Could someone possibly toss me a life preserver now and then? I’m trying to keep my head above these endless tides! Crazy, crazy, crazy!
By Dr. Mercola
Contrary to popular belief, depression is not likely caused by unbalanced brain chemicals; however there are a number of other biological factors that appear to be highly significant. Chronic inflammation is one. As noted in the featured article:3
“George Slavich, a clinical psychologist at the University of California in Los Angeles, has spent years studying depression, and has come to the conclusion that it has as much to do with the body as the mind.
‘I don’t even talk about it as a psychiatric condition anymore,’ he says. ‘It does involve psychology, but it also involves equal parts of biology and physical health.’
The basis of this new view is blindingly obvious once it is pointed out: everyone feels miserable when they are ill. That feeling of being too tired, bored and fed up to move off the sofa and get on with life is known among psychologists as sickness behaviour.
It happens for a good reason, helping us avoid doing more damage or spreading an infection any further. It also looks a lot like depression.”
One researcher even goes so far as to suggest depression should be rebranded as an infectious but non-contagious disease,4 while the author of the featured article playfully compares depression with an allergic reaction—in this case “an allergy to modern life”—considering the many environmental factors that are known to cause inflammation, from diet to toxic exposures and stress.
Scientists have also found that your mental health can be adversely impacted by factors such as vitamin D deficiency and/or unbalanced gut flora—both of which, incidentally, play a role in keeping inflammation in check, which is really what the remedy to depression is all about.
As discussed in an article by Dr. Kelly Brogan, depressive symptoms can be viewed as downstream manifestations of inflammation.
“The source itself may be singularly or multiply-focused as stress, dietary and toxic exposures, and infection… [I]nflammation appears to be a highly relevant determinant of depressive symptoms such as flat mood, slowed thinking, avoidance, alterations in perception, and metabolic changes,5” she writes.
Certain biomarkers, such as cytokines in your blood and inflammatory messengers like CRP, IL-1, IL-6, and TNF-alpha, show promise as potential new diagnostic tools, as they’re “predictive6 and linearly7 correlative” with depression.
For example, researchers have found8 that melancholic depression, bipolar disorder, and postpartum depression, are associated with elevated levels of cytokines in combination with decreased cortisol sensitivity (cortisol is both a stress hormone and a buffer against inflammation). As explained by Dr. Brogan:
“Once triggered in the body, these inflammatory agents transfer information to the nervous system, typically through stimulation of major nerves such as the vagus, which connects9 the gut and brain. Specialized cells called microglia in the brain represent the brain’s immune hubs and are activated in inflammatory states.
In activated microglia, an enzyme called IDO (indoleamine 2 3-dioxygenase) has been shown10 to direct tryptophan away from the production of serotonin and melatonin and towards the production of an NMDA agonist called quinolinic acid that may be responsible for symptoms of anxiety and agitation.
These are just some of the changes that may conspire to let your brain in on what your body may know is wrong.”
Speaking of biomarkers, research11 by Dr. Helen Mayberg, a professor of psychiatry at Emory University, may also pave the way toward a more refined and customized treatment plan. Her research is discussed in the video above.
Dr. Mayberg has identified a biomarker in the brain that can be used to predict whether a depressed patient is a good candidate for medication, or might be better off with psychotherapy. As noted by the New York Times:12
“Patients who had low activity in a brain region called the anterior insula measured before treatment responded quite well to cognitive behavior therapy (CBT} but poorly to Lexapro; conversely, those with high activity in this region had an excellent response to Lexapro, but did poorly with CBT….
[T]he insula is centrally involved in the capacity for emotional self-awareness, cognitive control and decision making, all of which are impaired by depression. Perhaps cognitive behavior therapy has a more powerful effect than an antidepressant in patients with an underactive insula because it teaches patients to control their emotionally disturbing thoughts in a way that an antidepressant cannot.”
A number of studies have confirmed that gastrointestinal inflammation specifically can play a critical role in the development of depression, suggesting that beneficial bacteria (probiotics) may be an important part of treatment. For example, a Hungarian scientific review13 published in 2011 made the following observations:
- Depression is often found alongside gastrointestinal inflammations and autoimmune diseases as well as with cardiovascular diseases, neurodegenerative diseases, type 2 diabetes and also cancer, in which chronic low-grade inflammation is a significant contributing factor.Thus researchers suggested “depression may be a neuropsychiatric manifestation of a chronic inflammatory syndrome.”
