Some seaweeds, like those shown here, are a source of essential nutrients, but they can also expose consumers to dangerous levels of heavy metals. Credit: Adapted from ACS Food Science & Technology 2024, DOI: 10.1021/acsfoodscitech.3c00476
Key Point:
- Researchers measured beneficial nutrients and toxic elements in six Hawaiian sea trees.
- At least 4 out of 6 were good sources of at least one essential mineral.
- However, two farmed species contained high lead levels that exceeded levels recommended for safe consumption in Taiwan.
Seaweed is a popular food around the world, but it has its drawbacks. That is, consumers can be exposed to heavy metals that accumulate in the leaves before harvest.
Given the importance of seaweed in Hawaii, researchers at the University of Hawaii at Mānoa decided to analyze key nutrients and metals in seaweed species grown around the island. Regarding this research, ACS Food Science & Technology, The researchers obtained six types of seaweed, either cultivated or collected in the wild. They measured the beneficial nutrients and toxic elements of each species and used statistics to differentiate the samples. They discovered:
- Four of the six seaweeds tested were good sources of at least one essential mineral, with iron, manganese, or both calcium and magnesium meeting the recommended daily intake per serving. It contained more than 20%.
- The amounts of protein, fat, carbohydrate, and fiber varied widely among the species tested and were broadly consistent with previous nutritional evaluations of the three seaweeds.
- Two wild species that are not usually eaten. S. aquifolium and S. echinocarpumcontained the highest levels of arsenic-containing compounds, far exceeding safe consumption limits established by other countries.
- There are two types of cultivated species, H. formosa and G. parvisporacontained high lead levels, exceeding levels recommended for safe consumption in Taiwan.
Overall, the research team found that while Hawaiian seaweed contains many essential minerals and nutrients, consumers may be exposed to dangerous levels of heavy metals, depending on factors such as the type of seaweed and growing conditions. I discovered that there is.
Previously published research suggests that boiling or rinsing other seaweed species not included in this study may remove some harmful substances. However, these techniques can also rob you of beneficial nutrients.
Researchers are currently working with seaweed producers to study the effects of growing location and common cooking methods on heavy metal and nutrient levels in Hawaiian seaweed. Their findings could inform future regulations and ensure nutritious and safe seaweed foods.
