Tag: cognitive health

Noise on Cognitive Health

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Have you ever felt you could focus better and enter your flow state when working in a cafe? You may have noticed that it might be the background noise in the cafe that helped you stay focused. But have you also felt stressed by a loud background noise, like the drilling sound from a construction site nearby? Today, we will explore the impact of noise – especially those we are exposed to in urban areas – on our cognitive health!

What Are Noise Levels?

Noise levels are measured by decibels (dB). According to the US Centers for Disease, Control and Prevention (CDC), the US Environmental Protection Agency (EPA), and the World Health Organization (WHO) recommend maintaining a noise level below 70 dB over 24 hours to prevent noise-induced hearing loss. Listening to loud music, going to concerts, or hearing sirens are some of the risky activities that could lead to hearing loss.

Just to get a sense of varying levels of dB, here are some examples. Your typical breathing sound is approximately 10 dB, a soft whisper is about 30 dB, and normal conversations have a sound level of 60 dB.

According to the CDC, at sound levels between 70 and 85 dB, you may feel annoyed, and above 85 dB, you may experience hearing loss after a prolonged exposure.

How Does Background Noise Affect Us?

It appears that depending on the noise level, we are affected differently. It appears that the quality of studies investigating the relationship between the exposure to a range of noise levels and cognitive function level generally has low quality. A 2022 systematic review study found that most of the studies on this topic were low-quality studies.

Having that said, there are some studies that indicate cognitive decline with exposure to the high noise level. A 2020 study has shown that an average increase of 10 dB increases the likelihood of cognitive decline and dementia.

In contrast, a 2022 experimental study showed at noise level less than 45 dB helped individuals to focus on their work. While a noise level of around 65 dB also helped with focus, it also increased stress.

A 2021 neuroimaging study using electroencephalography (EEG) explains that background noise affects stress, attention and mental load. Another 2019 EEG study showed that verbal/auditory attention decreases significantly when exposed to the noise levels above 90 dB. A 2013 study showed that children exposed to background noises may face challenges with learning, especially recalling verbal recalls.

Exposure to noise can increase stress hormone level, which may have negative consequences to cognitive health, too. Misophonia is a condition in which a person has increased irritability once hearing sounds like a chewing sound, is an example where noise can increase the stress level. Chronic stress can lead to a cognitive health decline.

What Can We Do About Background Noise?

Now that we have learned how exposure to noise affects our cognitive health, we will explore ways to reduce the noise level in our environment. The US CDC has a few recommendations:

  1. Use earplugs or earmuffs: earplugs have many benefits when sleeping. There are different types that you can choose to fit your needs. There are proper steps to using earplugs.
  2. Stay away from loud environments.
  3. Use devices that measure sound level. Smartwatches and smartphones may have apps and other functions to measure the environmental sound level.

Summary

Today, we explore how exposure to noises can affect our cognitive health. We found noise levels below 45 dB may be helpful for focus, but prolonged exposure to sound levels above 65 dB may increase stress levels that may be harmful. We also found that we could use smartwatches or smartphones to measure the environmental noise level and use earplugs to reduce the exposure. We hope this blog has helped you understand how noise affects our cognitive health!

Cognitive Benefits of Walking in Nature

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Have you felt a sense of calm and relaxation when you walk around a garden, a park, or a forest? Especially in urban areas, green spaces give a sense of peace in the middle of chaotic urban life. Today, we will explore the benefits of walking in nature.

  1. Types of Nature
  2. What Are the Benefits of Walking in Nature?
  3. How Does Walking in Nature Help Cognitive Health?
  4. How Can We Increase Access to Nature?
  5. Summary

Types of Nature

Let’s first go over what we mean when we talk about nature. Compared to rural or suburban regions, urban areas often lack access to nature, such as trees, grass, and shrubs. In order to increase access to nature, local governments promote building infrastructure that supports community access. The types of such structures include:

  • Green Street: a type of street with perennials, shrubs, and trees to capture rain/stormwater and pollutants
  • Green Space: an open space in an urban setting, such as parks, community gardens, and green roofs.

If you are interested in looking up how much green space your neighborhood has, you can look up the Normalized Difference Vegetation Index, which captures the level of green space concentration in a region.

What Are the Benefits of Walking in Nature?

The National Institute on Aging cites a 2022 JAMA Network Open paper studying 13,000 middle-aged women between 2014 and 2016 by a team of researchers from Harvard University and Boston University who found that increasing residential space may be associated with cognitive benefits among middle-aged women. They found that women have higher scores on thinking speed, attention, and overall cognitive score, about 1.2 years younger.

