Kick-start health with carotenoids

In the wake of the Covid-19 pandemic, the market for supplements is booming. Whether it is vitamin C, vitamin D, probiotics, omega-3 or carotenoids, millions of consumers are looking for ways to boost their health through a better diet and a robust regimen of supplements.

Carotenoids are a particularly interesting focus for this market growth, as they have not been specifically linked with any improvement in immunity against Covid-19. Instead, they bring a host of other benefits for the human body, particularly when it comes to cardiovascular health.

There are varying estimates of how fast the market for carotenoids is growing. One 2019 forecast by Global Market Insights suggests that the CAGR for carotenoid supplements will exceed 4.5% between 2020 and 2025.

“Some estimates say that the carotenoids market was worth $1.5bn in 2019 and is projected to increase to $2bn by 2026,” notes Volker Bohm of industry body Eurocaroten and lecturer at the Institute of Nutrition at Friedrich Schiller University, Jena. “The factors responsible for the increasing market are the increasing use of natural carotenoids as food colourants, innovative technologies for the extraction of carotenoids, and the growing use of carotenoids in preventive healthcare.”

Several studies have shown that, as well as being beneficial for cardiovascular health, carotenoids – natural compounds found in many fruits and vegetables and often associated with a red-orange colour – work as powerful antioxidants, boosting the body’s inflammatory and immune responses, and improving the condition of eyes, skin and brain.

“Carotenoids are fat-soluble antioxidants,” Bohm adds. “Thus, they prevent oxidative stress by scavenging reactive oxygen species (ROS) and inhibiting oxidation reactions. They also act as anti-inflammatory compounds.”

More than an antioxidant

Depending on the region, the largest consumption of carotenoids is in Europe, with 37% of the market, followed by North America (27%) and China (22%), according to a study entitled ‘The Global Carotenoids Market, 2022-2028’ by 360 Research Reports.

In these and other markets around the world, the growing consumption of carotenoid supplements is based on a growing body of research that shows these ancient and versatile secondary metabolites play key roles in nature and in human health.

According to ‘Molecular Basis for Nutrition and Aging’ by a team at Ben-Gurion University of the Negev and Soroka Medical Centre in Israel, more than 750 different carotenoids have so far been identified in animals, plants, macroalgae, fungi and many prokaryotic and eukaryotic microorganisms.

According to the WHO, which collected data from its health evidence network, antioxidants are an important component in general health. The human body needs oxygen, but certain chemical processes can create oxygen free radicals that damage cells, contribute to ageing and play a role in the onset of diseases such as arteriosclerosis and cancer. Among the most effective protective agents against oxygen-free radicals is beta-carotene, a well-known carotenoid.

However, according to a recent review co-authored by Bohm, ‘Health-promoting Biological Actions of Carotenoids: Mechanisms for and Contributions to Reduced Risk’, it is not only their antioxidant properties that make carotenoids a source of health benefits.

“Although the possible health benefits of carotenoids are still usually attributed to direct antioxidant mechanisms, which are very difficult to demonstrate in vivo, there may be other mechanisms that create these health benefits, such as pro-oxidant mechanisms, enhancement of gap junctional intercellular communication, modulation of signalling pathways or immune function, and absorption of visible light, and all these may interact,” the review states.

“The biological actions of carotenoids may be due to some extent to apocarotenoids and other carotenoid derivatives, which can be present at low levels in foods and formed in the body,” it continues.

The effect on cardiovascular health is particularly significant, given that cardiovascular diseases are among the biggest killers on the planet. According to the US CDC, one person dies every 36 seconds in the US from cardiovascular disease, and around 659,000 people die from heart disease each year, accounting for one in every four deaths.

Arteriosclerosis, which occurs when the blood vessels that carry oxygen and nutrients from the heart to the rest of the body become thick and stiff, thereby restricting blood flow to organs and tissues, is among the major threats against which carotenoids have shown to be effective.

Oxidative stress is universally accepted as a key factor in the pathogenesis of all major diseases, including those of the cardiovascular system. It activates transcriptional messengers, such as nuclear factor-kB, which tangibly contributes to endothelial dysfunction, the initiation and progression of atherosclerosis, irreversible damage after ischemic reperfusion, and even arrhythmia, such as atrial fibrillation. Nevertheless, although there is a clear connection between oxidative stress and cardiovascular disease, no specific therapeutic interventions are currently in place to tackle this key problem. It is left to consumers to choose a diet and a supplement regimen rich in antioxidants.

