By Lisa Egan
We already know that inflammation is the likely cause of a multitude of health conditions, including arthritis, asthma, cancer, chronic pain, headaches, and heart disease.
Now research suggests an addition to the growing list of ailments with possible links to inflammation: depression.
According to the World Health Organization (WHO), more than 350 million people of all ages (globally) suffer from depression. Worldwide, only about half of the afflicted receive treatment. As many as a third of patients don’t respond to antidepressant medications. And, the medications we currently have aren’t without side effects – some of which are devastating.
If inflammation is indeed a major cause of depression, things look brighter for sufferers. That’s because there are lifestyle changes that can be made to alleviate chronic inflammation – and in turn, its associated disorders.
First, it is important to understand what inflammation is – and what it isn’t.
Inflammation: The Fire Inside
The word inflammation comes from the Latin “inflammo”, meaning “I set alight, I ignite”. Inflammation sparks your immune system into action in an attempt to protect you from harm. It is part of a complex biological response to damaging stimuli, including injuries, pathogens, and irritants. Inflammation is NOT an infection, but can it be caused by infection.
Inflammation can be classified as acute or chronic.
If you’ve ever broken a bone, cut yourself, or had strep throat, you’ve experienced acute (short-term) inflammation. The swelling, heat, redness, and pain you feel after an injury or during an infection are signals that your immune system is doing it’s job by firing up the inflammatory process, which begins healing and reminds you to care for the affected area.
Most of the time, acute inflammation is a good thing.
But when inflammation becomes chronic (long-term), serious health issues can result. Asthma, autoimmune diseases, arthritis, Crohn’s, colitis, celiac disease, periodontitis, rheumatoid arthritis, and some cancers have been linked to chronic inflammation.
And sometimes, inflammation can cause MORE inflammation…trapping you in a vicious cycle.
Depression and Inflammation – Evidence for a Link
A growing body of research suggests that a link between depression and inflammation exists.
Medical Daily explains:
“…a 2013 study in BMC Medicine reported inflammation was already on its way to being recognized as “a mediating pathway to both risk and neuro-progression in depression.” A protein called cytokines is responsible for chronic inflammation, which occurs when the body’s first attempt at protection against harmful stimuli fails, and thus the body continues to attack healthy tissue. Prior studies have shown healthy participants given infusions to trigger the release of this protein results in classic depressive symptoms.
Cytokines are needed to reduce inflammation, physically identifiable by red, sore, or swollen skin and joints; it’s when cytokines are continually produced that they start to travel away from the inflamed part of the body and into the bloodstream, the effects of which can range from muscle tissue damage to plaque buildup in arteries.
About 20 years ago, researchers started noticing that the levels of cytokines and T-cells, (which help drive immune responses and secrete cytokines), were higher in blood samples from people diagnosed with depression.
The results of a study published in JAMA Psychiatry in December 2014 suggest that treatment with anti-inflammatory medication can decrease depressive symptoms without increased risks of adverse effects.
Other studies and observations also support the link:
- When people with skin cancer or chronic hepatitis C take a type of cytokine medication called interferon-alpha to spur their bodies’ immune systems, they often start having symptoms of depression.
- Numerous studies have also found that healthy adults who produce above-average levels of cytokines are more likely to develop depression later in life.
- Four small studies published between 2006 and 2012 by research groups in Europe and Iran found that adults diagnosed with depression who took aspirin or another anti-inflammatory drug called Celecoxib, along with an antidepressant, got more relief from feelings of sadness, hopelessness, guilt and fatigue compared with those taking an antidepressant alone.
- Both cytokines and inflammation have been shown to rocket during depressive episodes, and drop off in periods of remission in people with bipolar disorder.
- Healthy people can also be temporarily put into a depressed, anxious state when given a vaccine that causes a spike in inflammation.
- People with inflammatory diseases such as rheumatoid arthritis tend to suffer more than average with depression.
One researcher, Andrew Miller, a professor of psychiatry at Emory University, noted a flaw in some of those smaller studies: the inflammation levels of participants were not measured prior to treatment with anti-inflammatory medication. His team measured inflammation levels in 60 adults with depression and treated half of them with a potent anti-inflammatory medication called Infliximab. They found that people with high levels of inflammation experienced a reduction in their symptoms, but those with normal levels did not.
The takeaway? Not all people with depression should be treated with anti-inflammatory medications.
When you consider the potency of Infliximab, that point becomes even more clear: the drug blocks the body’s inflammatory response and reduces immune system activity. People who use Infliximab have an increased risk of developing serious – and sometimes fatal – infections.
Drugging ourselves to “cure” ailments is much like taking the batteries out of a screeching smoke detector instead of putting out the fire.
Fortunately, there are far more safe and healthful ways to prevent and reduce inflammation that attack the cause without harming your immune system or damaging your health.
