Can Diet Affect Hormones?

cortisol diet endocrine disruptors estrogen goitrogens hormones insulin phytoestrogens sex hormones soy supplements testosterone thyroid hormone Apr 22, 2023

a variety of healthy foods and a blood glucose monitoring kit

The foods we eat influence our hormones in different ways. First, they provide our bodies with the raw materials needed for hormone production. Second, they promote or hinder the release of hormones. Third, certain foods contain endocrine disruptors. These natural or man-made substances interfere with our own hormones, thus impairing the body functions they control. Endocrine disruptors include pesticides, as well as chemicals found in food containers and cookware coating.¹ Unfortunately, these harmful substances can find their way into our food and drink.

In this article, we will focus on the effect of diet on the following:

Insulin
Cortisol
Thyroid hormone
Sex hormones (testosterone and estrogen)

Let’s now discuss some specific foods and supplements that affect these hormones.

Insulin

Insulin controls the level of sugar called glucose in the blood. After a meal, beta cells in the pancreas produce this hormone and release it into the bloodstream. Insulin allows the body's cells to absorb glucose from the food and use it for energy and other important processes.²

Insulin sensitivity is how well our bodies respond to the effects of insulin. High insulin sensitivity means that little insulin is needed to decrease blood sugar levels. By contrast, if insulin sensitivity is low, a lot of insulin is needed to reduce glucose in the blood.²

Insulin resistance is a condition in which cells cannot use insulin effectively. As a result, glucose builds up in the blood. People with insulin resistance have low insulin sensitivity. Having insulin resistance also increases the risk of developing type-2 diabetes.²

Carbohydrates, proteins, and fats are all components of a balanced, healthy diet. Among these three macronutrients though, carbohydrates increase blood glucose and insulin levels the most. This is why low-carb diets are effective in treating diabetes.^3,4

There are three main kinds of carbohydrates: starch (complex carbs), sugar (simple carbs), and fiber (carbs that the body cannot digest). The three types have different properties, including glycemic index (GI). This number measures how much certain foods raise glucose in the blood. Our bodies break down low-GI foods more slowly. In effect, such foods make blood sugar levels rise gradually over time, and they decrease the rate of insulin secretion. Foods high in fiber usually have a low GI. For this reason, eating fiber-rich foods can help optimize the body's insulin sensitivity and lead to healthy blood glucose levels.^3,5,6

Protein consumption has been linked to a greater feeling of fullness and helps preserve lean body mass during weight loss. Like carbohydrates, proteins stimulate insulin secretion, though at a slower rate. In fact, a diet with too much protein can affect insulin levels in more or less the same way that a high-carb diet does.³

Compared to carbohydrates and proteins, fats get metabolized in a different way. So, fats do not have the same effect on insulin as carbs and proteins do.³

When it comes to minerals and supplements, zinc supports insulin production and release. Meanwhile, chromium reduces insulin resistance. Magnesium also assists with blood sugar control. On the other hand, too much iron can impair insulin sensitivity.²

Cortisol

Known as the body’s stress hormone, cortisol keeps us alert and boosts our energy.⁷ It reaches its highest levels in the morning just before we wake up, and decreases gradually toward nighttime. This natural variation means cortisol plays an important role in the sleep-wake cycle.⁸ It also explains why too much of this hormone at night can make it hard for us to sleep. This often happens when we drink coffee before going to bed, since coffee has caffeine – a substance that stimulates the release of cortisol.⁹

Excessive cortisol levels in the long term can cause other health issues, such as mood swings, impaired immunity, high blood pressure, and even heart disease. Consistently high cortisol counters the effects of insulin, contributing to insulin resistance. Because of this relationship between cortisol and insulin, excess cortisol is linked to weight gain and diabetes. A diet high in added sugar and refined grains has also been linked to high cortisol.^7,10,11

On the other hand, foods like dark chocolate and whole fruits and vegetables contain antioxidants that lower cortisol secretion. Studies have also shown a strong connection between a healthy gut microbiome and good mental health. So, eating foods that promote a healthy gut may aid in cortisol and stress management. Examples of such foods are legumes and lentils. Probiotics (friendly bacteria in foods like yogurt and kimchi) and prebiotics (soluble fiber) help lower cortisol as well.^12,13,14

Lastly, ashwaganda is an herb that is traditionally used to reduce stress and promote wellbeing. Multiple studies have now shown that this adaptogenic herb can decrease cortisol levels.^15,16

Thyroid Hormone

The thyroid gland produces both thyroxine (T4) and triiodothyronine (T3). Of these two hormones, only T3 is metabolically active, which means it directly affects cells in the body. T4, the inactive form, gets converted to T3 by an enzyme. Together, T4 and T3 control growth and metabolism.¹⁷

