Fructose: Not As Bad For You As Fruit Is Good For You?
Fructose found in sodas and corn syrup has been labelled as ‘alcohol without the buzz’ in the past due to the damage it does to your liver. But since fruit contains natural fructose, should we consider that to also pose a risk of inflicting liver damage?
In a word, no. It is only industrial fructose that is associated with declining liver function, and the same thing can be said for a risk of high blood pressure too. However, given that other scientific findings show that a diet that contains fructose in natural fruit is better for you in terms of weight loss than a diet with no fructose at all, surely fructose can’t be that bad after all, right? In actual fact, it is claimed that the positive effects of other nutrients such as fibres in fresh fruit and antioxidants that create this supposed inconsistency with our perception of fructose.
Well, that’s been put to the test
A study published back in 2012 investigated the difference in our bodies when consuming table sugar and fruit. The results provide interesting insight into how our bodies reacts to fructose.
In simple terms, if you drink a glass of water with three tablespoons of sugar in it (similar to a can of soda), you of course get a large increase in your blood sugar levels rather quickly. In response to this rise, our bodies panic and release so much insulin that it actually becomes too much, dropping our blood sugar levels back down but below where they started before drinking the water. The consequence? A lot of fat entering our blood stream as our body looks to solve the issue thinking we are hungry because of the sudden drop in blood sugar levels.
Now here’s the interesting bit. If in addition to the water and sugar you eat blended berries your body responds differently, even if you blend enough berries to equal an additional tablespoon worth of sugar. Despite the berries containing these sugars of their own, the initial blood sugar level spike does not increase anymore than it did for the glass of water with three spoons of sugar, and crucially, your body does not experience a hypoglycemic dip either. The experiment saw blood sugar levels go up and down without decreasing below the starting point meaning no fat was released into the subject’s blood.
As for the proposed reasons for this difference, the effect the blended berries had may in part be down to their semi-solid consistency meaning the stomach would not empty as quickly as it does with liquids alone. Furthermore, the fibre in berries has a gelling effect in our intestines the slows the release of sugars.
With this in mind, an additional study has further demonstrated the beneficial power of berries with an experiment analysing insulin increases in our bodies. White bread increases our insulin levels significantly within two hours of consumption, however if you eat that same bread with some berries the spike in insulin levels is blunted and does not rise as high despite all the sugars berries contain.
There’s the power of fruit for you, folks.
- R H Lustig, Fructose: It’s “Alcohol Without the Buzz. Adv Nutr. 2013 Mar 1;4(2):226-35.
- S Petta, G Marchesini, L Caracausi, F S Macaluso, C Camma, S Ciminnisi, D Cabibi, R Porcasi, A Craxi, V Di Marco. Industrial, not fruit fructose intake is associated with the severity of liver fibrosis in genotype 1 chronic hepatitis C patients. J Hepatol. 2013 Dec;59(6):1169-76.
- M Madero, J C Arriaga, D Jalal, C Rivard, K McFann, O Perez-Mendez, A Vasquez, A Ruiz, M A Lanaspa, C R Jimenez, R J Johnson, L G Lozada. The effect of two energy-restricted diets, a low-fructose diet versus a moderate natural fructose diet, on weight loss and metabolic syndrome parameters: a randomized controlled trial. Metabolism. 2011 Nov;60(11):1551-9.
- R Torronen, M Kolehmainen, E Sarkkinen, H Mykkanen, L Niskanen. Postprandial glucose, insulin, and free fatty acid responses to sucrose consumed with blackcurrants and lingonberries in healthy women. Am J Clin Nutr. 2012 Sep;96(3):527-33.
- R Torronen, M Kolehmainen, E Sarkkinen, K Poutanen, H Mykkanen, L Niskanen. Berries reduce postprandial insulin responses to wheat and rye breads in healthy women. J Nutr. 2013 Apr;143(4):430-6.