Authors: Joanna Blythman
Accumulating evidence suggests that frequent consumers of these sugar substitutes may also be at increased risk of excessive weight gain, metabolic syndrome, type 2 diabetes, and cardiovascular disease.
Surprised? After all, if artificial sweeteners contain no calories, how could they make you fat? One possibility is that a sweet taste, unaccompanied by the calories that come with conventional sugar, sends the body on a calorie hunt, seeking out those missing calories elsewhere, so encouraging over-eating. While classic sugar leaves us feeling content, it has been suggested that ‘sweetness decoupled from caloric content offers partial, but not complete, activation of the food reward pathways’. In other words, artificial sweeteners awaken the brain’s pleasure centre but don’t deliver the anticipated satisfaction. So, for instance, although we choose the diet drink thinking that we are making a healthier choice, it could leave us craving a doughnut. Another theory is that artificial sweeteners wreak havoc with our appetite-regulating hormones, leptin and ghrelin, making us more liable to overeat.
Currently, what manufacturers crave is a ‘no-sugar sugar’, a dream-ticket substance that supplies the all-essential sweet taste, but one that has none of the health and safety baggage that attaches to sugar, HFCS and artificial sweeteners. Food and drink manufacturers know that consumers see ‘natural’ as good and ‘processed’ as bad, so if they want to have a healthy positioning in the market, the strategy is to go natural. Traditional sweeteners such as honey, maple syrup, coconut and palm sugar don’t hit the spot for food manufacturers because they are much more expensive than sugar, HFCS and artificial sweeteners. They also taste too much of themselves, so they don’t have the requisite neutrality to work in a wide range of products. Natural sweeteners, unless highly refined, exhibit a spectrum of flavours – treacle, caramel, smoky, resinous, butterscotch and so on – and this character gets in the way for food and drink manufacturers.
A few years back, agave syrup, sometimes sold with the more exotic title agave nectar, had a star billing in health food stores as a healthier substitute for sugar. It is derived from a spiky, cactus-like South American plant, and is about one and a half times sweeter than sugar. Here’s how one agave brand promotes itself:
The Aztecs prized the agave as a gift from the gods and used the liquid from its core to flavor foods and drinks. Now, due to increasing awareness of agave nectar’s many beneficial properties, it is becoming the preferred sweetener of health conscious consumers, doctors, and natural foods cooks alike.
Agave nectar is often labelled as raw, but it is actually extracted either at a low temperature, or using enzymes. In its less processed form, dark agave syrup has a slight caramel flavour, but in its lighter, purer forms, it is mild and anonymous, characteristics that tick two key food-processing boxes. However, agave’s image and commercial prospects took a nosedive when initial enthusiasm was tempered by a long, hard look at its chemical composition. Agave syrup has a higher fructose content than HFCS, and in the words of one food campaigner, ‘most agave nectar or agave syrup is nothing more than a laboratory-generated super-condensed fructose syrup, devoid of virtually all nutrient value’.
As the agave moon has waned, another natural and traditional-sounding sweetener has twinkled brightly in the sugar-free firmament. Stevia, a leafy plant native to central and South America, where, we are told, it was traditionally chewed and used in teas by native populations, is the next great white hope for sugar redemption. Like agave, stevia has a covetable wisdom-of-the-ancients backstory that is a gift to marketing departments but, unlike agave, its trump card is that it is zero calorie.
Stevia is finding its way into soft drinks and manufactured food. In 2013, Coca-Cola started using Truvia®, the Cargill company’s stevia-based sweetener, in Sprite, which allowed it to reduce the sugar content of this beverage by 30%. Coca-Cola stresses stevia’s naturalness and ancient lineage: ‘The stevia plant is a relative of the chrysanthemum, native to Paraguay, and has been used to sweeten drinks ever since indigenous people first discovered its flavour. It has been grown, harvested and used in South America for around 200 years.’
