Seaweeds are a type of macroalgae that are a source of many bioactive compounds and health promoting properties. They are rich in vitamins, minerals, antioxidants, and fibers. Seaweeds have anti-inflammatory, antimicrobial, anti-cancer, and blood sugar regulating effects. Sri Lanka has potential for seaweed farming and production, but it is currently at a preliminary stage compared to the multibillion dollar global seaweed industry.

1. Health Promoting
Properties of
Seaweeds
By K.G.Anupa Sudharaka

2. Content– Introduction
• What Are Algae?
• What Are Seaweeds?
• Types of Seaweeds
• General Characters of Seaweeds
– Health Promoting Properties of Seaweeds
• History of Seaweeds
• Nutrient Profile of Seaweeds
• Common Uses & Advantages of Using Seaweeds
– Global Seaweed Production
– Sri Lankan Situation
– References

3. Introduction

4. Introduction Contd…
What Are Algae?
– Algae, a group of autotrophic plant-like organisms
containing Chlorophyll
– Unicellular or multicellular vegetative organisms
– Vary in size and morphology
– Do not have true roots, stems, or leaves like terrestrial
plants.

5.  Classification of Algae according to their size:
Algae
Microalgae
Macroalgae
(Seaweeds)

6. What Are Seaweeds?
– Primitive plants belonging to algae family
– Marine macroalgae are plant-like organisms
– Generally live attached to rock or other hard substrata in
coastal areas

7. Types of Seaweeds
Macroalgae
(Seaweeds)
Green Algae Brown Algae Red Algae

8. General Characters of Seaweeds
Several characteristics are used to classify macroalgae,
including the;
Nature of Chlorophyll
Cell Wall Chemistry

9. Green Algae, Brown Algae & Red Algae
Green Algae Brown Algae Red Algae
Division Chlorophyta Phaeophyta Rhodophyta
Pigments Chlorophylls a,b
carotenes, lutein,
several
Xanthophylls
Chlorophylls a,c
beta-carotenes,
fucoxanthins,
several other
Xanthophyles
Chlorophylls a,d
phycocyanins,
phycoerythrin,
several
Xanthophylls
Storage Product Starch Laminaran
mannitol
Floridean starch
Structural cell
wall
Cellulose, Xylans, Mannans

10. Health Promoting Properties of
Seaweeds
History of Seaweeds
• Since prehistoric times people had used marine plants
in many different ways as food, dietary supplements &
medicine

11. History of Seaweeds Contd…
• Chinese historians have found documentations dating
back over 9000 years of the medical use of seaweeds.

12. History of Seaweeds Contd…
• 18-19 th century, there was a part of the European
medical tradition known as “Thalassotherapy” ,which
derived from the Greek word for sea.

13. History of Seaweeds Contd…
• At present, US & British hospitals use seaweeds for bed
sores in hospitals which is far superior to anything man
made.

14. Nutrient Profile of Seaweeds
– Depending on the species, fresh seaweeds are 70–90 % water by
weight.
– The composition of the dry ingredients in the different types of
seaweeds can vary a great deal, but the approximate proportions
are about;
– 45–75 % carbohydrates and fiber
– 7–35 % proteins
– <5 % fats &
– A large number of different minerals
and vitamins

15. – They are an excellent source of vitamins such as A, Bl, B12,
C, D and E, Riboflavin, Niacin, Pantothanic acid and Folic
acids etc.
Rich Source of Vitamins

16. – The primary mineral components in seaweeds are Iodine, Calcium,
Phosphorous, Magnesium, Iron, Sodium, Potassium and Chlorine.
– Trace elements such as Zinc, Copper, Manganese, Selenium,
Molybdenum, and Chromium.
Eg: Konbu contains more than 100–1,000 times as much Iodine as Nori.
Rich Mineral Profile
Konbu Nori

18. Rich in Polysaccharides
All seaweeds contain their own array of
Polysaccharides in the form of,
– Algin
– Fucoidan
– Carageenan
– Agarose
– Beta glucans
.

