One of the most serious risks associated with old age is the loss of mental powers. Senile dementia, Parkinson’s and Alzheimer’s diseases. All of these can turn our lives and those of our loved ones into hell.
Fortunately, it is quite simple to minimize the risk of such problems. The brain is an organ that is quite sensitive to free radical damage, among other reasons, because it can’t regenerate itself and what is once damaged won’t repair itself. That is why it is so important to protect it. It is not made easier by the fact that many antioxidants do not penetrate the blood-brain barrier, so they are less useful in this case.
The most important thing, of course, is to avoid free radicals and other sources of damage. There is not much philosophy. You shouldn’t eat things commonly considered unhealthy, and you shouldn’t smoke. Studies have found that high meat consumption increases the risk of Alzheimer’s disease by up to 2-3 times. Since I’ll probably be accused of propaganda here, I’m providing links to the study :
https://www.ncbi.nlm.nih.gov/pubmed/8327020
https://www.ncbi.nlm.nih.gov/pubmed/20385883
Chemical contamination should be avoided, whether in food or in the workplace.
Vitamin B12 is very important. To get full protection against nervous system disorders, its level should be high enough, much higher than the lower limit of the norm in most countries. You should aim to keep it above 500 pg/ml (370 pmol/L), keeping in mind that at least 2 weeks before the test you must not take any supplements containing it, as this falsifies the result. Contrary to popular belief, deficiencies are very common and do not only affect vegetarians, and to make matters worse, almost every elderly person has a problem absorbing B12.
Substances such as resveratrol and cysteine protect brain cells from damage quite strongly, especially cysteine. Carnitine was also highly effective, but with it you have to take into account potential side effects, such as overproduction of TMAO in the gut. Without going into details, this is a very dangerous phenomenon, which can lead to faster development of atherosclerosis and increase the risk of cancer. Antioxidants of all kinds are invaluable, even if they don’t work directly, they will reduce the burden on the body in other regions and remove free radicals from the blood before they are transferred to the brain. Nothing can replace a diet rich in fruits and vegetables.
A study in which cysteine had such a strong protective effect that clinical trials are being considered as a drug against Alzheimer’s disease:
https://www.ncbi.nlm.nih.gov/pubmed/28411131
An article that considers the role of resveratrol in preventing neurodegenerative diseases:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5664214/
Protective effects of carnitine:
https://www.ncbi.nlm.nih.gov/pubmed/1944900
By the way, carnitine has a synergistic effect with alpha lipoic acid, the one to buy at any pharmacy as a supplement against diabetic neuropathy. The effect was really powerful when they occurred together, the protective effect appeared already at concentrations 100-1000 times lower than when they were used separately:
https://pubmed.ncbi.nlm.nih.gov/20414966/
Preliminary research suggests a very large role for active omega 3 acids, EPA and DHA, in the prevention of disease and even in the treatment of existing disease. They are not found in vegetable oils, only in fish or in very expensive algae supplements. Algae themselves contain too little of them to make a difference in health.
Studies have shown that people who sustain mental activity are much less likely to suffer from such diseases, and even when they do occur, their course is greatly slowed. Engaging in music, such as singing lessons or playing instruments, had a particularly strong impact here.
Quite a long article, where risk factors for Parkinson’s disease are analyzed in detail. In a nutshell, milk and milk products are a very big risk factor, while vegetables, fruits, omega 3 acids, especially DHA (absent in vegetable oils), soy products, and coffee and tea play a protective role:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3945400/
Finally, care should be taken to keep homocysteine levels low enough; in one study, lowering homocysteine levels slowed gray matter atrophy in the brain by as much as seven times!
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3677457/
There have been reports that Alzheimer’s disease has its origins in neuroinfections, if confirmed, the therapy will be quite simple and effective, just high doses of zinc and maybe other antiviral agents, especially cysteine.