Last Updated on July 29, 2019
Sucrose [glucose] and fructose are two different kinds of sugars that make part of our diet. Sucrose is the common sugar we consume, fructose is consumed in the form of sweetening syrup. Fructose consumption is part of Western diets but is on the rise in other parts of the world too.
Apart from common sugar, glucose also comes from potatoes and another carbohydrate-rich diet. Glucose is the principal sugar in our body. It is one of the primary molecules which serve as the energy source and is a cellular molecule vital to life.
Humans do not produce fructose.
Glucose and fructose are metabolized very differently by the body.
Where is Fructose Found?
Naturally, fructose is one of the main types of sugars found in fruits such as apples, in fruit juices, and in honey. Fructose is also found in processed foods such as desserts, dairy products, and preservatives.
Properties of Fructose
On the face of it fructose is just another sugar but it is metabolized in the body differently. As a sweetener, fructose is up to twice as sweet as sucrose. That means with half the sugar, you get the same amount of sweetness while calorie consumption is halved.
Fructose does not cause a rapid rise and subsequent large fall in blood glucose levels. In other words, it has a low glycemic index [ Glycemic index measures glycemic load per gram of carbohydrate].
Glycemic load per gram fructose is only 19, while that of table sugar is 65 – midway between its component parts glucose and fructose.
Though theoretically low glycemic carbohydrate foods may be of benefit to people with diabetes, but other effects of fructose negate this.
What is Bad About Fructose?
The basic point is that while every cell of the body is deft in utilizing glucose, only liver is able to metabolize fructose effectively.
What happens when you start consuming fructose?
The liver gets overloaded and starts converting the fructose into fat.
Some scientists strongly believe that excess fructose consumption may be a key to the causation of many diseases like obesity, type II diabetes, heart disease, and even cancer.
Repeated studies have pointed strong evidence that
- Fructose, which is metabolized by the liver is converted into fat, namely VLDL cholesterol. This causes dyslipidemia, causes fat deposition around the organs and increases the risk of heart disease.
- Causes an increase in blood levels of uric acid.
- Fat deposition in the liver leads to non-alcoholic fatty liver disease.
- Fructose causes insulin resistance, which leads to obesity and type II diabetes. Moreover, insulin resistance leads to raised levels of insulin and insulin-like growth factor (IGF-1) which increases the risk of cancer.
- Though lesser fructose is required to sweeten the food, fructose doesn’t affect satiety in the same way as glucose. This leads to increased intake of total calories automatically.
- Excess fructose causes leptin resistance. This causes disruption of the regulation mechanism of body fat metabolism and contributes to obesity.
- Fructose may be addictive.
- Leptin resistance, elevated insulin and vicious addictive cycles of cravings and binge eating are a recipe for fat gain.
Be aware that not all of this has been proven beyond a shadow of a doubt in controlled trials, but the evidence is still very strong and more studies will paint a clearer picture in the coming years and decades.
If that is not worrying enough, it has been suggested by a new study that fructose alters hundreds of brain genes, which can lead to a wide range of diseases.
Though there are contrarian voices and it is the truth that absolute evidence is not yet with us but whatever is being suggested by different studies, is quite scary.
A higher amount of continued intake of fructose is not good for your health.
Scientists report that diet rich in omega-3 fatty acids can reverse the damage.
A range of diseases — from diabetes to cardiovascular disease, and from Alzheimer’s disease to attention deficit hyperactivity disorder — are linked to changes to genes in the brain. A new study by UCLA life scientists has found that hundreds of those genes can be damaged by fructose, (a sugar that is common in the Western diet), in a way that could lead to above-mentioned diseases.
However, the researchers discovered good news as well: An omega-3 fatty acid known as docosahexaenoic acid, or DHA, seems to reverse the harmful changes produced by fructose.
Are Not Fruits As Bad Then
NO!
There is a difference in the way fruits are manufactured by nature.
Fruits are foods with low energy density and lots of fiber.
Otherwise, also fruit is a minor source of fructose in the diet compared to added sugars.
The harmful effects of fructose occur when the body is confronted with a high amount of fructose as added sugar. That amount is not possible while eating fruits.
What is the Status of High Fructose Corn Syrup (HFCS)
The name “high fructose corn syrup” is used because it has a higher content of fructose compared to regular corn syrup.
It is a sweetener and is used to sweeten foods and beverages. However, HFCS is not the same as fructose. HFCS is a mixture of fructose and glucose, made by an enzymatic process from glucose syrup from corn. It contains a substantial amount of glucose
Therefore, it is incorrect to use the terms “fructose” and “HFCS” interchangeably.
There are two types of HFCS
- HFCS 55 contains 55% fructose and 45% glucose. It is commonly used in soft drinks and is very similar in sweetness to table sugar.
- HFCS 42 contains 42% fructose and 58% glucose. It is commonly used in canned fruits, ice cream, desserts, and other sweetened processed foods.
Thus High fructose corn syrup is not entirely fructose, though it contains a lot of fructose. And consuming an excess of HFCS may mean you are consuming a lot of fructose.
High fructose diet, according to the present study, may cause defects in the placenta and restrict fetal growth and increases a baby’s risk for metabolic health problems later in life.
This has been suggested by the experimental study conducted on mice by a team at Washington University School of Medicine in St. Louis.
The study has been published online in journal Scientific Reports.
