Your Cart is Empty

July 08, 2023 8 min read

Are you struggling with hypothyroidism (underactive thyroid) and wondering how to manage your fiber intake? Understanding the right types of fiber to consume and what to avoid can be a game-changer in dealing with this thyroid disease. Dr. Ray Peat, a respected expert on hormones and nutrition, offers a unique perspective on fiber as it relates to hypothyroidism and thyroid health. In this article, we'll delve into Dr. Peat's recommendations on fiber-rich foods to include in your diet and those you should steer clear of, ultimately helping you improve your overall well-being and hypothyroidism management!

Is dietary fiber beneficial for people with hypothyroidism?

Dr. Ray Peat has a different take on fiber compared to what we usually hear about nutrition. He believes that we should avoid indigestible fibers, also known as dietary fibers, as much as possible to keep our gut clean. This might seem odd, as many healthy diets promote fiber-rich foods.

You can find these indigestible fibers in whole-grain products like unrefined flours, grains, seeds, raw veggies, salads, and not-so-ripe fruits. Our bodies can't digest them because they're made of cellulose, and we don't have the right enzymes to break them down. So, these fibers don't really give us any nutrients.

However, the bacteria in our gut can use these fibers for energy. Dr. Peat suggests not eating too many of them because it can cause an overgrowth of bad bacteria in our gut.

Even when our digestive system is working well, gut bacteria always produce some substances called endotoxins, which can be irritating to our intestines. This might lead to the release of inflammation-causing molecules like serotonin and histamine. In a healthy gut, these processes usually don't cause any trouble.

But if we have too many bad bacteria in our gut, it can produce way more endotoxins and inflammation-causing molecules than normal, leading to irritated and inflamed intestines. This can cause issues like irritable bowel syndrome, constipation, or diarrhea. If the inflammation gets really bad, it could even allow endotoxins, serotonin, histamine, and bacteria to leak into our bloodstream. This would spark a body-wide inflammation, and the endotoxins could damage our cells' ability to produce energy, making us feel tired and weak.

How to manage dietary fiber intake to improve thyroid function

To minimize your intake of indigestible fibers, it's advisable to choose refined foods over whole-grain products. Opt for white rice, white pasta, and other similar refined products instead of their whole-grain alternatives. Not only do the refined versions have less indigestible fiber, but they also contain lower levels of polyunsaturated fats and impurities.

However, it's important to note that consuming large amounts of starch should be avoided. When consuming starch, consider pairing it with saturated fats for better digestion.

Salads, raw vegetables, and unripe, crisp fruits are high in indigestible fibers, which may cause digestive problems for some individuals. To counteract this issue, always cook your vegetables, including potatoes, and serve them with saturated fats. Cooking helps break down the indigestible fibers, making them easier to digest. The same principle applies to unripened, crisp fruits like apples and peas - cook them and serve them with saturated fats like whipped cream for optimal digestion. Ripe and sweet fruits, like bananas, can be consumed raw, as their starch content is reduced during ripening.

Is antimicrobial fiber a better option?

A woman looking happy while taking thyroid medication.

While avoiding dietary fibers is generally recommended, incorporating specific antimicrobial fibers into your diet can contribute to maintaining healthy digestion. These unique fibers are naturally equipped with antimicrobial substances that inhibit bacteria from using them as sustenance and, instead, work to eliminate bacteria and fungi present in the intestine.

Raw carrots and cooked bamboo shoots are great examples of foods rich in antimicrobial fibers. Their natural chemicals help reduce the presence of bacteria and fungi, such as yeast (Candida), within the digestive system. Additionally, antimicrobial fibers play a role in binding endotoxins produced by gut bacteria, further promoting gut health.

A remarkable benefit of consuming antimicrobial fibers is their ability to bind estrogen and prevent its reabsorption in the gut. This process aids in reducing overall estrogen levels in the body. By decreasing intestinal bacteria, endotoxins, and estrogen, antimicrobial fibers effectively reduce the body's general inflammation and improve hormonal balance. Consequently, liver and thyroid functions are enhanced, cortisol levels are lowered, and progesterone levels have the opportunity to rise, ultimately supporting better hypothyroidism management.

Where can you find antimicrobial fiber and other beneficial fibers?

