The Hunter-Gatherer Diet Debate
We almost don’t need to include the question of “Did Palaeolithic man eat artificial or non-nutritive sweeteners”? Obviously they didn’t. And yet dismissing sweeteners as “not Paleo” because our ancestors didn’t consume them would be like stopping using computers because our ancestors didn’t use them. Just because they weren’t available to include in a hunter-gatherer diet doesn’t automatically render them inappropriate to the modern human diet.
One thing is important to comment on, however. When assessing hunter-gatherer diets for clues as to what modern man is biologically evolved to consume, we must temper our analysis by understanding that hunter-gatherer nutrition probably wasn’t arrived at through choice. It was undoubtedly a question of availability. For us at Paleo in the UK, this is why we are not interested in the strict anthropological accuracy of Paleo dietary re-creations. As we have said in our About Us page – the Modern Paleo diet is based on anthropological EVOLUTION, not just a single moment in human history. Understanding the biochemical interaction of modern foods with modern bodies tends to root us in more ‘ancient’ eating styles – but this is not an absolute and the Modern Paleo template may include some foods that not every ancient tribe had access to.
So we come to assessing the case of sweeteners. The hunter-gatherer diet wasn’t only devoid of sweeteners because they hadn’t yet been discovered. Instead, our ancestors simply didn’t require a replacement for sugar.
Hunter-gatherers were always hunting for sweeter foods. The sweetness of a food was a prime indicator of caloric density and in an environment and situation where energy was not always available, sweet stuff was prioritised because it meant easy energy.
One of the most important tenets of everything we promote here at Paleo in the UK is that our biology has not evolved as fast as our environment and our food supply. In our modern society, food is plentiful and the availability of refined foods and sugars limitless. Our biology is rooted in our ancestry where sweet stuff was a rarity and eating it in large quantities (when available) was a survival strategy. We, as modern humans, have NOT evolved to avoid the attraction of all the sugar that is freely available in the modern food environment.
It could theoretically be argued, therefore, that artificial and non-nutritive sweeteners are actually PERFECT scientific inventions designed to compensate for our LACK of human evolution when compared with the transformation of the food environment.
We might be absolutely suited to consuming these non-food, artificial substances because they satisfy our outdated ancestral motivation to seek out the sweet WITHOUT incurring the consequences of gorging on other ‘modern’ inventions such as candy and confection: nutritionally poor, calorically dense, refined, sugary foods.
Maybe this is true. So therefore, beyond all of this ideology and ‘food landscape’ discussion, we actually need a non-theoretical understanding of how artificial sweeteners affect the modern human body. Rather than analysing their place in the ancient environment and/or the perils they save us from in the modern environment, we want to look at what these sweeteners actually do. Are they, though calorically and nutritionally lacking, just a benign and beneficial replacement for sugar? Or do they carry consequences for their consumption?
Searching for Sweet Stuff
Artificial sweeteners and non-nutritive sweeteners were, once upon a time, the world’s answer to obesity and drastic sugar over-consumption. Chemically developed ‘artificial sweeteners’ like aspartame and acesulfame k were placed into sugar-sweetened beverages as a replacement for sucrose, glucose and high-fructose corn syrup (HFCS). Scientists then developed powders from more ‘natural’, incredibly sweet plant leaves which contained a fraction of the calories of sugar. These became known as ‘non-nutritive sweeteners’ and used instead of, and sometimes as well as, their chemical siblings – in drinks, yoghurts, processed foods and candies and even ‘diabetic chocolate’.
The clue with artificial and non-nutritive (literally meaning ‘no nutrients’) sweeteners really is in the names. They are either entirely fake substances, or they are processed ‘natural’ substances which are nutritionally dead. According to the ‘nutrient dense’ and ‘more nutrients than anti-nutrients’ principles of Paleo, these sweeteners should therefore have absolutely no place in a Paleo diet…
Or should they…? Because SUGAR should not be over-consumed in a Paleo diet – and if artificial sweeteners are the modern way of avoiding overconsumption of sugar, are they instead a GOOD thing?
Is Natural the Only Way?
Many would argue that the mere fact that something is a ‘processed food’ does not automatically mean that the food is ‘bad for you’.
They are correct, of course – just look at honey, molasses, ghee and even coconut oil. These products are all refined, originally from nature but ‘processed’ to get to the state in which we purchase and consume them. This is true of the Stevia sweetener you can buy which is refined from the Stevia leaf – which would imply that like any ‘processed’ plant (think olive oil), Stevia isn’t inherently ‘bad’.
Others would suggest that simply being artificial does not make a substance suitable for dismissal – after all, it’s far better than sugar, right?
And again, though it may surprise you, we believe they may also be right. In those where the choice is sugar or artificial sweeteners, it is always going to be a close run race. In those for whom the craving for a sweet taste is going to completely topple their dietary aspirations then perhaps the artificial sweetener or non-nutritive sweetener is a ‘better’ alternative.
