Pancakes made with bananas, not refined sugar, topped with maple syrup; healthy treat or just as bad as candy? Picture from Piviso/Pixabay
A sweet dessert every once in a while, even people who are dieting like to treat themselves. But too much sugar is bad for us and can result in weight gain but also cause diseases like diabetes. That’s why many foodies try to avoid refined sugar all together. And yet, you can find many recipes on YouTube and Instagram for which honey or maple syrup are used instead of sugar. But, are these natural sweeteners truly good alternatives, or are we kidding ourselves since we want to eat treats without the linked disadvantages?
Why are some forms of sugar considered healthier than others?
It is a trend to use honey, agave-, maple syrup, coconut sugar, etc. instead of refined sugar. These foods are considered healthy options, but still they all contain sugar, and a lot of it. Honey contains approx. 82 %, maple syrup around 68 % of pure sugar. So why are they still considered healthier than refined sugar? It’s because the products contain different kinds of sugars, which have varying effects on the rise of blood glucose levels, in the two hours after eating these different foods. This is quantified with the glycemic index (GI). Since high blood glucose levels are linked with negative effects on health, a high GI food is considered unhealthy. And there are food sources that result in higher peaks of blood glucose levels, and thereby insulin levels, than others. Though the amount to which these peaks vary between food sources can be low 1, 2, 3, 4.
Many foods were tested for their glycemic index (GI) in the recent years. And this information was used to sort food groups in good and bad for consumers. Honey has a GI of about 55, maple syrup of about 54, refined sugar has a GI of approx. 65. The difference appears low, yet, these so-called natural sugars are ranked with a medium GI. While refined sugar is classified with a high GI. But is this difference really enough to claim health benefits?
“The rise in blood glucose levels varies from person to person.”
Actually, the glycemic indexes stated above are just the average numbers given by google. These are used to group food in good or bad. But doing this contradicts scientific studies which suggest that the effect of food on blood glucose levels varies from person to person. Thus, honey for instance can have a high GI in one and a medium GI in another man. This means that foods cannot be sorted the way they are, since average GI values assume that edibles have the same effect on everybody 3, 4. But even if the GI of a food varies per person, the average value at least shows that many people’s bodies react similar to the food. But, does the GI say anything at all about the effects of food on health and is it thus still useful as guideline for a healthy diet?
Is the GI actually related to the health effects of sugar consumption?
Researchers have analyzed the effect of low GI diets on certain health factors in the blood of study participants. That means, they have looked beyond the blood glucose levels and analyzed health all together. Measured factors were for instance; insulin sensitivity, cholesterol- and triglyceride levels, as well as blood pressure. All these factors can indicate a risk for cardio-vascular disease and diabetis. The effects of such a low GI diet were in some studies small, in some studies not found. And the variation of results between different people was again high. Thus, the risk for diabetes and cardio-vascular disease most likely remained the same. Even though the blood glucose levels may have risen to a lesser extend with the low GI foods, they still contain sugar, which in the long turn has negative impacts on health 2, 3.
Another study attributes a subordinate role to the glycemic index.
The researchers of this study compared the effects of low carb to low fat diets and at least in terms of weight loss, it doesn’t matter which site you chose. The scientists watched weight loss results over a year, and these were identical. The same number of people lost weight others even gained, no matter the diet. The researchers concluded that many people don’t stick to a diet for such a long time, thus the low success-rate. However, with the low carb diet blood results were better, meaning the risk for diabetes and cardio-vascular disease decreased, compared to the low fat diet. The scientists also looked at GI which was only slightly lower for the low carb diet. This further indicates that the GI plays a minor role, carbohydrates should rather be reduced all together. But this should be done in a healthy way. Which means that we should focus on fresh, whole foods with lots of vegetables, fiber, and whole grain sources of carbohydrates, while staying away from added sugar, white flower, but also trans-fats 5.
“The most important thing about a diet is to keep it up.”
Why did small scientific results lead to big health claims?
Medicinal studies are very hard to conduct and interpret. The set-up of the study can already impact the results. Duration, experiment type, number-, background-, and attitude of participants can all play a role. People may have existing disease, or their genetics influence how they react to the study, yet they are taken as representatives for all mankind. And it is hard to control people 24/7. Most studies have participants self-report on their diet. But some may have snuck in a chocolate bar or two and not mentioned it, while that influences the test results. And even if a study was performed as good as it could be, inter-personal variation may be so great that it is impossible to determine a standard that is suitable for all 3.
But people want clear yes or no answers from science. It seems as the message changes like it does during a game of Chinese whispers. Scientists like to oversell their work, because the impact of their results has a big influence on their future career. Journalists then take this message and pick part of it, to generalize the meaning. And this is what goes around the world. This way, a small change in blood glucose levels for some subjects can result in dietary advice for all mankind. I believe that is why there are so many different diet systems. Because there are so many studies that hint in one direction or the other and people use this, to make big claims out of that. You can either choose a low fat or a low carb diet and you will find lots of blogs that will back up either site. Then it boils down to what you find suitable for yourself, since the healthiest diet is worth noting if you cannot keep it up.
Over-all, honey and maple syrup contain more nutrients than refined sugar. But that does not make them healthy. For some people the effect in blood-glucose levels might be lower than for others. But in general, it would be advisable to eat sweet things rarely. In the end, we should distance ourselves from too many carbohydrates and heavily processed foods. For the sake of your health, stay away from sugar as much as possible, but make sure that you still enjoy your eating habits. Because what matters most for a diet to be effective, is that we can stick to it.
Most important references
- Esfahani, A., Wong, J. M., Mirrahimi, A., Srichaikul, K., Jenkins, D. J., & Kendall, C. W. (2009). The glycemic index: physiological significance. Journal of the American College of Nutrition, 28(sup4), 439S-445S.
- Sacks, F. M., Carey, V. J., Anderson, C. A., Miller, E. R., Copeland, T., Charleston, J., … & White, K. (2014). Effects of high vs low glycemic index of dietary carbohydrate on cardiovascular disease risk factors and insulin sensitivity: the OmniCarb randomized clinical trial. Jama, 312(23), 2531-2541.
- Vega-López, S., Venn, B. J., & Slavin, J. L. (2018). Relevance of the glycemic index and glycemic load for body weight, diabetes, and cardiovascular disease. Nutrients, 10(10), 1361.
- Zeevi, D., Korem, T., Zmora, N., Israeli, D., Rothschild, D., Weinberger, A., … & Suez, J. (2015). Personalized nutrition by prediction of glycemic responses. Cell, 163(5), 1079-1094.
- Gardner, C. D., Trepanowski, J. F., Del Gobbo, L. C., Hauser, M. E., Rigdon, J., Ioannidis, J. P., … & King, A. C. (2018). Effect of low-fat vs low-carbohydrate diet on 12-month weight loss in overweight adults and the association with genotype pattern or insulin secretion: the DIETFITS randomized clinical trial. Jama, 319(7), 667-679.