Managing Inflammation – Naturally
Many experts believe that inflammation begins in the gut. Having a healthy digestive system is important because a healthy system filters out things that can damage it (like that bad bacteria, toxins, chemicals, and waste products). It also helps us absorb and deliver the good stuff like nutrients from our food.
About 70% of our immune cells are in our digestive system, and they make direct contact every bit of food we consume. If the immune system is triggered by bacteria in food, flags a food as an allergen, or has an imbalance of important hormones such as insulin, it can cause inflammation.
Celiac disease presents us with an excellent (and devastating) example of a chronic autoimmune/inflammatory disorder that originates in the gut, but affects the entire body when untreated. In people with celiac disease, the villi of the small intestine are damaged when gluten (a protein found in wheat, rye, and barley) is consumed. In short, the body attacks itself every time a person with celiac disease consumes gluten. This interferes with absorption of nutrients from food, which can lead to malnourishment.
If left untreated, celiac disease can lead to serious health problems. These include the development of other autoimmune disorders like Type I diabetes and multiple sclerosis (MS), dermatitis herpetiformis (an itchy skin rash), anemia, osteoporosis, infertility and miscarriage, neurological conditions like epilepsy and migraines, short stature, and intestinal cancers.
Depression has also been linked to untreated celiac disease:
Researchers have observed an association between celiac disease and depression that dates back to the 1980s. In 1982, Swedish researchers reported, “depressive psychopathology is a feature of adult celiac disease,” as they found depressive symptoms in patients recently diagnosed with celiac. The researchers concluded that the depressive symptoms were the result of untreated celiac disease, possibly due to malabsorption (Hallert & Aström, 1982). A 1998 study reported one-third of individuals diagnosed with celiac disease also suffer from depression (Ciacci, Iavarone, Mazzacca, & De Rosa, 1998). Adolescents with celiac disease also have higher than normal rates of depression: 31% compared to 7% of adolescents without celiac disease (Carta, Hardoy, Usai, Carpinello, & Angst, 2003).
Researchers are still exploring the link between celiac disease and depression. Most recently, a survey of 177 women with celiac disease found that 37% met the threshold for depression and 22% met the threshold for disordered eating (Arigo, Anskis, & Smyth, 2011). (source)
What to Eat
Fatty fish: Oily fish, like salmon, mackerel, tuna and sardines, are high in omega-3 fatty acids, which have been shown to help reduce inflammation. If you don’t like the taste of fish, consider taking a fish oil supplement.
Dark leafy greens: Studies suggest that vitamin E may play a key role in protecting the body from inflammation. The best sources of this vitamin are dark green veggies like spinach, kale, broccoli, and collard greens.
Nuts: All nuts are abundant sources of antioxidants, which give them inflammation-fighting and damage-repairing qualities. Top choices: walnuts, which contain high amounts of omega-3, and almonds, which are particularly high in fiber, calcium, and Vitamin E.
Tomatoes: Lycopene is a powerful antioxidant which has been shown to reduce inflammation in the lungs and throughout the body. Cooked tomatoes contain even more lycopene than raw ones, so tomato sauce is an excellent source. Lycopene is also found in apricots, watermelon, papaya, and pink grapefruit. If you want to increase your absorption of lycopene from tomatoes, cook them with olive oil.
Olive oil: Rich in monounsaturated fatty acids (MUFAs), olive oil has long been known to have anti-inflammatory properties. And, at least one study has shown that olive oil seems to have a slight protective effect against depression.
Garlic and onions: Studies have shown that garlic shuts off pathways that lead to inflammation. Onions contain anti-inflammatory chemicals including quercetin and allicin.
Beets: These bright red root vegetables have antioxidant properties and have been shown to reduce inflammation.
Ginger and turmeric (curcurmin): These spices, commonly used in Indian and Asian cooking, have both been shown to reduce inflammation in several studies.
Berries: While all fruits can help fight inflammation because they contain antioxidants, berries are anti-inflammatory superstars. This is likely due to anthocyanins, the powerful chemicals that give berries their rich color. Studies have shown that red raspberry extract can help protect animals from developing arthritis, blueberries can protect against intestinal inflammation and ulcerative colitis, and that women who eat more strawberries have lower levels of C-reactive protein (an inflammation marker) in their blood.
Tart cherries: Some researchers believe that tart cherries have the highest anti-inflammatory content of any food. And studies are promising: they have found that tart cherry juice can reduce the inflammation in lab rats’ blood vessels by up to 50%. In humans, it’s been shown to help athletes improve their performance and reduce their use of anti-inflammatory pain meds.
Pineapple (bromelain): Some evidence suggests that the enzyme bromelain has potent anti-inflammatory properties.
Tea: White, oolong, and green teas are full of catechins, antioxidant compounds that reduce artery plaque and inflammation.
Chocolate and wine: Red wine contains anti-inflammatory chemicals like resveratrol. Dark chocolate (look for 70 percent or higher cacao content) protects against inflammation, and research suggests that hot cocoa does too.