19. These dietary glyconutrients are helpful for,
• Building immune health,
• Nourishing the skin,
• Soothing in inflammation,
• Detoxifying the body and providing a long
burning fuel source

20. – Dietary fiber, a group of non-starch carbohydrates
basically of plant origin which are essential part of a
healthy diet.
– Promote the digestive health during its passage through
the gastrointestinal track.
Dietary Fibers in Seaweeds

21. The consumption of this dietary fiber has been
related to the following health-promoting effects:
– Promotes the growth and protection of the
beneficial intestinal flora
– Reduces the overall glycemic response
– Greatly increases stool volume &
– Reduces the risk of colon cancer
Dietary Fibers in Seaweeds Contd…

22. – Gupta, Abu-Ghannam, & Scannell, 2010 showed that the
presence of prebiotics(non-digestible part of foods) in
seaweeds support the growth of lactic acid bacteria and
subsequently probiotics (live beneficial bacteria) that can
benefit human health.
– Thus, seaweeds have the potential to be used as a
functional food ingredient or as a nutraceutical (Nutrition
+ Pharmaceutical)
Presence of Prebiotics

23. Antioxidant Properties
– The order of scavenging activity for the seaweeds tested was;
Fucus > Laminaria > Undaria > Porphyra
– Thus, the radical scavenging capacity of brown seaweeds was
clearly superior to that of red seaweeds.
(Bocanegra et al.,2009)

24. Common Uses & Advantages of Using
Seaweeds
Use of Seaweeds for Skin Care
• The antioxidants in seaweed can help prevent free
radical damage to the skin and protect against skin
aging.
Moisturizes skin
good at combating acne
• A “seaweed body wrap” is a very popular detoxification
treatment in many spas around the world.

25. • Seaweed nourishes the membranes, making it
good for nervous disorders, skin conditions,
colds and constipation.
Use of Seaweeds for Cosmetics

26. • Algin or alginates from brown seaweed and agar from
red seaweed are widely used in bakery products,
toothpaste, ice creams and creams and jellies
Use of Seaweeds in Industrial
Products

27. For Hair Growth
– Positive health benefits for hair health
– Strengthening the hair roots and making the hair thicker.

28. Solution for Iodine deficiency
– Nearly 19 million babies born globally every year (14
percent) are at risk of permanent yet preventable brain
damage and reduced cognitive function due to a lack of
iodine in the earliest years of life.
(Source: UNICEF Press release 2018,March )

29. • Dietary obesity and obesity-related diseases are among
the widely occurring nutritional health problems in most
of the developed nations in the western world.
• Dietary fiber in seaweed is not taken up by the human
body and provides a low caloric value to the diet.
For Reduction of Obesity

30. Reduction of obesity contd...
• A Study carried out with a drug developed using alginic
acid extracted from seaweeds revealed that volunteers
who were 25 – 30% overweight significantly decreased
their body weight after treating with the drug (Rajapakse
& Kim, 2011).

31. Reduction of cardiovascular risks
– Lower the levels of LDL cholesterol and triglycerides
present in the body
– Help to reduce the risks of heart conditions such as heart
failure and atherosclerosis.

32. Prevents chances of having stroke
– The bioactive peptide present in seaweeds possess quite
the same properties as many ACE (Angiotensin-converting
enzyme inhibitors)
– So seaweeds reduce the chance of getting cardiac attacks
and cerebral stroke.

33. For Detoxification
–Alginic acid is found in seaweeds
–Seaweeds have the potential to assist the
body with the detoxification process through
its rich alginate properties
Alginic acid formula

34. Anti-diabetic properties
• The Chromium (Cr) content in seaweeds helps to
control blood sugar levels (Gupta et al., 2011)
• Supplementation with chromium has consistently
demonstrated improvement in:
 blood sugar levels
 insulin sensitivity
 helpful lipid profiles

35. Antibacterial and algicidal properties
• With increasing resistance of pathogens to
antibiotics, there is a public health priority for
exploring and developing;
 cheaper and effective natural antimicrobial
agents with better potential,
 less side effects than antibiotics,
 good bioavailability
 minimal toxicity.