The thyroid gland has to be healthy in order to produce the right levels of thyroid hormone. Iron, selenium, and zinc are essential for thyroid health. These minerals are naturally found in nuts, seeds, eggs, bananas, whole grains, animal meat, and dairy products.^18,19,20

To produce thyroid hormone, the thyroid gland needs iodine. For this reason, iodine is often added to table salt. Other good sources of iodine include seafood like fish, shrimp, and seaweed.¹⁷

Goitrogens are chemicals found in some foods that prevent the thyroid gland from getting enough iodine. Certain vegetables like broccoli, cabbage, cauliflower, and kale contain goitrogens. Soy foods and ingredients made from soy have these compounds as well. Too much of any of these foods can mess up thyroid hormone levels.²¹

Finally, autoimmune thyroid conditions often come with celiac disease, a disorder in which the body has an immune reaction to gluten. For this reason, a gluten-free diet may bring benefits to people with an overactive or underactive thyroid.²²

Sex hormones (testosterone and estrogen)

Testosterone and estrogen are made in the body from cholesterol.²³ Thus the common advice to avoid cholesterol actually deprives the body of its raw material for these important hormones. The most common dietary sources of cholesterol are eggs, chicken, beef, shrimp, cheese, and butter.²⁴

A study shows that a low-fat diet reduces levels of testosterone in men.²⁵ Eating healthy fat sources such as fish and avocados may thus help increase testosterone.^26,27 Other studies indicate that oxidative stress (stressful conditions for cells caused by some oxygen-containing substances) and inflammation can also decrease testosterone levels.^28,29,30 So, it may be beneficial to eat foods that fight these conditions. Specifically, leafy green vegetables like spinach and kale are rich in magnesium, a mineral that lowers oxidative stress.³¹ Meanwhile, dark chocolate and other cocoa products have high flavonoid content. Flavonoids are known for their antioxidant and anti-inflammatory properties.³² In effect, consumption of leafy green vegetables and cocoa products may promote healthy testosterone levels.

As for estrogen, it gets boosted by phytoestrogens, which are natural chemicals found in plants. Because phytoestrogens are similar in structure to estrogen, they can bind to estrogen receptors and mimic estrogen action on target organs.³³ This is why phytoestrogens are considered endocrine disruptors. Among all foods, soy is the main source of phytoestrogens, so it increases estrogen the most.³⁴ Since estrogen is also produced from testosterone by an enzyme called aromatase, it can be easy to wind up with an excess of estrogen. Too much estrogen is linked to a variety of health problems, ranging from cancer and stroke to snoring.

Finally, a few herbs and supplements can alter the amounts of sex hormones in the body. One of them is maca root, which is available in powder or capsule form. As an adaptogen, maca root aids in balancing hormones.³⁵ Other supplements inhibit aromatase, the enzyme that converts testosterone to estrogen. Therefore, natural aromatase inhibitors like diindolylmethane (DIM) and synthetic ones such as anastrozole affect the levels of both hormones.^36,37

Conclusion

Certain foods and supplements can change hormone production or secretion, thereby affecting crucial body functions. Of all the foods identified above, soy has disruptive effects on both thyroid hormone and estrogen. Thus, a soy-free diet can help keep these hormones at the right levels for optimum health. Plus, avoiding soy works wonders if you snore. Discover the link between soy and snoring through the Snoring Diet Solution, a proven six-week program that can end snoring for good!

References

1 Endocrine Disruptors (nih.gov)

2 Insulin and Insulin Resistance (nih.gov)

3 Macronutrient Composition and Management of Non-Insulin-Dependent Diabetes Mellitus (NIDDM): A New Paradigm for Individualized Nutritional Therapy in Diabetes Patients (nih.gov)

4 Efficacy and safety of low and very low carbohydrate diets for type 2 diabetes remission: systematic review and meta-analysis of published and unpublished randomized trial data (nih.gov)

5 Glycemic index and Glycemic load values (nih.gov)

6 What is the glycaemic index (GI)? - NHS (www.nhs.uk)

7 Physiology, Cortisol - StatPearls - NCBI Bookshelf (nih.gov)

8 Sleep and Circadian Regulation of Cortisol: A Short Review - PMC (nih.gov)

9 Caffeine Stimulation of Cortisol Secretion Across the Waking Hours in Relation to Caffeine Intake Levels - PMC (nih.gov)

10 Excessive Sugar Consumption May Be a Difficult Habit to Break: A View From the Brain and Body - PubMed (nih.gov)

11 Increasing Dietary Carbohydrate as Part of a Healthy Whole Food Diet Intervention Dampens Eight Week Changes in Salivary Cortisol and Cortisol Responsiveness - PMC (nih.gov)