Can diet help in the fight against Alzheimer's? It seems so, based on the most recent scientific research that associates a diet rich in fruit and vegetables, foods rich in flavonoids such as green tea and dark chocolate, fish and extra virgin olive oil with a reduced risk of developing Alzheimer's. Today a new element is added, namely the protective role given by the carotenoids lutein, zeaxanthin and lycopene, as emerges from the research published in The American Journal of Clinical Nutrition by an American team from Harvard TH Medical School in Boston (Yuan et al, Am J Clin Nutr, Nov 2020).
The same team of researchers had already observed, a few months ago, the ability of carotenoids in general to protect the brain from the risk of Alzheimer's. With the research we are talking about today scientists have gone further, managing to precisely establish, among all the different types of carotenoids, the most effective in the fight against brain degeneration. For this purpose, the researchers analyzed the eating habits and health status of 927 people, choosing them from the participants in the large study called Rush Memory and Aging Project, which began in 1997 and ended in 2005 with the aim to understand habits and lifestyles to maintain the health of brain and cognitive function. The scientists calculated the dietary intake of carotenoids based on the food choices of the study participants. From this it emerged that, as was already known, the consumption of carotenoids in general decreases the risk of developing Alzheimer's. But the researchers also observed that, among the carotenoids, the greatest protection was given by luteins and zeaxanthin thanks to their ability to inhibit the accumulation of deposits of beta amyloid proteins and fibrils, which instead characterize Alzheimer's disease. Other carotenoids, such as beta carotene and beta cryptoxanthin, have shown weak protective properties. Instead, lycopene, another carotenoid, was found to be beneficial for brain health by contributing to the prevention of all types of pathology related to this organ.
Lutein and zeaxanthin, which are antioxidants also beneficial for sight health, are contained in corn, eggs, orange pepper, broccoli, kale, spinach, peas, parsley, lettuce, pumpkin, asparagus and pistachios. Lycopene is contained in dried tomatoes, in tomato sauce and, when it is the season, also in watermelon.