Access to green space may benefit even those who are diagnosed with dementia. A 2020 mixed-review study suggests that there may be benefits for people with dementia to live in a community setting with access to green space and promote horticultural programs, such as green care farms and gardening. A 2018 UK study with 28 participants found that people with mid-late stage dementia experienced increasing mood improvement with increasing time spent in the garden up to 80 minutes.

More research could be funded to better understand the association between increased access to nature and cognitive health. A 2016 systematic review investigating the association between long-term green space exposure and cognition across the life course found a limited number of available studies, most of which were poor or fair quality. Perhaps this is a field that more researchers can investigate. Another 2019 study based on the Ginko Evaluation of Memory Study (GEMS) with 3048 participants found a moderate association between green space exposure and dementia progression among US adults aged over 75 years old.

Access to green space also appears to help young people, who may experience the benefit for a more extended period of their life. A 2017 systematic review of 12 articles studying the effect of green space and the mental well-being of children found that access to green space increases attention restoration, memory, self-discipline, and lower ADHD behaviors.

How Does Walking in Nature Help Cognitive Health?

One reason walking in nature helps with cognitive health could be because the vegetation in greenspaces can capture both air and water pollution. The greenspaces may help improve cognitive health by capturing air pollution, which reduces cognitive function levels.

Another reason that spending time in nature helps cognitive function is that it reduces the risk of depression. Studies have found that spending time in nature reduces the rate of depression. Having depression was also found to be a risk factor for cognitive decline and dementia.

There are a couple theories as to what might be happening to our minds when we walk in nature. The Attention-Restoration Theory (ART) hypothesizes that urban environments often have high levels of stimulation that lead to attention fatigue. Some suggested that being in the natural environment can alleviate attention fatigue. Another theory, the Stress Reduction Theory (SRT), hypothesizes that exposure to natural environments reduces physiological and psychological stress, leading to positive emotions.

Study results appear to support both theories. A 2022 EEG study with 63 participants found that walking in nature reduced amygdala activation after the walk in nature compared to walking in an urban environment. Another 2022 EEG study with 42 participants found that even walking while watching 6 1-minute videos of green urban spaces produced more calm, positive emotions.

How Can We Increase Access to Nature?

There could be ways to increase access to green spaces. Here are a few suggestions:

  1. Create mini-forests. A Japanese graduate student, Akira Miyawaki, found ways to grow trees, shrubs, and other plants native to Japan and successfully grew them in small patches of urban land.
  2. Use your building’s roof. Building a garden on your roof could help reduce energy use and create a space for the residents/office workers to rest.

Summary

In this post, we explored types of green space, how green space gives emotional and cognitive benefits, what could be mechanism that works, and how we can increase access to green space. If you have more ideas that you would like to share on how to increase green space, please comment below! We hope this post has helped you understand the importance of exposure to green space and building more of them.

Alcohol: Negative Cognitive Health Effect

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Drinking alcohol is prevalent in most cultures. Some claim that liquor is a social lubricant, allowing people to bond. But many would also attest to feeling they couldn’t walk straight, talk without slurred speech, or remember what happened the day after drinking alcohol. In this post, we will explore the potential long-term adverse effects of drinking liquor.

Please note depending on where you live, there may be an age limit (e.g., 21 years old if you live in the United States) on when you can legally purchase and drink alcohol.

What are Alcoholic Drinks?

Liquor is an alcoholic drink often produced by distilling fermented grains, fruits, or vegetables. Common types of liquor include beer, wine, and hard liquor, such as whiskey.

The United States Centers for Disease Control and Prevention (CDC) recommends 1 or fewer drinks in a day for women and 2 or fewer drinks in a day for men. A “drink” standard drinking size in the United States contains 14 grams (0.6 ounces or 1.2 tablespoons). This is equivalent to:

  • 12 ounces of 5% alcohol beer
  • 8 ounces of 7% wine
  • 1.5 ounces of 40%alcohol liquor.

The CDC defines binge drinking as drinking 4-5 or more drinks a day and heavy drinking as drinking 8-15 or more drinks per week. Binge drinking could lead to alcohol poisoning, a medical emergency from high blood alcohol levels because excessive drinking exceeds the body’s capacity to process alcohol.

Symptoms of alcohol intoxication include decreased judgment and control, slurred speech, reduced muscle coordination, vomiting, reduced consciousness and cognitive function, and coma.

What Are the Effects of Alcohol on Cognitive Health?

Heavy drinking was found to be associated with an increased risk of dementia. A 2018 longitudinal study in the United Kingdom following people’s alcohol consumption level for 23 years suggests that those who drank more than 14 drinks a week had an increased risk of dementia.

