The health statistics for cardiovascular disease (CVD) are disconcerting. In the "2015 Heart Disease and Stroke Statistics Update", the American Heart Association reported that CVD remained the leading global cause of death. For example, one American dies of cardiovascular disease every 40 seconds.

The human cardiovascular system consists of all the fine capillary networks located at the interface of all biological functions, as well as the blood vessels, arteries, and veins through which the heart pumps blood. Some of the most prominent risk factors leading to CVD are widely recognised, and they interact and influence one another, ultimately manifesting in disease.

The list of factors that have a significant probability of contributing to CVD is relatively long, and includes: atherosclerosis (chronic inflammation), hypertension, type 2 diabetes, obesity, and stress. These risk factors, and most probably others, are significantly enhanced by diet, the constituents of which can influence them either positively, or negatively.

Fortunately, nutritional sciences have identified the health-promoting constituents that enable food to fulfil the fundamental role of sustaining growth, repair, and vital processes in humans. However, much of society has deviated widely from a nutrition-based diet, to one of convenience, which is often charged with high-fat, highsalt, high-sugar, and overly processed foods that are often consumed in excess.

THE HEART-HEALTHY INGREDIENTS FOUND IN SEAWEED

Numerous factors are at play here, but for many in food production industries, there exists a social responsibility to capitalise on scientific know-how in an effort to improve the nutritional content of consumer diets, and in doing so, help alleviate the prevalence of CVD. A remarkable tool to accomplish this is readily available in the form of an ancient, natural, and sustainable resource: seaweed! It is a food already eaten for centuries in many regions, but totally underutilised globally.

With thousands of species yet to explore, the opportunities to combat the risk factors associated with CVD are enormous. Increasingly, consumers are becoming more educated with respect to the wide range of benefits derived naturally from seaweeds, and this is leading to wide acceptability, and a corresponding demand for seaweed-based options.

An additional advantage of dietary seaweeds from a food-formulation perspective is that beyond their general provision of all the essential nutrients, seaweeds are nutritionally low in calories, which is not necessarily a negative attribute in this era of chronic obesity. These characteristics enhance the ability to create natural synergies from within ingredient blends.

Seaweeds are also high in fibres, both soluble and insoluble. The former improves effective passage through the gastrointestinal tract, and the latter nourishes those essential health-promoting gut microbes.

Numerous studies have shown beneficial effects of seaweeds and seaweed extracts on type 2 diabetes, inflammation, hypertension, and other pathologies leading to cardiovascular diseases. The recent announcement that obese children have a different mix of microorganisms living in their gastrointestinal tract (GIT) as compared to lean children speaks to the importance of selecively nourishing wellness-enhancing micro-organisms within the gut.

The microbial profiles in the GIT of the obese children matched those of obese adults and an analysis of this particular mix of gut microbes showed that they appeared to accelerate the conversion of carbohydrates into fat. Other microbial blends have been identified that are clearly associated with CVD risks, such as types 1 and 2 diabetes, certain cancers, and various autoimmune diseases.

Additional studies showed that a carefully selected mix of probiotic strains of microorganisms could lower blood cholesterol, a recognised risk factor for CVD in humans. To continue to nourish those beneficial gut microbes, the appropriate (prebiotic) dietary fibres are required, ideally altering the balance of the gut microbiome in a positive and stable way. These fibres are typically found in all seaweeds.

Interestingly, the prebiotic effects of seaweeds have been well established in laboratory animals, but the number of human trials is still rather limited. Human-based studies around foods and nutrient availabilities are challenging, as there are limitations on the control of fundamental variables such as genetics, life history, and combinations with other foods in the diet.

However, there is, indeed, a substantial body of evidence which supports the prebiotic validity of dietary seaweeds in terms of an increase in total short chain fatty acid production, enhanced mineral absorption capabilities, and significantly higher numbers of gut microbes that are widely considered to be beneficial. These effects may contribute significantly to overall health, especially when targeted against obesity, hypertension, and other non-communicable pathologies leading to CVD.

Researchers of one study supplemented the diets of lab rats showing signs of obesity and impending cardiovascular disorders with five percent of either dried Ulva ohnoi, or Derbesia tenuissima for eight weeks. Although the specific effects differed, Ulva demonstrated significant cardiovascular benefits as compared to Derbesia. Nonetheless, the Derbesia also showed improved insulin utilisation, a condition conducive to improved glucose metabolism and delayed onset of diabetes.

