Brain on Fire — How Inflammation Damages Mental Health
From depression to dementia: How to reduce inflammation naturally
Inflammation is often visible and painful. Red, angry swellings make their presence felt. But inflammation can also be invisible and painless; you would never know it was there. When inflammation flares in the brain, it does so silently.
What is inflammation?
Inflammation is not always a bad thing — it is a normal immune response to injury or infection and means that the healing process has begun. The body repairs itself or prepares to fight off an intruder. Sometimes, however, things go awry. The inflammatory process goes on for longer than necessary, or is activated when it is not required.
The response may be either acute or chronic. Acute inflammation is healthy and short-term. It is usually localized and triggered by a wound or an infection.
Chronic inflammation, on the other hand, is systemic and less obvious. Internal organs — the heart, lungs and kidneys — may be affected. It is involved in virtually every chronic disease, including cardiovascular disease, diabetes, metabolic syndrome, rheumatoid arthritis, asthma, and cancer.
With chronic inflammation, you won’t see any redness or swelling, and the only way you know it’s there is by testing for something called C-reactive protein (CRP), a marker for inflammation in the blood.
Inflammation in the brain
Chronic, low-grade inflammation in the brain is a factor in the development of many neurodegenerative diseases, including depression and dementia. It is also seen in Parkinson’s disease, multiple sclerosis and Huntington’s disease.
Depression
‘Diet-related inflammation can promote depression, and diet-linked depression in turn heightens inflammation.’
Scientists increasingly acknowledge that depression is an inflammatory disorder. According to data from the National Health and Nutrition Examination Survey, an extraordinary 47% of people with clinical depression also have heightened inflammation.
Interestingly, it has been observed that when clinical depression goes into remission, so too does inflammation.
When inflammation begins, substances called cytokines are released by the affected tissue to alert and prime the immune system. In the brain, inflammatory cytokines are able to induce depression by altering activity in the regions of the brain that control mood, resulting in feelings of negativity and fatigue. This effect has also been seen in cancer therapy. Cytokines are used to treat some cancers and viral infections — and can provoke the onset of major depression in up to 45% of patients.
Dementia
Inflammation is a common feature of the ageing brain, as levels of proinflammatory cytokines increase with age.
Current understanding of the development of Alzheimer’s disease is focussed largely on amyloid-β (Aβ) protein. Deposition of amyloid-β in the brain activates an immune response, including inflammation. If the inflammatory response persists, there may be brain injury and neuronal death, along with dysfunction of the blood-brain barrier, an important protection system which controls what passes in and out of the brain.
Four ways to reduce inflammation naturally
To do this, you simply need to remove the causes of inflammation, and increase anti-inflammatory agents. Diet is at the heart of this process. Below is a description of the most common dietary causes of neuroinflammation and how to put them into reverse.
1. Remove sugar, prevent metabolic syndrome
‘Glucose is pro-inflammatory… A total of 75g glucose intake causes acute oxidative and inflammatory stress’
In 2017, the journal Scientific Reports published a study that examined the link between dietary sugar and depression. The researchers found that men who consumed 67 grams or more of sugar every day were 23% more likely to suffer from depression, over the following 5 years, than men who consumed less than 40 grams of sugar each day.
To get some perspective, consider that just one can of sugar-sweetened soda may contain around 40 grams of added sugar.
Regular, high intake of sugar can lead to insulin resistance, when the body is no longer able to regulate blood sugar levels normally. Insulin resistance can lead to metabolic syndrome, a condition characterised by high blood pressure, high blood sugar and obesity. Metabolic syndrome puts you at risk of developing cardiovascular disease, stroke, and type 2 diabetes. You are also at risk of developing neurodegenerative disorders.
There is a high prevalence of metabolic syndrome in people with psychoneurological disorders, including schizophrenia, bipolar disorder and depression. A systematic review of patients with bipolar disorder found that over 37% had metabolic syndrome.
2. Avoid vegetable oils
Vegetable cooking oils are such a well-established kitchen staple that it is easy to forget that they only entered the culinary landscape a century ago. Sold as healthy alternatives to saturated fat, these novel oils were at the centre of the brave new world of the processed food industry.
The crops most commonly grown to produce these oils are corn, soya, sunflower and canola. The oils extracted from these crops are used liberally in processed foods and ready meals.
