Why eliminating sugar from your diet is one of the best health choices you can ever make – Part 1

There are certain events in our lives that become turning points. One of the turning points in my life happened about 6 years ago when a friend asked me if I wanted to eat the ice-cream that he had gotten for free, because otherwise he would throw it away. At that time, I got quite astounded – why would someone throw away such a tasty ice-cream?!?! I guess that if you are an ice-cream lover you will understand my surprise. But my friend explained to me why he did not want to eat the ice-cream – he was convinced that a chronic sugar consumption was responsible for this father’s heart attack. At that moment, it was very hard for me to believe him. I was working in the health area and had done part of of my biomedical engineering studies in the medical school, how was it possible that I had never heard about this? I started then questioning and extensively researching by myself about this topic. I read many eye-opening books and scientific articles. I must say that I was overwhelmed by the amount of scientific evidence relating refined sugar to just any chronic disease. Nowadays, there are here and there some articles in the mainstream media about how bad sugar is, but 6 years ago not so many people were talking so openly or often about it. So, after getting informed, I finally came to a conclusion: my friend was absolutely right in not wanting to eat that ice-cream (which by the way didn’t contain only sugar but also artificial colours and tastes – anything but natural). And although nobody can ever say with 100% confidence that sugar was the cause of his father’s heart attack, it is quite likely that it was at least one of the main culprits. This because many high impact scientific studies have shown a relationship between sugar consumption and increased risk for cardiovascular disease [1, 2]. If you go to the American Heart Association homepage, you can read [3]:

“Getting too much added sugar in your diet could significantly increase your risk of dying from cardiovascular disease.”

Unfortunately, sugar overconsumption does also lead to many other chronic diseases, as you will see in this article.

Nowadays, I do know that eliminating sugar from our diet is one of the wisest decisions people can make for their own health, not only for preventing but also for overcoming certain diseases.

But I also do know that quitting sugar completely is really hard, mainly due to four reasons:

1. Sugar is in everything.

Seriously, sugar is in almost everything you buy in a package, for instance:

– breakfast cereals

– bread and crackers (I have noticed that some of those contain maltose or dextrose, two types of sugar).

– yoghurt (nowadays, yoghurts are more like a candy than anything else, loaded with sugar and artificial flavours, even if many people consume them because they think they are healthy – if you eat yoghurt at least make sure it is an organic natural yoghurt without added sugar)

– peanut butter

– some beers

– salad dressing and prepared sauces, such as ketchup, mustard, mayonnaise etc…

– processed meats

– soups (!)

– canned fruits

– rice milk, oat milk and nut milk (almond milk, for example)

– some frozen fruits

– pickles

– chilli oil (this one was quite shocking for me, why would sugar be added to something that is supposed to be spicy?!)

– almost any prepared meal you can buy in a supermarket. Take a look for example at the ingredients list of this prepared chicken burger (the red boxes highlight sugars):

– this list could go on and on…

So, lots of foods that we wouldn’t even think that could contain sugar, and that we even would consider as healthy, actually do contain sugar.

As Jamie Oliver nicely points out in his documentary “Jamie’s Sugar Rush”, having 3 “healthy” looking meals a day can easily surpass the World Health Organization (WHO) maximal limit of 7 teaspoons of sugar per day. In his example, for breakfast, he would eat cereals with yoghurt and berries and a glass of orange juice (14 teaspoons of sugar – so the double of the WHO recommended amount already in the first meal of the day); for lunch, a tomato soup and wholemeal bread (3 teaspoons of sugar), for an afternoon snack, a flavoured water and a cereal bar (9 teaspoons) and for dinner, vegetables with lemon and ginger sauce (bought, not homemade) (10 teaspoons). So, meals that apparently looked quite healthy yielded 36 teaspoons of sugar per day, more than 5 times the recommended WHO maximal sugar intake per day. Now just imagine how it is with the not so “healthy” looking meals….and if you add on top of them some sodas during the day.

And be aware that in the label they might state sugar under one (or more) of their 50 different names (sugar, sucrose, fructose, dextrose, maltose…basically everything that ends in “ose” and everything that says “syrup”, such as high fructose corn syrup or glucose syrup).

