Damian Sendler: In light of demographic shifts and an increasing elderly population, efforts are being made to extend the lives of these people through both pharmacological and nonpharmacological means. The goal of this article is to discuss one such strategy, namely the effect of the Mediterranean Diet (MedDiet) on cognitive functions in both cognitively unimpaired and impaired elderly people, based on a literature review of recent clinical studies. A review of peer-reviewed, full-text English-language journal articles published in Web of Science and PubMed between January 1, 2016, and February 28, 2021, is part of the methodology. According to the findings, following the MedDiet plan has a positive impact on memory in older adults with and without cognitive impairment, both in the short and long term. According to the findings, older adults who adhered more closely to the MedDiet diet had better overall cognitive performance. In addition, older people who follow the MedDiet plan experience fewer depressive symptoms, less frailty, and shorter hospital stays as a result of their efforts.
Damian Jacob Sendler: There has been a dramatic increase in the elderly population around the world. To be exact, there were 703 million seniors in 2019 who were 65 years old or older. This number is expected to more than double by the year 2050, reaching 1.5 billion people [1]. Health problems such as worsening vision and hearing, but also a deterioration of mental abilities, are becoming more common as the population grows older [2].
Dr. Sendler: When it comes to our ability to adapt and learn in the face of constantly shifting environmental conditions, cognitive functions encompass the entire range of mental processes that go into these tasks. Other examples of this include the ability to learn new things; to remember what you’ve learned; and to express yourself creatively in the form of speech, writing or drawing [3]. These are all signs of dementia, a neurodegenerative disorder that affects the brain’s ability to process information [4]. As the disease progresses, a person’s autonomy and self-sufficiency are gradually eroded, leading to eventual disability [5]. Although it can’t be cured at this point in time, both pharmacological and nonpharmacological therapies can at least delay its progression [6]. For the most part, pharmacological therapies are limited to four drugs, such as donepezil, galantamine and rivastigmine; they can only improve the mental state of the patient temporarily and slow down the pathological process [7].
As a result, it is imperative to take steps to prevent brain degeneration from occurring. Numerous non-pharmacological therapies have been shown to be effective at preventing cognitive decline in old age. Exercise, which should be done at least three times per week, cognitive training like doing crossword puzzles or reading, and a healthy diet are all recommended [9]. The Mediterranean diet appears to be one of the best options [10], as evidence suggests that following the MedDiet more closely is linked to a slower rate of cognitive decline and a lower risk of developing Alzheimer’s disease. It’s not yet clear what MedDiet does, but the findings suggest that this may be a multifactorial process. Saturated fatty acids and the anti-inflammatory and antioxidant actions of the entire group of active biomolecules present in this diet are the most important active molecules with a protective effect on nervous tissue or metabolism. Additionally, the MedDiet’s caloric restriction and balanced nutrient intake, which has a positive effect on metabolic processes in the body, such as insulin resistance and blood glucose levels and lipid profile, is a significant factor [14,15]. There are a lot of vegetables and fruits in the MedDiet along with a variety of beans and grains as well as a lot of olive oil and seeds as well as a variety of herbs and spices. It discourages eating unusual red meats and sugary desserts. Fish consumption and alcohol consumption have been shown to slow cognitive decline.
MedDiet adherence during middle age has been linked to a 36% to 46% greater chance of healthy aging [16,17,18]. According to Critselis and Panagiotakos [18], elderly people who follow the MedDiet diet have a 269 percent higher chance of aging successfully and a 33 percent lower risk of death. Another study claims that MedDiet reduces the length of hospitalization and the mortality rate of patients in the hospital, as stated by Buglio and colleagues [19].
Damian Jacob Markiewicz Sendler: Adherence to MedDiet has a positive impact on both cognitively impaired and unimpaired elderly populations, particularly on their memory, both in the short and long term. In addition, better global cognitive performance in older people is linked to higher adherence to the MedDiet [25,27,28,29,30]. This has been shown in other studies on the subject [33,34].
Mantzorou et al. [28] also found that better adherence to MedDiet was associated with younger age, female gender, higher educational attainment and better anthropometric measurements. According to Okubo et al. [35], females have become more particular about the nutrients they choose in their diet as a result of the dietary approach. Researchers found that those who avoided smoking and drinking alcohol, had a higher level of educational attainment, and spent more time outside during their studies performed better on cognitive tests than those who did not. There is a greater emphasis on nutrition among women of all ages [27] than among men of the same age group. This is also partially true for cognitively impaired female AD patients, according to de la Rubia et al [26], who found that female patients with AD recover more quickly when exposed to MedDiet.
