Scientific understanding of cholesterol has become much more complex over the decades. Nutritionists once thought there was just one kind of cholesterol, that it was universally bad, and that your body produced it when you ate any kind of fat or oil. Nutritionists now recognize three different kinds of cholesterol that affect human health, and that even foods without any fat content -- such as soda -- can affect your cholesterol levels.
Kinds of Cholesterol
The three kinds of cholesterol are high-density lipoproteins, low-density lipopropteins and triglycerides. LDL and triglycerides are bad cholesterols. They increase your risk of heart disease, high blood pressure, heart attack and stroke by obstructing the flow of blood through your veins and arteries. HDL, by contrast, is good for your circulatory health. It cleanses your blood of harmful substances, including other kinds of cholesterol.
Cholesterol and Diet
What you eat is the single largest factor affecting how much and what kind of cholesterol you have in your blood. Your body produces HDL and LDL cholesterol in response to eating fat: LDL for saturated fats and HDL for unsaturated fats. Triglycerides form in response to spikes in your blood glucose levels, such as when you eat sugar or other unrefined carbohydrates.
Soda and Cholesterol
Soda contains no fat, meaning it will have no effect at all on your levels of HDL and LDL cholesterol. However, soda is very high in sugar as compared to its volume. This "sugar rush" creates exactly the kind of blood sugar spike that stimulates your body to produce triglycerides. Although triglycerides don't increase your heart risk as severely as comparable amounts of LDL cholesterol, they will raise your level of harmful cholesterol.
Diet Soda
Diet soda contains no sugar, and thus has about the same effect on your cholesterol level as drinking tap water. However, high-sodium soft drinks can hurt your circulatory health for other reasons.