I hear sometimes people saying “I rarely eat sugar”, but actually what they mean is that they don’t add deliberately sugar to their food or eat foods that obviously contain sugar (such as cakes, cookies, chocolates, ice creams, sodas, jams, etc.). But they are still consuming sugar without even being aware of it! The only way to know if a food contains added sugar(s) is to read the ingredient list. I highly recommend everyone to start doing this so that you at least know what you are eating.

But why is sugar added to everything? Well, it might be because of next point (which I would guess food companies appreciate…).

2. Sugar is extremely addictive.

Once you have it, you keep wanting more – yep, just like a drug. In a very interesting study, rats were given the option of choosing between water sweetened with saccharin (a sweetener) or sucrose (also known simply as sugar) or intravenous cocaine. The majority of animals (94%) preferred the sweet taste of saccharin or sucrose over cocaine [4]! Even when the rats were injected with more cocaine, their preference for the saccharin or sucrose did not change. Also, rats did not only prefer sucrose over cocaine but they were also willing to work harder for it than for cocaine. The authors concluded:

” Our findings clearly demonstrate that intense sweetness can surpass cocaine reward, even in drug-sensitized and -addicted individuals. We speculate that the addictive potential of intense sweetness results from an inborn hypersensitivity to sweet tastants. In most mammals, including rats and humans, sweet receptors evolved in ancestral environments poor in sugars and are thus not adapted to high concentrations of sweet tastants. The supranormal stimulation of these receptors by sugar-rich diets, such as those now widely available in modern societies, would generate a supranormal reward signal in the brain, with the potential to override self-control mechanisms and thus to lead to addiction.”

Have you heard about dopamine? It is the main brain chemical (neurotransmitter) involved in the pleasure and reward responses. Sugar causes the release of dopamine and therefore it activates our reward system. You feel good when consuming it, so you keep wanting to consume more. However, when we overstimulate this reward system, problems such as loss of control and cravings (addiction symptoms) start showing up. Moreover, in obesity, there is a decreased dopamine sensitivity (meaning that although you have more dopamine, your brain doesn’t feel it and you need  to consume more and more sugar to feel good) and the heavier the individuals, the less responsive they seem to be to dopamine [5]. Drugs such as nicotine, cocaine, heroin and alcohol stimulate the release of dopamine which cause people to constantly seek these drugs that make them feel good. However, dopamine receptors are also impaired in cocaine addicts and alcoholics in the same way they are in obesity [6]. This study suggests that the same underlying mechanism of impaired dopaminergic pathways leads to an addictive behavior in both obesity and drug addiction. These studies shed a light why people seek to eat more sugar to make them feel better.

So, if sugar shares all the addictive properties and mechanisms of drugs, why shouldn’t we call it a drug as well? If people ask me whether eating sugar once per week would be ok, I would say: honestly, no! Precisely because of this addictive property: if you keep eating sugar here and there you will continue craving it! You will still be addicted! If you are addicted to a drug and want to give up on it, you cannot expect to consume it still here and there: no, it doesn’t work! So the best way is just trying to quit sugar for good. And if you have a sweet tooth, don’t worry – eliminating sugar, doesn’t mean eliminating sweet food! Not at all! You still can have many healthy desserts and snacks made of “real” foods (we have been publishing some of these in this blog, so please check them out 🙂 ).

Once you give up on sugar you will see that so many things will improve in your health: your blood sugar spikes will stop, you will lose weight, your blood pressure will become normal, your mood will improve, you will stop feeding cancer cells and harmful bacteria in your gut, etc… and you will actually feel the taste of the food or drinks! When I first stopped eating sugar, I remember once going to a coffee shop with some of my dear portuguese girl friends and asking for tea. The tea contained already added sugar and was soooo sweet! I had order that tea many times before but I had never realized how sweet it was until that moment! You will see that when you don’t add sugar to your food you will feel so much more the actual taste of the food you are eating.

