A study found that consuming added sugars increases cardiovascular disease risk, while eating more dietary fiber can help decrease risk. Juan Moyano/Stocksy
  • Researchers investigated the effects of different carbohydrates on cardiovascular health.
  • They found that consuming more added sugars increases cardiovascular risk, and that more dietary fiber decreases cardiovascular risk.
  • Reducing the intake of added sugars could reduce cardiovascular risk.

Sugars are carbohydrates that occur in two varieties: free and non-free sugars.

“Free sugars” include sugars added to foods and drinks such as chocolate and flavored yogurts. They are also in honey, unsweetened fruit juices, and vegetable juices.

Non-free sugars occur in foods such as vegetables, grains, and dairy products. As these sugars are contained within cell walls, they are harder for the body to absorb and don’t generate the same “sugar high” as free sugars.

Higher free sugar intake correlates to higher triglyceride levels, which are linked to ischemic heart disease — reduced blood flow to the heart. Studies also suggest that high fiber intake — another type of carbohydrate — is linked to a lower risk for heart disease.

Understanding how carbohydrate intake influences health could lead to better preventive strategies for cardiovascular health.

Recently, researchers analyzed health data to understand more about how carbohydrates relate to cardiovascular risk.

They found higher free sugar intake is linked to higher cardiovascular disease incidence and triglyceride levels.

“Added sugars found in sweet snacks and sugary drinks are just as bad for us as our parents said – if not even worse,” ​​Dr. Daniel Atkinson, GP Clinical Lead at Treated, not involved in the study, told Medical News Today.

“It’s not just our teeth they can damage, but the health of our heart as well. If you want to make some changes to look after your heart health, cutting out cola is probably more helpful than cutting out crisps,” Dr. Atkinson noted.

The study was published in BMC Medicine.

For the study, the researchers analyzed healthcare data from 110,497 participants in the UK Biobank study.

Participants recorded what they ate over 24 hours between 2-5 occasions. The researchers compared this data with health records detailing the diagnosis of cardiovascular conditions and risk factors such as triglyceride levels. Participants were followed for an average of 9.4 years.

Over the follow-up period, the researchers recorded 4,188 cases of cardiovascular disease, 3,138 cases of ischemic heart disease, and 1,124 cases of stroke.

They found that those with a higher intake of free sugars were at a higher risk of cardiovascular disease and stroke. Meanwhile, those who consumed more fiber had a lower risk of cardiovascular disease.

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From further analysis, the researchers found that higher free sugar intake was linked to higher triglyceride levels. They also found that replacing 5% of energy from free sugars with non-free sugars was linked to a lower risk of cardiovascular disease and stroke.

Dr. Elexander Atkinson, family medicine doctor at Novant Health in Charlotte, NC, not involved in the study, told MNT that one of the study’s main takeaways is that different kinds of carbohydrates affect cardiovascular risk differently.

“The problem is simple, refined, and processed carbohydrates — in excess. The study actually found that higher levels of fiber- a carbohydrate- reduced the risk of heart disease,” Dr. Atkinson explained.

When asked how added sugars may increase cardiovascular risk, he said:

“It does this in many ways. It increases your risk for diabetes, which is a major risk factor for heart disease. It can also increase your blood pressure, which is also a major risk factor for heart disease.

Metabolically, your body may not be able to process all of this sugar in a healthy way, and that can cause an increase in your triglycerides, which was seen in this study. Triglycerides are also related to heart disease. People who eat more sugar are more likely to be overweight, and again this is a risk factor for heart disease.”

MNT also spoke with Dr. John Higgins, a sports cardiologist at the UTHealth Science Center at Houston – McGovern Medical School and the Memorial Hermann Ironman Sports Medicine Institute, Houston, TX. Dr. Higgins noted that high added sugar intake could also increase inflammation and cause vascular dysfunction, which increases cardiovascular risk.

Dr. Humair Mirza, a cardiologist with Memorial Hermann in Houston, Texas, not involved in the study, told MNT: “This is an indirect association. It is, in addition, unclear if the link is due to increased caloric intake and weight gain, or other lifestyle factors that may co-exist, such as smoking, lack of exercise, other food choices, or due to excess consumption of refined carbohydrates such as high-fructose corn syrup used to sweeten beverages.”

The researchers concluded that different types of carbohydrates affect cardiovascular risk differently.

When asked about the study’s limitations, Dr. Trent Orfanos, FACC, ABIHM, Director of Integrative and Functional Cardiology at Case Integrative Health, not involved in the study, told MNT:

“The primary limitation when considering this study is that much of the dietary data was self-reported, so it is subject to a certain level of error. Additionally, the majority of participants in the study were of white European descent, which makes it difficult to apply to different populations.”

Dr. Taylor Wallace, CEO at Think Healthy Group and a professor in the Department of Nutrition and Food Studies at George Mason University, not involved in the study, told MNT:

The participants had provided at least two dietary assessments (maximum of 5), which isn’t much over a 9-year period. Think about your diet as a whole and if two random days in 9-years would be representative of your long-term dietary pattern. Still this is a very strong and well-done prospective cohort study. Most of these types of studies have these same limitations.”

Dr. E. Atkinson added: “For me, the bigger problem is that the study is only looking at carbohydrates and heart disease. We know heart disease is multifactorial. This means many things contribute to heart disease, including blood pressure, family history, diabetes, smoking history, cholesterol levels, physical activity. Because these were not considered in the study, it is difficult to say that the effects seen are only from diet. However, we know that diet is a direct risk factor for heart disease, and this study does provide evidence of that.”

“I would like to point out that it is not as simple as telling people to eat less sugar. There are many factors at play here. What if someone does not have a grocery store nearby and has no access to fresh vegetables? What if they don’t know how to cook and therefore eat mostly microwave dinners? Yes, we should still encourage healthy diets, but we need to make sure it is accessible to everyone as well,” he explained.

Beata Rydyger, BSc, RHN, Registered Nutritionist based in Los Angeles, CA, not involved in the study, told MNT:

“The authors themselves suggest that increasing fiber intake and replacing refined grains and free sugars with whole grains and non-free sugars (natural sugars found in fruits for example), may prevent cardiovascular disease. This helps to further validate the idea that the quality, rather than quantity, of carbs that we eat is important for health.”

Dr. Higgens added: “Avoiding adding sugar to food or beverages can lead to reduced cardiovascular risk. In addition, increasing fiber and replacing refined sugars with wholegrain starch and non-free sugars may protect against cardiovascular disease.”

“So get rid of the sugar bowl from the table or coffee/tea room, and instead, get wholegrain starches (Wheat, oats, barley, rye and rice) and sugar from fresh fruits (e.g. bananas, raspberries, strawberries & red grapes) and vegetables instead,” he concluded.