Probiotics are often referred to as “good bacteria”, but they are actually products that contain helpful microorganisms (usually Lactobacillus or Bifidobacterium) that may help with digestion and offer protection from harmful bacteria.
But perhaps the most important thing probiotics can do for you involves your immune system. If your immune system isn’t working correctly, conditions like allergic reactions, autoimmune disorders (including colitis, Crohn’s, and arthritis), and infections can start coming around. Keeping your good and bad bacteria in balance may be able to help prevent or help with those conditions.
What NOT to Eat
Certain foods and ingredients can cause or increase inflammation. Limit your intake, or eliminate them from your diet entirely if you are looking to reduce inflammation.
Trans fats: These mostly man-made fats are not only bad for health overall, but they promote inflammation. And, at least one study has shown strong evidence of a link between trans fat consumption and depression:
The study authors found that when they compared the volunteers who consumed trans fats regularly with individuals whose dietary fat consisted primarily of olive oil, the trans fat consumers had a 48% higher risk of developing depression.
The amount of trans fat consumed was directly related to depression risk – the more they ate, the higher the risk.
Sugar and white flour: “Sugar can play a role in inflammatory diseases,” says Dave Grotto, RD, a spokesperson for the American Dietetic Association. “Poor regulation of glucose and insulin is a breeding ground for inflammation.”
The more refined carbohydrates that you eat, the more likely you are to be giving your body more sugar than it can handle. A Harvard School of Public Health study found a strong parallel between diets high in refined carbohydrates and heart disease. Sugar-rich diets stress the heart via the body’s release of free radicals, which stimulate the immune response and inflame the lining of the blood vessels leading to the heart.
Saturated fats from animal sources: Animal fats have been linked to inflammation in several studies. This is in part because they contain high amounts of arachidonic acid, a molecule used by the body to create inflammation.
Excess alcohol: Avoid drinking more than one or two alcoholic beverages a day. Too much alcohol can cause changes in the intestinal lining, allowing bacteria to pass through into the bloodstream – triggering inflammation.
MSG (monosodium glutamate): Some animal research shows this preservative and flavor enhancer can cause inflammation.
Gluten: People who suffer from celiac disease aren’t the only ones who experience inflammation from the consumption of this protein. Dr. William Davis, cardiologist and author of the best-selling book Wheat Belly, noticed that when his pre-diabetic and diabetic patients follow a wheat and grain-free diet, they show improvements in (or total relief from) inflammation-related diseases and disorders – including more stable moods and emotions.
Other Factors to Consider
Environmental toxins: Synthetic fibers, latex, glues, adhesives, plastics, air fresheners, cleaning products and perfume are examples of everyday chemicals that can trigger an inflammatory response. Chronic exposure, at even low doses, can drive your immune system crazy, resulting in inflammatory autoimmune diseases. (source)
Obesity: Research published in the December 2013 issue of The FASEB Journal shows that there is an abnormal amount of an inflammatory protein called PAR2 in the abdominal fat tissue of overweight and obese humans and rats. This protein is also increased on the surfaces of human immune cells by common fatty acids in the diet.
Study author David P. Fairlie, Ph.D. said, “This important new finding links obesity and high-fat high-sugar diets with changes in immune cells and inflammatory status, highlighting an emerging realization that obesity is an inflammatory disease.”
Gerald Weissmann, M.D., Editor-in-Chief of The FASEB Journal, said, “The bottom line of this report is that obesity is an inflammatory disease, and inflammation plays a greater role in the downward spiral to obesity than most people realize.”
Sleep: Lack of sleep is associated with inflammation. You need sleep to allow your body to recover and repair – both mentally and physically. Sleep experts recommend getting 7–9 hours nightly to function optimally. (For tips on improving sleep, click here.)
Stress: Studies have shown that chronic stress changes gene activity of immune cells before they enter the bloodstream so that they’re ready to fight infection or trauma – even when there is no infection or trauma to fight. This leads to increased inflammation. (For tips on stress management, click here.)
Exercise: A study that followed more than 4,000 men and women for over 10 years found that participants who completed 2.5 hours of moderate exercise each week – about 20 minutes a day – lowered their markers of inflammation by at least 12%. Those who began exercising midway through the study also significantly lowered their levels of inflammation, meaning it’s never too late to benefit from exercise.
What does all of this mean?
A growing body of evidence – both anecdotal and scientific – strongly suggests a link between inflammation and depression. As with any medical condition, it is important to consider individual circumstances to determine WHY a person has a certain ailment.
Adopting an anti-inflammatory lifestyle has many benefits, and it appears that the alleviation of depression may be one of them. Although research hasn’t confirmed a link without a doubt, for now it is worth considering – and certainly couldn’t hurt to try. After all, who wouldn’t benefit from eating a more healthful diet, reaching their optimum weight, exercising regularly, sleeping well, and managing stress?