3. Sugar publicity is very strong.

You see everywhere advertisements from all the big food companies that consciously or unconsciously persuade you to consume more of their products, which contain high amounts of sugar.

4. Not enough information.

This has been the case for many years, but I do believe this is changing. We start hearing all around about the detrimental effects of sugar on the TV, documentaries, etc. People are becoming more and more aware.

Sugar is as poisonous as alcohol

Besides being a drug, sugar is also a toxin…or a poison, as Dr. Lustig from University of California wisely calls it and demonstrates in his lecture [7] and in his multiple scientific articles. For example, you can check these ones [9,10] or this one [8] published in Nature.

For our body, namely for the liver, fructose is just as poisonous as alcohol [9]. Ethanol and fructose are metabolized in the same way in the liver. But if you think about it, it’s actually not surprising: ethanol is obtained by sugar fermentation. Therefore they are taken by the liver in the same way. However, the brain does metabolize alcohol but not fructose. This means that you don’t feel anything by acute fructose exposure. Nevertheless, even if you don’t feel it in your brain, sugar is as bad for you as alcohol [9]. Like ethanol, fructose increases lipogenesis (fatty acids and triglycerides synthesis), inhibits fatty acid oxidation (use of fat) and has been implicated in non-alcoholic fatty liver disease (NAFLD) [10].

Remember that refined fructose can be given to us under the name of high-fructose corn syrup, sugar (sucrose – which is actually a disaccharide, meaning that it contains two sugar molecules:  1 molecule of glucose and 1 of fructose) or simply fructose. Be aware that this is not the same as fructose in fruits!!! You will see more about this in our next article. For simplicity, I use the word sugar for any industrial sugar, being fructose, sucrose, etc..

Actually, in my opinion, sugar could be potentially more dangerous and toxic than alcohol for some people (that consume alcohol very rarely, otherwise a high alcohol consumption is obviously extremely toxic as well) because:

1) people consume sugar every single day in an shockingly high amount without even realizing – including children. It would be unthinkable to give alcohol to a child, but you wouldn’t see too much of a problem to give him/her sugar. Sugar consumption is so established in our society that it has even become a sentimental issue: giving candies to kids by family members is like a sign of love and caring. But to parents, grandparents and everyone else that care about their kids: these candies, loaded with sugars are NOT good for them and are actually promoting many future health problems.

I found particularly interesting what is mentioned on the label of some sweets. Take a look at the top right picture below. You can read “May have an adverse effect on activity and attention in children”.

2) it has no obvious acute effects (rather than making children jumping all around in an apparent burst of hyperactivity). When you have an acute disease due to a certain factor, it is easy for you to relate the disease with the cause. The problem of sugar is that you can take years or decades to start manifesting the symptoms of a very serious condition related to sugar consumption. Indeed, when consumed chronically (which pretty much everyone does since birth), it can lead to many chronic diseases (see our next article). From diabetes and metabolic syndrome to cancer. I think the following paragraph taken from a recent article in The Guardian states this point well [11]:

” Once we have observed the symptoms of consuming too much sugar, the assumption is that we can dial it back a little and be fine – drink one or two sugary beverages a day instead of three; or, if we’re parenting, allow our children ice cream on weekends only, say, rather than as a daily treat. But if it takes years or decades, or even generations, for us to get to the point where we display symptoms of metabolic syndrome, it’s quite possible that even these apparently moderate amounts of sugar will turn out to be too much for us to be able to reverse the situation and return us to health. And if the symptom that manifests first is something other than getting fatter – cancer, for instance – we’re truly out of luck….. If it takes 20 years of consuming sugar for the consequences to appear, how can we know whether we’ve consumed too much before it’s too late? Isn’t it more reasonable to decide early in life (or early in parenting) that not too much is as little as possible?”

As I said before, I really believe that the best is to aim to consume no sugar, at least in the things you can control. Of course if you eat at a restaurant and they put sugar in your sauce, you have no control over it. But there many things that you can really change.