These oils all have one common denominator: they are rich in pro-inflammatory, omega-6 polyunsaturated fatty acids (PUFAs).
‘Elevated n-6 intakes are associated with an increase in all inflammatory diseases, which is to say virtually all diseases.’
The 2017 U.S. Department of Agriculture report, US Trends in Food Availability, reveals that between 1970 and 2014, salad and cooking oil consumption rose by a staggering 248%.
There are two classes of PUFA: omega-6 and omega-3 (n-6 and n-3).
Both omega-6 and omega-3 PUFAs are metabolised in the body to hormone-like substances called eicosanoids. Generally speaking, omega-6 eicosanoids are pro-inflammatory and omega-3 eicosanoids are anti-inflammatory. Omega-3 eicosanoids work by directly blocking pro-inflammatory omega-6 eicosanoids.
There is nothing intrinsically wrong with omega-6 PUFAs: we need them. They are an essential component of each cell membrane and are involved in brain, reproductive, immune and bone health.
We evolved on, and are genetically adapted to, a diet that provides more or less equal amounts of omega-3 and omega-6. That’s how it was for hundreds of thousands of years.
The problem is that omega-3 and omega-6 fats compete with each other for absorption in the body, including the brain — where excessive omega-6 displaces omega-3.
Now, with the industrialisation of our diets, and the vast quantities of vegetable cooking oils that go into them, the ratio between omega-6 and omega-3 has shifted enormously and we consume up to 25 times more omega-6 than omega-3. This diet reorientation has been described as ‘a total new phenomenon in human evolution.’
‘Diets with high n-6:n-3 PUFA ratios may enhance risk for both depression and inflammatory diseases.’
3. Eat oily fish
Omega-3 PUFAs are found in high amounts in oily fish. Shellfish is also a good source. The two omega-3 fatty acids that are most important to the brain are EPA and DHA EPA is converted to DHA, the most abundant omega-3 fatty acid in the body.
Anti-inflammatory DHA is found abundantly in oily fish, including salmon, mackerel, trout, sardines, herring and fresh (not tinned) tuna. Without regular fish and seafood, it is difficult to obtain sufficient DHA, although meat (and eggs) from animals that are pasture-fed contain small amounts.
If you can’t stomach oily fish, the only vegetarian alternative is micro-algae supplementation. Algae are the original source of DHA, consumed by small fish, in turn consumed by larger fish, and so on up the food chain.
4. Get protected
Because the brain is 60% fat, it is vulnerable to oxidation, in the same way that oils are vulnerable to rancidity. Substances called free radicals are formed when oxygen is burned to produce energy, but they are also generated by pollution, stress, smoking and certain cooking methods that involve burning food, such as barbecuing.
Antioxidants are the antidotes that disarm those free radicals and reduce the inflammation they create. It is this effect that links them to lower risk of a number of chronic diseases, including Alzheimer’s and depression.
The most effective of those protective chemicals in the brain are the carotenoids.
Carotenoids are made by plants and consumed by animals. Therefore, many plant foods, and some animal-source foods, provide good levels of this phytochemical.
At least 600 carotenoids have been identified, most famously beta carotene. But when it comes to the brain (and eye, an extension of the brain), the most important that we know of is lutein, found in spinach, kale, broccoli, carrots, pumpkin, squash, yellow and red peppers. It is also found in egg yolk.
Muscle meat can be a good source of carotenoids, including lutein, but only meat from pasture-reared animals. You can see this by the colour of the fat, which tends to be more yellow than that of animals given concentrate feed. Grass-fed steers incorporate significantly higher amounts of total carotenoids in their meat and livers than their grain-fed counterparts.
Lutein works predominantly in the central nervous system. It is concentrated across all brain areas and appears to play a role in protecting cognitive function. During the early stages of Alzheimer’s, there is increased oxidation of fat and increased levels of inflammatory markers. Lutein has been found to be significantly lower in people with mild cognitive impairment, the pre-dementia stage.
Diet is key to reducing inflammation and the risk of developing neurodegenerative disease. But diet can also trigger inflammation: for every action there is an equal and opposite reaction. Don’t fan the flames.
So far, everyone is so resistant to the idea that what they eat is the problem and the solution.
Great advice! I started following steps like these several months ago, and I can say from experience that the difference is palpable. Diet is such a huge factor in wellness. I cannot over-state how big of a difference I experienced as a direct result of informed dietary choices and a solid exercise plan.