A 2019 systematic scoping review conducted on articles published between 2000 and 2017 suggests that heavy alcohol use was associated with changes in brain structures, cognitive impairments, and increased risk of dementia. A 2023 systematic review in Europe also found a similar effect: moderate to high alcohol consumption was associated with an increased risk of cognitive impairment, memory loss, and risk of dementia.

Another study conducted in 2019 with 785 individuals from the Jackson Heart Sleep Study suggests that evening drinking alcohol can impair sleep quality, which may lead to a high likelihood of memory impairment and other cognitive functions.

Other effects of drinking alcohol include:

  • Liver disease: fatty liver, cirrhosis, hepatitis, fibrosis, and liver cancer
  • Heart disease: arrhythmias, cardiomyopathy (enlarged heart), hypertension, stroke
  • Muscle loss: muscle waste (reduced muscle tissue)
  • Depression & Anxiety: higher likelihood of depression & anxiety
  • Obesity: increased likelihood of weight gain

Are There Benefits of Drinking Alcohol?

A moderate amount of drinking (1-2 drinks) was associated with a lower risk of dementia. Some studies suggest light drinking (drinking low alcohol content) can help with rehydration after a workout, but some studies produced evidence suggesting that it may impair muscle recovery.

In the early 2000s, discoveries were made that resveratrol, a chemical found in red wine, has an antioxidant property that may have an anti-aging effect in mice. However, the researchers also found that you would have to consume about 1000 bottles of wine in order to find a similar effect in humans.

Summary

We explored the effects of alcohol on our mind, body, and overall health. Drinking above the recommended amount of alcohol (1-2 drinks) was associated with an increased risk of cognitive decline. We hope this post has helped you learn some of the consequences of excessive drinking and help you have a healthy drinking life. Please drink (if you are legally allowed to) responsibly!

If you have an alcohol disorder or any other health concerns related to alcohol, please contact your physician or the SAMHSA (Substance Abuse and Mental Health Services Administration).

Air Pollution Impairs Your Mind

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On June 7th, 2023, New Yorkers woke up to an unfamiliar scene: an orange-colored sky above New York City’s skyscrapers. New York Times reported that this was the historically worst air pollution in NYC. Other parts of the United States are experiencing similar air pollution due to the forest fires in Canada. Today, we will explore how exposure to air pollution could affect our cognitive health.

What is the Cause of Air Pollution?

The current air pollution was caused by forest fires in British Columbia and Alberta in the west side of Canada and Quebec on the east side of Canada, moving south towards the United States. Half of the forest fires are caused by humans, while the other half are ignited by lightning strikes. According to the Wall Street Journal, May of 2023 was the hottest May in British Columbia and Alberta.

Other types of air pollution include smog (a form of air pollution when combusted fossil fuels react with sunlight), pollen/mold (exposed within a residential apartment/house), and asbestos.

What Is In the Air Pollution?

Such wild forest fires produce gaseous pollutants (such as carbon monoxide), hazardous air pollutants (HAPs) (such as polycyclic aromatic hydrocarbons [PAHs]), water vapor, and particle pollution. Particle pollution is a term used to describe a mixture of solid and liquid droplets suspended in the air.

According to the United States Environmental Protection Agency, particles in particle pollution can be made up of different elements, such as biological materials (e.g., pollen and mold spores), acids (e.g., sulfuric acid), inorganic compounds (e.g., ammonium sulfate, ammonium nitrate, and sodium chloride), organic chemicals, soot, and metals.

You will often see in news articles notations such as PM10 or PM2.5. PM10 means particulate matter 10 micrometers or less in diameter, PM2.5 is particulate matter 2.5 micrometers or less in diameter. PM2.5 is generally described as fine particles. AQI is another acronym that is often used to indicate air pollution level. AQI stands for Air Quality Index. It was a range of values. For example, good air quality AQI ranges from 0 to 50, moderate air quality ranges between 51 and 100, and unhealthy for sensitive groups ranges between 101 and 150. There are more ranges with higher AQI values.

What are the Effects of Air Pollution on Cognitive Health?

A 2014 study conducted by Columbia University researchers showed that when pregnant mothers are exposured to PAHs (Polycyclic Aromatic Hydrocarbons), the likelihood of the child developing Attention-deficit/hyperactivity disorder increased. A 2022 study in China showed similar results. Other types of disorders due to prenatal exposures to air pollution include lower birth weight, smaller brain size, autism spectrum disorder, and lower IQ score.

