The popular keto diet could be bad for your heart, Australian and international researchers have warned.

Therapy involving ketone bodies could be useful in fighting heart disease, but the keto diet is not a good way to go about it, a study published in the Journal of the American College of Cardiology warned.

Ketone bodies are water-soluble molecules that circulate in the body as a result of low sugar levels in the bloodstream, often due to fasting.

While the idea of using ketone bodies to trigger weight loss is what underpins the keto diet, emerging evidence suggests the diet itself could instead increase the risk of heart disease due to its lack of ‘heart-healthy’ fats.

How does the keto diet work?

The ketogenic or ‘keto’ diet has been around since the 1920s but has surged in popularity in recent years thanks to a slew of celebrity followers.

Adherents of the diet eschew carbohydrates in favour of meaty, high-fat meals in an effort to force the body into a state of ketosis.

Keto diet followers eat very low amounts of carbohydrates, but lots of fats that could harm the heart. Photo: Getty

Ketosis is a metabolic state where ketone bodies pump through the body and cause the body to fuel itself by burning fat as energy.

Critics of the diet point to mounting evidence against its long-term efficacy and warn that it entails consuming high levels of unhealthy fats with little evidence of long-term effectiveness as a weight-management tool.

What did the study find?

Researchers reviewed current data and found that ketone bodies have a protective effect on patients with heart disease, but that the keto diet was not an effective way to administer them.

“We found that data from experimental and human studies suggest ketone bodies exert protective effects on patients with heart disease,” said the study’s senior author B Daan Westenbrink, a cardiologist and translational scientist at University Medical Centre Groningen in the Netherlands.

Heart disease is the leading killer worldwide, and finding new ways to protect heart health is key, Dr Westenbrink said.

Emerging evidence suggests that boosting ketones may help reduce risk factors of heart disease including blood pressure, body weight, blood glucose or blood sugar, and cholesterol, the researchers found.

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The researchers looked at the pros and cons of the keto diet as one of a number of mechanisms for boosting the body’s ketone levels.

However, they found that while the diet could help boost ketones, it comes with some worrying side effects, and long-term compliance to the diet is low, often due to gastrointestinal distress.

While the keto diet has become increasingly popular, there are concerns about untoward effects on the heart,” Dr Westenbrink said.

Other therapeutic methods are therfore preferable to the keto diet, the researchers found.

“Administration of ketones may be an alternative to a keto diet as a means of elevating ketone bodies for their protective effects,” Dr Westenbrink said.

However, more research into ketosis is needed, he said.

“With numerous pathways to achieve ketosis, ketone bodies have potential clinical implications that require further study,” Dr Westenbrink said.

“Further exploration of therapeutic approaches to harness the beneficial effects of ketosis are necessary.

“I believe in the coming years we will have a much better grasp on whether ketone bodies can be optimised and used in the treatment and prevention of heart disease.”