Incorporating antimicrobial fibers into your diet can greatly contribute to the health of your thyroid gland. Here are some prime examples of these beneficial fibers:

1. Raw carrots

Consuming just 1-2 raw carrots per day provides significant antimicrobial effects. It's essential to eat the carrots raw, as juicing or cooking them destroys these beneficial properties and releases carotene. Therefore, unlike most vegetables, carrots should be eaten raw for optimal thyroid health.

Carotene is an unsaturated hydrocarbon that impairs thyroid function, similar to polyunsaturated fats. Moreover, carotene hinders the action of vitamin A, which is necessary for synthesizing protective anti-aging and anti-stress hormones like pregnenolone, progesterone, and DHEA.

To make the most of the antimicrobial fibers in raw carrots, try Dr. Ray Peat's Carrot Salad Recipe for a nutritious and delicious option:


  1. 1 large organic raw carrot

  2. 1 tsp. organic olive oil or organic coconut oil

  3. 1 tsp. apple cider vinegar

  4. A pinch of sea salt and black pepper


  1. Grate the carrot lengthwise.

  2. In a bowl, add the oil, vinegar, and seasoning, and mix with a fork.

  3. Combine the dressing with the grated carrot, and enjoy!

As stated in the Fats chapter, the fatty acids in coconut oil are known to stimulate thyroid function. The carrot fiber, on the other hand, helps tone the bowel and bind toxins. Choosing MCT oil as your saturated fat is an optimal choice, as it's liquid at room temperature and contains lower levels of polyunsaturated fats compared to olive oil.

2. Cooked bamboo shoots

Cooked bamboo shoots are another excellent option for incorporating antimicrobial fibers into your diet. You can consume the canned forms, but make sure to look out for any additives.

Bamboo has been associated with humans for a long time, mainly known for its industrial uses. However, it's the young bamboo shoots that have become a popular food choice, consumed fresh, fermented, or canned.

Rich in proteins, carbohydrates, minerals, and fiber and low in fat and sugar, these delicious young shoots also contain phytosterols and a high amount of fiber recognized as nutraceuticals or natural medicines. Their growing appeal among health advocates and scientists has led to increased attention and research into their health-promoting properties.

Modern studies showcase a range of health benefits associated with bamboo shoots, including improved appetite and digestion, weight loss, as well as protection against cardiovascular diseases and cancer. Their anticancer, antibacterial, and antiviral activities further add to their appeal, and their antioxidant capacity stems from the presence of phenolic compounds.

As health consciousness increases among consumers, bamboo shoots have found their way into various functional foods, including breakfast cereals, fruit juices, bakery, and meat products, sauces, shredded cheeses, cookies, pasta, snacks, and frozen desserts. This growing interest in the health benefits of bamboo shoots highlights their potential for utilization as a nutritious and functional food. In fact, studies have shown that bamboo shoots can have positive effects on lipid profiles and bowel function when used as a dietary fiber source.

3. Oat and wheat bran fibers

If you're looking for variety in your antimicrobial fiber sources, oat, and wheat bran fibers can serve as occasional substitutes for carrots and bamboo shoots. However, according to Dr. Ray Peat, they may not be as antimicrobial as their counterparts.

Oat and wheat bran fibers can help reduce estrogen reabsorption from bile and provide bulk to your diet. They are particularly helpful for individuals who have difficulty incorporating carrots and bamboo shoots into their diets.

Due to the high starch content attached to both types of bran, it's necessary to wash them thoroughly to remove most of the starch, which can otherwise cause gas. To prepare, soak the brans overnight and rinse them with water in the morning before cooking (simmer for approximately 40 minutes).

By following these steps, you can create a beneficial fiber-rich porridge similar to oatmeal. Wheat bran alone might not give the desired consistency, but combining it with oat bran can result in a smoother porridge. Feel free to top it with fruit, sugar, honey, or Greek yogurt for added flavor and nutrition. For more nutrients, consider making the porridge with milk instead of water.

Again, while oat and wheat bran fibers can be a great addition to your diet, keep in mind that they may not provide the same level of antimicrobial benefits as carrot and bamboo shoot fibers. Nonetheless, they offer a valuable alternative for incorporating antimicrobial fibers into your daily meals.

What to keep in mind when consuming antimicrobial fiber

A woman eating antimicrobial fiber alone in her apartment. Hypothyroidism diet.

Incorporating antimicrobial fibers into your diet can contribute to a healthier gut. However, it's essential to know the best way to consume them to maximize their benefits and avoid any adverse effects.

