Sugar

When a food causes a spike in blood glucose, we say it has a high ‘glycaemic index’ (GI). High blood glucose is very harmful. What makes it high?

Fructose does NOT cause an immediate spike (i.e. it would count as ‘low GI’, which is why GI is not enough to consider), yet over time, chronic high-fructose consumption causes constantly higher blood glucose and higher spikes after eating. High-fructose diets cause insulin resistance. This leads to elevated blood glucose and insulin, causing metabolic dysfunction, and ultimately Type 2 diabetes. Type 2 diabetes is when specific cells in the body stop responding appropriately to insulin signaling. The result? Elevated blood glucose and insulin, both of which independently and together have many harmful effects and increase the risk of all of the major chronic diseases.

Bottom line: If the blood glucose regulatory system does not function well, and blood glucose gets into a high range frequently, and/or for longer durations, this causes damage to arteries and tissues, and has many detrimental health consequences, including but not limited to metabolic syndrome. Fructose interferes with this system and increases the risk of insulin resistance and chronically high blood glucose, hyperinsulinemia and harmful spikes in blood glucose.

Fructose consumption generates visceral fat; fat around the waist is usually indicative of this type of fat. Visceral fat is fat between and within key organs such as the liver and pancreas, where the altered tissue structure disrupts the functioning of these crucial organs. Associated risks of this include fatty liver disease, insulin resistance, Type 2 diabetes, cardiovascular disease and obesity.

Fructose is the chronically toxic part of sucrose and you can avoid it by checking labels and by tasting if what you are eating a) tastes sweet and b) does not include natural, sugar-free sweeteners.

(i) Alnuwaiser M.A., (2017), Content of Sugars in Fresh Grapes and Raisins, and Fresh and Dried Apricot: A Comparative Study. Int. j. res. granthaalayah. 5, pp. 1770186

One mechanism (means) by which fructose increases fat generation and storage, and reduces fat-burning, is via its generation of uric acid. While many mammals have an enzyme (uricase) that helps them to break down uric acid, humans do not. Genetic research reveals that our ancestors lost the uricase enzyme during the early Miocene, when progressive climate-cooling challenged early hominids’ diets, particularly in Eurasia. Losing uricase – elevating uric acid levels – likely provided a substantial survival advantage by increasing fructose’s fat-storage effects in these then-frugivorous species (i, ii).

In human history, the time during which sugar consumption began to increase until what it is today is less than c. 0.1% of our existence as a species: it is clear that the biology of human beings has not had time to evolve to deal with the large quantities of sugar we currently consume. In fact, our biology is still geared towards reacting to fructose by storing body fat, a great survival mechanism in the food-scarce past, a harmful one in the sugar-filled present food environment.

(i) Kratzer, J. T. et al. (2014) ‘Evolutionary history and metabolic insights of ancient mammalian uricases’, Proceedings of the National Academy of Sciences of the United States of America, 111(10), pp. 3763–3768

(ii) Cicerchi, C. et al. (2014), ‘Uric acid‐dependent inhibition of AMP kinase induces hepatic glucose production in diabetes and starvation: evolutionary implications of the uricase loss in hominids’, The FASEB Journal, 28, pp. 3339-3350

• Honey
• Agave Syrup
• Raw Cane Sugar
• High Fructose Corn Syrup
• Maple Syrup
• Coconut Sugar
• Table Sugar
• Date Syrup
• Fruit Juice Concentrate

Brown sugar is biochemically and practically identical to white sugar. It contains c. 1% more fibre and just a small amount of iron. It has 373 kcal/100g vs. 396 kcal/100g and is still c. 97% sucrose. There is NO meaningful health benefit of choosing brown, muscovado, raw cane sugar and/or coconut sugar.

Lactose: We’ve discussed what glucose and fructose are, and their combination as sucrose. Lactose is another common dietary carbohydrate found in milk that is a disaccharide, made of the monosaccharides glucose and galactose. Those who are lactose intolerant no longer have the ability to secrete the enzyme lactase that helps to break down lactose. They are often still able to eat butter, which contains only a tiny amount of lactose. For those who can tolerate lactose, there is no definitive health reason to avoid lactose.

Confusion Clarified: There are many types of fibre. They share a similar structural feature in being long chains of molecules that are not readily cleaved by our digestive enzymes. Some have names that sound foreign to us. These are all healthy fibres for example: fructo-oligosaccharides, inulin, glucomannan.

It is essential that we consume sufficient healthy fibre in our diet. Evidence suggests that our ancestors consumed >100g fibre/day, and the average adult eats only c. 18g/day (i, ii). Current governmental guidelines suggest 30g/day are required for adults to maintain health.

There are many healthy natural dietary fibres such as insoluble and soluble fibre, fructans, fructo-oligosaccharides, inulin, glucomannan and beta glucans, which can all be found in foods.

Cacao contains significant insoluble fibre, and its consumption has been demonstrated to improve bowel function for example (ii).

(i)  Eaton S. B., (2006). The ancestral human diet: what was it and should it be a paradigm for contemporary nutrition? Proceedings of the Nutrition Society, 65(1), 1-6

(ii) Sarriá, Beatriz et al. (2012). “Effects of regularly consuming dietary fibre rich soluble cocoa products on bowel habits in healthy subjects: a free-living, two-stage, randomized, crossover, single-blind intervention.” Nutrition & metabolism vol. 9 33