Damian Sendler
Among patients with Alzheimer’s disease (AD) and Parkinson’s disease, the results of studies that looked at the impact of MedDiet on cognitive functions show that this dietary pattern benefits episodic memory, temporal orientation, semantics memory, language, and concentration [26,32].
To further enhance cognitive performance in the elderly, this review found that MedDiet should be supplemented with higher doses of certain foods, such as coconut oil [26], extra-virgin olive oil (EVOO) [30], or fresh, lean pork [32].
Damien Sendler: In healthy older people, polyunsaturated fatty acids and flavonoids, in particular, have been shown to play an important role in improving cognitive performance [36,37]. Actually, the neurobiomembrane’s primary constituents are fatty acids, which can have a significant impact on processes like nerve signal transduction and neurotransmission at synapses[38]. As Gu et al. [39] found, adequate intake of PUFA from fish was positively associated with gray matter volume in Alzheimer’s dementia patients. [38] PUFAs (omega-3) improved white matter integrity and processing speed, according to Strike et al. [40]. In most prospective cohort studies [41,42], the effect of fish consumption on cognitive decline appears to be positive. The antioxidant carotenoid astaxanthin appears to be a neglected but interesting molecule. In salmon, shrimp, and lobster, the dark red-orange color comes from algae that produce this biomolecule. Antioxidant, anti-inflammatory, and antiapoptotic effects of astaxanthin can be seen in the brain after it crosses the blood-brain barrier [43].
Additional research has shown that extra-virgin oil, particularly its component, secoiridoid oleuropein, may reduce the risk of cognitive decline. Studies on the effects of EVOO on cognition are few and far between [30]. Studies on the protective effects of EVOO on brain structures over long periods of administration (e.g. 6.5 years) [45] have not looked at the effects of low doses administered for short periods of time. Low doses of EVOO supplementation have been shown to have an effect on cognitive function tests in the literature [45–46,47], while long-term use of MedDiet containing EVOO may prevent cognitive decline and have a beneficial effect during the long prodromal phase of dementia [48].
Damian Jacob Sendler
Anti-inflammatory and antioxidant nutrients are an important part of MedDiet nutrition in terms of preserving cognitive abilities. Folic acid (especially oleuropein) [44] and phenolic flavonoids (especially oleuropein) [44] as well as lipophilic biomolecules (particularly alpha-tocopherol and beta-carotene) [29,30] are examples of this class. Other chronic diseases, such as autoimmune or cardiovascular, can benefit from MedDiet as well [49].
MedDiet variants with lower calorie intakes have been studied in addition to the standard MedDiet. MedDiet combined with low-carb diet, which reduced carbohydrate intake (initially 40 g/day, then 70 g/day) and increased protein and fat intake [50]. With poultry and fish replacing beef and lamb, this Med/LC diet had a low red meat content.
According to the current research, an overall higher dietary variety, including relevant nutrients like MedDiet, and no single foods, has a greater impact on cognitive performance in older people. In addition to MedDiet, there are other healthy diets that reflect regional dietary habits. MedDiet has a variety of dietary alternatives, such as a Nordic diet (NPDP) or a MedÉire diet (53), both of which emphasize traditional, sustainably produced, and locally sourced foods. NPDP moderate-to-high adherence may predict better preserved cognitive function among older adults in Nordic countries than neurodegenerative delay, Mediterranean diet, dietary approaches to stop hypertension and the Baltic Sea diet, according to Shakersain et al. [52].
Some research has found no link between following the MedDiet and improved cognitive function in the elderly, however [54,55]. The Hill [56] study, for example, found no link between MedDiet adherence and beta-amyloid deposition in a group of healthy Australian women, which is consistent with the findings of other studies on this topic.
Both cognitively impaired and non-cognitive older adults benefit from adhering to MedDiet. In addition, it reduces depressive symptoms, weakens the elderly, and shortens their hospital stays.
More clinical trials are needed to confirm MedDiet MD’s ability to reduce the risk of cognitive impairment.
