How Stress Messes With Your Metabolism + How To Fix It, According To An RD
Whether emotional, cognitive, physical, or environmental, stress is inevitable. It can be perceived as negative, such as from a divorce, as well as positive, such as from a new baby or taking on a new career. No matter which type it is, if stress becomes chronic, it can disrupt hormonal balance and throw off your metabolism.
Understanding the stress response.
Let's start with the basics: the sympathetic and parasympathetic nervous systems. Both are part of the autonomic nervous system, a regulatory center that influences organs, vessels, glands, genitals, and digestive system, driving the survival reactive and regulatory involuntary functions of the body.
The parasympathetic system manages metabolism, reproductive health, sleep and energy cycles, body temperature, and fluid regulation and is often referred to as the "rest and digest" state while the sympathetic nervous system is the reactive survival response is often referred to as "fight or flight."
When the body is under stress, it favors the sympathetic nervous system. This drives the activity of the hypothalamic-pituitary-adrenal axis (HPA axis), stimulating the adrenal glands to release cortisol and stress-responding neurotransmitters.
In a balanced body, cortisol serves to provide negative feedback to the HPA-axis, telling it the stress-responding chemical has been released and the body can go back to its regulatory, parasympathetic state. However, in a chronic stress state, the body does not shift from sympathetic mode back into parasympathetic, instead continuing to fire stress response chemicals while suppressing the regulatory function.
Unfortunately, in our modern lifestyle, stressors are plentiful and constant. This is where we start to see the influence of chronic stress on hormone balance.
How stress influences metabolic hormones.
Hormones serve as regulatory substances, providing stimulation or repression of signals based on receptor function and balance in the body. Our metabolism, sleep, sexual hormone function, and mood are all influenced by the hormone regulation of our autonomic nervous system and balance of our HPA-axis. Chronic stress can disrupt hormone regulation and cause major metabolic consequences.
Thyroid hormone regulation
Let's start with the thyroid. When the body is at rest, the hypothalamus releases thyroid-releasing hormone (TRH). In response, the pituitary gland releases thyroid-stimulating hormone (TSH), increasing thyroid hormone production and regulation.
But, in times of stress, the adrenals are prioritized over thyroid regulation, and energy is shunted to them. What's more, cortisol, which is released in response to stress, can interfere with how the inactive thyroid hormone, T4, is converted to the active form, T3. In addition, stress can interfere with T3 expression, all of which puts the brakes on metabolism.
The body has these mechanisms at play because if you were in a survival situation, say running from a predator, it would not be a good time to burn calories. However, the chronic stressors we are now battling are often not physical, which can drive weight gain and sluggish metabolism.
The stress hormone cortisol is a glucocorticoid, a hormone that produces blood sugar from the liver and reduces sensitivity on insulin receptors. Therefore, cortisol increases blood sugar levels, insulin resistance, and drives body fat storage.
Cortisol does have some beneficial properties, like serving to reduce inflammation and enhance survival. But when chronically elevated, it can drive blood sugar imbalance and weight gain.
Another metabolic hormone influenced by stress is leptin, a satiety hormone. Leptin is produced by our fat cells in response to body fat storage levels and fat consumption. It regulates energy balance by inhibiting hunger to encourage the use of stored fat for fuel.
Leptin generally tells the body when it is fed, supporting healthy metabolism. In a chronically stressed state, though, the body can become resistant to the signaling of leptin, leading to overeating and weight gain.
When cortisol levels are elevated, it can disrupt the metabolism of sexual hormones both directly and indirectly. First, by interfering with the way the liver excretes excess circulating hormone and second by interfering with the production and conversion of sexual hormones.
Essentially, if the body is under chronic stress, it will prioritize survival, not regulation. This is why stress can be heavily linked to infertility. The body wants to feel safe to ensure it can support the growth and development of a child. When a woman is chronically stressed, estrogen can be suppressed. In men, testosterone can be inhibited by stress, driving impotence and loss of libido.
5 foods that support metabolic balance.
Using a food-as-medicine approach to support your body's stress response will also favorably influence the metabolism. The foods below all have an ability to influence thyroid, blood sugar, metabolic, or sexual hormone balance while serving to balance your mood and support stress resilience:
1. Seaweed (nori, wakame, kelp)
2. Citrus (orange, lemon, lime)
Citrus is a great source of vitamin C, an antioxidant that is most concentrated in the adrenal glands. Vitamin C plays a role in the regulation of cortisol metabolism and production. The incorporation of citrus also provides anti-inflammatory and antihistamine bioflavonoids, such as hesperidin, rutin, and quercetin, to synergistically work with cortisol to reduce excess demands.
Broccoli is rich in indole-3-carbinol (I3Cs), which can favorably modulate the metabolism of estrogen, reducing dominance or excess while providing antioxidant effects. As a source of chromium and fiber in the diet, broccoli can also aid in blood sugar regulation and reduced insulin resistance. Cruciferous vegetables, including broccoli, also provide a source of sulfur in the diet, which promotes detoxification and reduces inflammation.
The main compound in turmeric, curcumin, is an anti-inflammatory, immune-boosting antioxidant that can reduce oxidative stress in the body and brain. Thus, it reduces chronic stress impact and the need for continued cortisol demands. Curcumin boosts brain-derived neurotrophic factor (BDNF) levels, which can aid in mood stability and stress tolerance.
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