Why Is Sugar Bad for You?

It’s smart to cut back on salt to manage your blood pressure, but there’s debate about whether you’ll need to cut back on sugar as well. Could sugar be worse?

You remember, of course, when the public health battle cry rang out against excessive salt consumption years ago, after it was linked to high blood pressure and cardiovascular risk.

Ever since, many people have tapped that shaker a little lighter to flavor their food. We were urged to cut out processed foods, which are often high in salt. But they’re also high in added sugars, which may be the more serious problem.

Any number of chronic diseases are promoted by eating sugar: obesity, diabetes, and fatty liver, plus high blood pressure and death from heart attacks and stroke.

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Why is sugar bad for you?

The huge array of processed foods and beverages that line supermarket and convenient store isles are high in both salt and added sugar, especially a kind called fructose.

The argument against sugar is based on evidence describing a cycle in which added sugar increases your blood sugar, which triggers higher insulin levels. That leads to blood vessel damage, which could cause high blood pressure.

Studies recording ambulatory blood pressure over 24-hours have found increases after consuming sugar greater than what you’ll see after a salty meal.

Basic science, population studies, and experimental trials in animals and humans have demonstrated that added sugars increase blood pressure and blood pressure variability. They also increase heart rate and the need for oxygen, two danger signs.

This argument led to calculations that people who ate the most sugar — representing about 25 percent of daily calories — increased their risk of death from cardiovascular disease over the next 15 years by 30 percent.

Ivan Pacold, MD, a cardiologist at Loyola University Health System in Chicago, agrees that the role sugar plays in increased blood pressure and a higher risk of cardiovascular disease is underappreciated.

“The association has been made before now that if people consume high amounts of sugar they are at greater risk of heart disease,” he says. “The concern is valid, especially over high fructose syrup, the consumption of which has gone up substantially in this country. My view is that there is an association (with high blood pressure) and that (high sugar intake) is clearly harmful.”

As Pacold explains, if you consume a lot of sugar, you typically gain weight, and weight can cause higher blood pressure. Conversely, when people with high blood pressure lose weight, their blood pressure generally comes down.

Sugar's connection to metabolic syndrome

One way fructose raises cardiovascular risk is by promoting a condition called metabolic syndrome.

Metabolic syndrome is the nexus of several factors that together increase your risk for heart disease, diabetes, and stroke. These factors include insulin resistance, obesity, high blood pressure, and high blood fats (fatty acids, cholesterol). More than 30 percent of American adults have metabolic syndrome.

The most recent overview of the evidence linking sugar consumption to heart disease noted, however, that we don’t actually have evidence that eating fewer added sugars has any effect on deaths, strokes, or heart attacks.

Confused? You don’t need to be. There are plenty of reasons to avoid processed foods. Researchers know that both salt and added sugars contribute to inflammation, which in turn plays a role in dementia, depression, and other diseases of modern life, including cardiovascular disease.

Salt is not off the hook, though

Cutting back on sugar is not an invitation to eat more salt, especially if you already have high blood pressure or heart disease.

The Centers for Disease Control and Prevention (CDC) maintains that “most Americans should consume less sodium.” Period. It remains a problem because, as the CDC puts it, salt is everywhere. Foods that otherwise seem healthy may have high levels of sodium. Examples include cottage cheese and turkey deli meat. Before getting to the store, raw chicken and pork can be injected with saline solution, and you don’t know it.

The state of your health is a complex mix of many factors. If your intake of sugar and salt is low, but you’re a sofa spud and you smoke and abuse alcohol, will you live to 105?  Only time will tell.

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