- An increasing number of clinical studies have shown that treating gastrointestinal inflammation with probiotics, vitamin B, vitamin D, may also improve depression symptoms and quality of life by attenuating pro-inflammatory stimuli to your brain.
- Research suggests the primary cause of inflammation may be dysfunction of the “gut-brain axis.”
Your gut is literally your second brain — created from the identical tissue as your brain during gestation — and contains higher levels of the neurotransmitter serotonin, which is associated with mood control.
It’s important to understand that your gut bacteria are an active and integrated part of serotonin regulation and actually produce more serotonin than your brain. Optimizing your gut flora is a key part of the equation to optimize your levels. If you consume loads of processed foods and sugars, your gut bacteria will be severely compromised because processed foods tend to decimate healthy microflora. This leaves a void that is filled by disease-causing bacteria and yeast and fungi that will promote inflammation and decrease the health of your second brain.
Besides distorting your microflora, sugar also triggers a cascade of other chemical reactions in your body known to promote both chronic inflammation and depression. For starters, excessive sugar consumption leads to elevated insulin levels. That can have a detrimental impact on your mood and mental health by causing higher levels of glutamate to be secreted in your brain, which has been linked to agitation, depression, anger, anxiety, and panic attacks.
Sugar suppresses activity of a key growth hormone called BDNF (brain derived neurotrophic factor) which promotes healthy brain neurons. BDNF levels are critically low in both depression and schizophrenia, which animal models suggest might actually be causative.
Cultured and fermented foods, on the other hand, help reseed your gut with a wide variety of healthy bacteria that promote mental and physical health as long as your keep your sugar and processed food intake low. For instance, one 2011 study14found that the probiotic Lactobacillus rhamnosus has a marked effect on GABA levels in certain brain regions and lowers the stress-induced hormone corticosterone, resulting in reduced anxiety- and depression-related behavior. So the three-prong dietary answer for treating depression is to:
- Severely limit sugars, especially fructose, as well as grains, as all forms of sugar feed pathogenic bacteria in your gut. The easiest way to do this is to avoid processed foods, and start cooking from scratch using whole ingredients. As a standard recommendation, I suggest limiting your daily fructose consumption from all sources to 25 grams per day or less.
- Avoid foods with genetically engineered ingredients, as they too have been implicated in the destruction of gut flora, along with promoting chronic inflammation. Keep in mind that conventionally-grown foods may also be contaminated with glyphosate, which has been found to selectively destroy beneficial, health-promoting gut bacteria, so ideally, you’ll want to make sure as much of your food as possible is organically grown to avoid pesticide exposure.
- Introduce fermented foods into your diet to rebalance your gut flora.
Beware that your gut bacteria are also very sensitive to and can be harmed by the following, all of which should be avoided:
Antibiotics, unless absolutely necessary (and when you do, make sure to reseed your gut with fermented foods and/or a probiotic supplement) Conventionally-raised meats and other animal products, as CAFO animals are routinely fed low-dose antibiotics, plus genetically engineered grains Chlorinated and/or fluoridated water Antibacterial soap
Vitamin D deficiency is another important biological factor that can play a significant role in mental health. In one 2006 study,15 seniors with vitamin D levels below 20 ng/ml were found to be 11 times more prone to be depressed than those with higher levels. It’s worth noting that the mean vitamin D level was just under 19 ng/ml, which is a severe deficiency state. In fact, 58 percent of the participants had levels below 20 ng/ml. A 2007 study16 suggested that vitamin D deficiency is responsible for symptoms of depression and anxiety in patients with fibromyalgia. Vitamin D deficiency is also a well-recognized cause in Seasonal Affective Disorder17 (SAD). A double-blind randomized trial18 published in 2008 also concluded that:
“It appears to be a relation between serum levels of 25(OH)D and symptoms of depression. Supplementation with high doses of vitamin D seems to ameliorate these symptoms indicating a possible causal relationship.”
More recently, researchers19 found that seniors with depression had vitamin D levels that were 14 percent lower than those who were not depressed. Here, those with vitamin D levels below 20 ng/ml had an 85 percent increased risk of depression, compared to those with levels above 30 ng/ml. Yet another paper20 published in 2011 noted that:
“Effective detection and treatment of inadequate vitamin D levels in persons with depression and other mental disorders may be an easy and cost-effective therapy which could improve patients’ long-term health outcomes as well as their quality of life.”
