be able to:
- 6.2.1 Discuss the impact of nutrition on neurological illness.
- 6.2.2 Discuss the impact of nutrition on psychiatric illness.
Nutritional Requirement for Optimal Neurological Health
Although the development of neurologic conditions varies in process, there are several common threads in reduced cognition and other neurologic functions. Neurologic chronic conditions are associated with a variety of factors, such as increased oxidative stress , neuroinflammation , and a disruption in energy metabolism . Each of these factors can be influenced and modified by dietary intake.
The nurse should screen all clients with neurologic illness for malnutrition in conjunction with the health care team, using the tools described in Applying Clinical Judgment to Promote Nutrition for Neurological Wellness. This screening is especially important because clients with neurological conditions may have difficulty chewing or swallowing . Aphasia , apraxia , depression , or altered cognitive states may further challenge adequate intake. Key nutritional recommendations for preventing neurologic deterioration in neurodegenerative conditions are provided in this section.
The effect of specific diets (such as ketogenic and Mediterranean diet) among clients with neurologic conditions, such as epilepsy, traumatic and atraumatic brain injury, multiple sclerosis, autism, and various neurodegenerative conditions, such as Alzheimer’s disease, Parkinson’s disease, and amyotrophic lateral sclerosis (ALS), have been explored in various clinical trials and are described in this section. While the type of diet is important, it is fundamental that the nurse assess the client’s physical ability to eat. The nurse should assess the client’s current food intake, signs of fatigue, loss of movement, and evidence of dry mouth as these findings can make eating challenging. Meeting the nutritional requirements of clients who have difficulty swallowing ( dysphagia ) secondary to a stroke or other condition can be particularly challenging because these clients require additional diet modifications so that foods can be consumed safely to decrease the risk for choking or aspiration.
Meeting the nutritional requirements of clients with a stroke can be challenging, given the potential for difficulty swallowing (dysphagia). Although the ideal diet for a client who has had a stroke is generally similar to a cardiac diet (low salt, low fat, high fiber), this may be challenging.
Ketogenic Diet
The ketogenic diet is high in fat and low in carbohydrates, and has been used to facilitate treatment for clients with drug-resistant epilepsy . The impact of the ketogenic diet, as well as variations like a modified Atkins diet or low glycemic diets is to promote the formation of ketone bodies. The brain uses ketones to generate energy, and this type of diet reduces the magnitude of glycolysis . Although the science is still somewhat unclear, it is thought that this generation of ketone bodies alters the metabolism of certain neurotransmitters and improves mitochondrial function in a fashion that reduces oxidative stress , improves mitochondrial function , and activates certain signaling pathways (Francis & Stevenson; Miller, et al., 2020).
The beneficial impact of ketogenic diets in clients with epilepsy is well known to be a reduction in seizures that have been previously intractable to drug therapy. In addition, the impact of a ketogenic diet in children with epilepsy often includes an improvement in cognitive function and a reduced rate of developmental delays, if initiated very early. However, the impact on cognition may be directly related to the diet or to a brain injury associated with uncontrolled seizures.
The ketogenic diet shows some promise in other conditions as well, such as multiple sclerosis , autism , and Alzheimer’s disease (Li, 2021). In a study of clients with multiple sclerosis, a ketogenic diet may improve concentration, attention, and memory (Francis & Stevenson, 2018). Although limited data exists due to small sample sizes and difficulty with blinding procedures, a ketogenic diet has been shown to improve autistic behavior, but individual food preferences and the gastrointestinal impact of this diet may impact feasibility (Francis & Stevenson, 2018). The effect of the ketogenic diet is to produce a state of ketosis, and among individuals with Alzheimer’s disease, a modest improvement of cognitive function occurs when ketosis is achieved. However, among individuals with Alzheimer’s disease, cognitive improvement was observed only when clients engaged in a ketogenic diet achieved ketosis, even among those with severe Alzheimer’s disease (Tabaie, et al., 2022). Among individuals with ALS , a high-fat diet, such as the ketogenic diet, has been shown to slow disease progression, while a calorie-restricted diet has been shown to reduce survival rates (Jiang et al., 2022).
