Key Takeaways
  • Microplastics are plastic fragments broken down in oceans and rivers, reaching our dinner tables through the food chain.
  • Several studies have detected microplastics in many commercial sea salts, and researchers point out that plastic pollution has extended to salt.
  • While mouse experiments have reported accumulation in organs and increased oxidative stress, the impact on humans is still uncertain and requires further research.
  • As countermeasures, it is effective to aim for appropriate salt intake without excessive restriction, reduce plastic use, and make practical efforts such as choosing packaging and origin.

The Story of Microplastics Lurking in Sea Salt — Even in Our Daily 'Salt'?

Salt is an essential basic seasoning in our diet, but many of you may have been surprised by recent reports that many commercial sea salts contain microplastics. When we first heard this, we were also surprised, thinking, 'Even in salt?!' However, considering the current state of ocean plastic pollution, it's not entirely unexpected. Here, we will explain in an easy-to-understand way what microplastics are, how they get into salt, and how much we should worry about their health effects.

What are Microplastics? From the Ocean to Our Dinner Table

Sources and Changes in the Ocean

Microplastics are a general term for small plastic particles measuring a few millimeters or less, originating from fragments of plastic bags and PET bottles, as well as microbeads from cosmetics. Plastics that flow out from land reach the ocean and are gradually pulverized and miniaturized by ultraviolet rays and wave action. A 2015 study in Science magazine estimated that millions of tons of plastic flow into the ocean annually, and plastics in the ocean disperse and accumulate over time.

Transfer Through the Food Chain

Fish and shellfish that ingest microplastics retain them within their bodies or digestive tracts. It has been pointed out that consuming these organisms may lead to the transfer of trace amounts of plastic to humans. However, there are also reports that much of the plastic in fish remains in the intestines rather than organs, and views that the amount ingested depends on the fish species and cooking methods.

How Much Do Microplastics Affect Health? What Research Knows and Doesn't Know

Insights from Animal Experiments

Studies using mice have reported the accumulation of microplastics in the liver, kidneys, and intestines, an increase in oxidative stress, and even changes in molecules related to the nervous system (according to papers such as Scientific Reports). While these are warning signs, it is not yet confirmed whether the same effects occur in humans, as mice and humans differ in body size, metabolism, and exposure levels.

The Impact of Chemical Substances Cannot Be Ignored

Plasticizers and additives (such as bisphenol A) used in plastic manufacturing may have endocrine-disrupting effects, raising concerns about their impact on hormone balance. It is also noteworthy that not only the physical effects of microplastics themselves but also adsorbed substances and coexisting chemical substances pose problems.

Commercial Sea Salt and Microplastics — Research Findings and Tips for Choosing

How Much Has Been Found?

Microplastics have been detected in sea salt in multiple surveys. News reports and research sometimes cite figures like 'detected in about 90% of sea salts,' suggesting that many sea salt products contain some fine particles. However, the detected amounts vary, with differences depending on the manufacturing process, harvesting area, and the degree of filtration and refining.

Is Himalayan Salt Safe?

Compared to sea salt derived from seawater, rock salts like Himalayan salt are sometimes reported in some studies to have relatively lower levels of contaminants. However, Himalayan salt cannot be said to be completely 'harmless,' and it is important to consider packaging materials, origin, and processing methods comprehensively when choosing salt. We also usually use multiple types of salt and try not to rely too heavily on one type.

What You Can Do in Daily Life — Practical Measures Against Salt and Plastic Pollution

  • Salt is necessary, but consume it in moderation: Avoid extreme salt reduction and aim for appropriate salt intake to prevent unnecessary anxiety.
  • Check packaging: It's a good idea to choose products with less or no plastic packaging, such as glass bottles or paper packaging.
  • Vary cooking methods: For seafood, removing internal organs and washing off excess fat and dirt can reduce ingestion risks.
  • Reduce daily plastic use: Reducing plastic bags and disposable containers leads to a reduction in ocean pollution itself.
  • Stay informed: Check new research findings and public institution guidelines, and make wise choices while avoiding excessive anxiety.

Summary

Combining our research with existing studies, it's clear that microplastics are often found in sea salt, but their health effects on humans are not yet fully understood. While mouse experiments show points of concern, further research is needed to draw definitive conclusions. In daily life, while prioritizing 'appropriate salt intake,' choosing salt with an awareness of packaging and origin, and reducing plastic use are practical and effective measures. We don't have all the perfect answers, but we believe it's important to continue updating our information together.

Disclaimer: The information in this article is for general informational purposes only and does not constitute medical advice. Please consult a qualified healthcare professional before making any health-related decisions.