One thing you need to keep in mind is that consuming large amounts of antimicrobial fibers might slow down digestion and affect the absorption of nutrients from other foods. To prevent this, consider eating these fibers in between meals, ensuring they don't interfere with your blood sugar levels or disrupt the digestion of other nutrients consumed during meals.

It's important to note that antimicrobial fibers can reduce the number of intestinal bacteria responsible for vitamin K production. To counteract this effect, consider supplementing with vitamin K or consuming calf liver, which is rich in vitamin K, particularly when consuming these fibers regularly. This approach will help maintain optimal vitamin K levels in your body, supporting overall health and well-being while reaping the benefits of antimicrobial fibers.

Don't forget your thyroid hormone replacement

While antimicrobial fiber plays a crucial role in supporting thyroid health, it's essential not to overlook the importance of proper thyroid hormone replacement. If you're taking thyroid medication, adhering to your prescribed thyroid hormone replacement medication is vital in maintaining optimal thyroid hormone levels and promoting normal thyroid function. Maintaining healthy thyroid function can also help manage autoimmune thyroid diseases and prevent potential complications.

The primary thyroid hormone replacement medication prescribed is levothyroxine, which is a synthetic form of the T4 thyroid hormone. However, some individuals with hypothyroidism may find that natural desiccated thyroid (NDT) medication or supplements are a more suitable option for their thyroid health. NDT is derived from pig thyroid glands and contains both T4 and T3 thyroid hormones, which is why it's often preferred over levothyroxine.

As a natural alternative, NDT has gained popularity among those seeking a more holistic approach to thyroid health. You can buy desiccated thyroid online, such as VitaliThy. This NDT supplement offers a convenient solution for those interested in exploring NDT as a potential option for their thyroid hormone replacement needs.

A balanced hypothyroidism diet and a healthy lifestyle can contribute significantly to your overall well-being, address iodine deficiency (if any), and support thyroid hormone production. However, it's important to remember that thyroid supplements and thyroid medication absorption can be affected by certain food and nutrients. Be mindful of potential interactions and, if necessary, consult with your healthcare provider or nutritionist to ensure an appropriate diet plan that complements your thyroid medication.

The bottom line: Consider adding antimicrobial fibers

Dr. Ray Peat presents an alternative perspective on fiber in relation to nutrition. While conventional wisdom promotes the consumption of fiber-rich foods, he advises against ingesting indigestible fibers, as they may contribute to an overgrowth of bad bacteria in our gut. Instead, he recommends focusing on antimicrobial fibers sourced from raw carrots and cooked bamboo shoots.

These antimicrobial fibers provide numerous health benefits, such as reducing the presence of harmful bacteria and fungi, binding endotoxins, and preventing the reabsorption of estrogen in the gut. By incorporating these fibers into your diet, you can promote gut health, improve hormonal balance, and ultimately support better hypothyroidism management.

However, it's crucial to remember that relying on antimicrobial fibers alone isn't enough. Ensure that you continue with your thyroid hormone replacement medication or supplement and maintain a nutritious and balanced diet. Overall, adopting a comprehensive approach that includes these fibers will enhance your well-being and contribute to maintaining optimal thyroid function.

Wojciech Majda
Wojciech Majda

Leave a comment

Comments will be approved before showing up.

Also in Natural Desiccated Thyroid blog

What are my chances of getting pregnant with hypothyroidism?
What are my chances of getting pregnant with hypothyroidism?

July 17, 2023 13 min read

When it comes to getting pregnant, it's not just about the birds and the bees. There are actually a whole host of medical factors at play. One such factor is your thyroid function. It's time to shed light on an essential question: "How can hypothyroidism influence my chances of becoming pregnant?"
PCOS and hypothyroidism: what's the connection?
PCOS and hypothyroidism: what's the connection?

July 17, 2023 11 min read

How to boost metabolism with hypothyroidism: Metabolic thyroid supplement, exercises, and more
How to boost metabolism with hypothyroidism: Metabolic thyroid supplement, exercises, and more

July 17, 2023 9 min read

Hypothyroidism can be a challenging condition for everyone, but there are some simple steps you can take to boost your health! From metabolic thyroid supplements to exercises, this article will show you how to get your metabolism up and running again.

Sign up for our Newsletter