Don’t you just love the sales pitch? But just how natural, exactly, is commercial stevia? It would seem that there is a world of difference between the sweet green stevia leaves chewed and brewed by native populations, and purified, highly concentrated chemicals extracted from these leaves. For starters, these modern stevia extracts are much sweeter. Whereas dried green leaves of stevia are a relatively feeble 40 times sweeter than sugar, the chemical extracts isolated from these leaves are 200–300 times sweeter. And while stevia leaves in their whole unprocessed state contain a raft of compounds – diterpene glycosides – that contribute to their sweetness, the stevia extracts that are already on the market, or in development, generally isolate only one or two glycosides from the plant. Truvia, Cargill’s product ‘born from the leaves of the stevia plant’ uses one particular glycoside, rebaudioside A (reb A), and combines this with other ingredients. The major ingredient in Truvia is not stevia, but erythritol, a polyol, of which more below. Truvia also contains flavourings. ‘Natural flavors are used to bring out the best of Truvia® natural sweetener, like pepper or salt or any other spice that would be used to enhance the taste of food’, the company explains.
In the USA, Cargill has found itself defending class action lawsuits disputing Truvia’s claim to naturalness. One such action complained that ‘reb-A is not the natural crude preparation of stevia’ so its manufacture is not ‘similar to making tea’, as Cargill’s packaging suggests. Rather, it is ‘a highly chemically processed and purified form of stevia-leaf extract’. The complaint also stated that the main ingredient in Truvia, erythritol, is ‘synthetically made’. To date, such lawsuits have been settled out of court, with Cargill saying that they want to avoid the time and expense associated with further litigation. They have also agreed to modify their tagline in certain areas. Meanwhile, any manufacturer initially inclined to view stevia as a safe pair of hands might be having second thoughts.
And even if disputes over the use of the word ‘natural’ to describe highly processed stevia products could be resolved, there’s still no getting away from stevia’s less than perfect taste profile. One of the reasons stevia is only used to replace up to 30 per cent of the sugar in food and drink is its lingering, slightly cooling, almost mentholated aftertaste, reminiscent of liquorice or quinine. Sales of Sprite nosedived after stevia was added to the recipe. One influential panellist in an industry blind tasting suggested why: ‘The aftertaste [of stevia] was strong and unpleasant.’ Scientists are isolating more minor glycosides from stevia that might taste better. In theory, plant geneticists could breed the ‘next’ stevia: cultivars with higher levels of the more desirable glycosides. For the time being, although Stevia is the current sweetheart of the global high-intensity sweeteners market, it doesn’t look like a prêt-à-porter solution for sugar reduction.
If stevia is still something of an unknown quantity for most people, what on earth are we to make of polyols, yet another emerging group of sweeteners? They appear on product labels by name – erythritol, mannitol, sorbitol, isomalt, lactitol, xylitol are the most common – and because European regulators regard them as additives, they each have an E number. But what exactly are they? Also called sugar alcohols, polyols are used as bulk sweeteners. Most are made in an industrial process by treating sugars – glucose, fructose, lactose, xylose – with hydrogen in the presence of a nickel catalyst. Polyols can also be produced by fermentation. Erythritol, for instance, is produced from dextrose in corn, in a fermentation process that is catalysed by the introduction of a strain of yeast.
Some polyols, especially xylitol, absorb heat when dissolved in the mouth, causing a cooling effect – a property that’s handy in chewing gums, but not that many other products, so this limits their usefulness to food processors. The main consumer selling point for polyols is that because they are only partially digested in the gut, they have a lower calorific value, but this putative benefit has a murky underbelly: they can also cause fermentation in the lower gut, producing diarrhoea and flatulence. This is why, in the EU, products that are more than 10 per cent composed of them must carry a warning label that ‘excessive consumption can cause a laxative effect’. As a wholesale alternative to sugar, sugar alcohols are about as solid an option as mud.