Based on the evaluation of healthy populations that get plenty of natural sun exposure, the optimal range for general physical and mental health appears to be somewhere between 50 and 70 ng/ml. So, if you’re depressed, you’d be well advised to get your vitamin D level checked, and to address any insufficiency or deficiency. The D*Action Project by GrassrootsHealth is one cost effective testing solution. As for optimizing your levels, sensible sun exposure is the ideal way. Alternatively, use a tanning bed with an electronic ballast, and/or an oral vitamin D3 supplement. GrassrootsHealth has a helpful chart showing the average adult dose required to reach healthy vitamin D levels based upon your measured starting point. Keep in mind that if you opt for a vitamin D supplement, you also need to take vitamin K2 and magnesium, as these nutrients work in tandem.
Antidepressant drugs come with a long laundry list of risks, and are therefore best left as a last resort, if all else fails. Medical journalist and Pulitzer Prize nominee Robert Whitaker has detailed the many drawbacks and benefits of various treatments in his two books: Mad in America, and Anatomy of an Epidemic: Magic Bullets, Psychiatric Drugs, and the Astonishing Rise of Mental Illness in America, noting that physical exercise actually comes out on top in most studies—even when compared against antidepressant drugs.
Exercise primarily works by helping to normalize your insulin levels while simultaneously boosting “feel good” hormones in your brain. But researchers have also discovered that exercise allows your body to eliminate kynurenine, a harmful protein associated with depression.21 And, again showing the link between inflammation and depression, your body metabolizes kynurenine in the first place via a process that is activated by stress and inflammatory factors… While I addressed several dietary factors to restore health to your gut, I also recommend supplementing your diet with a high quality animal-based omega-3 fat, such as krill oil. This may be the single most important nutrient for optimal brain function, thereby easing symptoms of depression. Vitamin B12 deficiency can also contribute to depression, and affects one in four people.
Last but not least, make sure you get enough sleep. The link between depression and lack of sleep is well established. Of the approximately 18 million Americans with depression, more than half of them struggle with insomnia. While it was long thought that insomnia was a symptom of depression, it now seems that insomnia may precede depression in some cases.22 Recent research also found that sleep therapyresulted in remarkable improvements in depressed patients. The take-home message here is that one or more lifestyle factors may be at the heart of your depression, so you’d be well advised to address the factors discussed in this article before resorting to drug treatment—which science has shown is no more effective than placebo, while being fraught with potentially dangerous side effects.
By Dr. Mercola
As time goes by, science provides more and more evidence that your brain is malleable and continually changing in response to your lifestyle, physiology, and environment.
This concept is called neuroplasticity, or brain plasticity—meaning, you are literally reforming your brain with each passing day. It used to be thought that your brain was static, except during some critical developmental periods, but today, we know this isn’t true.
Your brain possesses the remarkable ability to reorganize pathways, create new connections and, in some cases, even create new neurons throughout your entire lifetime.
Our views of the nature of the brain have changed in a similar way as our views of DNA. It used to be thought that DNA did not change—in other words, you’re stuck with what you’re born with.
This, too, has been disproven by researchers like Bruce Lipton, who have introduced an entirely new branch of biological science called epigenetics. Your DNA changes continuously based on your experiences, emotions, and environment.
The point is, you have much more control over your body, mind, and brain than you might think. If you can mold and shape your brain, you are not entirely at the mercy of your genetics or the neural pathways you brought into this world or formed as a child—and this is great news!
A recent study1 discussed in Scientific American2 illuminates your brain’s remarkable ability to rewire itself in response to experience. Mice with amblyopia or “lazy eye” (partial blindness caused by visual deprivation early in life) improved faster if they were exposed to visual stimuli while running on a treadmill.
Amblyopia can happen to someone born with a droopy eyelid, cataract, or other defect not corrected early in life. If the eye is opened in adulthood, recovery is usually slow and incomplete.
In this experiment, researchers induced amblyopia in mice by suturing one eye shut for several months. After the sutures were removed, the mice were shown a “noisy” visual pattern while running on a treadmill for four hours a day for three weeks.
The pattern was chosen to activate nearly all the cells in the animals’ primary visual cortex. After two weeks, the animals’ responses were comparable to those of normal mice that had never been visually deprived. Neither running nor visual stimulation alone had this effect.
