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Mediterranean Diet (Meddiet) And Neuro-degeneration

 Sep 23, 2022
MedDiet and Neuro-degeneration

Prospective observational studies and clinical trials carried out in Mediterranean and non-Mediterranean nations with various health outcomes have extensively explored this eating pattern, which has been customarily followed for centuries by inhabitants from the Mediterranean countries. This substantial data demonstrates its favorable effects in preventing a number of non-communicable diseases (NCDs), including dementia and cognitive deterioration.

According to a systematic evaluation of prospective cohort studies, persons who adhered to the MedDiet the best had a 33% lower risk of acquiring MCI or AD than those who adhered the least. In the PREDIMED (Prevention con Dieta Mediterranea) trial, adults (aged 55 to 80 years) at high cardiovascular risk who followed a MedDiet supplemented with extra virgin olive oil (EVOO) or nuts experienced fewer cardiovascular events—a known risk factor for cognitive decline—over the course of a 5-year follow-up period than those who followed a low-fat diet. An improvement in cognitive performance with the MedDiet supplemented with either EVOO or nuts vs. a low-fat diet has been documented in sub-analyses of this research. Higher adherence to a MedDiet was linked to shorter cognitive decline and incident AD in prospective longitudinal trials done in the USA and France (Dr. Mario).

According to several reviews, there is some evidence indicating that adhering to a MedDiet is linked to a lower chance of getting AD, although further research in other communities and ethnic groups is still required. Several of the results are in disagreement. The Australian Imaging, Bio-markers and Lifestyle (AIBL) study, found that patients with AD or MCI showed lower adherence to the MedDiet as compared to controls. Another Australian study, the Personality and Total Health (PATH) through Life longitudinal study, found no protection of the MedDiet for cognitive decline. In 3790 over-65 adults from the Chicago Health and Aging Project longitudinal cohort who were followed for seven years, Tangney et al. assessed adherence to the Healthy Eating Index (HEI)-2005 or to the MedDiet in regards to alterations in cognitive performance. After controlling for co-variates, they discovered that higher MedDiet adherence scores were linked to decreased rates of cognitive decline, but no link was identified for HEI-2005 levels. As previously indicated, the MedDiet is the eating plan for which the most studies have been published to far in the medical literature (Dr. Tangney).

Morris et al. recommended combining the most neuro-protective elements of MedDiet and DASH in a dietary pattern known as MIND diet based on the data that both were related with decreased incidence of cognitive decline. These two dietary models contain sources of a number of vitamins, antioxidants, polyphenols, monounsaturated fatty acids (MUFAs), polyunsaturated fatty acids (PUFAs), and docosahexaenoic acid, which is the explanation of why the dietary patterns led to better cognitive health because they combined all these neuro-protective nutrients (Dr. Morris).

The MedDiet, DASH, and MIND diets are mostly plant-based and consist of these nutrient-dense foods: vegetables, fruits, nuts & seeds, whole grains, legumes, healthy fats, fish, and chicken. Additionally, the MedDiet, DASH, and MIND diets advise limiting consumption of foods and beverages that are frequently connected to Western dietary patterns and poor health outcomes, such as red meat, sweets, processed meals, and beverages sweetened with sugar. Indeed, a higher risk of AD has been linked to the Western food pattern, however the exact mechanisms are still unclear. Western diets increased brain inflammation and beta-amyloid protein formation in experiments.

Additionally, the MedDiet, DASH, and MIND diets lower middle-age CV risk factors, such as vascular disease, hypertension, stroke, diabetes, and obesity, which are all risk factors for AD. Particularly in midlife, risk factors for vascular disease are linked to beta-amyloid buildup in the brain. Focusing on modifiable lifestyle risk factors can theoretically prevent or delay the onset of roughly 40% of dementia cases. The components of these three healthy eating patterns may therefore have synergistic effects on physiological processes and signalling pathways linked to cognitive performance and decline, according to growing research, which also points to these diets' other benefits. Thus, there is a lower incidence of cognitive impairment and incident AD with the MIND diet, which combines components of the MedDiet and DASH. After adjusting for confounders, Morris et al. found a positive association between following the MIND diet and a slower decline in five specific cognitive domains as well as in overall cognitive performance among nine hundred and sixty individuals of the Memory and Aging Project who had been followed for an average of 4.7 years. Participants aged 58 to 98 years old who adhered to the MIND diet the best showed a decrease in incident AD compared to those who adhered the least. Considering all available data, just one study showed inconsistent findings when testing the MIND diet (Dr Morris).

In conclusion, the MIND diet can be regarded as a dietary pattern that promotes neuro-protection. However, to prove its applicability to brain health, replications of the promising outcomes with the MIND diet are required in different populations.