So if these sweeteners are actually just refined and perhaps stopping overzealous sugar bingeing: why do we still recommend they are AVOIDED on the Paleo diet?
The major concern that we have here at Paleo in the UK is that artificial sweeteners are not actually ‘better’ than sugar – even if they replace the sugars in the diet. In fact, they could be damaging,
Firstly, we are not in favour of eliminating all forms of sugar in a draconian exercise, limiting the pleasure of the diet. We always say: food is about so, so much more than food. Sometimes there is a role for the sweet stuff in our lives – the REAL sweet stuff – in a balanced way and when you are really able to enjoy the pleasure that you get from it.
Artificial and non-nutritive sweeteners are, to our minds, a poor replacement for sugar. They do seem to elicit some (though not all) of the neurotransmitter responses that sugar does. However, they do not instigate any of the satiety or hormonal responses. Moreover they are increasingly being shown to carry adverse consequences.
The science of sweeteners is actually quite complex. Each artificial sweetener is a different chemical compound and, as such, acts in a slightly different way in the body. Studies are therefore tricky to do – and much of the ‘evidence’ on the effect of sweeteners, particularly on behaviour and psychological states, stems from anecdotal stories and single case studies.
The reality of the science of sweeteners is that there is, quite frankly, a lot of unknowns. We simply don’t have the data which demonstrates the longterm effects of consuming many of these artificial and non-nutritive sweeteners. When it comes to artificial sweeteners, evidence is mounting that they carry consequences (see below). But we don’t really know whether there are quantity limits for safety – and though ‘upper limits’ are suggested, it is difficult to gauge whether these are found from studies or hypothesised by simply extrapolating from existing data. We also don’t know whether the upper limits need to be in place for the more ‘natural’, non-nutritive alternatives.
For this reason, much of the recommendation we give to avoid these foodstuffs arises out of the fact that we simply cannot – yet – guarantee that they are fully safe.
More that that, the studies we DO have suggest that the sweeteners studied thus far are far from benign. Below is our understanding and verdict, thus far. This is subject to change as more information becomes available…
Research has examined the effect of non-caloric artificial sweeteners (NAS) on four key areas: weight, metabolism, hormones and the gut microbiome… It yielded some perhaps surprising and definitely worrying results.
- Feeding mice on NAS was shown to lead to glucose intolerance (i.e. high spikes of glucose in the blood after sugar was consumed). Unclear as to the mechanism behind this impact, further testing linked this inability to tolerate glucose after NAS consumption to changes that the NAS caused on the microbiome. Normal glucose tolerance was restored after the microbiome was eliminated using antibiotics and then restored.
- These tests were repeated in both normal and artificially obese mice with the same results which suggests that adiposity and current metabolic health made no difference to the impact of the NAS on glucose tolerance. NAS seemed to be impacting glucose tolerance through their direct effects on the gut microbiome, independent of the adiposity of the ‘host’.
Basically, by not eating sugar and instead consuming artificial sweeteners it appears you down-regulate your ability to effectively tolerate and metabolise normal sugar. These mice studies continued in multiple directions, each time confirming that the ‘negative’ effects of the NAS were linked to microbiome shifts.
- In humans, correlations have been drawn between NAS and all the typical signs of metabolic syndrome: increased weight, increased waist-to-hip ratio, higher fasting blood glucose levels etc. Originally this was thought to be a correlation – those who are known to be overweight and have metabolic syndrome were more likely to be consuming the NAS in an attempt to avoid eating sugar. However, when researchers accounted for this possibility the effect remained. Randomised Controlled Trials developed to study this more closely confirmed the results – NAS were increasing the markers of metabolic syndrome. Some of this was shown to be through the microbiome. Other hypotheses included that the sweeteners were altering the hunger cues and satiety signals, actually driving overeating behaviours. Because it is difficult to isolate what true behavioural cues are, this becomes tricky to actually study in depth.
It does get more complex, however, because ‘sweeteners’ aren’t just one thing – there’s sugar alcohols, artificial sweeteners and then ‘natural’ sweeteners. Science is young in all of these fields.
Focusing on sugar alcohols – these are some of the technically ‘natural’ products which have been refined. These alcohols are not fully absorbed by the human gut and do ferment, meaning they feed gut bacteria which could be the mechanism through which the microbiome shifts and glucose tolerance is down-regulated.
Gram negative bacteria – those fed by sugar alcohols – are linked to health implications such as inflammation, immune dysregulation and a variety of chronic health conditions. Anything shown to feed these bacteria, such as sugar alcohols, would not be recommended on a Paleo or AIP diet – diets based on attempts to reduce inflammation and chronic ill health. Early studies also indicate that sugar alcohols may increase intestinal permeability – but again, the science is in its infancy and human trials are not yet complete.
But what about other NAS? Well here, rather than focus on microbiome or gut-specifics, we can look at overall health outcomes in patients who consume NAS-sweetened foods and beverages compared with full sugar versions.
