The Depression-Inflammation Connection

Most of us associate having the flu with not only coughing, sneezing, and sore throat, but also intense fatigue, apathy, brain fog, irritability, and loss of appetite. Being sick can wreak havoc with our emotions and throw us psychologically off-balance.

It’s common to feel as if our “get up and go” has got up and gone.

With good reason.

It turns out that there is indeed a significant connection between a heightened state of inflammation and depression.

When we’re under attack from an infection, the instinct to withdraw is adaptive in the short run, helping us to focus our energy on healing, while the burgeoning army of pro-inflammatory cytokines (types of protein molecules) go to work at the site of the infection. If we just want to sleep all day and avoid other people until we’re past our bout with the flu, that may be best for all concerned – we’ll get extra rest, and those around us will be less likely to catch our bug.

However, when such inflammation becomes long-term, these initially adaptive defenses can turn on us, causing widespread tissue damage, neuroinflammation (inflammation of the brain), and an associated feeling of general malaise. Such an overabundance of proinflammation cytokines can contribute to diseases such as heart disease, asthma, autoimmune disorders, obesity, and chronic pain — as well as depression and anxiety.

In other words, our overly zealous immune system can become our enemy.

Consider the following:

A 2016 study published in the Journal of Clinical Psychiatry reviewed health data from over 14,000 adults, from the National Health and Nutrition Examination Survey (NHANES). The study found that levels of C-reactive protein (CRP, a measure of inflammation) were 31% higher in people with depression than in people without depression.

In autoimmune conditions such as rheumatoid arthritis and systemic lupus erythematosus, nearly 70% of patients will suffer from depression. In fact, one large study found that the risk of depression rose by 45% in patients with a history of autoimmune disease, and that having previously been hospitalized due to an infection increased depression risk by 62%. The rate of depression is 15% to 25% in cancer patients.

Of course, you might say that dealing with a chronic or serious illness could result in depression. However, studies have shown that manipulating the ratio of pro- to anti-inflammatory cytokines can affect mood. For instance, adding aspirin (a non-steroidal anti-inflammatory) to patients’ medication regime has been shown to reduce depression. Conversely, giving people without depression pro-inflammatory cytokines, such as interferon to treat hepatitis C, can often bring on depression.

Certainly, even people without an inflammatory condition can develop depression. Many psychological and circumstantial factors contribute to depression, and to add fuel to the fire, emotional stress seems to activate inflammation. Nutritional deficiencies can also be a factor in inflammation. So, there is no major bullet that will balance out our immune system and wipe out depression.

However, the following suggestions may help:

Eat a healthy diet. 

Eat plenty of anti-inflammatory foods like broccoli, tomatoes, leafy greens, beets, salmon, blueberries, pineapple, celery, bok choy, flaxseed, and turmeric. A balance of protein, healthy fat (olive oil, seeds, nuts, avocado, and omega-3 fatty acids found in fish and walnuts) and high-fiber carbohydrates (from fruits, vegetables, and whole grains) can help to stabilize your glucose levels.

Try to avoid wide blood sugar fluctuations. Our modern American diet is anything but healthy, with its abundance of high-sugar, trans-fat, and artificial ingredients. Diabetes is a pro-inflammatory condition and may possibly be a precursor to Alzheimer’s disease, according to some physicians. White sugar consumption impairs brain cell communication and can eventually damage and kill off brain cells.

Adopting a gluten-free, dairy-free, and soy-free diet for awhile might be illuminating, as some people are sensitive to these substances. The most common allergens are dairy, grains containing gluten (wheat, barley, and rye), soy, peanuts, tree nuts (walnuts, almonds, pine nuts, pecans, and Brazil nuts), fish, and shellfish. So, foods that may be considered healthy for many people (see above) may not be the best choice for you. It’s best to work with a medical doctor and have allergy tests done, so you don’t end up avoiding foods that are fine for you.

Moderate your alcohol and caffeine intake, as both substances may impair your immune system if consumed in excess. Remember that moderate alcohol intake is defined as up to one drink a day for women and men over the age of 65, and up to two drinks a day for men under 65. One drink means a five-ounce glass of wine, 12-ounce beer, or 1.5 ounces of distilled spirits (hard liquor).

Maintain (or obtain) a healthy body weight. Check with your medical doctor about the appropriate weight range for you (given your height, body frame, age, and gender). Take steps to move toward this number. Obesity is a pro-inflammatory condition, and the rate of world-wide obesity has nearly doubled since 1980.

Reduce the amount of processed food you eat. Many foods contain so many additives that reading the label can be a baffling experience. Some nutritionists suggest (and only half-jokingly) to steer clear of anything you can’t pronounce. The common sweetener Equal can cause migraine headaches and mental confusion, for instance.

Get adequate sleep (generally, adults need from seven to nine hours a night). Insufficient sleep can lead to impaired immunity. Put away your cell phone, iPad, and laptop at least two hours before going to bed, to maximize your melatonin levels during the night.

Exercise regularly (several times a week, for at least 30 minutes). A combination of aerobic, strength-training, and stretching is ideal.

Try taking a yoga, tai chi, or mindfulness class, or practice deep “belly” breathing, to reduce your levels of cortisol (the “stress” hormone).

Address any sources of chronic stress in your life, be they with your family, friends, or coworkers. Seeking psychotherapy may be a wise move, to help you reevaluate your environment, identify what changes may need to be made (either around or within you), and develop the tools to effect such shifts.

Make sure that you’re receiving excellent medical care, and that any chronic conditions are being adequately managed.

To recap:

Inflammation is a healthy and appropriate response to infection and injury, but long-term inflammation can be damaging.

Inflammation can concentrate on a specific area of the body (including the brain) or be widespread.

Neuroinflammation is implicated in many mental disorders, such as depression, anxiety, and bipolar disorder.

You can significantly influence the level of inflammation in your body by practicing healthy lifestyle habits – and also help to ward off depression in the process.

Reference:

Soledad Cepeda, S., Stang, P., & Makadia, R. (2016). Depression is associated with high levels of C-reactive protein and low levels of fractional exhaled nitric oxide: Results from the 2007-2012 National Health and Nutrition Examination Surveys. J Clin Psychiatry 77:12 (1666-71).