36. Antibacterial and algicidal properties
Contd…
• Antimicrobial effects of phlorotannins from brown
algae, in relation to the food and pharmaceutical
industries is well documented.(Gupta et al., 2011)

37. Anti-viral properties
• The sulphated polysaccharides found in some of the
brown seaweeds are being explored as antiviral
agents (Gupta et al., 2011)

38. Anti-cancer properties
– Glycoprotein and sulphated polysaccharides
Ex: Kombu, Kelp
(Gupta et al., 2011)

39. Anti-coagulant properties
– Yoon, Pyun, Hwang, and Mourao (2007), acidic
polysaccharide from Laminaria cichorioides collected
from east coast of Korea which was shown to have a
potent anti-coagulant activity mainly mediated by
thrombin inhibition by heparin cofactor II.

40. Global Seaweed Production
– At present, the seaweed industry offers a wide range of
compounds to meet the increasing demands of the textile,
cosmetics, and food sectors.
– Industrially cultivated seaweed now supplies more than
90% of the algae marketed internationally.

41. – Nowadays, edible seaweeds are increasingly consumed
in Europe and especially in France.
– Seaweeds have been a famous delicacy, especially
China, Japan and Korea.
– Porphyra tenera (Nori)
– Laminaria(Konbu)
– Hizikia (Hiziki)
– Undaria(Wakame)

42. What Are Kelp Forests?
– Kelps are large brown algae seaweeds that make up
the order Laminariales.
– There are about 30 different genera.

43. • Longest seaweed in the world Macrocystis pyrifera,
commonly known as giant kelp or giant bladder kelp, is
a large brown algae.
Pacific coast of North America from central
California to Baja California (Source: Google)

44. Sri Lankan Situation
– Sri Lanka has a coastline of approximately 1700 km
along which many varieties of seaweeds are found.
– About 320 species belonging to different families have
been identified by several workers.

45. • Microdictyon sp.
• Halimeda sp.
• Padina sp.
• Liagora sp.
• Amphiroa sp.
• Crustose coralline red algae

46. – Sargassum is the most economically important species of
brown seaweed found in Sri Lanka.
– In addition to Sargassum several other species such
as Laminaria, Macrocystis, Turbinaria, Fucus &
Ascophyllum which are found in Sri Lanka are rich in
alginates.
Seaweeds in Kamburugamuwa Beach, Matara, Sri Lanka

47. Locations where seaweeds are collected for commercial purposes
in Sri Lanka (Source : National Aquatic Resources Agency-NARA).

48. Summary
• Seaweeds are Primitive plants belonging to algae family.
• Seaweeds are considered as a source of bioactive compounds as
they are able to produce a great variety of secondary metabolites
characterized by a broad spectrum of biological activities.
• They are rich in vitamins, minerals, antioxidants and because of
their unique composition they possess several health promoting
properties.
• At present, Seaweed farming along with production of
pharmaceuticals has become a multibillion-dollar industry.
• In Sri Lanka, seaweed farming is at a preliminary stage when
compared with the global market.

49. References
Berge JP, Debiton E, Dumay J, Durand P, Barthomeuf C. In vitro anti-inflammatory and anti-proliferative
activity of sulfolipids from the red alga porphyridium cruentum. J Agric Food Chem. 2002;50(21):6227–
6232.
Bocanegra, A. et al. (2009) ‘Characteristics and Nutritional and Cardiovascular-Health Properties of
Seaweeds’, JOURNAL OF MEDICINAL FOOD, 12(2), pp. 236–258. doi: 10.1089/jmf.2008.0151.
Gupta, S., & Abu-Ghannam, N., Bioactive potential and possible health effects of edible brown seaweeds,
Trends in Food Science & Technology (2011), doi:10.1016/j.tifs.2011.03.01
Jayasuriya, P. (2019). Report of the Regional Workshop on the Culture & Utilization of Seaweeds.[online]
Fao.org. Available at:http://www.fao.org/docrep/field/003/ab727e/AB727E06.htm [Accessed 15 Feb. 2019].