**3. Alzheimer's disease**

It is expected that the number of Alzheimer's disease (AD) cases will rise to 152 million by the year 2050. It is estimated that over 50 million people worldwide are affected by AD [19, 20]. According to projections, approximately one in ten individuals over the age of 65 will be diagnosed with Alzheimer's disease in the coming years [1, 21]. AD is one of the most common types of dementia worldwide, accounting for two-thirds of all dementia cases [21]. Lifestyle and genetic factors play a role in the development of AD, with oxidative stress playing an important role in the pathogenesis of the disease [6]. AD is characterized by cognitive impairment, typically starting with memory loss and progressing to a state where individuals become dependent on caregivers [15, 20]. It is described as a degenerative brain disease characterized by memory decline, language impairment, and cognitive deficits [1, 19]. VC has been reported to have a neuroprotective effect due to its ability to scavenge free radicals, reduce β-amyloid activity, and participate in the chelation of iron, zinc, and copper

[21]. Despite adequate nutrient intake, Alzheimer's patients have low levels of VC, making VC supplementation a therapeutic approach for AD. VC has been reported to be a potent acetylcholinesterase inhibitor [6]. Mitochondrial dysfunction, high oxidative stress, and amyloid plaque formation play significant roles in the pathogenesis of AD. Long-term VC intake has been reported to significantly reduce amyloid plaque formation [3]. VC supplementation as an adjuvant therapy has gained significant interest in individuals with AD and Parkinson's disease (PH) [10]. Alzheimer's patients have reported low plasma levels of VC, which are associated with increased oxidative stress [1]. A study has reported that a VC-rich diet increases amyloid precursor protein levels [22].