Fructose, as we know is a sugar occurring naturally in fruits and honey. It is also used to make sweet syrups and used across sugary drinks. It is also used in high-fructose corn syrup which is very popular in Western diets as a food sweetener.
Many recent searches have pointed out that fructose in processed foods and sugary drinks may be linked to diabetes and obesity.
The authors suggest that since the early 1970s, we’ve been eating more fructose than we should and it becomes increasingly critical to understand how fructose consumption is impacting human health.
The problem with fructose is that it is processed differently than other sugars such as glucose. While other sugars can be converted to energy by the body, fructose is broken down by liver cells that turn the sugar into a form of fat known as triglycerides. It also leads to high uric acid levels.
High fructose exposure in mice caused elevated uric acid and triglycerides in otherwise healthy mice. It also led to smaller fetuses and larger placentas.
High fructose exposure may also cause a small fetus to become wired to grow more after birth than a normal-sized fetus.
Not only this, but maternal health may also suffer. Metabolic problems caused by high levels of uric acid and fat increase a woman’s risk of developing pregnancy complications such as pre-eclampsia — a potentially serious condition in pregnancy often marked by high blood pressure, swelling and high protein levels in the urine — and gestational diabetes.
Researchers found a correlation suggesting similar maternal and fetal effects occur in humans.
Interestingly, in the mouse model, researchers found that when mice with high-fructose levels were given the common drug allopurinol — a medication that reduces uric acid — it reversed the negative maternal and fetal effects of fructose.
The authors advised pregnant women to limit fructose in their diets and suggested consideration of use of allopurinol [if required], which crosses the placenta and generally is considered safe to take late in the second trimester or third trimester during pregnancy.
The best advise the authors give is to eat natural food to ensure healthy maternal and fetal outcomes.
So next time you are going to make a sweet choice, be little diligent.
References
- Kimber L. Stanhope et al. Consuming fructose-sweetened, not glucose-sweetened, beverages increases visceral adiposity and lipids and decreases insulin sensitivity in overweight/obese humans. Clin. Invest. 119:1322–1334 (2009). doi:10.1172/JCI37385
- Kim-Anne Lê, Michael Ith, Roland Kreis, David Faeh, Murielle Bortolotti, Christel Tran, Chris Boesch, and Luc Tappy. Fructose overconsumption causes dyslipidemia and ectopic lipid deposition in healthy subjects with and without a family history of type 2 diabetes Am J Clin Nutr June 2009 89 no. 6 1760-1765.
- Takahiko Nakagawa, Hanbo Hu, Sergey Zharikov, Katherine R. Tuttle, Robert A. Short, Olena Glushakova, Xiaosen Ouyang, Daniel I. Feig, Edward R. Block, Jaime Herrera-Acosta, Jawaharlal M. Patel, Richard J. Johnson. A causal role for uric acid in fructose-induced metabolic syndrome. American Journal of Physiology – Renal Physiology Published 3 February 2006 Vol. 290 no. 3, F625-F631 DOI: 10.1152/ajprenal.00140.2005
- Xiaosen Ouyang,Pietro Cirillo,Yuri Sautin,Shannon McCall,James L. Bruchette,Anna Mae Diehl,Richard J. Johnson,Manal F. Abdelmalek1. Fructose consumption as a risk factor for non-alcoholic fatty liver disease. Journal of Hepaotology June 2008Volume 48, Issue 6, Pages 993–999.
- A W Thorburn, L H Storlien, A B Jenkins, S Khouri, and E W Kraegen Fructose-induced in vivo insulin resistance and elevated plasma triglyceride levels in rats.. Am J Clin Nutr June 1989 49 no. 6 1155-1163.
- Heather Basciano, Lisa Federico and Khosrow Adeli. Fructose, insulin resistance, and metabolic dyslipidemia. Nutrition & Metabolism20052:5 DOI: 10.1186/1743-7075-2-5.
- Susanna C Larsson, Leif Bergkvist, Alicja Wolk. Consumption of sugar and sugar-sweetened foods and the risk of pancreatic cancer in a prospective study.
- Fructose-induced leptin resistance exacerbates weight gain in response to subsequent high-fat feeding Alexandra Shapiro, Wei Mu, Carlos Roncal, Kit-Yan Cheng, Richard J. Johnson, Philip J. ScarpaceAmerican Journal of Physiology – Regulatory, Integrative and Comparative Physiology Published 1 November 2008 Vol. 295 no. 5, R1370-R1375.
- Qingying Meng, Zhe Ying, Emily Noble, Yuqi Zhao, Rahul Agrawal, Andrew Mikhail, Yumei Zhuang, Ethika Tyagi, Qing Zhang, Jae-Hyung Lee, Marco Morselli, Luz Orozco, Weilong Guo, Tina M. Kilts, Jun Zhu, Bin Zhang, Matteo Pellegrini, Xinshu Xiao, Marian F. Young, Fernando Gomez-Pinilla, Xia Yang. Systems Nutrigenomics Reveals Brain Gene Networks Linking Metabolic and Brain Disorders. EBioMedicine, 2016; DOI: 1016/j.ebiom.2016.04.008
- Washington University in St Louis Press Release
- Zeenat A. Asghar, Alysha Thompson, Maggie Chi, Andrew Cusumano, Suzanne Scheaffer, Noor Al-Hammadi, Jessica L. Saben, Kelle H. Moley. Maternal fructose drives placental uric acid production leading to adverse fetal outcomes. Scientific Reports, 2016; 6: 25091 DOI: 1038/srep25091
