Fucoxanthin — Food Sources, Structure, Health Benefits, and Supplements
Summary
Fucoxanthin is an epoxy xanthophyll carotenoid that accounts for about 10% of all carotenoids produced. It is found in various species of microalgae (diatoms) and macroalgae (brown seaweeds) and is sold as a dietary supplement.
Limited access to sunlight, the pH, salinity, and conductivity of seawater during winter increase fucoxanthin production, whereas high seawater temperature and prolonged sunlight exposure during summer decrease its concentrations.
FDA has allowed the use of fucoxanthin from Phaeodactylum tricornutum as a new dietary ingredient. The approved daily dose has been 3mg daily for an indefinite time or 5mg for up to 90 days.
Fucoxanthinol may be the primary active metabolite of fucoxanthin in humans. It is mainly stored in white adipose tissue (body fat).
Fucoxanthin has various beneficial health effects, such as antioxidant, anti-obesity, antidiabetic, hypoglycemic, anticancer, and anti-inflammatory. It also protects the skin, liver, nervous, and cardiovascular systems.
However, most studies are on animals, and more human studies are required to confirm the potential health benefits of fucoxanthin and its possible downsides and risks.
Introduction
Fucoxanthin is a marine carotenoid found in large quantities in edible brown algae and available as a dietary supplement. It is researched for its various beneficial effects on health, which will be discussed below, along with its classification, structure, metabolism, daily dose, and more.
Classification & Structure
Fucoxanthin is an epoxy xanthophyll carotenoid (epoxycarotenoid) with a molecular formula of C42H58O6, accounting for about 10% of total produced carotenoids. It is also a non-provitamin A carotenoid, meaning it doesn’t exhibit vitamin A activity.
Fucoxanthin is an accessory pigment and a vital structural component of light-harvesting complexes. It also protects the microalgae from the molecular damage caused by sunlight.
Fucoxanthin degrades when exposed to light, heat, enzymes, oxygen, unsaturated fats, and prooxidant molecules. Its low water solubility and bioaccessibility limit its applications in the pharmaceutical and food industries (1, 2, 3).
Absorption & Metabolism
According to animal studies, fucoxanthin is hydrolyzed to fucoxanthinol by the digestive enzymes lipase and cholesterol esterase in the gastrointestinal tract and further converted to amarouciaxanthin, halocynthiaxanthin, fucoxanthinol-3′-sulfate, etc. in the liver.
Fucoxanthinol may be the primary active metabolite in humans. Over 80% of fucoxanthin metabolites were found to be stored in white adipose tissue (body fat) and the rest in other tissue fats.
This distribution may be related to its anti-obesity and antidiabetic properties (2, 4, 5).
Food Sources & Extraction Methods
The main food sources of fucoxanthin are various species of microalgae (diatoms) and macroalgae (brown seaweeds) found in different countries.
The table below demonstrates fucoxanthin content and sample condition in several brown seaweed species (2, 4, 5).
| Species | Fucoxanthin content in mg/g | Sample condition |
| Euchema cottoni | 0.94 | Dried |
| Sargassum polycystum | 0.15-0.6 | Dried |
| Sargassum siliquosum | 1.41-2.01 | Dried |
| Sargassum binderi | 7.4 | Dried |
| Sargassum fusiforme | 2.62 | Fresh |
| Fucus serratus | 3.57 | Dried |
| Alaria esculenta | 0.87 | Fresh |
| Cystoseira Hakodatensis | 0.63-4.14 | Dried |
| Hincksia mitchellae | 5.50 | Dried |
| Cystoseira indica | 0.77-3.56 | Dried |
| Himanthalia elongata | 18.6 | Dried |
| Undaria pinnatifida | 0.7–2.08 | Dried |
| Undaria pinnatifida | 0.39–4.96 | Fresh |
Many factors affect fucoxanthin content in seaweed, such as its species and genus variations, geographical location, harvesting season and light, as well as physicochemical properties and nutritional profile of seawater. Limited access to sunlight during winter increases the photosynthetic activity in brown seaweed, increasing fucoxanthin concentrations. Moreover, the pH, salinity, and conductivity of seawater during winter also lead to increased fucoxanthin production and concentrations. Conversely, high seawater temperature and prolonged sunlight exposure during summer decrease fucoxanthin concentrations in seaweed. Some studies suggest the algae condition may also affect fucoxanthin levels (higher in fresh seaweed and lower in dried), whereas others don’t (5).