Mediterranean Diet
While the Mediterranean diet (Figure 6.4) has shown effectiveness in preventing heart disease, the antioxidant and anti-inflammatory benefit of this diet can help prevent stroke events and slow cognitive decline in clients with Alzheimer’s disease, in part because of the long-chain polyunsaturated fatty acids and olive oil. Moreover, the polyphenols obtained from fresh fruits and vegetables have been shown to mitigate the phosphorylation of tau protein , preventing tangle formation, and to negate beta-amyloid aggregation in the brain. The net effect of reducing oxidative stress and neuroinflammation is to enhance neurogenesis , improve transmission across synapses, and reduce neuronal death (Román et al., 2019).
Alternative Food and Supplement Options
While the ketogenic and Mediterranean diets have shown promise in the prevention and management of neurologic conditions, the metabolism of lipids in the brain are dramatically disrupted when there is an excessive intake of carbohydrates , particularly those found in processed foods such as high-fructose corn syrup and artificial sweeteners. However, complex carbohydrates, such as those found in fresh fruit, vegetables, and high-fiber cereal grains, are recommended for the management of cognitive decline (Román et al., 2019).
Client Teaching
In general, a diet rich in fruits and vegetables, whole grains, nuts, seeds, fish, meats, eggs, dairy products, healthy fats (olive oil, avocado, coconut, and flaxseed oils), and probiotic-rich foods (yogurt, kimchi, kefir, sauerkraut), as well as fresh herbs and spices are neuroprotective.
For clients with neurologic conditions, preventing further brain inflammation can mitigate or slow degenerative processes. Resveratrol is a polyphenolic compound that is present in grapes, mulberries, tea, seeds, some cereals, and red wine consumed in moderation. It can protect the body from developing increased levels of triglycerides and cholesterol and can have a positive effect in the early stages of neurodegenerative disorders (Oppedisano et al., 2020).
Ensuring optimal intake or supplementation of vitamins and certain minerals, such as magnesium, can prevent acute episodes of brain fog and fatigue in persons with MS . When supplementing clients with deficiency of vitamins A, B 12 , and D 3 , it is helpful to administer these supplements with magnesium , as they do not compete with one another during for absorption. Reducing carbohydrate intake can also help to mitigate the fatigue of MS. Coenzyme Q10 ( CoQ10 ) has been shown to have a significant antioxidant effect to produce energy and is well known for the prevention of heart disease, but it also has neuroprotective effects. CoQ10 is not available in foods but is synthesized by the body. In clients who have experienced ataxia because of neurologic conditions, supplementation of CoQ10 has been shown to improve both gait and posture (Oppedisano et al., 2020).
A diet high in antioxidants and fiber can help fight inflammation in clients with MS and will slow further demyelination and prevent constipation. Some sources suggest that a ketogenic diet prevents or slows symptom to manifest in clients with MS (Dynka et al., 2022).
Read the following clinical scenario and then answer the questions that follow. This case study is a follow-up to Case Study Part A.
During John’s visit it becomes apparent that he is experiencing some cognitive decline. The health care provider is recommending further neurological evaluation for possible dementia. The provider is also concerned about the client’s weight loss and wants the nurse to work with John to improve his food intake.
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Increase intake of complex carbohydrates.
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Switch to drinking diet beverages with artificial sweeteners.
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Limit fluid intake and focus on solid food intake.
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Vitamins and supplements are used as a last resort.
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Vitamins and supplements do not contain adequate amounts of needed nutrients.
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Taking vitamins and supplements may be confusing for the client and difficult to remember to take.
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Research shows that eating a nutrient-rich diet is the best source of micronutrients to support cognition.