The researchers believe the impressive response has something to do with built in mechanisms that allow animals to keep track of environmental stimuli from a distance:
“It makes sense to put the visual system in a high-gain state when you’re moving through the environment, because vision tells you about far away things, whereas touch only tells you about things that are close.”
The scientists do not know whether or not their findings apply to humans but are planning further studies. The current thinking is that “activity stimulates plasticity”—and this applies to your brain as well as other parts of your body. Plasticity is what allows tissues to heal.3
Neuroplasticity is, in simple terms, the ability of your brain to change and adapt in response to experience.4 You can think of those neurological changes as your brain’s way of tuning itself to meet your needs.
There are two types of brain plasticity—functional plasticity (your brain’s ability to move functions from a damaged area to undamaged areas) and structural plasticity (its ability to actually change its physical structure as a result of learning).5
Think about what happens when you’re learning a new skill. The more you focus and practice something, the better you become, and this is a result of new neural pathways that form in response to your learning efforts. At the same time, your brain is undergoing “synaptic pruning”—elimination of the pathways you no longer need.
Until recently, it was believed that the human brain, which consists of approximately 100 billion neural cells, could not generate new ones. The old model assumed that you were born with a finite number of brain cells, and when a cell died, no new cell grew in its place.
This old model is no longer relevant, as it’s been proven that certain areas of your brain can generate new cells (neurogenesis), as well as creating new neural pathways.
Environment plays an essential role in the process, but genetics can also have an influence. These neural processes have been well documented in people recovering from stroke-related brain damage.
This phenomenon even applies to emotional states. For example, if you have a history of anxiety, your neural pathways become wired for anxiety. If you develop tools to feel calm and peaceful more of the time, those anxiety pathways are pruned away from lack of activity—“use it it or lose it” really applies here.
According to “What is Neuroplasticity:”6
“It was once believed that the human brain had a relatively small window to develop new pathways in our life span, then after that the pathways became immutable.
This old theory thought our ability to generate new pathways dropped off sharply around the age of 20, and then became permanently fixed around the age of 40.
New studies have shown through the use PET, and MRI brain scanning technology, that new neural cells are generated throughout life as well as new neural pathways. Even the elderly are capable of creating measurable changes in brain organization. These changes are not always easy but can happen through concerted focus on a defect area.”
Your brain’s plasticity is also controlled by your diet and lifestyle choices, including exercise. Despite what the media tells you, your brain is not “programmed” to shrink and fail as you age. The foods you eat, exercise, emotional states, sleep patterns, and your level of stress—all of these factors influence your brain from one moment to the next.
Any given gene is not in a static “on” or “off” position. You may be a carrier of a gene that never gets expressed, simply because you never supply the required environment to turn it on. As neurologist David Perlmutter explains:
“We interact with our genome every moment of our lives, and we can do so very, very positively. Keeping your blood sugar low is very positive in terms of allowing the genes to express reduced inflammation, which increase the production of life-giving antioxidants. So that’s rule number one: You can change your genetic destiny. Rule number two: you can change your genetic destiny to grow new brain cells, specifically in the hippocampus…
Your brain’s memory center regenerates. You are constantly growing new brain cells into your 50s, 60s, 80s, and 90s – throughout your lifetime – through a process called neurogenesis. That said, these two ideas come together because you can turn on your genes through lifestyle choices that enhance neurogenesis and that enhance regrowth of cells and expansion of your brain’s memory center. This was proven by researchers recently. They demonstrated that there are factors under our control that can make that happen.”
The blind mice study is just one more piece of evidence for how important exercise is for your brain. Recent science has shown that physical exercise is as important as mental exercise when it comes to keeping your mind fit.7, 8 A number of studies show that exercise can promote growth of new brain cells, enlarge your memory center, improve IQ scores, and help prevent brain deterioration as you age.
One study found that one 20-minute weight training session improved memory. In a year-long study, individuals who exercised were actually growing and expanding their brain’s memory center one to two percent per year, whereas typically that center would have continued to decline in size. Strength training, especially high-intensity interval training (HIIT), is especially beneficial for boosting long-term memory and reducing your risk for dementia.
Exercise prompts nerve cells to release one growth factor in particular, called brain-derived neurotrophic factor (BDNF). BDNF triggers numerous other chemicals that promote neural health and directly benefit cognitive functions, including learning. Fasting also triggers BDNF, andexercising while fasting can go a long way toward keeping your brain and muscles biologically young.
