鈥淎 spoonful of sucrose helps the medicine go down,鈥� as Mary Poppins told us. But she neglected to say that it also increases our risk of cardiovascular disease. Actually, Mary didn鈥檛 say sucrose, she said a 鈥渟poonful of sugar.鈥� Sucrose is the chemical term for table sugar and is actually composed of two smaller molecules, glucose and fructose joined together. All three are referred to as 鈥渟imple sugars,鈥� in contrast to 鈥渃omplex sugars鈥� such as the starch in food, or the glycogen stored in the liver, that are composed of long chains of glucose molecules.
Cardiovascular disease (CVD) is a general term that describes a disease of the heart or blood vessels. Sugar has been implicated as a culprit before, but now data from the ten-year long 鈥淏iobank study鈥� of some 110,000 people in the UK, aged 37 to 73, has provided further evidence of harm. Participants in the study periodically filled out dietary questionnaires and made their health records available to the researchers. All subjects were free of cardiovascular disease at the beginning of the study, but by its end, about 8500 had developed some sort of cardiovascular disease. The more 鈥渇ree sugar鈥� they consumed, the greater the risk!
As opposed to the sugar that is a natural component of fruits and vegetables, 鈥渇ree sugar鈥� is the sugar that is added to soft drinks, pastries, cereals, and a host of processed foods to increase sweetness. Honey, maple syrup, and agave syrup also count as 鈥渇ree sugar.鈥� The Biobank researchers not only managed to demonstrate that excessive free sugar intake is associated with increased risk, they also attempted to quantify the risk. In simple terms, the data indicated that for every one hundred people who increase their calorie intake from free sugar by 5% over ten years, seven will develop some sort of cardiovascular disease that can be blamed on sugar.
Let鈥檚 introduce some numbers here. The usual recommendation is that men consume no more than about 40 grams (160 calories) of free sugar a day, and women no more than 35 (140 calories). Let鈥檚 say a doughnut is added to the diet every day. That is 8 grams of sugar (32 calories). This increases calories from sugar by 20% for a man, and 23% for a woman with the implication that for every 100 people who do this over 10 years, there will be 7 who would develop cardiovascular disease. Make it two doughnuts, and you double the increase in risk. Not insignificant.
Free sugar in the diet can add up very quickly. A 350 mL (12 oz) sugar-sweetened beverage contains 40 grams of sugar. Have one of those a day and you are already at the suggested maximum daily intake. Here are some other numbers to note. A serving of Raisin Bran has about 18 grams of sugar, about the same as in a serving of sweetened yogurt. A tablespoon of Nutella has 10 grams of sugar, a bagel 6, a croissant 4, a tablespoon of ketchup 4, and a slice of sourdough bread 2. And that doughnut? Make it chocolate glazed, and you are adding another 11 grams of sugar!
Just why sugar increases the risk of cardiovascular disease isn鈥檛 clear. It may be multi-factorial. Extra calories from sugar increase the risk of obesity, and that increases the risk of all sorts of diseases. But in the UK study, there was an increased risk of cardiovascular disease with increasing free sugar consumption even when there was no increase in body mass index (BMI). It is also known that extra sugar can be converted to fat in the liver and that can lead to fatty liver disease. This in turn contributes to the risk of diabetes which raises the risk of heart disease. Some studies have also shown that sugar can raise blood pressure, elevate triglycerides and increase the risk of inflammation, all of which are associated with an increased risk of cardiovascular disease.
Sugar is not a dietary requirement. While it is a source of glucose, which is our main source of energy, glucose can be derived from complex sugars in the diet, or if need be, from fats or proteins. We can get along perfectly well without sucrose. Well, maybe not perfectly. The stuff tastes darned good and makes for a sweeter life. Unfortunately, that life, sweetened with sugar, may not be quite as long as without it. Cutting down is in order. Eliminating sugar-sweetened beverages would be a step in the right direction. Artificially sweetened drinks have their own issues. What鈥檚 wrong with drinking water?
To leave this discussion on a positive note, the Biobank researchers also found that an increase of five grams of dietary fiber per day lowers the risk of cardiovascular disease by 4%. How do you get five grams of fiber? A half-cup of blueberries and a banana will do it. So will a third of a cup of beans or a baked potato with its skin. A real winner here is Fiber One cereal, with 13 grams of fiber per half cup serving! I have Fiber One every day with blueberries and half a banana. Maybe that makes up for the 4 grams of sugar in a croissant I sometimes sneak in.
