Fructose – What is it?
Fructose is a type of sugar contained in natural foods such as fruits, vegetable juice and honey. In these forms, fructose can be part of a healthy diet.
However, in its isolated form it can harm the body. In fact, fructose is one of the main ingredients in syrup that is used to sweeten soda and candy.
The effects of fructose on human health
The effects of fructose on human health are still controversial. Most studies believe that an excess of this molecule can cause negative effects on the body. (1) (2) (3)
According to research, consuming fructose in moderate amounts is considered safe. However, there’s sufficient evidence to state that an excess of this type of sugar can lead to diabetes, overweight and obesity. (4)
The following article details whether fructose is bad for your health or not and what its effects are on the human body.
Which foods contain fructose?
Fructose is type of sugar contained in natural foods such as fruits, vegetables and honey. Of the natural sugar substitutes, it’s one of the sweetest. Its sweetening power is greater than other types of sugar, including white sugar. The foods with the highest fructose content are:
- Fruit juice
- White sugar
- Coconut sugar, muscovado, brown sugar
- Agave syrup
- Foods with high fructose syrup
- Dehydrated fruits
Some vegetables contain fructose in smaller amounts. These are:
Table sugar is composed of 50% glucose and 50% fructose. Many people forget that honey and industrial foods are usually high in fructose in the form of syrup. Avoiding excess sugar is a basic rule for diabetics.
High fructose syrup contains up to 60% of this type of sugar and the rest is glucose. In fact it’s very similar in composition to other types of sugar.
Is fructose harmful? – Effects on the body
Fructose contained in foods such as fresh fruits and vegetables has positive effects on health. Processed forms such as high fructose syrup and all foods that contain it can have negative health effects. The effects of an excess of fructose on the body are:
- Leptin resistance (hunger hormone)
An excess of fructose can increase the levels of the hunger hormones ghrelin and leptin. This can cause a person to feel less satiated after eating. (1) (4)
2.Addiction to sweet foods
There’s evidence to suggest that fructose may cause addiction to sweet foods. Glucose activates reward pathways in the brain, which can lead to an increase in sugar cravings during the day. (2)
- Higher risk of overweight and obesity
The consumption of large amounts of fructose is related to an increased risk of overweight and obesity. When a person consumes it in excess, it can stimulate the deposit of extra fat in the liver. (4)
4 Insulin resistance
People who consume high amounts of fructose syrup foods have higher levels of insulin resistance. This translates into a greater chance of developing diabetes and heart disease in adults.
- Bad cholesterol level increase
An excess of foods with fructose can lead to an imbalance of blood lipids. It has been proven that it can raise VLDL cholesterol levels, a type of fat related to the increase in heart disease. (4)
Contraindications and side effects
There’s sufficient evidence to state that an excess of fructose is bad for your health. The effects on the body are similar to those of other simple carbohydrates.
In moderate amounts fructose has no side effects on the body. However, in excess it can lead to weight gain and carbohydrate metabolism disorders.
Foods that contain high amounts of added fructose are contraindicated for diabetics. It’s recommended that no more than 10% of total calories come from this energy source. (5)
Studies suggest that soft drinks sweetened with this type of sugar are also high in calories. This may explain the link between fructose and obesity.
Fructose vs glucose
Both fructose and glucose are simple carbohydrates. In their pure forms their glycemic index is high. In other words, they provide energy excessively quickly.
The main difference between glucose and fructose is that the body is able to synthesize glucose in the cells. In fact it’s the body’s preferred carbohydrate source as an energy source.
Fructose can bind to glucose, which results in white table sugar or sucrose.
There isn’t enough evidence as to say that foods with glucose are better than foods with fructose. Their effects on the body are similar. In a healthy diet, regulating foods with both types of added sugars is essential.
Eating fresh and natural foods should be the basic rule to avoid the negative effects on the body.
Date: January 10th, 2020
Fructose is a type of natural sugar contained in fruits, vegetables and honey. In its natural form it’s a good source of energy. Foods that contain this type of sugar in a concentrated fashion cause negative effects on the body such as: unbalance of the hormones insulin, leptin and ghrelin, weight gain and increased risk of diabetes and cardiovascular disease.
Fructose metabolism and metabolic disease. https://www.researchgate.net/publication/322867527_Fructose_metabolism_and_metabolic_disease
Fructose overconsumption causes dyslipidemia and ectopic lipid deposition in healthy subjects with and without a family history of type 2 diabetes. https://www.ncbi.nlm.nih.gov/pubmed/19403641
Health implications of fructose consumption: A review of recent data. https://www.researchgate.net/publication/47678059_Health_implications_of_fructose_consumption_A_review_of_recent_data
Fructose consumption and its health implications; fructose malabsorption and nonalcoholic Fatty liver disease. https://www.researchgate.net/publication/260372921_Fructose_consumption_and_its_health_implications_fructose_malabsorption_and_nonalcoholic_Fatty_liver_disease
Alimentación sana. https://www.who.int/es/news-room/fact-sheets/detail/healthy-diet
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