---
title: "The health benefits of seaweed – a bath full of bladderwrack might be just what the doctor ordered"
description: "Seaweed can offer a variety of health benefits as a food and topical treatment."
type: "NewsArticle"
publisher: "Daily Maverick"
site: "https://www.dailymaverick.co.za"
section: "THE CONVERSATION"
author: "Leanne Timpson"
author_url: "https://www.dailymaverick.co.za/author/leanne-timpson/"
canonical_url: "https://www.dailymaverick.co.za/article/2024-08-26-the-health-benefits-of-seaweed-a-bath-full-of-bladderwrack-might-be-just-what-the-doctor-ordered/"
published: "2024-08-26T11:00:16"
updated: "2024-08-24T16:48:31"
lang: "en-ZA"
word_count: 818
---

# The health benefits of seaweed – a bath full of bladderwrack might be just what the doctor ordered

> Seaweed can offer a variety of health benefits as a food and topical treatment.

By Leanne Timpson · Published 26 August 2024, 13:00 SAST · Updated 24 August 2024, 18:48 SAST

## Content

Seaweed, the colourful macroalgae that grows in the ocean, is a food source for marine life and humans. Each type of seaweed has a unique set of [nutrients](https://www.dailymaverick.co.za/article/2024-07-22-three-ways-to-eat-more-nutritiously/) and can boost vitamin and mineral intake if eaten regularly.

Seaweed is widely consumed in Asia, and a staple ingredient in many Japanese, Korean and Chinese dishes. For example, nori is well known as the seaweed used to wrap sushi rolls, while wakame or kelp are often found in comforting ramen noodle dishes. These seaweeds impart an instantly recognisable savoury taste – known as [umami](https://www.sciencedirect.com/science/article/abs/pii/S0165993620301059) flavour – to food and can add a variety of vitamins and minerals to meals.

Seaweed types can be broadly classified according to their [colour](https://www.sciencedirect.com/science/article/pii/B9780128027721000038): red, green and brown. Around 145 species of seaweed are [eaten](https://www.bbc.com/future/article/20240103-seaweed-should-we-be-eating-more-of-it) around the world. Seaweed is valued for its [antioxidant](https://www.oxfordlearnersdictionaries.com/definition/english/antioxidant) properties, which helps protect cells against [free radical damage](https://www.cancer.gov/about-cancer/causes-prevention/risk/diet/antioxidants-fact-sheet#:%7E:text=Antioxidants%20are%20chemicals%20that%20interact,antioxidants%20are%20called%20endogenous%20antioxidants.).

Many seaweeds contain [phenolic and flavonoid compounds](https://www.sciencedirect.com/topics/food-science/phenolic-compound), which are [important antioxidants](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6165118/), as well as omega-3 fatty acids, amino acids, fibre, vitamins A, C and E – and minerals such as copper, zinc and iodine.