According to brain plasticity expert Dr. Michael Merzenich (interviewed in the video above), engaging in challenging new activities throughout your life, staying socially active, and practicing “mindfulness” are other ways to boost your brain function. He also stresses the importance of having a genuine interest in your chosen activities. Just going through the motions is not enough to build these neural pathways—you have to really care about what you’re learning.
Lifestyle strategies proven to promote neurogenesis and target BDNF include the following:
- Exercise, especially high-intensity interval training
- Reducing overall calorie consumption
- Reducing carbohydrate consumption (especially grains and sugars)
- Enough healthy fat consumption to eliminate insulin resistance
- Enough high-quality omega-3 fats and eliminating damaged omega-6 fats (processed vegetable oils) will improve your omega-3 to omega-6 ratio. I prefer krill oil to fish oil, as krill oil also contains astaxanthin, which is particularly beneficial for your brain. Astaxanthin is a carotenoid that’s very good for reducing free radical-mediated damage to fat—and your brain is 60 or 70 percent fat
There are three other important considerations for brain health:
- Vitamin D: This vitamin/hormone plays a fundamental role in brain health, inflammation, and immune function. Vitamin D influences the expression of 2000-3000 genes. Researchers have located metabolic pathways for vitamin D in the brain’s hippocampus and cerebellum, areas that are involved in planning, information processing, and memory formation. In older adults, research has shown that low vitamin D levels are associated with poorer brain function. Appropriate sun exposure is all it takes to keep your levels where they need to be. If this is not an option, a tanning bed that uses electronic ballasts is the next best alternative, followed by a vitamin D3 supplement.
- Gut Health: Your gut is your “second brain;” gut bacteria transmit information from your GI tract to your brain via your vagus nerve. Just as you have neurons in your brain, you also have neurons in your gut—including neurons that produce neurotransmitters like serotonin, which is linked to mood. Abnormal gut flora has been associated with abnormal brain development. In addition to avoiding sugar, one of the best ways to support gut health is to consume beneficial bacteria. You can take a probiotic supplement, but I’m particularly fond of using fermented vegetables, as they can deliver extraordinarily high levels of beneficial bacteria for minimal cost.
- Choline: Choline reduces inflammation, plays a roll in nerve communications, and prevents the buildup of homocysteine in your blood (elevated homocysteine is linked to heart disease). Eggs and meat are two of the best dietary sources of choline. If you do not consume animal foods, you may be at risk of a deficiency and want to consider supplementation. If you’re pregnant, make sure your diet includes plenty of choline-rich foods, as research shows higher choline intake leads to changes in epigenetic markers in the fetus.
Research shows that how you respond to stress may be a key factor in how your brain ages. An animal study9 showed how elevated stress hormones may speed up short-term memory loss in older adults. Previous research has also linked chronic stress with working memory impairment.10Chronic stress can actually trigger a genetic switch that results in loss of brain volume, and this in turn contributes to both emotional and cognitive impairment.11 Given this, it makes sense why a recent study12 showed that your daily stress responses have long-term implications for your mental health.
Researchers found that people with increased stress have increased risk for mental disorders a decade later, especially anxiety and depression. The message is clear: managing daily stress is a key factor in keeping your brain healthy as you age, and this has implications for everything from depression to dementia. My favorite tool for stress management is Emotional Freedom Technique (EFT), an energy psychology tool that can help reprogram your body’s reactions to everyday stress.
Recent research has shown that EFT (or “tapping”) significantly increases positive emotions, such as hope and enjoyment, and decreases negative emotional states, such as anger and shame. EFT has been shown to lower cortisol levels13 (one of your major stress hormones) and is actually an epigenetic intervention that can alter gene expression.14 EFT is a powerful tool for transforming your stress reactions into more adaptive ones, and replacing old dysfunctional patterns with new. For more information, I invite you to visit my EFT page.
Again, the good news is that you’re not at the mercy of your genes or the dysfunctional neural pathways you might have developed in childhood. Your brain can literally be rewired, and you are doing so already—every day of your life! Old neural patterns are continuously being overwritten by new ones. Diet, exercise, sleep, stress, and other lifestyle choices all impact your brain’s structure and function, and how “gracefully” it ages. You are in the driver’s seat, so pay attention to the choices you make today, as they are forming the brain you’ll have tomorrow.