Does Keto Cause Heart Attacks?

Does Keto Cause Heart Attacks?

Does Keto Cause Heart Attacks?

Sensational headlines are attention-catching, but there may be more than meets the eye

Bret Scher, MD

Sensational headlines about health topics are everywhere these days. For example, one recent headline claimed that the keto diet will increase your risk of heart attack. Is this true? Should you stop your nutritional ketosis therapy?

Read on for more about what we know and what we don’t know, as well as tips for interpreting news stories about health.

What study is this CNN article citing?

The first question that comes up when reading a headline like that of the CNN article “‘Keto-like’ diet may be associated with a higher risk of heart disease, according to new research”, is what research are they citing? Turns out this study has not been published anywhere. It was presented at the American College of Cardiology’s annual scientific session together with the World Congress of Cardiology. The information was presented at a meeting but was not published and not peer reviewed.

Does the article that was shared have merit?

The article uses the title, “Keto-like diet," which in itself shows a lack of understanding about what a keto diet is. You are either in ketosis or you are out of ketosis. There are degrees of ketosis, but there is a clear line of whether you are in ketosis or not. There is no such thing as “sort of” keto or “keto-like”.

The diet that they refer to is 25% carbohydrate and 45% fat. Just for reference, if you’re eating 2000 calories a day, 25% carbohydrate is 125 grams of carbs. That’s not “keto-like.” You would not be in nutritional ketosis unless you are super thin, exercise a ton, and maybe eat all your calories in one meal. Then, you might be in and out of ketosis with 125 grams of carbs, but that is not a ketogenic diet!

Why was this article presented as a credible study?

In this CNN article, they quoted Dr. Christopher Gardner, a researcher at Stanford who says, “This study provides an important contribution to the scientific literature and suggests the harms outweigh the benefits.”

According to the information that was presented here, there are no ideas shared about what the benefits are, so it can’t really be said that the harms outweigh the benefits, especially if the harms are a lab value that has to be put into context. Popular media often pull quotes out of context, so maybe they didn’t include the whole context of what he said, but the way it’s phrased on CNN is problematic because we have no idea what the benefits are. The harms are more theoretical and, at the same time, not to be ignored.

What can we take away from this?

  1. Work with your doctor: If you are using nutritional ketosis for a medical intervention, working with your clinician, and you’re actually in nutritional ketosis, then this article and this study that was presented at this conference have absolutely nothing to do with you.

  2. Take a closer look: It can be helpful to say to yourself, “Look, when we see new studies like this, first and foremost, if it’s not published and peer-reviewed we have no idea about the details. Maybe the people they were following have a higher fat, lower carb diet, or maybe they were not actually in ketosis.” These are things you need to know from a published study before taking it more seriously.

  3. Know the definitions: It’s so important to know the definitions. For example, this information has nothing to do with nutritional ketosis, but they’re throwing the word “keto” out there, likely to get some attention and more clicks, but it’s completely inaccurate to refer to this as a keto diet.

  4. Look at what outcomes they’re talking about. Are they talking about people having heart attacks or dying, or are they talking about a lab abnormality? Those are two very different outcomes that you need to put into perspective.

Helpful Resources


Sensational headlines about health topics are everywhere these days. For example, one recent headline claimed that the keto diet will increase your risk of heart attack. Is this true? Should you stop your nutritional ketosis therapy?

Read on for more about what we know and what we don’t know, as well as tips for interpreting news stories about health.

What study is this CNN article citing?

The first question that comes up when reading a headline like that of the CNN article “‘Keto-like’ diet may be associated with a higher risk of heart disease, according to new research”, is what research are they citing? Turns out this study has not been published anywhere. It was presented at the American College of Cardiology’s annual scientific session together with the World Congress of Cardiology. The information was presented at a meeting but was not published and not peer reviewed.

Does the article that was shared have merit?

The article uses the title, “Keto-like diet," which in itself shows a lack of understanding about what a keto diet is. You are either in ketosis or you are out of ketosis. There are degrees of ketosis, but there is a clear line of whether you are in ketosis or not. There is no such thing as “sort of” keto or “keto-like”.

The diet that they refer to is 25% carbohydrate and 45% fat. Just for reference, if you’re eating 2000 calories a day, 25% carbohydrate is 125 grams of carbs. That’s not “keto-like.” You would not be in nutritional ketosis unless you are super thin, exercise a ton, and maybe eat all your calories in one meal. Then, you might be in and out of ketosis with 125 grams of carbs, but that is not a ketogenic diet!

Why was this article presented as a credible study?

In this CNN article, they quoted Dr. Christopher Gardner, a researcher at Stanford who says, “This study provides an important contribution to the scientific literature and suggests the harms outweigh the benefits.”

According to the information that was presented here, there are no ideas shared about what the benefits are, so it can’t really be said that the harms outweigh the benefits, especially if the harms are a lab value that has to be put into context. Popular media often pull quotes out of context, so maybe they didn’t include the whole context of what he said, but the way it’s phrased on CNN is problematic because we have no idea what the benefits are. The harms are more theoretical and, at the same time, not to be ignored.

What can we take away from this?

  1. Work with your doctor: If you are using nutritional ketosis for a medical intervention, working with your clinician, and you’re actually in nutritional ketosis, then this article and this study that was presented at this conference have absolutely nothing to do with you.

  2. Take a closer look: It can be helpful to say to yourself, “Look, when we see new studies like this, first and foremost, if it’s not published and peer-reviewed we have no idea about the details. Maybe the people they were following have a higher fat, lower carb diet, or maybe they were not actually in ketosis.” These are things you need to know from a published study before taking it more seriously.

  3. Know the definitions: It’s so important to know the definitions. For example, this information has nothing to do with nutritional ketosis, but they’re throwing the word “keto” out there, likely to get some attention and more clicks, but it’s completely inaccurate to refer to this as a keto diet.

  4. Look at what outcomes they’re talking about. Are they talking about people having heart attacks or dying, or are they talking about a lab abnormality? Those are two very different outcomes that you need to put into perspective.

Helpful Resources


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