December 30, 2021

Is the Keto Diet Heart-Healthy?

Find out how this low-carb diet affects your heart

Keto diet and your heart

If you’re trying to lose weight or just live healthier, starting a new diet can help. The ketogenic (“keto”) diet has been trending for several years now, due to its success with weight loss and muscle-building. Some have even come to believe that following this diet can aid in preventing or reversing heart failure.


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As we get into the health benefits of the keto diet, heart failure cardiologist and researcher W.H. Wilson Tang, MD, wants you to understand the basics before hopping on this enduring trend.

“The keto diet is based on eating little carbs, so the idea is for you to get those extra calories in from protein and fat instead,” says Dr. Tang. “The key is to eliminate carbs that come from unhealthy options like soda, sweets, white bread, as well as healthy options like fruit, milk, and whole grains,” adds registered dietitian Katherine Patton, RD.

Dr. Tang wants you to know that just because you’re lessening your carb intake, it doesn’t mean you’re automatically preventing heart disease with the keto diet.

In fact, you could be facing increased risks of heart disease if not monitored closely by a medical professional.

Is the keto diet heart-healthy?

“Our skeletal muscles are fueled primarily by glucose, which is a form of sugar derived from the carbohydrates we eat. On the flip side, our hearts derive up to 70% of fuel from fat,” says Dr. Tang.

Ketone bodies are an alternative source of fuel that your liver makes from fat. So, if you want to train your body to switch from using glucose to ketones, you must decrease your carb intake and replace with lean protein and unsaturated fat. This is the essence of the keto diet.

For people at risk of developing heart disease, the success of keto’s short-term weight loss can be helpful. When following the keto diet, you tend to feel less hungry — therefore, aiding in weight loss.


Other benefits of the keto diet include:

  • Lowering blood sugar (helpful in preventing diabetes).
  • Lowering triglycerides (a type of fat in your blood that increases the risk of heart disease and stroke).

While these short-term benefits can make you feel better, the long-term effects of the keto diet remain unclear.

If you’re thinking of starting the keto diet, beware of certain side effects, like:

  • Nausea and vomiting.
  • Fatigue.
  • Lightheadedness/dizziness.
  • Constipation.

“Because there is no consensus on exactly what the diet includes, this leaves the door open to thinking it’s safe to live on saturated fats and processed foods,” says Dr. Tang.

As for heart-health, the jury is still out on whether or not this diet is actually beneficial.

Does the keto diet have benefits for cardiac patients?

“I do not know of any high-quality dietary studies that consistently show ketosis is helpful in human hearts,” says Dr. Tang. “However, there have been some exciting new data that may point to potential benefits in subsets of heart failure patients. So, our group and others are actively studying this to see if there is any new dietary intervention opportunity for some patients.”

Can the keto diet cause heart issues? Dr. Tang fears some people who have heart failure doing a ketogenic diet might have increased risks of:

  • Diabetic coma.
  • Non-alcoholic fatty liver disease.
  • A spike in LDL (“bad”) cholesterol.
  • Dehydration.
  • Kidney failure.

In general, if you have heart failure, you’re more likely to develop a blood sugar abnormality. And with keto dieters consuming high levels of fat and protein, it’s hard to determine when it turns from healthy to harmful.

Recommendations for heart patients on the keto diet

“It’s possible some patients might benefit from the keto diet, but some might get worse,” says Dr. Tang.

Because of the potentially harmful effects of the keto diet on heart patients, Dr. Tang and other heart failure specialists advise taking a less-strict approach.

For heart patients, Dr. Tang (and aligning to the latest clinical guidelines on dietary recommendations from the American Heart Association) recommend:

  • Eating a balanced diet that contains complex carbohydrates, unsaturated fats and lean proteins.
  • Controlling portions.
  • Choosing fresh fruits and vegetables.
  • Limiting red meat and adding in more fish.
  • Skipping processed foods.
  • Cutting back on sugars, simple carbohydrates, saturated fats and trans fats.
  • Replacing sodium with flavorful herbs, spices and vinegars.

If you’re really determined to follow a strict keto diet, Dr. Tang suggests two “natural,” safe options for generating ketone bodies. “The first is to sleep more, as sleep generates ketosis naturally. The second is to consider reducing caloric intake through intermittent fasting — although this still warrants close monitoring by your doctor. It is certainly wise to discuss with your doctor before proceeding, should you choose to pursue a specific diet.”

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