One of the major recurring themes of the Paleo f(x) Theory to Practice Symposium I attended this past weekend was the importance of managing your stress.
Beyond poor diet, many other lifestyle factors can greatly increase your level of stress, such as overtraining, not sleeping enough, or not including enough pleasure in your daily life. Many of the conference speakers (including myself) focused on how stress causes cortisol dysregulation and subsequent weight gain, sleep disturbances, and even a reduction in life span.
Stress also plays a major role in the health of one of our most important organ systems: the gut.
The word stress is a broad term, and can refer to any real or perceived threat to the homeostasis of an organism, eliciting adaptive responses to help maintain internal stability and ensure survival. (1) Stress can be acute or chronic, and it tends to be those chronic stressors from our lifestyle or environment that are far more damaging to our health.
The gut is especially vulnerable to the presence of chronic (and even acute) stress, demonstrating stress-induced changes in gastric secretion, gut motility, mucosal permeability and barrier function, visceral sensitivity and mucosal blood flow. (2) There has also been evidence to suggest that gut microbiota may respond directly to stress-related host signals. (3)
I’ve spoken extensively before about the brain-gut axis and its role in health. As I’ve mentioned before, the intestinal mucosa is infiltrated by the myenteric plexus, which is a network of nerve fibers and neuron cell bodies that are influenced by signaling from the brain. In this sense, the gut is an integral part of the nervous system, so the brain can easily effect gut function. We anecdotally recognize our brain-gut connection as a “gut feeling”, which can range from butterflies in the stomach to full-on anxiety-induced nausea. (4)
The biochemical changes that occur in times of stress have significant and immediate impact on gut function.
A family of peptides called corticotrophin releasing factors (CRF) are responsible for coordinating the body’s response to stress, and CRFs have a potent effects on the gut through modulation of inflammation, increase of gut permeability, contribution to visceral hypersensitivity, increased perception to pain, and modulation of the gut motility. (5) This hormone affects the hypothalamic-pituitary axis (HPA) to eventually stimulate the secretion of cortisol from the adrenal glands.
Not only does stress affect the physiological function of the gut, but it has also been shown to actually cause changes in the composition of the microbiota, possibly due to the changes in neurotransmitter and inflammatory cytokine levels. (6) Research in mice has found that exposure to stress led to an overgrowth of certain types of bacteria while simultaneously reducing microbial diversity in the large intestine of the stressed mice. (7, 8) Furthermore, this disruption of the microbiota increased susceptibility to enteric pathogens.
Chronic exposure to stress may lead to the development of a variety of gastrointestinal diseases such as gastroesophageal reflux disease (GERD), peptic ulcer disease, IBD, IBS, and even food allergies. (9) Experimental studies have shown that psychological stress slows normal small intestinal transit time, encourages overgrowth of bacteria, and even compromises the intestinal barrier. (10) Chronic stress may therefore play an important role in the development of small intestinal bacterial overgrowth (SIBO) and leaky gut syndrome.
The Gut-Brain-Skin Axis plays an important role in our overall health.
Another fascinating line of research that dates back to the 1930s is the relationship between skin, gut, and mental health. I recently recorded a podcast in which I discussed the role that gut health plays in the development of acne, and research suggests that chronic stress may also play an integral part in the gut-skin axis. (11) Stress-induced alterations to microbial flora could increase the likelihood of intestinal permeability, which in turn sets the stage for systemic and local skin inflammation. (12) When gut integrity is compromised, an increase in circulating endotoxins derived from gut microbes can manifest as skin eruptions such as rosacea and acne.
On the flip side, having a healthy gut flora can modulate the hypersensitivity and leaky gut permeability that comes from chronic exposure to stress. Consuming probiotic foods and/or supplements might influence both mood and acne, by reducing systemic inflammatory cytokines and oxidative stress, increasing peripheral tryptophan levels, normalizing brain levels of stress hormones, modulating tissue lipid levels, and possibly even regulating glycemic control. (13, 14, 15, 16, 17)
Recently, research has demonstrated significant improvements in depression, anger, anxiety, as well as lower levels of cortisol among otherwise healthy adults taking a daily probiotic supplement as compared to a placebo. (18) This data suggests that not only can chronic stress change the diversity of microflora in the gut, but that the quality and health of friendly gut bacteria may also conversely have an effect on mental health and wellbeing.
As we continue to learn more about the intricacies of the interplay between stress and gut health, what steps can we take in our daily lives to help minimize the health damage that arises from chronic stress?
One interesting method of treatment that researchers used in the 1930s to treat acne and mood disorders was the combination of “an acidophilus milk preparation and cod liver oil”, which we now know provided patients high levels of probiotics, omega-3 fatty acids, and fat soluble vitamins A and D. (19) Healing the gut, reducing inflammation, and providing a diverse array of friendly bacteria can make a big difference in your gut’s susceptibility to the negative effects of stress. Taking cod liver oil and probiotics on a regular basis may make a significant difference in your overall resilience to stress.
That said, it goes without saying that a major component of a healthy lifestyle should include stress reduction techniques.
As I mentioned before, many of my colleagues at the Paleo f(x) Conference focused on reducing stress as a key component of weight loss, longevity, and mental health. Stress may even cause hypothyroid symptoms such as weight gain, blood sugar swings, fatigue, decreased immunity, and sleep disturbance. I highly recommend that anyone struggling with these types of symptoms evaluate the level of stress in their life, and incorporate different strategies for minimizing stress on a regular basis.
There are many ways to mitigate the impacts of stress, including meditation, yoga, taiji (“Tai Chi”), deep breathing and spending time in nature – to name a few. However, here are two options that I’ve found to be particularly helpful for healing the gut-brain axis:
- The Body Scan (Mindfulness-Based Stress Reduction, MBSR): MBSR was developed by clinical psychologist and long-time Buddhist practitioner Jon-Kabat Zinn to cultivate greater awareness of the ways the unconscious thoughts, feelings, and behaviors can undermine emotional, physical, and spiritual health. It has been studied extensively at the Stress Reduction Clinic at the University of Massachusetts Medical Center for over 30 years, and is clinically proven to relieve chronic pain and illness. You can download a free audio recording of the Body Scan here, and I recommend doing it once a day if possible. If you prefer more in-depth training, MBSR is offered as an 8-week intensive in hospitals and medical centers around the world. It is also offered as an online course, and can be done via home study with books and audio recordings.
- Rest Assured is marketed as a program for healing insomnia naturally – and it’s very effective for that purpose. However, the way this is accomplished is by maintaining a greater state of relaxation and ease throughout the day, which will improve not only sleep but other physiological processes like gut function. As I’ve shown in this article, operating in a state of constant hyper-arousal (which many of us do) is a sure-fire path to digestive problems. The Rest Assured program contains simple exercises that coordinate breath and movement. Many of the exercises can be performed in as little as 3-4 minute throughout the day, while some take 20-30 minutes and can be done when you have a little more time – or while you’re laying in bed before sleep. I’ve found these to be incredibly helpful myself, and my patients have as well.
You can read more about my tips for stress reduction, as well as other components of an optimally healthy life, by signing up for my Beyond Paleo email series.