In order to not turn this article too long and therefore boring for you, we decided to divide it in two parts. In part 2, I will discuss:

–  the link between chronic diseases and sugar consumption

– why the belief that our brain needs refined sugar is totally wrong

– why fruit fructose has nothing to do with refined industrial fructose

– what the World Health Organization says about sugar consumption

– what you can do about it. And if you cannot eat sugar, what can you eat instead?


Live healthy 🙂




[1] Q. Yang, Z. Zhang, E. W. Gregg, W. D. Flanders, R. Merritt, and F. B. Hu, “Added sugar intake and cardiovascular diseases mortality among US adults,” JAMA Intern Med, vol. 174, no. 4, pp. 516-24, Apr, 2014.
[2] R. K. Johnson, L. J. Appel, M. Brands, B. V. Howard, M. Lefevre, R. H. Lustig, F. Sacks, L. M. Steffen, J. Wylie-Rosett, P. A. American Heart Association Nutrition Committee of the Council on Nutrition, Metabolism, E. the Council on, and Prevention, “Dietary sugars intake and cardiovascular health: a scientific statement from the American Heart Association,” Circulation, vol. 120, no. 11, pp. 1011-20, Sep 15, 2009.
[3] http://www.heart.org/HEARTORG/HealthyLiving/HealthyEating/Nutrition/Added-Sugars-Add-to-Your-Risk-of-Dying-from-Heart-Disease_UCM_460319_Article.jsp#.WPaGlmekKUk.
[4] M. Lenoir, F. Serre, L. Cantin, and S. H. Ahmed, “Intense sweetness surpasses cocaine reward,” PLoS One, vol. 2, no. 8, pp. e698, Aug 01, 2007.
[5] P. Iozzo, L. Guiducci, M. A. Guzzardi, and U. Pagotto, “Brain PET imaging in obesity and food addiction: current evidence and hypothesis,” Obes Facts, vol. 5, no. 2, pp. 155-64, 2012.
[6] N. D. Volkow, G. J. Wang, J. S. Fowler, D. Tomasi, and R. Baler, “Food and drug reward: overlapping circuits in human obesity and addiction,” Curr Top Behav Neurosci, vol. 11, pp. 1-24, 2012.
[7] D. R. Lustig. “Sugar: the bitter truth,” https://www.youtube.com/watch?v=dBnniua6-oM.
[8] R. H. Lustig, L. A. Schmidt, and C. D. Brindis, “Public health: The toxic truth about sugar,” Nature, vol. 482, no. 7383, pp. 27-9, Feb 01, 2012.
[9] R. H. Lustig, “Fructose: it’s “alcohol without the buzz”,” Adv Nutr, vol. 4, no. 2, pp. 226-35, Mar 01, 2013.
[10] M. K. Hellerstein, “Mitigating factors and metabolic mechanisms in fructose-induced nonalcoholic fatty liver disease: the next challenge,” Am J Clin Nutr, vol. 96, no. 5, pp. 951-2, Nov, 2012.
[11] https://www.theguardian.com/society/2017/jan/05/is-sugar-worlds-most-popular-drug?CMP=fb_gu.

2 Responses to “Why eliminating sugar from your diet is one of the best health choices you can ever make – Part 1

  • Maria Pefkou
    7 years ago

    Thanks for this post and congratulations to all three of you for the great work you’ve been doing here! I thought to share this video with you (https://www.youtube.com/watch?v=dBnniua6-oM), it’s a talk that explains the biochemistry of how sugar is metabolized, in case it is of interest to you. I found it quite inspiring as it answered lots of my own questions on the link between sugar consumption and obesity. Keep up the excellent work!

    • Ana Coito
      7 years ago

      Hey Maria! Thank you so much for your nice words! I’m happy to know that you are liking the blog! 😀 Thank you for sharing this link, indeed it is the lecture of Dr. Lustig that I mention in reference [7] of this article 🙂 I really agree with you, it is very inspiring and I really recommend everyone to watch it. He explains very clearly the liver metabolism of alcohol and fructose and shows that they are basically the same. I don’t know whether you already saw it, but he also has a second lecture on the topic about why sugar is so addictive https://www.youtube.com/watch?v=ceFyF9px20Y
      Cheers! 🙂

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