Spinach, lettuce, beetroot... these are some of the foods not to be missed as they are capable of protecting the brain and reducing the risk of dementia over the years. This emerges from a very recent scientific study published in the journal The American Journal of Clinical Nutrition by a Dutch team from the Erasmus University Medical Center, Rotterdam (de Crom et al, Am J Clin Nutr, Jul 2023).
How vegetables can protect the heart and brain
Nitric oxide is a substance that regulates the dilation of blood vessels and inhibits platelet aggregation, thus improving blood circulation and protecting the health of the cardiovascular system. Nitric oxide can be produced by the body or introduced through diet. In particular, the nitrates contained in some vegetables, such as beetroot, lettuce and spinach, can be easily converted into nitric oxide by our body. This is due to the presence, in vegetables, of other compounds such as vitamin C, which stimulate this transformation process. Since the health of the cardiovascular system is linked to the health of the brain, it is believed that a regular intake of vegetables containing nitrates can help prevent and combat dementia. However, studies carried out so far have not been able to reach certain conclusions, this is because the population samples analyzed were too small and because the research was carried out in the short term, when it is reasonable to hypothesize that the protective action provided from nutrition should instead be observed in the long term. And this is where the research we're talking about today comes into play.
The study
Dutch scientists have developed a vast study, which involved 9543 people, average age 64 years and healthy at the beginning of the research, which began in 1990. The volunteers were asked to fill in a questionnaire indicating their eating habits, in order to extrapolate the quantity of nitrates consumed in the diet, dividing between vegetable sources, such as green leafy vegetables, and meat, in which nitrates are used for preservation. The volunteers were followed until January 2020 to evaluate their health status. What emerged was that a greater intake of nitrates from plant sources reduced the risk of developing dementia. Instead, no protective action emerged from nitrates ingested through non-vegetable sources, such as meat. Finally, it has not been possible to understand the neuroprotective mechanism of nitrates from plant sources. Even when analyzing the state of the blood vessels through medical tests, no clear correlation emerged. It is possible, as hypothesized, that the blood vessels involved are small and therefore able to escape analysis. Not only that, it is also possible that nitrates act not only through the circulatory system but also through the regulation of antioxidants and free radicals.
Conclusions
The study is noteworthy as it is very vast and conducted over a long time interval. In this way it was possible to clearly show that the intake of vegetables rich in nitrates, such as lettuce, spinach, celery and beetroot, reduces the risk of dementia. Vegetables are a synergy of compounds, such as vitamin C, that promote the conversion of nitrates into nitric oxide, which in turn protects the brain. However, meat, another source of nitrates, did not show the same beneficial action. It is believed because the nitrates in meat, not being accompanied by compounds such as vitamin C, are only partially transformed into nitric oxide. The rest can convert into nitrosamines, which can instead damage the brain, thus nullifying the benefits of nitric oxide.
