Circadian Rhythm Disruption & Hormonal Imbalance

Hormones are chemical messengers produced by different glands in the body. Our hormone system (aka the endocrine system) is like our body’s internal communication network. Hormones are released by different glands in the body, and they travel in the bloodstream to our organs and tissues where they exert specific actions.

We have over 50 different types of hormones in the body that influence things like metabolism, reproduction, growth, mood, digestion, and more.

There are so many things that impact your hormones, including diet, exercise, stress, the environment, and so much more.

Circadian rhythms are another huge factor that significantly influence hormones and overall health.

As a functional medicine dietitian and women's health specialist, I might even argue that one of the most overlooked factors contributing to hormonal imbalance symptoms in our modern world is circadian rhythm disruption.

What Are Circadian Rhythms?

Circadian rhythms are physical, mental, and behavioral changes that follow roughly a 24-hour cycle. Circadian rhythms work by helping to make sure that your body’s internal processes are optimized at various points during a 24-hour period. In other words, it helps make sure that everything in your body is happening in the right place & at the right time.

Circadian rhythms are regulated by a “master clock” known as the suprachiasmatic nucleus (or SCN) located in the hypothalamus in the brain. We also have peripheral clocks found throughout the body in various tissues and organs.

The master clock in the brain receives information from the outside world, and shares it with the rest of the body. It sends signals to other clocks and stimulates the release of hormones and neurotransmitters that influence and control countless functions in the body.

Circadian rhythms are influenced by a few specific external factors: primarily light and dark exposure, when we sleep, when we eat, and when we exercise.

What do circadian rhythms control or coordinate?

• Sleep-Wake Cycles

• Hormone Fluctuations

• Immune Function

• Appetite regulation

• Metabolism

• Detoxification & DNA Repair

• Digestion

• Cardiovascular Health

• Mood & Cognition

What Disrupts Circadian Rhythms?

Unfortunately, there are a lot of common things in our modern world that disrupt circadian rhythms. Some of the most common disruptors include:

• Inappropriate light and dark exposure. With light and dark exposure being the biggest regulator of circadian rhythms, disturbances with light/dark exposure can be a significant circadian rhythm disruptor. This happens when we “trick” our bodies into thinking it’s daytime when it’s actually night, and vice versa. This is especially important for people who work night shifts, frequently travel across time zones, spend most of their time indoors under artificial light and working at a computer during the day, and who frequently use electronics that emit blue-light after the sun goes down. The biggest disruptors with light & dark exposure that we see in practice impacting women's hormones are:

  • Lack of natural sunlight exposure in the morning

  • Excess blue light exposure and screen time at night

• Erratic sleep schedules. Erratic sleep timing has a profound impact on circadian rhythms. Our bodies' thrive off of consistency and disruptions to your sleep schedule disrupts the synchronicity between your internal body and it's environment. This might look like: waking up several hours later and staying up late on the weekends, travel across time zones, staying up late working or watching Netflix.

• Exercise. Research has found that exercise is a strong signal for circadian rhythms. Exercise impacts your body’s cortisol and melatonin levels, which are hormones closely tied to sleep and circadian rhythms. This means that exercise can positively or negatively impact sleep depending on the timing and how it’s incorporated. Research shows that late evening exercise may disrupt cortisol and melatonin levels, which can alter sleep patterns and delay sleep onset.

• Eating habits. It’s not just what you eat, but when you eat that matters - especially when it comes to circadian rhythms. It's not uncommon for us to work with clients that are skipping breakfast or prolonging their overnight fast, and then eating late at night. Digestion is circadian – meaning our bodies are prepped and primed to digest and metabolize food optimally during the morning hours. Eating breakfast helps to stimulate and synchronize your biologicals clocks. At night time – our body’s want to be focused on producing hormones that help us fall asleep as well as focusing on important repair processes. So if we’re eating late at night and the body needs to shift gears to digest food – this can disrupt our internal rhythms.

Health Impacts of Circadian Rhythm Disruption

Circadian rhythms influence countless essential functions in your body. In addition to your hormones and neurotransmitters, your circadian rhythm also impacts your digestion, detoxification, metabolism, body temperature and sleep. If the core factors that regulate our circadian rhythms are disrupted, this may lead to:

Short-Term CR Disruption (1-7 days)

• Brain fog

  1. Elevated blood sugar (Circadian rhythms have a MASSIVE impact on glucose metabolism and insulin sensitivity...you really can’t untangle blood sugar from circadian rhythms)

  2. Irritability 

  3. Moodiness

  4. Increased hunger hormones and weakened satiety (fullness) hormones

  5. Unpleasant shifts with digestion like indigestion, bloating and shifts with bowel movements

  6. Muscle aches, soreness, and poor recovery from workouts

  7. Increased susceptibility to illness and getting sick

Long-Term CR Disruption (weeks, months, years)

• Metabolic Dysfunction (altered lipid metabolism, shifts with weight and body composition)

  1. Chronic Inflammation

  2. Mood Disorders

  3. Gut Diseases

  4. Disrupted sex hormones, which can interfere with ovulation

  5. Disrupted thyroid hormones

  6. Fertility challenges

  7. Neurodegenerative Diseases

  8. Chronic Disease (hypertension, type 2 diabetes, heart disease)

Action Steps for Supporting Circadian Rhythm Alignment

If you're working to address hormonal symptoms, digestive concerns, or to support you're overall health, focusing on supporting your circadian rhythms is foundational.

Action steps for supporting your circadian rhythm can be broken down into two categories: daytime and nighttime. While you are likely awake for more than 12 hours during the day and sleep less than 12 hrs per night, it can be helpful to mentally break up your day into these 2, 12 hr increments for bringing in any of the supportive strategies outlined below.

For your 12-hr daytime window (ex: 7am-7pm):

• Set a consistent wake-up time

• Get natural sunlight exposure upon waking (ideally within the first hour - even if it's only 10 minutes!)

• Eat a protein-rich breakfast within 1-2 hours of waking

• Engage in forms of movement and exercise that you enjoy

• Take breaks from blue light-emitting electronics and get outside as often as possible 

For your 12-hr nighttime window:

• Be consistent with your bedtime, both during the week and on weekends. No one is perfect here, and even closing the gap with big discrepancies with your bedtime between the weekdays and weekends can make a difference!

• Eat a well balanced dinner with fiber-rich carbs, ideally 2-3 hrs before bedtime to allow your body time to digest before bed. Carbs help to calm cortisol and to keep blood sugar stable over night. Reminder: ALWAYS honor your hunger first and foremost and be sure to have a snack if you are truly hungry closer to bedtime. If you're chronically hungry at night, this might be an indication that you're under-fueling during the day.

• Minimize blue light exposure and screens before bed. Aim for 60 minutes of screen free time before sleep and consider using blue light blocking glasses whenever you need to be on screens later in the evening.

• Sleep in a cool and dark room.

In Summary

Your circadian rhythm heavily influences your hormones, which in turn impact your health, hormone, and digestion. While there are many things that can disrupt your circadian rhythms, implementing simple + small action steps and creating supportive habits with your routines can play a big role in re-balancing your circadian rhythm and supporting your overall health.

Balancing Circadian Rhythms = Hormonal Homeostasis

Supporting circadian rhythms is always a priority in our work with 1:1 clients, and we also cover circadian rhythms extensively and support women with establishing CR supportive habits in our group programs.

Need more support for addressing your hormone and digestive health symptoms naturally? Use this link to fill out an application for our 1:1 waitlist!