Short-term dietary intervention trials have indicated that diets rich in fruit and vegetables can reduce coronary risk factors and reduce cardiovascular mortality, with the abundant, plant-derived, fat-soluble pigments in carotenoids shown to be particularly effective.

“Vitamins and carotenoids have multiple roles both as participants in many important metabolic processes throughout the body and to counter the oxidative stress resulting from normal metabolism and daily exposure to environmental agents,” says a study by Itakura Hiroshige of the Ibaraki Christian University in Japan. “Epidemiological studies have consistently indicated that the consumption of vegetables and fruits is inversely related to the incidence of cardiovascular and cerebrovascular diseases and cancer. Marine animals supply astaxanthin which is a carotenoid and antioxidant.”

The results of the study, entitled ‘Multivitamin and Carotenoid Supplements’, showed evidence that the consumption of marine animals producing astaxanthin inhibits low-density lipoprotein (LDL) oxidation and, therefore, might contribute to the prevention of atherosclerosis.

A multi-faceted compound

As the study by Hiroshige suggests, different types of carotenoid may have different effects. The most widely known carotenoids are astaxanthin, Beta- Carotene (??-carotene), canthaxanthin, lycopene, zeaxanthin, annatto and lutein. All of these are widely used in human food, animal feed, dietary supplements, pharmaceuticals, and cosmetics, though their range of health-giving properties varies.

“Carotenoids differ in their biological activities,” observes Bohm. “One reason is the number of conjugated double bonds within the molecule. Another reason is the oxygen-containing substituents. We made comparisons of antioxidant activity of various carotenoids by using several assays. Depending on the assay used, the carotenoids showed significantly different activities.”

Another paper co-authored by Bohm, entitled ‘Comparative antioxidant activities of carotenoids measured by ferric reducing antioxidant power (FRAP), ABTS bleaching assay (aTEAC), DPPH assay and peroxyl radical scavenging assay’, showed lycopene, as well as hydroxy carotenoids, were the most effective carotenoids in reducing ferric ions in the FRAP assay, suggesting that it has the strongest antioxidant properties.

It is astaxanthin, however, that has been gaining the most attention in recent years. A red-orange carotenoid pigment, it has been shown in animal and clinical studies to have powerful antioxidant properties. It is abundant in marine animals and plants, with one of the richest sources being Haematococcus pluvialis algae.

“Algae astaxanthin’s effect on cardiovascular health has been the subject of numerous studies,” says Allen Levine, CEO of the Natural Algae Astaxanthin Association (NAXA). “As a carotenoid with strong antioxidant properties, algae astaxanthin has shown success in cardiovascular clinical studies. Its antioxidant activity is greater than beta-carotene and other carotenoids such as lutein, canthaxanthin, zeaxanthin, and vitamin C.”

Not only is astaxanthin a powerful antioxidant with a unique property of being able to insert into membranes and lipid bilayers, it is also a potent anti-inflammatory agent and, as such, is a promising therapeutic agent for patients with cardiovascular problems.

So far, studies have shown no significant adverse events with the use of astaxanthin, though it attenuates biomarkers of oxidative stress and inflammation. Experimental investigations in a range of species using a cardiac ischaemia-reperfusion model demonstrated cardiac muscle preservation with the oral or intravenous delivery of astaxanthin prior to the induction of ischaemia or the decreased blood flow and oxygen to the heart muscle.

While the health benefits of carotenoids are increasingly well-established, there is some debate within the industry as to the relative benefits of natural carotenoids compared with their synthetic counterparts. Most of the commonly used carotenoids including canthaxanthin, astaxanthin and betacarotene are largely produced by chemical synthesis, but Naxa is advocating for natural algae astaxanthin.

“Although synthetic carotenoids account for a high share in the market, consumers prefer opting for natural and clean-label products, which is projected to drive the growth of the naturally-sourced carotenoids market in Europe,” says Bohm. “Synthesised carotenoids have the same activities compared to natural carotenoids, when comparing single compounds. However, in natural extracts, often several compounds act synergistically.”

Natural or synthetic, carotenoids undoubtedly have a key role to play in preventative healthcare in the years ahead. It seems that orange is now the new health hack.