Olfactory impairment may be a sign of cognitive decline, but "olfactory training" may help!

May 13, 2019 / BIOON / - as we grow older, our olfactory ability often suffers from problems (called olfactory disorders) Older people may not be able to recognize or distinguish one odor from another In some cases, they may not be able to detect the smell at all Odor recognition difficulties are common in people with neurodegenerative diseases, including Alzheimer's In the absence of known medical reasons, olfactory impairment may be a predictor of cognitive decline It is estimated that in five years, the elderly who have difficulty identifying common odors are twice as likely to develop dementia as those who do not have a significant loss of smell Photo source: http://cn.bing.com olfactory dysfunction usually occurs before other cognitive symptoms occur, although the loss may not have been detected Olfactory problems are not only a potential early indicator of Alzheimer's disease, but also a potential safety risk, such as inability to smell gases, smoke or rotten food Olfactory ability is also closely related to our taste ability Therefore, the loss of olfactory ability will lead to the loss of appetite, leading to malnutrition In turn, olfactory defects reduce quality of life and increase the risk of depression But there is new evidence that olfaction or "olfactory training" can improve olfactory ability These findings may provide some hope for the elderly who are experiencing olfactory difficulties and declining quality of life How does our sense of smell relate to our brain? The olfactory process activates the complex olfactory network in the brain For example, when we smell a rose, the receptors in our nose detect many molecules that make up the smell of the rose This information is then sent to many areas of the brain (including the olfactory bulb and olfactory cortex, hippocampus, thalamus and prefrontal cortex of the eye socket) to help us process information about smell Photo source: http://cn.bing.com in order to name the rose, we obtained the stored knowledge about its odor molecular pattern based on our past experience Therefore, it is considered a cognitive task to recognize the smell of roses What is olfactory training? From flies to primates, olfactory training of various animals has been studied The number of brain cells in animals exposed to multiple odors increased, and the connections between brain cells also increased This process has been shown to enhance learning and memory of odors For humans, olfactory training usually involves smelling out a series of strong odors representing the main odor categories -- floral (such as rose), fruity (lemon), aromatic (Eucalyptus) or resinous (clove) Participants may be asked to focus on a particular odor, try to detect a particular odor, or pay attention to the intensity of the odor Generally speaking, repeat training for several months every day It is suggested that the period of the elderly should be more than three months This kind of training has been proved to improve people's ability to distinguish and distinguish smells To a lesser extent, it can help people with various forms of olfactory loss, including those with brain damage, such as head injury or Parkinson's disease, carry out odor detection Photo source: http://cn.bing.com it is important that a recent study on olfactory training for the elderly found that olfactory training can not only improve the ability to recognize smells, but also improve other cognitive abilities For example, compared with the control group who completed Sudoku exercises, the participants who received olfactory training had improved language fluency (the ability to name words related to a certain category had improved) How does olfactory training work? Neuroplasticity, the ability of our brain to constantly respond to experience, may be the key to olfactory training Neuroplasticity involves creating new connections and / or strengthening existing connections between neurons (brain cells), which in turn can lead to changes in thinking skills or behavior When we practice a skill, such as playing an instrument or learning a new language, we can see evidence of neural plasticity Olfactory network is considered to be a special neural plasticity Therefore, neural plasticity may be the basis of the positive results of olfactory training, both in improving olfactory ability and other cognitive tasks Can olfactory training become a new brain training? Source: http://cn.bing.com brain training to maintain or enhance cognitive function has been widely studied in Alzheimer's patients or people at risk of dementia The established cognitive training methods usually train participants to use visual or auditory stimulation learning strategies So far, no one has tried to use smell for formal cognitive training However, using neural plasticity of olfactory networks and evidence-based cognitive training techniques, olfactory and cognitive deficits may be targets, especially in the elderly at risk of dementia It seems that we can train our brain through the nose Reference materials: [1] an improved sense of smart can signal coherent decline, but 'smart training' could help [2] d.p.devanand et al Olfactory identification definitions, cognitive decision, and dementia in older adults The American Journal of German psychological Volume 24, issue 12, December 2016, pages 1151-1157 https：//doi.org/10.1016/j.jagp.2016.08.010
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