All around the globe, scientists funded by big food and drink corporations are energetically questing after a problem-free sugar substitute that can be commercialised profitably and presented as natural. Much attention is being lavished on monk fruit, also known as Luo Han Guo, an Asian melon-like gourd, which contains compounds (mogrosides) that are 300 times sweeter than sugar. Just like stevia, in its raw, unprocessed, unsynthesised form, it has a venerable history of use, this time in Eastern traditional medicine. Monk fruit-derived sweeteners are hitting US shelves in cereals, drinks and meal replacers, but are not yet approved in the EU. Does this new contender have a rosy commercial future? The recent history of sugar substitutes has been one sorry serial tale of new generation miracle products that try – and fail – to fix the problems of the ones that went before. After the initial honeymoon period, flavour of the moment sweeteners have all foundered when informed consumers have caught up with how they are made. As one global trends analyst puts it:
Natural sweeteners like those based on stevia and monk fruit, which are in vogue right now, may not have such an easy ride further down the line. The level of processing that these ingredients undergo is quite considerable, and consumers may, in time, turn against them in their quest for more natural options.
But what more natural option is there? Given the chequered history of sugar substitutes, one can’t help wondering if finding an alternative to the gold standard taste and performance of sugar (sucrose) is a mission impossible, for nothing else seems to provide its unique flavour, nor fill the mouth in that pleasing way. Food engineers can use polyols to reproduce its mouthfeel and round out the brashness of artificial sweeteners. They can blend these with synthetic flavourings and acids in a vain attempt to disguise the slow build-up of sweet flavour, and cover up obtrusive aftertastes. In the words of one beverage scientist, ‘an integration of polyols, nutritive [calorie containing] sweeteners, high intensity sweeteners and flavours allows our ingredient experts to achieve a more sucrose-like sweet perception’. But it’s still not enough. All they can do is ape sugar; they can’t match it.
And anyway, if it proves to be correct that a sweet taste, in and of itself, encourages us to want more of the same, then the hunt for sugar substitutes is a fool’s errand. The literature of taste science shows a strong correlation between a person’s customary intake of a flavour and his or her preferred intensity for that flavour. We know, for instance, that the more chilli you eat, the more you enjoy high levels of chilli in your food. If the cook puts one piquant green chilli in a curry, regular chilli eaters will find it too mild, while irregular chilli eaters will find it way too hot. Children accustomed to bland modern apple varieties, such as Gala, which have been bred to taste sweet, can find traditional varieties with their higher acidity levels too sharp. Taste isn’t fixed but learned, based on culture, experience and familiarity. Judged against the muted sugar levels in Japanese confectionery, a cube of British fudge seems absurdly sugary and cloying. There is no universal baseline for sweetness the world over. Perception of sweetness is relative.
With sugar, as with everything else in life, we can’t have our cake and eat it. However you try to dress up and repackage it, sugar is bad news, and candidates to replace it, no better. Addressing the very real possibility that we need to curb our desire for a sweet taste may prove to be an altogether more productive line of enquiry. If we want to be healthier, then the answer most likely lies in ‘unsweetening’ our diet: consuming less of any ingredient or additive that tastes sweet, irrespective of its source, production method, composition, or the calories it contains. Drinks are the first place to start, because it is so much easier to
drink
excessive amounts of sugar than it is to
eat
them. Drinking water rather than soft drinks and juice, and cutting down, then gradually eliminating sugar in tea and coffee, will quickly bring any rampant sweet tooth to heel, and from there, it can be retrained. Luckily, reducing sweet tastes is easier than it might sound as the taste receptors in our mouth and tongue adjust surprisingly quickly. You’re talking weeks, not months, or years. All you have to do is try it.
7
Saturated fat was the nutritional folk devil of the second half of the 20th century. For 50 years, the dietetic establishment, first in the USA, then in the UK and worldwide, scapegoated it for obesity, heart disease, and stroke. Public health advice fuelled the panic, embedding saturated fat avoidance in ‘healthy eating’ guidelines. Because this dietary dogma was advanced with all the characteristic self-confidence of ‘evidence-based’ science, it became an unquestionable, unimpeachable orthodoxy, one that was recycled and diffused not only through all relevant government departments and health services, but also by the processed food industry, which enthusiastically adopted its new role as purveyor of supposedly healthier alternatives.
This casting of saturated fat as the dietary devil incarnate seemed counterintuitive to many. How could natural fats that had sustained populations for centuries – butter, ghee, suet, dripping, lard, chicken, duck, goose, palm and coconut fat – suddenly be so bad for us? Why would Mother Nature create such deviant fats to shorten the life expectancy of the human race?