PNP NUTRITION BASICS: Lesson 7 - High Fructose Corn Syrup: Why It Matters
What is High Fructose Corn Syrup?
When reading food labels, it's crucial to look beyond calories and macronutrients (protein, carbohydrates, and fats) and examine the ingredients list. Ingredients provide a clearer picture of what is in the food. Commonly found sugars include fructose, high fructose corn syrup (HFCS), corn syrup, and corn syrup solids. Fructose is an isomer of glucose, meaning it has the same molecular formula as glucose but a different structure.
Why is Fructose Used in Foods?
Fructose is used commercially in food and beverages primarily because of its high relative sweetness and low cost. It is the sweetest naturally occurring carbohydrate (perceived to be 1.73 times as sweet as sucrose). The sweetness of fructose is detected earlier and peaks higher than that of sucrose or dextrose, but it diminishes more quickly.
Natural Sources of Fructose
Fructose naturally occurs in fruits, vegetables, and honey. It can exist as a free monosaccharide (simple sugar) or be bound to glucose as a disaccharide. Foods containing free fructose typically have an approximate 1:1 ratio of fructose to glucose. Some fruits, like apples and pears, have higher proportions of fructose to glucose, while others, like apricots, have lower proportions.
The Problem with Fructose
Fructose has received criticism due to how the body processes it which is different from other sugars. Unlike glucose and dextrose, which are readily converted to muscle glycogen (a form of stored carbohydrate in muscles), fructose must be processed in the liver before conversion to glycogen. If liver glycogen stores are full, fructose is converted to fat and stored, potentially raising triglyceride levels.
The body's absorption capacity for fructose ranges from 5g to 50g. For example, a 12oz can of Coke® contains 40g of fructose, which can exceed the liver's capacity to process it. For every 120 calories of glucose consumed, less than 1 calorie is stored as fat, compared to 40 calories stored as fat from the same amount of fructose.
Health Risks of Fructose and High-Fructose Corn Syrup
All fructose is metabolized in the liver, which prioritizes its processing over other functions. Consuming whole fruits like oranges provides bulk, promotes satiety, and contains fiber, making them a healthier option than fruit juices or sugary beverages.
High-fructose corn syrup (HFCS) is made from corn syrup and is sweeter than regular corn syrup. It's commonly found in processed foods and sodas. Studies have shown that HFCS can have adverse health effects, including increasing the risk of heart disease, diabetes, and other metabolic disorders.¹ ²
Key Facts About Fructose and Corn Syrup Products:
Corn syrup solids contain dextrose sugar, which is approximately ¾ as sweet as sucrose.
Crystalline fructose may contain contaminants like arsenic, chloride, and heavy metals.³
Corn syrup solids, also known as corn syrup powder, are manufactured by removing 97% of the water from corn syrup liquids.
HFCS undergoes further processing to adjust the percentage of fructose.
Studies have detected unsafe mercury levels in HFCS.⁴
Nearly all corn syrup is made from genetically modified corn, posing additional risks.
In a study conducted over 10 weeks, volunteers on a high-fructose diet developed new fat cells around their heart, liver, and other organs and showed signs of metabolic abnormalities linked to diabetes and heart disease. A control group consuming glucose did not exhibit these issues.⁵
Understanding the impact of high-fructose corn syrup and other forms of fructose on your health is crucial. Limiting consumption of these sugars and opting for whole foods with natural sugars and fiber can help mitigate health risks and promote better overall well-being.
References
Stanhope, K.L., et al. (2015). "Both Sucrose and High Fructose Corn Syrup Linked to Increased Health Risks." UC Davis Health. https://www.ucdavis.edu/health/news/both-sucrose-and-high-fructose-corn-syrup-linked-increased-health-risksUC Davis
Malik, V.S., et al. (2015). "Fructose and Cardiometabolic Health: What the Evidence from Sugar-Sweetened Beverages Tells Us." Journal of the American College of Cardiology, 66(14), 1615–1624. https://www.jacc.org/doi/10.1016/j.jacc.2015.08.025JACC+1PMC+1
"Crystalline Fructose." The Chiro Joint. https://www.thechirojoint.com/crystalline-fructosethechirojoint.com
Dufault, R., et al. (2009). "Mercury from chlor-alkali plants: measured concentrations in food product sugar." Environmental Health, 8(1), 2. https://pubmed.ncbi.nlm.nih.gov/19171026/IATP+3Wikipedia+3PubMed+3
"High Fructose Corn Syrup Increases Risk Factors for Heart Disease, Diabetes." News-Medical.net. https://www.news-medical.net/news/20200918/High-fructose-corn-syrup-increases-risk-factors-for-heart-disease-diabetes.aspxNews-Medical
