The recent scientific literature has many articles showing that sugar added to foods and drinks increases risk for many diseases:
• heart attacks (Crit Rev Clin Lab Sci, 2016;53(1):52-67)
• diabetes, kidney damage and high blood pressure (Current Hypertension Reports, May 3, 2016)
• brain damage (EbioMedicine, July 2016)
• certain cancers (Cancer Res, January 1, 2016;76(24))
• obesity and metabolic syndrome (Am J Clin Nutr, June 2015;101(6):1144-54)
• strokes (N Engl J Med, June 4, 2015; 372:2197-2206)
• fatty liver (Journal of Hepatology, May 29, 2015)
• high cholesterol, high triglycerides, insulin resistance and high uric acid (Curr Hypertens Rep, June 2016;18(6):44 and Am J Clin Nutr, June 2015;101(6):1144-54).
Fructose is More Harmful than Glucose
The most common sugars added to foods are fructose and glucose. Sucrose is a double sugar with fructose and glucose bound together (cane sugar or table sugar), while high fructose corn syrup (HFCS) contains fructose and glucose separately. Other sweeteners used in processed foods are also usually fructose and glucose; see the lengthy list of names in my report on Hidden Sugars.
Fructose causes more damage than glucose because it is far more likely to deposit fat in your belly, which causes higher blood sugar levels and increases risk for diabetes, heart attacks and death (Current Hypertension Reports, May 3, 2016). Glucose is processed by every cell in your body, but almost all fructose is processed only by your liver where most is converted to fatty triglycerides which cause the highest rise in blood triglycerides and a drop in the good HDL cholesterol.
Studies on fructose show that it is more likely to lead to fat in the liver, higher levels of blood sugar, triglycerides and uric acid (gout), and nerve and kidney damage (Curr Hypertens Rep, June, 2016;18(6):44 and Crit Rev Clin Lab Sci, 2016;53(1):52-67). A high intake of fructose-containing sugars is associated with higher blood levels of triglycerides and sugar and body weight gain (Int J Obes (Lond), March 2016;40 Suppl 1:S6-S11). Fructose increases risk for heart attacks and diabetes (Curr Hypertens Rep, June 2016;18(6):44). Fructose alters brain genes to increase risk for brain damage (EbioMedicine, April 2016).
Sugar-Added Foods Increase Heart Attack Risk
Adults who get more than 15 percent of their daily calories from added sugar are at very high risk for a heart attack. For the average-size person that is about 300 calories or 18 teaspoons of added sugar each day. A 12-ounce can of Coca-Cola has 10 teaspoons of sugar. A high intake of added sugars is associated with increased heart attack risk factors (JAMA, April 2010;21;303(15):1490-7) and heart attack deaths (JAMA Internal Medicine, Feb 4, 2014). People who take in 10-25 percent of their calories from sugared beverages and foods suffer a 30 percent higher risk for heart attacks, compared with people who take less than ten percent of calories from added sugars (British Medical Journal: Open Heart, Dec. 11, 2014).
The World Health Organization recommends no more than six teaspoons of added sugar per day. More than 80 percent of the 600,000 processed food products for sale in North America contain added sugars, and the highest sources are sodas, fruit drinks, desserts and candies. The fatter you are, the more likely you are to be damaged by added sugar in food, so overweight people in particular should try to avoid most processed foods with added sugars.
Sugared drinks, including fruit juices, are even more harmful than added sugars in foods, primarily because sugar in liquid form is absorbed very quickly. The more sugared drinks you take, the higher your heart attack risk factors (triglycerides, bad LDL cholesterol, apolipoprotein B, apolipoprotein CIII, and uric acid) and the lower your good HDL cholesterol (Am J Clin Nutr, June 2015;101(6):1144-54).
Why Sugar in Fruit is Safer than Sugars Added to Foods
Fruits contain fructose and glucose, but they also contain soluble fiber that binds to sugar and prevents it from being absorbed rapidly in your intestines (JAMA Intern Med, April 2014;174(4):516-24; J Food Sci, 2011 Jan; 76(1): R6–R15)). Fruits also contain polyphenol antioxidants that help to block inflammation that damages cells. Fruits are a far less concentrated source of sugar than many sugar-added foods; for example, an average-size apple contains about 19 grams of sugar and four grams of fiber, while a 16-ounce bottle of Pepsi has 55 grams of sugar and no fiber.
High Blood Sugar Can Damage All Cells in Your Body
When the concentration of sugar in your bloodstream rises,
• excess sugar is converted to triglycerides (high triglycerides)
• you use up your good HDL cholesterol in carrying triglycerides from your bloodstream to your liver (low HDL)
• the triglycerides (fat) accumulate in your liver (fatty liver)
• your liver is supposed to protect you from having high blood sugar levels by drawing sugar from your bloodstream, but fat in your liver keeps it from drawing sugar from your bloodstream so your blood sugar stays too high (diabetes)
The cell damage caused by uncontrolled high blood sugar leads to heart attacks, strokes, dementia and all of the other harmful effects of diabetes.
These new studies confirm that eating large amounts of sugar added to foods and drinks increases risk for a wide variety of diseases and premature death. I recommend that you:
• Restrict all processed foods that contain added sugars.
• Restrict sugar-added drinks and fruit juices, since sugar in liquid form causes even higher rises in blood sugar than sugared foods.
• Base your diet on fruits, vegetables, whole grains, beans, nuts and other seeds. These foods have fiber as well as polyphenols and other antioxidants that help to protect you from the sugars they may contain.