Fucoxanthin can be extracted using several methods, such as solvent, Soxhlet-assisted, enzyme-assisted, and ultrasound-assisted extraction. The solutions used may be ethanol, methanol, acetone, acetone-methanol, chloroform-methanol, ethyl acetate, n-hexane, etc. The methods and solutions used also affect fucoxanthin levels (5).
Daily Dose & Supplements
Even though clinical trials to evaluate fucoxanthin safety are lacking, the US Food and Drug Administration (FDA) has allowed the use of fucoxanthin extracted from the microalga Phaeodactylum tricornutum as a new dietary ingredient. The approved daily dose has been 3mg daily for an indefinite time or 5mg for up to 90 days (6, 7).
Fucoxanthin supplements are available in pills, softgels, and capsules. Fucoxanthin supplements may be sold as such and sometimes be named “brown seaweed extract,” and they can be combined with other carotenoids, antioxidants, or active ingredients.
Health Impact
Fucoxanthin has various beneficial health effects, such as antioxidant, anti-obesity, antidiabetic, hypoglycemic, anticancer, and anti-inflammatory. It also protects the skin, liver, nervous, and cardiovascular systems.
Most studies are on mice, and human studies are limited. Thus, more human studies are required to confirm the potential health benefits of fucoxanthin and its possible downsides and risks.
Anti-inflammatory & Anti-Cancer Effects
Fucoxanthin’s anti-inflammatory effects are possibly due to reduced production of proinflammatory mediators, such as PGE2 and NO, and cytokines, such as IL-1β, IL-6, and TNF-α. Fucoxanthin may also inhibit the activation of NF-κB and the phosphorylation of several kinases (6).
Animal studies have demonstrated that oral intake of fucoxanthin potentially reduces the risk of duodenal, stomach, colon, lung, bladder, skin, and liver cancers by inducing G1 cell cycle arrest, apoptosis (programmed cell death) of cancer cells and inhibition of metastasis (3, 6).
Metabolic Health & Obesity
Three human studies have been published on the effects of fucoxanthin on the liver. Fucoxanthin intake may decrease liver steatosis or liver fat content, toxicity, injury, fibrosis, and insulin resistance and improve liver function test results (7).
Fucoxanthin may decrease body weight and waist circumference, as well as C-reactive protein, triglyceride, and cholesterol levels, and regulate lipid metabolism (3, 7, 8).
Fucoxanthin may improve cardiovascular health and blood pressure levels by decreasing cholesterol levels, improving lipid metabolism, and having antioxidant effects. It may also decrease the risk of thrombosis by inhibiting the synthesis of thromboxane A2 (9).
Studies on mice suggest that fucoxanthin has antidiabetic effects due to decreased production of TNF-α and MCP-1, increased production of GLUT-4 (glucose transporter type 4), slowed carbohydrate absorption, reduced adipocyte production as they release saturated fatty acids and activate macrophage infiltration into adipose tissue, and more. Fucoxanthin may also reduce blood glucose and, like metformin, increase insulin levels (8).
Cognitive Functions
According to animal studies, fucoxanthin may improve cognitive functions and restore neurotransmitter concentrations. Additionally, fucoxanthin and fucoxanthinol have antioxidant and anti-inflammatory properties and protect cells from neurotoxicity (10, 11).
References
- https://link.springer.com/referenceworkentry/10.1007/978-3-031-28109-9_55
- https://www.frontiersin.org/journals/pharmacology/articles/10.3389/fphar.2022.929442/
- https://pubchem.ncbi.nlm.nih.gov/compound/Fucoxanthin
- https://www.sciencedirect.com/science/article/pii/S2211926423003909#
- https://pmc.ncbi.nlm.nih.gov/articles/PMC9368577/
- https://www.sciencedirect.com/science/article/abs/pii/S138819812030010X
- https://pmc.ncbi.nlm.nih.gov/articles/PMC10146066/
- https://pmc.ncbi.nlm.nih.gov/articles/PMC8269564/
- https://pmc.ncbi.nlm.nih.gov/articles/PMC3148495
- https://pubmed.ncbi.nlm.nih.gov/34792011/
- https://www.mdpi.com/1467-3045/46/6/357