A WHOLESOME NUTRITION PROVIDER

There is no question that all the nutritional requirements for human health, with the exception of fats, can be met by consumption of dietary seaweeds. However, the fats that are present in seaweeds are primarily fatty acids and they possess an ideal ratio of approximately 1:1 omega-6 to omega-3 essential polyunsaturated fatty acids. These fatty acids have anti-inflammatory and antioxidant activities, and have been shown to play important roles in the prevention of cardiac diseases.

As a functional source of protein, seaweeds are also rich in bioactive peptides such as lectins and phycobiliproteins, which have demonstrated anti-diabetic, anti-inflammatory, anti-hypertensive, anti-cancer, and antioxidant activities.

In terms of providing protein for growth, repair, and vital processes, seaweeds can also be a viable source, with Dulse (Palmaria palmata) containing up to 31 percent protein (dry weight basis), and some nori species (Pyropia) shown to contain as much as 47 percent.

Phycobiliproteins, and the wide array of biologically active polyphenols and other sulphated polysaccharides seaweeds contain are unique to marine algae, i.e. never found in other food sources. Underlying much of the bioactivity of seaweed-derived molecules is the variety and reserve of antioxidant compounds, which function to maintain optimum cellular balance.

The more components of an organism (such as in a human) that are fundamentally in balance, the healthier and more robust that entity is. This applies to not only each of the various elements of the cardiovascular system, but also to the whole human body and the functions within. This is, in part, sound rationale for the consumption of foods and food ingredients that can provide significant therapeutic benefits with their extensive nutritional/wellness profiles. Seaweeds easily fit the bill.

EVIDENCED FOR IMPROVED HEART HEALTH

Authors of a scientific review article assessed the therapeutic application of a specific sulphated polysaccharide—fucoidan —from brown algae to mitigate CVD by compiling references from a number of databases. They concluded from their research that fucoidan was an effective agent, and should be further investigated for its potential to help combat these cardiovascular related diseases. There are, indeed already, fucoidan-based health products in the marketplace.

Dietary treatment of CVD requires a multi-pronged approach, and seaweeds are exceptional candidates for supplementing other foods in the diet, offering therapeutic advantages against the various risk factors. In a study published in 2015, eight seaweed species were tested for their ability to reduce cholesterol.

The hypolipidaemic potential of three of these species, i.e. Jolyna laminarioides, Melanothamnus afaqhusainii, and Sargassum binderi, was considered to be comparable to common cholesterol control drugs such as bezafibrate (Lipocor) and fenofibrate (Fenoget).

In a published science review, over 30 species of seaweed were identified as providing therapeutic benefits regarding cardiovascular health. All were administered either as whole seaweeds, as extracts, or as tablets or supplements. Clearly, seaweeds have a distinct role to play in the restructuring of global diets such that health and wellness are a primary focus, and factors that lead to CVD are amended, or minimised.

These exciting opportunities still require some management, however, and similar to food of a land-based nature, more studies on the bioavailability of nutritive compounds and bioactive molecules need to be undertaken to further ensure the anticipated beneficial effects. Location, culture environment, seasonality, and species can all contribute to much variability within seaweed constituents.

Functional foods and ingredients require a substantial measure of standardisation, consistency, and safety. In addition, post-harvest and processing methods can also affect bioactivities and nutritional portfolios, and obviously, species-specific testing at all stages is in order. These steps are not significantly different from existing food industry protocols, and cultivated seaweeds, as well as diligently managed wild-harvested macroalgae, offer an important measure of food safety and control.

The detrimental risk factors leading to CVD are globally apparent, and attempts to alleviate this number one cause of death will require global intervention strategies. The evidence is in, and chronic obesity, hypertension, inflammation, and oxidative imbalance can all be readily and therapeutically impacted by diets containing seaweeds.

OFFERING VAST OPPORTUNITIES

Already there are numerous natural, seaweed-based products in the marketplace, originating mostly from smaller, localised enterprises. The versatility of seaweeds in terms of food formulations enables them to be utilised as an ingredient in a variety of commonly consumed products, including fast foods, bakery products, beverages, and snacks.

Much of the salt naturally present in seaweeds takes the form of potassium salt, a much more nutritious form than the sodium salt that is found in so many processed foods, and which is known to contribute to hypertension.

The opportunities that over 10,000 seaweed species present regarding the production of new, nutrient-dense, fibre-rich, functional foods are enormous. The overall benefits and success of a nutritional overhaul with respect to human health remain to be seen on a global scale, but the scientific evidence now exists to support the many health and longevity benefits attributed to a moderate, balanced diet containing seaweeds, fish, and vegetables.

It is commonly accepted that life as we know it evolved from the sea, and it simply makes sense that our fundamental food sources should come from there as well.