Unsweetened truth: How sugar affects the heart

Valeria Vlasova
3 min read

Sweetness is a basic taste we have from the very ancient times and naturally tend to like it. Nowadays sugar is the integral component of our daily diet. But it’s not as sweet as it sounds. There are many worries from health care systems all over the world that consuming sugar affects health in general and raises risks for heart disease in particular. So cutting off sugar completely from your diet could be the answer for a healthy life, but is it even possible?

Watermelon sugar high

Yep, even a lovely watermelon contains sugar. And so do many fruits, vegetables, grains and dairy — they all contain sugar which offers a steady supply of energy to our cells. Natural sugar is okay as it goes together with plenty of fiber, essential minerals and antioxidants. So keeping a diet with a high amount of vegetables, fruits and grains will help you to reduce the risk of chronic diseases, such as diabetes, and even some cancers. (1)   

Sweet enough?

One of the reasons why increasing sugar consumption became a problem is that food manufacturers have noticed that products with added sugar have more intense flavor and extended shelf life. Which, therefore, made the sales growth and inevitably started the “sugar centric” era.  It is evident for some foods to have plenty of sugar in them: soft drinks, fruit drinks, flavored yogurts, cereals, cookies, cakes, candy etc. But the main danger lies in the fact that added sugar is also present in items you would never think of, such as soups, bread, cured meats, ketchup, and others. (1)

These unobviously sweet products cause the risk of unconscious sugar consumption which is hard to control. The American Heart Association recommends that men consume no more than about 9 teaspoons of added sugar per day. (2) But in reality, according to the National Cancer Institute, an average man nowadays eats no less than 24 teaspoons of added sugar per day. (3) 

Take it to heart

Cardiovascular disease (CVD) is the single largest cause of mortality in the United States and worldwide – from 22% to 29% of all deaths at ages 15–59. (4) But how does a heart take the brunt of excessive sugar consumption?

There are surveys dedicated to the impact sugar has on the human body that show the gravity of the situation. A 15-year study by Dr. Hu and his colleagues linked a high-sugar diet with a greater risk of dying from CVDs. (5) It showed that even 10% but less than 25% of daily calories consumed from added sugar had a 30% higher risk of CVD mortality; and for those who consumed 25% or more of calories from added sugar, the relative risk was nearly tripled.

On the other hand, the relation between consumption of sugar, fructose, HFCS, sucrose, and CVD remains controversial. Recent studies show no evidence of a linear dose-response association for the incidence of CVD and CVD mortality, (6,7) and it requires further investigation. But among multiple underlying risk factors of heart disease that scientists agree upon are dyslipidemias, elevated blood pressure, an inactive lifestyle, obesity, diabetes, and cigarette smoking. (6) And excessive sugar consumption is due in no small part to some of these factors like obesity and diabetes, for example.

Rearrange your sweet habits

Humans' bodies are complicated and fine tuning systems, and it is commonly agreed that a well-balanced diet could help to maintain good health. Diversity of fiber, essential minerals, protein, calcium and antioxidants and even sugars are vital for nutritional practices.

The AHA (American Heart Association) listed 5 dietary goals to improve nutrition, keep the balance in your eating habits and thus lower the risk of CVD (8):

  • fruits and vegetables: ≥4.5 cups/128 grams. For example, it is 1 banana, 1 apple and 1 orange a day.
  • fish (preferably oily fish like salmon, trout, tuna): ≥two 3.5-oz servings a week which is nearly 100 grams.
  • fiber-rich whole grains: ≥1.1-g fiber per 10-g carbohydrates (≥ three 1-oz (28 g) equivalent servings per day). These are buckwheat, oatmeal, bulgur, quinoa and others.
  • sodium: <1500 mg per day. You can find it in ham, eggs, pickled cucumbers etc.
  • sugar-sweetened beverages: ≤450 kcal (36 oz / 1 liter) per week.


There is no question that multiple, important links exist between sugar consumption and heart disease, but there is still no consensus between scientists about to what extent. Of course, excessive consumption of added sugars is not recommended to anyone. But life is not a piece of cake. Food production uses our natural tendency to sweet taste, and it is getting harder to control whether one product has added sugar in it or not. How to keep the balance in our “sugar centric” era – the question remains open. What could help is to listen to advice of the AHA, improve your diet and consumption patterns and take care of your health.