For older adults, exposure to air pollution may lead to cognitive decline, neurodegenerative diseases, and osteoporosis. Following about 4000 people from 1978 to 2018, a 2021 study found that higher 10-year average exposure to air pollution increases the risk of all types of dementia. Another study published in 2020 followed about 60 million people from 2000 to 2016 and found increased likelihood of having a Parkinson’s disease or Alzheimer’s disease among those who had a higher exposure to air pollution. A 2023 study found that postmenstrual women who were exposed to air pollution were more likely to have osteoporosis.

A 2020 study cites multiple studies to explain why air pollution might be associated with cognitive decline. The authors explain that proteins such as Tau and beta-amyloid deposits in the brain, which have been found to be associated with neurodegenerative diseases, are also linked to hypertension and other cardiovascular diseases. Cardiovascular diseases, in turn, are associated with stroke and cerebrovascular diseases. The author suggests that air pollutants such as nitrogen oxide and ozone may cause inflammation in the brain and cause cognitive impairment and neurodegenerative diseases. A 2014 study showed an association between exposure to nitrogen oxide and cognitive impairment among older adults in Los Angeles, California.

Exposure to air pollution may vary depending on the neighborhood socioeconomic status. A 2022 study that followed 12,000 participants for more than 50 years showed that living in a lower neighborhood socioeconomic status could increase the likelihood of cognitive impairment. A 2022 study with Chinese Health and Retirement Longitudinal Study between 2011 and 2015 found small effect of air pollution on cognitive decline.

If you would like to learn more about the effects of air pollution on your health, please feel free to visit the National Institute of Environmental Health Sciences’s web page.

What Can We Do to Prevent/Mitigate Exposure to Air Pollution?

In order to check the air quality in your area, you can utilize tools like the EPA’s air pollution monitor, AirNow. You can stay indoors, where the central air system has a higher quality air filters such as High Efficiency Particulate Air (HEPA) filter.

  • Use electrostatic air cleaner: it works with static electricity to charge particles inside the air purifier, which can attract those charged particles to the sides of the internal filtration system and remove from the air.
  • Use portable filter-based air cleaners: these air cleaners can remove bacteria, viruses, and air pollutants. New York Times has a great list of air cleaner recommendations.
  • Avoid outdoors activities: in order to reduce the chance of inhaling air pollutants, avoid rigorous outdoors activities such as running and biking. Also, try to avoid traffic, which may have higher concentration of air pollutants.
  • Wear KN/N95 masks: wearing masks can reduce air pollutant inhalation like carbon monoxide.

A 2020 study showed that consuming omega-3-rich foods can have protective effect against brain shrinkage among older women.

Summary

We looked into what are components of air pollution. We then explored what could be health effects of inhaling air pollutants. Although it is unfortunate that there is limited activities we can do to immediately reduce the air pollution, we can take steps to prevent deteriorative health effects. If you have health concerns, please contant your physicians for concrete evidence and detail of your care.

Disclaimer: This web post is for information purposes. If you have medical needs, please contact your primary care physician

Cognitive Benefits of Physical Exercise

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Physical exercise has many benefits: losing weight, maintaining health, and preventing diseases from a sedentary lifestyle. Did you realize that you can also have cognitive benefits from regular physical exercise? In this post, we will explore ways physical exercise can improve cognition.

  1. What are the Benefits of Physical Exercise?
  2. How Does Physical Exercise Increase Cognitive Function?
  3. Other Benefits of Physical Exercise
  4. What are the Types of Physical Exercise?
  5. How to do Physical Exercise?
  6. Summary

What are the Benefits of Physical Exercise?

A 2018 systematic review cites studies that found improvement in cognitive functioning. Wait, but do you know what “cognitive functioning” means? The word “cognitive function” is used frequently in psychology literature when we talk about psychological benefits. So what is it? American Psychological Association defines it as “the performance of the mental processes of perception, learning, memory, understanding, awareness, reasoning, judgment, intuition, and language.” It’s the brain’s capacity to learn, memorize, do daily activities, and pay attention.

The cited studies in the systematic review found improvement in memory, decision-making, and paying attention. Among children, those who exercise were more likely to have better academic achievement, such as verbal and arithmetic tests, compared to those who do not regularly exercise. Children with ADHD who had regular exercise had improved decision-making ability than those who did not exercise. For older adults, incorporating regular physical exercise up to middle life provides the most protective effect against cognitive decline due to natural aging. A 2015 study suggests that older adults vulnerable to cognitive impairment may benefit from combining cognitive training and exercises. Regular physical exercise may reduce the risk of dementia and Alzheimer’s disease and improve quality of life.

