Diet and medical foods in Parkinson’s disease

Parkinson’s disease (PD) is a slowly progressive neurodegenerative disorder with motor and non-motorsigns, which begins long before the diagnosis can be made. Pharmacotherapy with dopaminergic drugsis the mainstay of PD therapy. There is no currently available cure or disease-modifying treatment. Dietand various foods have been proposed as possible risk factors for PD. Nutritional supplementation withomega-3 fatty acids, vitamin D, B vitamins, and coenzyme Q may have potential in the management ofPD. In addition, several strategies could possibly lead to the development of medical foods in PD. Forexample, ketogenic diets may have effects complementary to pharmacotherapy. Gut microbial dysbiosisand altered microbial metabolites found in PD may lead to chronic low-grade inflammation in gut andbrain. Interventions targeting gut microbiota, such as the supplementation of probiotics, may providenovel approaches to PD in regard to both symptomatic treatment and disease modification. High qualityrandomized controlled trials need to be conducted in order to evaluate whether these food-basedstrategies have symptomatic efficacy or the potential to delay the progression of PD.

Dietary seaweeds and obesity

Potential therapeutic benefits of seaweed consumption have been reported in the management of body weight and obesity.In vitro and in vivo animal studies provide the majority of data available at present.The majority of studies assessing the short-term effects of alginate consumption indicate that alginate may increase satiety,reduce energy intake and support weight reduction.Mechanisms suggested for these effects include delayed gastric clearance,stimulation of gastric stretch receptors and attenuated nutrient absorption.Long-term studies in humans are required in order to allow firm conclusions.Animal studies have investigated potential anti-obesity effects of seaweeds on adipogenesis and the inhibition of major lipid hydrolyzing and metabolizing enzymes.The results of these studies suggest beneficial effects of seaweed components such as fucoxanthin on body weight and the percentage of abdominal white adipose tissue.It is premature to extrapolate these findings to humans since consistent findings are still lacking.There is at present no solid evidence indicating that seaweeds are effective in long-term weight management.However,available findings suggest potential benefits of seaweed components on obesity.Future investigations are required to establish the therapeutic efficacy in the management of overweight and obesity in humans and elucidate the underlying mechanisms of actions.

Medical foods in Alzheimer’s disease

Alzheimer’s disease(AD)is the most prevalent cause of dementia worldwide.Treatments achieving a marked improvement in symptoms or preventing or delaying the progression of the disease are not available.Various diet-related risk factors for AD have been identified.Evidence for a protective effect of the Mediterranean diet on AD risk is inconclusive.Medical foods are designed to meet specific dietary needs for certain diseases.Improvements in symptomatology and regional brain atrophy in AD have been claimed for several medical foods,for example,those providing ketone bodies as alternative energy supply to neurons,those containing precursors believed to improve synaptic function,and those addressing oxidative stress related to memory loss.Many methodological shortcomings render the interpretation of the available findings of medical food trials in AD difficult.Optimal results of medical foods in AD may be expected when administered in presymptomatic or early stages of the disease.This requires the reliable identification of minimal neuropathological changes related to AD.The outcome measures currently used may not be able to detect subtle changes in cognition and function in early AD.Large-scale clinical studies using valid,sensitive,and reliable assessment tools are needed to establish the efficacy of medical foods in AD.

Ketogenic diets and Alzheimer’s disease

Alzheimer’s disease(AD)is a progressive neurodegenerative disorder characterized by decline in cognitive functions and associated with the neuropathological hallmarks of amyloid-peptide plaques and neurofibrillary tangles.Cerebral glucose uptake and metabolism deteriorate in AD and this hypometabolism precedes the onset of clinical signs in AD.The early decline in brain glucose metabolism in AD has become a potential target for therapeutic intervention.This has led to investigations assessing the supplementation of the normal glucose supply with ketone bodies which are produced by the body during glucose deprivation and can be metabolized by the brain when glucose utilization is impaired.The present review provides a synopsis of preclinical studies and clinical trials assessing the efficacy of ketogenic diets in the treatment of AD.Both the direct administration of ketone bodies and the use of high-fat,low-carbohydrate ketogenic diets have been shown to be efficacious in animal models of AD and clinical trials with AD patients.The mechanism underlying the efficacy of ketogenic diets remains unclear,but some evidence points to the normalization of aberrant energy metabolism.At present there is only limited evidence of the usefulness of ketogenic diets in AD.However,this dietary approach seems to be promising and deserves further clinical investigations.