The [seaweeds](https://www.dailymaverick.co.za/article/2023-11-03-people-in-europe-ate-seaweed-for-thousands-of-years-before-it-largely-disappeared-from-their-diets-new-research/) with the greatest [nutritional value](https://watermark.silverchair.com/nutritionreviews65-0535.pdf?token=AQECAHi208BE49Ooan9kkhW_Ercy7Dm3ZL_9Cf3qfKAc485ysgAAA4QwggOABgkqhkiG9w0BBwagggNxMIIDbQIBADCCA2YGCSqGSIb3DQEHATAeBglghkgBZQMEAS4wEQQMEdmZa-Xgu8ZQuHwlAgEQgIIDN7XkcXl8_-uWYImrgJ5SvsMrPX9zYJYQGPLlfHK9hcIcOlmtrbn49S7Q87Q8aLPDyer2NJKgEBi_9HBAwA5KPmLGvK5IEXeGaYT-cmdh3to5IvGzVV4OfK0aBJO5FtS5LTxpC7AJ1Xjxn5R-f-cxw-t3KKoAmp-p1MRhq23Fataww2EY1IW8PzFUuG9MGjMStahhbVdXAOTBgwYSCW67zw4DRQqKbCVViu1mYSrDshtlRgOm7Fznfd0A7c5GKZp_b0sMLOj5fjUkssV_gpJPJRkptL-6QDLKJSw0VbsUDFRflKWfE1a1CBbm6YI7tfl8roGf-Wx5IfyFfH8SB9Ai_85NYPu7pELTD8GwEGTiqdj9A9JGoJYY2KbSv3Cf5T3yYJpu9sANj8Bycg1HZ7zGYOlI4WR8l6QJyelAG5pU14gQi7vtPlhkyztDfsLSrdoISnNbMGQtpSN48DsB6vEVO98TziHwaF-RD4h84glqcrqLiIq1Bh0zljl0kyJoPYVk_KccqorF99b3wNjiJDnbiQK_Cgup3DXGGZfzsfwPeTxvbcd_oh3Ii-25rF49dH2d5DcV49eeP-xGWn8DmfiuN-Vun7wT7wDcjzr5_-1-Dz41Pkg1ifv6o-YVMC6kQjK3R_9EuOPcPuD1Y3Msx7KwkxuBRzkx9oKFmZf88GrS6nNgZfazsCbTs4frtuJqvinqp8Lho1e-JzldJd4pRXDwvXxtpkNREQgJdJ8cKRiQtvIzR6dnb2zpceefBoN8w2j8wPXegB7udrYJU9bcFzgmn9Qq0cprtiDFtfnNAnLIbox9LK_Tbdv0vusy6Sn_ityfpWpKQMaIcVncmR72lKLpsZDU4U_4zz7Wlv5dDbC1SrKu_UmxelnX49yBu_OGDvgSdp7kwSK9bYoPM3tEsga05YQvv6RIaN8keOPVoRet9llIv8ngJe5qvAM-0QUpuK6gLPxQFq97zouKH-YadPX50xZFrW4i5p0e5H-le8iAdDiRvL6RzNgBZkezztZYBaviebLetlf-AFXD4xCUP0VDIBI0PUh6fdTEaParP5FX_00z168Pebm-Fh7m0UnTigR-1fKqUCtijrs) include those often referred to as the “wracks”. Bladder, toothed and spiral wracks often have notably higher [antioxidant](https://www.mdpi.com/2076-3298/8/6/59) contents than many other seaweeds. However, nutritional content varies [depending on](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6551690/) the type of seaweed, harvest location and the season in which it’s harvested.

As well as being nutritious, seaweed has potential as a source of valuable antimicrobial agents. Research from [Queen’s University Belfast](https://pure.qub.ac.uk/en/publications/polyphenols-from-brown-seaweeds-as-a-potential-antimicrobial-agen) has shown that seaweed species can fight off the growth of harmful microorganisms in animals, some of which are becoming [resistant to antibiotics](https://theconversation.com/feeding-farm-animals-seaweed-could-help-fight-antibiotic-resistance-and-climate-change-113052).

While eating seaweed has an array of benefits, there are a few things to [watch out](https://www.healthline.com/nutrition/benefits-of-seaweed) for. Due to the high [iodine content](https://theconversation.com/ocean-acidification-will-increase-the-iodine-content-of-seaweeds-and-the-billions-of-people-who-eat-them-106568) in many seaweed species, seaweed consumption could exacerbate [thyroid](https://etj.bioscientifica.com/view/journals/etj/10/2/ETJ512971.xml) conditions or interfere with thyroid [medications](https://www.livestrong.com/article/470501-what-are-side-effects-of-eating-seaweed/).

Some [reports](https://efsa.onlinelibrary.wiley.com/doi/full/10.2903/j.efsa.2023.7798) also suggest that, depending on the habitat, seaweed species may accumulate [heavy metals](https://time.com/5559578/is-seaweed-healthy/) such as cadmium, which has been reported to cause [liver and kidney](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6551690/) toxicity, and mercury, a known [neurotoxin](https://www.nature.com/articles/s41598-023-44685-4).

It’s important, then, to check different countries’ [maximum contaminant levels](https://www.nature.com/articles/s41598-023-44685-4) (MCLs) for [heavy metal](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9887633/) concentrations in seaweed products and only purchase those which have been tested and deemed safe for [consumption](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6551690/).

![LONDON, ENGLAND - MAY 13: Demi Chef de Partie Nikesh Patel prepares kombu edible kelp in the kitchens at The Ritz London on May 13, 2021 in London, England. After closing its doors in the middle of December, The Ritz London is preparing to welcome guests on May 17, when coronavirus restrictions will be eased to allow hotels across the United Kingdom to re-open. (Photo by Leon Neal/Getty Images)](https://cdn.dailymaverick.co.za/i/11GdMW7h2XrNZlWNsex9GA-MlcQ=/200x100/smart/filters:strip_exif\(\)/file/dailymaverick/wp-content/uploads/2024/08/GettyImages-1317842406.jpg)

*Demi Chef de Partie Nikesh Patel prepares kombu edible kelp in the kitchens at The Ritz London on May 13, 2021 in London, England. (Photo by Leon Neal/Getty Images)*

#### **Seaweed bathing**

But diet is not the only way to experience the benefits of seaweed.

