What causes inflammation in the brain and what to do to reduce it


Inflammation is the body’s first line of immune response. Following injury or invasion, macrophages, leukocytes and other innate immune cells rush to the scene. A cascade of cell signaling pathways in the blood are activated to recruit more immune cells, eliminate invaders or damaged tissue, and increase blood flow to the affected area.

The inflammation in the brain it works a little differently. The central nervous system (CNS) blood vessels are separated from the peripheral circulation by a very restrictive barrier, called the blood-brain barrier (BBB). Typical immune cells in the blood cannot pass the BBB. However, chronic systemic inflammation over time can break down the BBB. When peripheral pro-inflammatory cytokines reach the brain’s circulatory system, the brain’s immune response is activated.

Brain cells called microglia are the main components of the innate immune system in the CNS. Normally they just “watch”, but they can be activated when inflammatory cytokines cross the BBB. When activated, microglia recruit more pro-inflammatory cytokines and, over time, further break down the BBB in a positive feedback loop. Result: swelling of the brain.

Symptoms of mild brain swelling may include:

  • brain fog
  • slow thinking
  • Tired
  • Depression
  • vision changes
  • Anxiety

Causes of inflammation in the brain

Many chronic diseases and modern lifestyles contribute to systemic inflammation which results in neurological inflammation and undesirable consequences in the brain.

poor gut health

Small intestinal bacterial overgrowth (SIBO), gut microbiota dysbiosis, leaky gut, and other gut issues can affect the brain. An unhealthy gut contributes to neurodegenerative diseases, including Alzheimer’s disease and Parkinson’s disease.

western standard diet

Here are the main components of the Western diet:

  • Industrial seed oils (cotton, corn, soy, sunflower, etc.)
  • processed sugar
  • refined carbohydrates

When ultra-processed foods make up more than half of the average American’s energy intake, it’s no wonder that chronic inflammation and disease are rampant. Diets high in these three foods reduce synaptic plasticity, a process involved in cognitive function and learning.


In obesity, fat cells work harder to store excess energy, generating excess reactive oxygen species (ROS) and triggering inflammatory cascades. As such, obese people have higher levels of inflammatory cytokines, and weight loss can reduce levels of these cytokines.

This inflammation reaches and impacts the brain. Obesity is a contributing factor to neurological disorders such as Alzheimer’s disease, in part through this inflammatory mechanism.

Diabetes and high blood sugar

In type 2 diabetes, high blood sugar increases the metabolic rate of brain cells. ROS are regular by-products of cellular respiration, but when excess ROS cannot be neutralized, oxidative stress occurs. Oxidative stress increases inflammatory cytokines and disrupts BBB gap junctions.

diabetes and neuroinflammation lead to cognitive impairment, brain atrophy, dementia and neurodegeneration. Some evidence indicates that Alzheimer’s disease can be considered “type 3 diabetes”, driven by insulin resistance in the brain.

digital media revolution

Brain imaging studies reveal striking similarities between heavy digital media users and drug addicts. These people may experience “withdrawal” symptoms when their internet access is cut off. “Gaming disorder” has been recognized as an official medical condition, showing how serious a problem technology addiction can be for the brain.


There is a lot of information about how stress affects health and contributes to disease. Stress activates the hypothalamic-pituitary-adrenal (HPA) axis to send hormones like cortisol and neurotransmitters like epinephrine directly to the brain.

Stress can also send information through the gut. Microbes make neurotransmitters which are sent by the vagus nerve.

Chronic stress leads to chronic inflammation and is linked to neurological problems such as depression, anxiety and obsessive-compulsive disorder (OCD).

Infections and toxins

Two other causes of neuroinflammation are toxins and infections. Environmental toxins, such as aluminum, and certain gut microbiota metabolites, such as LPS, can trigger brain inflammation.

Many viral infections can compromise the BBB, activate microglia, and increase brain inflammation, including measles, West Nile virus, Zika virus, and influenza.

Long-term consequences of inflammation in the brain

The brain is not meant to be chronically inflamed. Inflammation must be acute and temporary to neutralize an active threat. Sustained neuroinflammation disrupts neuronal homeostasis and can lead to long-term health issues, including:

  • Cognitive deficits
  • neurodegeneration
  • Alzheimer’s disease
  • Parkinson’s disease
  • Multiple sclerosis
  • Amyotrophic lateral sclerosis

How to Reduce Brain Swelling

Diet and lifestyle affect all aspects of health. Activities/practices that improve your mood, relax you, and reconnect you with the real world will help reduce neuroinflammation and take care of your brain.

Evaluate your use of technology

The internet isn’t inherently bad, but too much technology can affect our decision-making, cognition, and self-control.

Carefully evaluate their use and habits. Ask yourself the following questions and draw your conclusions:

How much time do you spend on technology? Compare this moment with important things in your life. Is it more time than you spend sleeping? More time than you spend with your family?
Is it intentional? Is picking up your phone just a habit, or have you intentionally set aside limited times to check email and social media?
Are you conscious when using technology?
Is it enriching for you? Is your relationship with technology an overall positive network in your life, or do you need to change something?

Try adjusting your tech habits to healthier levels or consider a digital detox if you feel you need a temporary break from tech.

Eat better to avoid oxidative brain damage

Since 20% of our body’s energy goes to the brain, what we eat affects our brain health. To help curb systemic inflammation, avoid the three main inflammatory foods endemic to the standard Western diet: industrial seed oils, processed sugars, and refined carbohydrates. Chronic consumption of these foods can negatively affect cognitive functions, learning and memory.

Foods rich in antioxidants, such as berries and colorful vegetables, will help prevent ROS from overwhelming neuronal cells. For extra support, consider including nootropics in your diet.

Cultivate awareness/mindfulness

Mindfulness is the antidote to today’s hectic digital world. Practicing mindfulness means setting aside time to be aware of your thoughts, feelings, sensations, and the environment around you, rather than worrying about the past or the future. Even just 10 minutes of mindfulness practice can reduce stress and lessen inflammation. Additionally, mindfulness protects against cognitive decline.

spending time in nature

Spending time outdoors is an important part of ancestral health. Exposure to nature boosts immune function, lowers levels of the stress hormone cortisol, and even protects against depression and cognitive decline.

get enough sleep

Although we don’t yet fully understand the functions of sleep, we do know that it is essential for good health. Not getting enough sleep increases inflammation and negatively affects cognitive function. Chronic sleep deprivation is linked to learning deficits, depression and Alzheimer’s disease. To take care of your body and brain, make sleep a priority.


Exercise increases brain-derived neurotrophic factor, a neural growth factor, improves the brain’s ability to eliminate waste through the glymphatic system, and reduces BBB permeability. Also, it decreases neuroinflammation by inhibiting microglial activation.

Forging supportive social bonds

Lonely people are more likely to be stressed and to suffer from depression or other mental illnesses. In contrast, people who have a support network tend to have lower levels of inflammatory proteins and stress hormones.

By focusing on these positive changes, you can potentially reduce the influence of our modern world and protect your brain from the damaging effects of inflammation.


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