by Cristina Marrone
Mitochondria are known as the powerhouse of the cell and are crucial for memory storage. Keeping them healthy (with diet and exercise) also protects against Alzheimer’s
They are the powerhouses of the cell and are crucial for the preservation of memory and memories: let’s talk about mitochondria, the organelles that produce the energy necessary for cells for all vital functions. In scientific research it is emerging that they could be key players in the fight against Alzheimer’s because damaged mitochondria are linked to the progression of the disease while healthy mitochondria would represent the key to avoiding cognitive decline.
There is still no therapy for Alzheimer’s
The way to keep mitochondria healthy is also the one that prevents tumors and heart disease or a number of other age-related diseases: exercise and a diet rich in antioxidants. It may certainly seem obvious and even boring, but that’s exactly how it is. Prevention still tests the main way to limit the risk of suffering from neurodegenerative diseases. In fact, to date there is still no truly effective cure for Alzheimer’s, despite the decades spent finding a therapy and 3.7 billion dollars spent in the United States alone. The research objectives so far have targeted amyloid, a protein that accumulates in the brain forming the typical plaques, a hallmark of the degenerative disease. The data on drugs such as Lecanebab (the only one to have obtained full approval from the Food and Drug Administration), Aducanumab and Donanemab indicated to counteract cognitive decline at the beginning of the disease are encouraging. Amyloid plaques decrease, however the results appear to be of little relevance from a clinical point of view, i.e. patients do not notice any benefits on a practical level. Furthermore, this type of therapy involves significant safety risks: during the trials, cases of cerebral hemorrhage were recorded, which in some cases were fatal. Promising results have also been published on a possible gene therapy against Alzheimer’s capable of lowering the tau protein, also known to be one of the causes of the disease. Many scientists suspect that amyloid beta plaques and tangles are not the cause of Alzheimer’s, but simply a downstream symptom. What lies upstream is mitochondrial health. And keeping mitochondria healthy might actually be a path worth taking.
When mitochondria malfunction
Mitochondria, known as the brain’s powerhouse, transform food into energy. Their tasks also include storing calcium and destroying cells that do not function well and generate heat. When mitochondria weaken they produce less ATP (a molecule that represents the main form of immediately available energy storage), poorly manage the concentration of calcium ions and do not regenerate effectively. Since our brains, when overheated, run out of mitochondria and absorb a fifth of our total calories and oxygen, they are particularly sensitive to oxidative damage. To stay in tip-top shape and efficient, the brain needs mitochondria. Mitochondrial dysfunction linked to aging and Alzheimer’s disease and occurs even before clinical symptoms appear. Recent studies they also suggest a link between abnormally functioning mitochondria and an overabundance of tau protein.
What happens to the brain with exercise
Exercise may be one of the keys to keeping your mitochondria healthy. Resistance training improves mitochondrial activity and has been shown to protect against brain atrophy in mice. In studies of Alzheimer’s patients, exercise increased blood flow to the brain, thickened the hippocampus, promoted the growth of new neurons, and improved cognitive performance. Instead, it has been seen that a sedentary lifestyle increases brain inflammation, the accumulation of oxygen free radicals and reduces mitochondrial activity. Poor mitochondrial function – agrees Gianfranco Beltrami, vice president of the Italian Sports Medicine Federation – could in fact be the cause that determines the accumulation of amyloid. That mitochondria should remain as healthy and fit as possible and that physical exercise helps in this is certainly correct.
Alzheimer’s prevention mechanisms
However, there are various mechanisms that contribute to the prevention of Alzheimer’s with physical exercise. Physical activity – explains Beltrami – reduces insulin resistance which plays an important role in the development of Alzheimer’s; facilitates the production of BDNF, a protein that has a neuroprotective effect and promotes the formation of new neurons and synapses, increasing the size of the hippocampus, a fundamental area for memory (in all subjects with Alzheimer’s the hippocampus is smaller); it also improves vascular functionality, which is crucial for the health of neurons and synapses; reduces stress which is a trigger of inflammation, a determining cause of all chronic degenerative diseases including Alzheimer’s. Finally, physical exercise promotes sleep, which greatly helps cognitive functions because it improves recovery and mood. In summary, physical exercise, in particular swimming, running, cycling, increases the survival of neurons and promotes the creation of new ones, counteracting brain aging: these are all functions linked to mitochondria.
How to know if our mitochondria are healthy
To know mitochondrial fitness, the best parameter is to measure maximum aerobic power, that is, the maximum quantity of oxygen that can be used in a certain time by an individual during a physical activity. Aerobic power is expressed as VO2 max, which is the maximum volume of oxygen consumed per minute. Essentially, it reflects the body’s ability to use oxygen for energy production (the mitochondria produce energy). Although a direct measurement of your VO2 max requires special equipment, most fitness watches provide an estimate of your VO2 max and the data varies between men and women. Measuring maximum aerobic power – adds the sports doctor – is a method also used successfully to measure the biological age of the person, which we know is often different from the chronological age.
The antioxidant diet
In addition to physical exercise, mitochondrial health improves with a diet rich in antioxidants with blueberries, red beans, tomatoes, spinach, artichokes, green tea. Calorie restriction and ketogenic diets (only under medical supervision) can also be protective. Stress, on the other hand, is a great enemy of the mitochondria: in animal studies it has been seen that chronic stress, anxiety, aggression and fear damage the mitochondria.
September 18, 2023 (modified September 18, 2023 | 09:44)
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