NAS have been linked to obesity, metabolic syndrome and hyper-insulinaemia. It is postulated that as your body tastes ‘sweet’ (from sweeteners) it releases insulin in preparation for the sugar it expects, despite there being no actual glucose in the body. This has proved difficult to isolate because it appears that it does not actually happen in everyone but is an observable effect in some. NAS have been shown to stimulate or inhibit certain hormones which play a role in insulin and glucagon regulation, independent of the ‘brain thinks it’s sugar’ response.
None of these studies are ironclad. It leaves many suggesting that sweeteners are as yet unproven to be unsafe. At Paleo in the UK we would recommend caution. We would prefer to wait for substances to be proven “safe” before consuming them freely – particularly if there is any suspicion of gut dysregulation, immune dysregulation, hormonal imbalances or inflammation. Those attracted to Paleo or AIP are often doing so based on pre-existing health concerns. Adding NAS to your diet is not safeguarding health, and it may be adding fuel to the fire.
But what about Stevia, the health-world’s favourite ‘guilt-free sweetener’… It is the powdered version of a green leaf, tastes sweet and is made up of 10 steviol glycosides which give it that sweetness.
Well… Stevia is safe – toxicology reports confirm as much. However, being ‘safe’ doesn’t make it automatically healthy. The processed/manufactured versions of Stevia tend to be either a) concentrated versions of just ONE of the (10) glycosides present in the original stevia leaf or b) cut with other ‘stuff’ (and no, they don’t always declare precisely what). Either of these options is not great. It is no longer ‘natural’ when you start to mix, isolate and process in this way. Plants are designed in synergy – and nutritional science’s attempts to isolate single compounds from certain other foods (like Resveratrol and Sulforophane) have shown us as much. Nutrients work together and we really don’t fully know what we’re doing when we play with ‘natural’ this way.
The issue with Stevia gets worse than just the ‘processing’ argument. Stevia’s glycosides are processed by the body the same way that a hormone would be. Or, put in a better way – the glycoside looks like a hormone and is structured like a hormone so the body attempts to process it like a hormone. Some more extreme studies suggest that because it looks like a hormone stevia can have contraceptive effects, though they were animal studies…
So instead of being alarmist, let us assess hormones and health in those with concerns about illness. If you have a chronic illness, or even excess inflammation which is dysregulating your body in any way, hormones interact with your body and your immune system in very specific ways to up regulate, down regulate, switch on and switch off all sorts of mechanisms. Throwing into your body a compound which your body identifies as hormone-like may (very much “may”, because we don’t 100% know) tip the balance, divert the process or have a negative effect that you do not want.
In short, we come back to the ‘better safe than sorry’ approach. We simply don’t know – yet – and, for our money and our health – until we do we’d prefer to recommend avoidance.
But if this precautionary lecture strikes you as overly pessimistic, let us close by mentioning quantity and frequency. As with real sugar, with sweeteners – be they natural, artificial, alcohols or glycosides – quantity and frequency are going to matter. Depending on your health and resilience, small amounts, occasionally may be entirely neutral for your body. If you DO want to experiment we’d advise seeking out whole leaf plant stevia, or small amounts of erythritol rather than going anywhere near the NAS group of acesulfame K/potassium, aspartame (Splenda), neotame, saccharin, Sucralose etc. as growing evidence suggests that all of these have more worrying effects than their more ‘natural’ Stevia alternative. Beyond the microbiome and the hormonal impacts some of these chemical substances are rumoured to have impacts on mental health, particularly in children, so steering towards natural alternatives is always advised.
Do We Really Need Alternatives?
Or better yet…
The question of whether sugar is good, bad or indifferent is covered in our All About Sugar page. And yet, to précis, we would like to close the topic of artificial sweeteners by reflecting on whether we really need to avoid sweet, natural sugars. In our view, hunter-gatherers were primed to hunt out sweet for a reason – and to deny ourselves the sweet foods in our environment is almost to deny our very animalistic, primal nature. As with anything that is hedonistic and rewarding, stimulating hormonal and neurotransmitter sensations of pleasure, as human beings it is easy to ‘over-do’ sugar. This means that exercising balance and restraint in a world where sugar is plentiful and cheap is an effortful battle of will.
Should this ‘battle’ be aided with the assistance of sweeteners? We believe not. The likelihood is that by adding either chemical or natural sweeteners into the body you will prolong the signals of cravings and gain absolutely none of the real, biological rewards. We would much rather recommend the consumption of whole, unrefined sources of sugar – fruit, raw honey, molasses – than playing tricks on your hormones and damaging your microbiome simply because you feel it’s ‘better’ to eat non-caloric sweeteners than real sugar. Again, Paleo is not a meritocratic assignment of labels to food – and in this case, despite all you might have read about sugar being toxic, there is mounting evidence that its fake alternative is even more toxic to the human body.