How Carrageenan Can Harm Your Bones And Your Health (And How To Avoid It)

New studies have linked a common food additive to increased insulin resistance and gut inflammation.

In this article, you'll learn all about carrageenan– where it comes from, what it does, and how to decrease your intake.

We'll explore how insulin resistance and inflammation affect bone health, helping you understand how carrageenan may be impacting your bone remodeling process.

All About Carrageenan

Carrageenan is a naturally occurring compound derived from edible red seaweed. It is used to create gelatinous dishes without gelatin and to improve the texture of food products.

This plant extract has been used for thousands of years, with recorded use in China as early as 600 AD and in Ireland 200 years before that. Today, the compound is primarily used as a food additive, mostly in dairy and meat products.

Carrageenan bonds easily with animal proteins to make the texture of meat and dairy food products more appealing. It is frequently found in ice cream, yogurt-based products, milkshakes, diet sodas, salad dressings, patés, processed meats, soy milk, and other plant milks, and sauces.

Carrageenan increases the thickness and viscosity of liquid food products, improves water retention in processed meats while making them easier to slice, and enhances the texture and flavor suspension in diet sodas. The compound is also used to clarify some beers, as it binds to proteins that can make beer look hazy.

There are also many non-food uses of carrageenan in shampoos, toothpaste, lubricants, and other viscous semi-liquid products.

While carrageenan has a long history in some regional food cultures, only in the past fifty years has the processed food industry turned it into one of the most common food additives. In the 1970s, the average daily intake of carrageenan was around 45 mg. Today, it is as much as five times higher – about 250 mg per day. ¹

Synopsis

Carrageenan is a seaweed extract that has been part of human food cultures for more than a thousand years. However, with a surge in its use as a processed food additive to enhance the viscosity of processed food and beverages, average daily intake has increased as much as five fold in the past five decades.

Carrageenan And Insulin Resistance

A study published in 2024 in the journal BMC Medicine used a randomized double-blind cross-over trial to examine the relationship between carrageenan intake and insulin resistance in 20 male participants.

While this sample size is small, the intensive high-quality study design makes these results valuable and relevant data about the relationship between a common food additive and a negative health outcome.

Each participant took 250 mg of carrageenan or a placebo every morning and evening for two weeks. The researchers measured the participants' insulin sensitivity using the oral glucose tolerance test and hyperinsulinaemic-euglycaemic clamp methods. They also tested for whole body and hepatic insulin sensitivity, MRI-measured brain inflammation and insulin resistance, intestinal permeability, gut microbiome composition, immune-cell activation, and pro-inflammatory markers.

The results showed that in overweight participants, carrageenan exposure reduced whole-body and hepatic insulin sensitivity, increased inflammation markers, and trended toward higher brain inflammation, compared to placebo. The carrageenan was also associated with increased intestinal permeability. ²

The researchers hypothesized that increased intestinal permeability was part of the mechanism by which carrageenan causes inflammation and insulin resistance. Their conclusion draws a direct link between carrageenan and these negative outcomes.

“These findings suggest that carrageenan, a common food additive, may contribute to insulin resistance and subclinical inflammation in overweight individuals through pro-inflammatory mechanisms in the gut.”²

Synopsis

In a 2024 randomised double-blind cross-over trial, researchers found that carrageenan exposure contributed to insulin resistance and inflammation in overweight participants.

Insulin Resistance, Inflammation, And Bone Mass

Studies have linked insulin resistance to bone loss.

Researchers from universities in China analyzed the results of two studies, one with 788,247 participants and another with 8,770 participants. These studies gathered data about participants' bone mass and triglyceride-glucose (TyG) index. TyG index is a measurement of two compounds, triglyceride and glucose, which together indicate insulin resistance.

The study results found a link between TyG indicated insulin resistance and an increased risk of low bone mass and osteoporosis. The researchers went as far as to suggest bone mass monitoring and implementing early osteoporosis prevention strategies in individuals with insulin resistance.³

This ties one of the effects of carrageenan (increased insulin resistance) directly to bone loss and an increased risk of osteoporosis.

Another concerning finding about carrageenan– increased intestinal permeability and gut inflammation– has also been linked to bone loss. One review of studies on the relationship between inflammatory conditions and bone loss opens with the following statements.

“Inflammation is among the major determinants of bone loss in chronic disease and aging. Bone metabolism is radically affected by inflammation with consequent bone loss and increased fracture risk.”⁴

While the study that linked carrageenan to these effects only found statistically significant links among overweight participants, there is another simple fact about carrageenan that tells us that it doesn't belong in a bone-healthy diet: it is an additive used in processed foods.

Reducing your carrageenan intake will also decrease your intake of processed foods, which are acidifying by nature. Ultra-processed foods— sometimes abbreviated as UPFs– are a hazard to your health and should be avoided.⁵

You can take some simple steps to reduce carrageenan in your diet.

• Reduce your overall intake of processed foods by choosing whole foods and preparing your own meals
• Check food labels for carrageenan — and assess how processed a product is
• Pay special attention to the ingredients of meat and dairy products, as they are most likely to contain carrageenan, along with other foods that are semi-liquid
• Make you own bone-healthy versions of processed foods
• Follow the 80/20 pH-balanced diet recommended in the Osteoporosis Reversal Program, which reduces acidifying foods to 20% of any meal, naturally limiting your potential for exposure

Synopsis

Insulin resistance and inflammation– both outcomes of carrageenan exposure among overweight study participants– each correlate to bone loss and an increased risk of osteoporosis. Carrageenan, as a food additive, is part of a class of foods we already know is bad for bone health: ultra-processed foods. Reduce your intake of processed foods, and foods containing carrageenan by eating whole foods, preparing your own meals, checking food labels, and following the Save Institute's 80/20 pH-balanced diet.

What This Means To You

The health risks of carrageenan illustrate how industrial food processing can turn a natural ingredient like edible seaweed into an unhealthy source of dietary imbalance. In typical Western diets that include a large amount of processed foods, individuals consume a staggering amount of this single additive.

The Save Institute emphasizes the importance of balance, moderation, and variety in your diet. That's why the 80/20 pH-balanced diet is so easy to follow and so effective. It naturally guides you toward eating whole foods in healthy proportions.

The Save Institute created a cookbook and meal planner to make your transition to a bone-healthy pH-balanced diet easy and delicious. Bone Appétit contains more than 300 recipes made from bone-healthy whole foods. You'll be amazed at how familiar and comforting these dishes are — and how easily a few simple substitutions can transform your favorite meals into powerful bone builders.

Learn more about Bone Appétit

Get additives out of your diet by reducing your intake of processed foods. With less carrageenan on your plate, you can reduce inflammation and support the production of strong, healthy bones.

References

¹ https://www.tandfonline.com/doi/abs/10.1080/03670240390265175

² https://bmcmedicine.biomedcentral.com/articles/10.1186/s12916-024-03771-8

³ https://www.sciencedirect.com/science/article/abs/pii/S8756328223000352

⁴ https://www.sciencedirect.com/science/article/abs/pii/S1521690X21001287

⁵ https://www.bmj.com/content/384/bmj-2023-077310