There’s a lot of marketing collateral these days that positions simple carbs and sugary treats as a ‘heart-healthy’ meal. There’s also some shaky ‘science’ indicating this online — like this study that states that carbs are critical for “fueling heart muscles.” So it’s no surprise that many of us relied on the outdated food pyramid to get our 55% to 60% carb intake for the day.
But we already know what following that got us: sky-high obesity, chronic disease, and cardiovascular disease, among many other things.
Where did this myth come from, and why is there still so much misinformation? And do you really need carbs to support your heart?
Here’s what the science says.
Article overview
- Understanding carbohydrates and how they work in the human body.
- Understanding how carbohydrates interact with your heart, and how they might not offer the best potential for enduring heart health.
- Exploring no-carbohydrate or low-carbohydrate dietary approaches that may work better for overall heart health
Why are carbs supposedly good for your heart?
Carbohydrates are organic macronutrients made of carbon, hydrogen, and oxygen. They fall into four classifications:
- Monosaccharides: ‘Simple’ or single sugars like glucose and fructose
- Disaccharides: Include lactose (milk sugar) and sucrose
- Oligosaccharides: Naturally found in plant foods like onions, beans, and lentils.
- Polysaccharides: Also known as ‘long chain sugars,’ or ‘complex carbohydrates,’ like the starch in potatoes
People in the ‘pro-carb’ camp make two major arguments for their importance in the everyday diet.
First, energy. Carbohydrates provide energy much quicker than fats or proteins, which means the body doesn’t need to do much before harnessing extra ‘power.’ That’s one of the reasons why elite athletes rely heavily on bananas, chocolate bars, and bread products to maintain performance. Although, I’d be remiss if I didn’t point out this recent paper suggesting that humans need just 10 grams of carbs to perform well on long runs (far below the common recommendations of 60, 90, or even 120 grams).
Another argument: fiber, which some studies suggest has favorable effects on blood pressure, heart function, and lipids. You’re likely familiar with the marketing material stating that your daily bowl of oatmeal can reduce LDL cholesterol and triglycerides. One July 2025 study posited that higher carbohydrate quality with ‘fiber-rich food’ was associated with better left ventricular structure and function (meaning the heart appeared structurally healthier in people eating more fibrous foods).
That said, there’s also quite a lot of evidence suggesting that fiber isn’t all that important for heart health. I’ll let you read the article and decide for yourself.
There are also a few miscellaneous claims about complex carbs worth knowing. For context, ‘complex carbs’ refer mostly to starch and fiber, with common recommendations of eating whole wheat bread or brown rice instead of white. You may already be familiar with some of the most common arguments for them:
- “Complex carbs decrease inflammation”
- “Complex carbs decrease plaque buildup in the heart”
- “Complex carbs keep you fuller for longer”
The problem is that none of these arguments make much sense in the real world.
We know most Americans aren’t getting marketed complex carbs like chia seeds and macadamia nuts. They’re being told to eat ultra-processed foods, sugar-sweetened ‘healthy’ snacks, and protein junk foods that claim to offer fiber on the label.
Yes, complex carbs are better than their simple, processed alternatives. But it doesn’t vindicate the message of eating carbs instead of fat for heart health. And it certainly shouldn’t uphold the Standard American carbohydrate intake. Or all the many misleading marketing campaigns and/or fitfluencer myths.
Why high carbs and heart health don’t go together
I’ve already alluded to much of this already, but let’s take a closer look at the mechanisms between carbohydrates and heart health.
Higher risk of cardiovascular disease
Simple carbohydrates can spike blood sugar, which contributes to cardiovascular disease. These simple carbs often stem from processed foods like white bread and rice, which are created from grains with the bran and germ removed.
Not only does this strip away the plant’s original nutritional density, but it also results in foods with a high glycemic index. Studies increasingly show that long-term consumption of high glycemic index foods leads to increased risks of heart attacks, strokes, and early death.
Increased autoimmune and chronic diseases
Although we’ve already spoken about how bad carbs can affect the heart, many other areas of your body that contribute to heart function may suffer as well.
See for yourself:
- Diabetes: Chronically elevated sugar can overload the pancreas and reduce insulin sensitivity. This insulin resistance is a hallmark of type 2 diabetes mellitus.
- Fatty Liver: Your liver must break down even complex carbohydrates into sugar, which can lead to fat building up in the liver itself. This can lead to the development of non-alcoholic fatty liver disease (NAFLD), which has recently been renamed metabolic dysfunction-associated steatotic liver disease, or MASLD.
- Obesity: The effect of excess carbohydrate consumption often leads to obesity. Obesity by itself is a major risk factor for many major diseases, especially those related to cardiovascular health.
- Chronic inflammation: A high carbohydrate intake can trigger a low-grade, systemic (body-wide) inflammatory response that decreases the functioning and health of your organs. It can also alter your gut microbiome by harming intestinal permeability, or your ability to absorb what you eat.
Worsening metabolic health
The modern world is experiencing a renaissance of bad metabolic health, and metabolic disorders and diseases are at an all-time high. Recent studies indicate that 93% of Americans demonstrate at least one metabolic risk factor. This includes elevated fasting blood sugar, high triglycerides, low HDL cholesterol, abdominal obesity, and high blood pressure.
Having three conditions out of the five of these suggests you may have metabolic syndrome.
The case for eating low to no carbs to protect your heart
If traditional food science tells us that carbs are good for our bodies, then why do they increase our risk for heart disease 1.15-fold? And if more than half of our diets should be breads, pastas, and potatoes, then why do high-carb diets lead to “insulin resistance, dyslipidemia and chronic inflammation?”
The solution to protect our hearts, it would seem, is not to consume more complex carbs. Instead, we should switch over to low or no carbs at all. This is what many people like to call a ‘proper human diet.’
A well-designed low-carb diet can help reduce cardiovascular risk factors, help with weight management, support blood sugar control, and improve your lipid metrics. Case in point: a study performed in 2021 linked low-carb diets with improved metabolic outcomes in overweight adults. This was the case even when patients increased their saturated fat consumption, which has long been a ‘boogeyman’ of maintaining your heart.
So, what should we eat instead of carbs?
I argue:
- Animal protein and seafood
- Dairy products
- Eggs
- Butter and beef tallow
- Low-carb vegetables, if you can tolerate them
Learn more about fats vs carbs in the great heart health debate.
And to learn more about eating foods with nutrients that your body can properly absorb, take a look at my new book Stay Off My Kitchen Table.