How Does Physical Exercise Increase Cognitive Function?

So how does regularly going out to exercise improve the brain’s capacity to learn and remember? The 2018 systematic review shows that regular physical exercise led to neuroplasticity, the capacity of neurons in the brain to change their connections. Authors cited a number of studies showing physical exercise increasing gray matter volume and reducing damage in the gray matter in frontal and hippocampal regions.

Physical exercise also increases blood flow, brings more nutrition (such as oxygen and energy from glucose and triglyceride breakdowns) to the brain, and stimulates the release of peripheral brain-derived neurotrophic factor (BDNF), which regulates the creation of synapses (neuron connection) and synaptic plasticity underlying learning. Changes in neurotransmitters, such as serotonin and endorphins, are cited as contributors to improved cognitive function as well.

Other Benefits of Physical Exercise

Physical exercise can also improve the sense of self-competency, self-efficacy, and self-esteem. This could help create positive social interactions and opportunities, possibly preventing cognitive decline. A 2023 study points out that social isolation, loneliness, and depression may be associated with cognitive decline. According to the 2018 systematic review, regular physical exercise can reduce depression and anxiety compared to those who do not exercise regularly.

It can also reduce unhealthy behaviors like smoking cigarettes, drinking alcohol, and gambling. These beneficial effects may last to even the next generation. The systematic review cites studies investigating epigenetic changes due to regular exercise, in which gene expression is regulated to give lasting cognitive benefit through increasing gene expression that produces proteins associated with memory and learning.

What are the Types of Physical Exercise?

Now that you may be interested in applying regular physical exercise to your daily life, you may wonder, “What type of physical exercise is good for me?” Factors to consider when choosing a physical exercise are intensity, frequency, duration, and whether you do it alone or in a group.

  • Aerobic exercises (exercises with intense oxygen usage) usually last long, with adjustable intensity. Typical aerobic exercises include jogging, running, cycling, and swimming.
    • Acute aerobic exercise: enhances mood and cognitive function (usually small effect)
    • Chronic aerobic exercise: increases neuroplasticity, and cognitive function (memory/decision-making), prevents neurodegeneration, and decreases anxiety and depression.
  • Anaerobic exercises (exercises with less oxygen usage) usually have high intensity and short duration. It does not use the energy created by the breathing system but instead uses energy stored in your muscles.
    • While some studies suggest improvement of mood with anaerobic exercises, a limited amount of studies suggest improvement of cognitive function with anaerobic exercises.
    • A 2017 study comparing anaerobic exercise against aerobic exercise among college-aged students found that there are no significant benefits found with anaerobic exercise but modest improvement with aerobic exercises.

How to do Physical Exercise?

So what kind of physical exercise should we do to improve our cognitive function level? Harvard Health Blog of Harvard Medical School recommends aerobic exercises such as running and cycling that can increase oxygen transported to the brain through the blood system. Other recommended forms of exercise include yoga and tai chi, although there is less evidence of improving cognitive functions. It cites the CDC’s recommendation of targeting at least 30 minutes of daily exercise five days a week.

American College of Cardiology 3 steps of planning exercise for those wanting to exercise.

  1. Plan your 3 “E”s
    • Energy: you should start exercising when you feel you have enough energy. If you just ate a meal, wait at least 1 hour before your exercise starts.
    • Environment: if you exercise outside, extreme temperatures should be avoided (>85’F or <32’F). Wear supportive footwear!
    • Effort: try starting with a comfortable level where you can carry on a conversation.
  2. Plan your exercise Type, Frequency, Intensity, and Duration.
    • Type: start with a warm-up with slow pace walking/biking and end with a cool-down with similar intensity. Stretch major muscle groups (hamstrings, calves, and Achilles tendons) for 20-30 seconds.
    • Frequency: you can exercise as short as 5 minutes daily and increase it to 5 times per week of 30-minute exercises.
    • Intensity: start with fairly light intensity and increase to a more intense level, then cool down to fairly light intensity again.
    • Duration: you can start with as short as 5 minutes, then increase to 30 minutes daily.
  3. Keeping your Motivation
    • Doing exercise in groups could help you keep accountable for your exercise goals. You can visualize the end result of your exercise. Try to recall all the benefits we discussed in this post!

Summary

Physical exercise can help improve mood, learning and prevent unhealthy behaviors. Simple steps can be taken to gain the advantage of these exercises, especially aerobic exercises. We also explore how exercise leads to biological changes that improve our cognitive function. We hope that this has helped you motivate exercise more!

Disclaimer: This web post is for information purposes. If you have medical needs, please contact your primary care physician.