In recent years, there has been an upsurge in [seaweed bathing](https://www.mdpi.com/2071-1050/16/8/3337), which is believed to be beneficial to [health](https://www.mdpi.com/2079-9284/5/4/68). A bath full of [bladderwrack](https://www.healthline.com/nutrition/bladderwrack-benefits) might not seem very appealing - but this strap-like, olive-coloured seaweed, found along the coasts of the North Sea, Atlantic Ocean and Pacific Ocean, has been shown to have beneficial effects as a topical treatment for [various skin issues](https://www.mdpi.com/2076-3417/12/23/11954) from skin ageing to wound healing.

The tradition of seaweed bathing, which has been practised for [hundreds of years](https://www.mdpi.com/2071-1050/16/8/3337), was [originally recommended](https://link.springer.com/article/10.1007/s10811-023-02965-6) for arthritis sufferers to ease pain, stiffness and inflammation of joints. Nowadays, it is also recommended for athletes after a strenuous [workout](https://www.mdpi.com/2079-9284/5/4/68) because seaweed’s high magnesium content is believed to be soothing for aching muscles.

Many companies that specialise in the harvesting of seaweed for bathing purposes aim to do so [sustainably](https://www.tandfonline.com/doi/full/10.1080/09670262.2017.1365273). This means that the seaweed is cut from the reef at low tide and is never pulled from the root to ensure regrowth. As demand increases, there is a [growing awareness](https://www.mdpi.com/2079-9284/8/1/8) of the [challenges](https://marinescience.blog.gov.uk/2022/05/05/the-developing-uk-seaweed-industry/) around growing and harvesting methods, technical know how and environmental [impact](https://www.nature.com/articles/s41893-022-01043-y) of expanding production.

The moisturising effects of seaweed are also [prized](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8539943/) by the beauty industry as today’s [consumers](https://www.sciencedirect.com/science/article/pii/S0301479721019617) place greater value on natural – and environmentally friendly – skincare ingredients.

![Kelp beds float in the Barkley Sound, British Columbia, Canada, on Monday, May 6, 2019.  Photographer: James MacDonald/Bloomberg via Getty Images](https://cdn.dailymaverick.co.za/i/4ur_0waZxlzb6QBYN7qgMH5sfW8=/200x100/smart/filters:strip_exif\(\)/file/dailymaverick/wp-content/uploads/2024/08/GettyImages-1142453751.jpg)

*Kelp beds float in the Barkley Sound, British Columbia, Canada, on Monday, May 6, 2019. Photographer: James MacDonald/Bloomberg via Getty Images*

Containing extracts of seaweeds such as toothed wrack and sea spaghetti, seaweed-based skincare lines claim [anti-photoaging](https://www.mdpi.com/1660-3397/19/3/172), hydrating and protective, nourishing and skin-plumping [effects](https://www.sciencedirect.com/science/article/pii/B9780128183052000292). But check the label: the closer to the top of the ingredient list, the greater the amount of seaweed in the product.

To enhance your health, seaweed can be easily [incorporated](https://www.integrativenutrition.com/blog/7-ways-to-eat-more-seaweed-and-why-you-should) into your lifestyle.

Add to your diet, in moderation, by exploring seaweed recipes and by sprinkling dried, ground seaweed mixtures featuring dulse, wakame, sea spaghetti and wracks into smoothies, over salads and even on pizza.

It is also possible to buy hand-harvested seaweed products for adding to the bath so that the benefits of submerging in marine algae can be realised from home – no matter how far from the sea we may live. **DM**

[Media](https://counter.theconversation.com/content/233367/count.gif?distributor=republish-lightbox-advanced)

[*This story was first published in* The Conversation.](https://theconversation.com/the-health-benefits-of-seaweed-a-bath-full-of-bladderwrack-might-be-just-what-the-doctor-ordered-233367)*Leanne Timpson is a Lecturer in Microbiology in the Department of Biosciences, Nottingham Trent University.*