Stress & Sleep (part one)
Over sixty percent of Americans will have trouble sleeping this year. And as most of you have experienced, stress is the principle reason why most people can’t sleep well or deeply. More troubling is the fact that research over the last few years has found a clear link between lack of sleep and being overweight. Some people choose to sleep less than they should, while others simply can’t fall asleep or stay asleep, which is where chronic stress comes into play. Not sleeping enough can start a dangerous cycle that disrupts the production of hunger hormones, disturbs glucose regulation, lowers resistance to colds and flu and alters your ability to regulate metabolism. Fortunately, lifestyle and dietary changes, coupled with smart supplementation, can bring you back in balance.
The Stress-Sleep-Weight Gain Connection
Do you stay up late trying to squeeze more productivity into your day? Or watch late night programming for some down time? While it was once thought to be a harmless habit , we now know that lack of sleep can significantly disrupt your health. In fact, if diet and exercise just don’t seem to get you anywhere, maybe it’s because you aren’t sleeping enough.
Many studies clearly and directly correlate lack of sleep with weight gain and increased risk of becoming obese, and further research has clarified some of the reasons why. For example, lack of sleep alters signals of important hunger-regulating hormones leptin and ghrelin. Under-sleeping decreases production of leptin, a hormone that tells you that you’re no longer hungry, while increasing production of ghrelin, a hormone that make you feel hungry.[i] In other words, you may be hungrier and find it much harder to control your appetite if you aren’t sleeping enough.
In addition, it is during our sleep at night that growth hormone is released.[ii] Growth hormone is what helps us to build and repair lean muscle mass. Lean muscle mass is the tissue responsible for keeping a higher resting metabolic rate, an important key to weight control.
But what if you would love to sleep more, but you simply can’t or worse yet you wake up at 2-3 a.m. thinking about the next day or the current stressful event in your life. What if you have insomnia? . Understanding why you can’t sleep, can help you to establish a plan to get you back to a peaceful night sleep.
What most people don’t realize is that the most common reason for sleep problems is a condition called hyper arousal. . Under hectic days and chronic stress, our brain gets continued signaling of fight or flight response. Basically, your brain gets overheated in the day with stress hormones, and can’t cool off at night when it is supposed to go into a rest cycle. In the hyper-aroused state, people continue to have elevated levels of the hormone cortisol at night, which is not the natural cycle.[iii] You should secrete highest levels of cortisol in the morning so that you are alert for daytime activities and less during the rest of the day, with lowest levels produced in the evening.
At night, the dark is supposed to be the signal to tell your pineal gland to release melatonin, which is the hormone that guides your sleep cycle. If insufficient melatonin is released, you can’t stay in a deep sleep. Melatonin is also a major antioxidant that along with DHEA protects the brain, so if you are chronically having trouble with sleep it can lead to short term memory loss. Cortisol is also known as “the stress hormone,” and a common cause of evening elevations of cortisol is chronic stress.[iv] When cortisol is high you also release more epinephrine or adrenaline. This leads to “feeling wired and tired” in the evening.
Most importantly, elevated cortisol levels lead to weight gain in several ways. First, high cortisol levels decrease the production of serotonin (a calming neurotransmitter). As serotonin levels decline, this can trigger cravings for comfort foods that are high in carbohydrates, fats and sugars, like chocolate chips, and pretzels.[v] In addition, serotonin is the precursor for the primary sleep hormone melatonin. So when chronic stress lowers serotonin, melatonin production will suffer, and this is why chronic stress can lead to insomnia.[vi]
Second, chronically elevated cortisol levels cause blood sugar to increase in ways that mimic diabetes.[vii],[viii] This raises insulin levels, leading to insulin resistance. When the body’s cells no longer respond well to insulin, glucose cannot be transported properly into the cells to be burned as fuel, and also prevents the break down of fat. This process drives the storage of belly fat and the inability to access fat as fuel when you are trying to shed excess pounds.
Third, elevated cortisol can shift thyroid hormone levels out of balance.[ix] Thyroid hormones drive cellular activity and metabolic rate. You have two principle thyroid hormones, T4 (thyroxine) and T3 (triiodothryonine). Your body must convert the T4 that is made in the thyroid gland to the most active thyroid hormone T3 in various tissues in the body. Cortisol blocks this conversion, leaving you with normal T4 levels but low or low normal T3. T3 is responsible for the majority of thyroid hormone function in your body. High cortisol levels can lower metabolism by as much as 40%.[x],[xi]
As a corollary, high stress also can use up the available pools of DHEA , which is normally used as a building block for sex hormones as well as stress hormones. Under chronic stress, DHEA is consumed to make cortisol, and make it less available for sex hormone production. More importantly DHEA supports immune and thyroid function and insulin response. Low levels of DHEA have been linked with increased belly fat.[xii] The most important findings on DHEA is that it acts as a protector of the brain. Studies have reported that when cortisol levels are high and DHEA is low, the area of the brain called the hippocampus shrinks. This causes memory loss. The study also found that if the DHEA levels remained normal, then the brain did not show the same shrinkage. So if you are under stress and are noticing that you are not as sharp mentally as you used to be, consider getting a 4-point salivary cortisol and DHEA panel.
The bottom line is lack of sleep—whether it’s caused by high levels of cortisol or simply by repeatedly burning the midnight oil—is hard on metabolic balance and health, and can make it very difficult to lose weight and worse yet lead to several illnesses if not addressed.