The keto diet is not particularly good for the heart, according to a new analysis published in Current Problems in Cardiology.[1] The high-fat, low-carb diet is associated with certain short-term benefits, but most of them appear to fade over time.
The keto diet has gained popularity in recent years, especially for its potential to help with weight loss. However, author Joanna Popiolek-Kalisz, MD, PhD, a specialist with the clinical dietetics unit at Medical University of Lublin and department of cardiology at Cardinal Wyszynski Hospital—both in Poland—explained that the keto diet is associated with potential safety issues. She explored data from a long list of clinical trials and meta-analyses to reach her conclusions.
Using 2021 recommendations published by the European Society of Cardiology as her guide, Popiolek-Kalisz wrote that the ketogenic diet “does not fulfill the criteria of a healthy diet.” She then reviewed the latest data on a variety of factors to make her case.
Initial benefits that may not last
For example, she explained that the keto diet can help with short-term weight loss, but it has not been consistently associated with improvements in long-term weight loss compared to a traditional balanced diet.
“There is scarce evidence for the long-term positive effects of the ketogenic diet for weight loss,” she wrote, adding that more research on this topic is still required.
Popiolek-Kalisz also noted that a person’s lipid profile is influenced by their carbohydrate intake. With this in mind, she wrote, keto diets have been shown to increase levels of total cholesterol, LDL cholesterol, HDL cholesterol and apolipoprotein B in normal-weight individuals. In obese individuals, meanwhile, the keto diet may help lower total cholesterol or triglyceride levels, but it does not make a significant impact in either direct for HDL or LDL cholesterol levels.
“Lower intake of carbohydrates in ketogenic diets can lead to triglyceride levels reduction, however, significantly increased levels of LDL were also noted,” Popiolek-Kalisz wrote. “What is more, the positive effects of the ketogenic diet on triglyceride levels seem to diminish in longer observations.”
A similar impact is seen on glucose levels and blood pressure. Some studies have found that keto diets may reduce a person’s hemoglobin A1C test levels, for example, but “this effect fades in longer observations.” And while reducing carbohydrate intake can help diabetic patients decrease their systolic blood pressure, the impact appears to fade somewhere between six and 12 months.
“One of the possible reasons for the short-term effect of the ketogenic diet on blood pressure can be increased diuresis as a result of ketosis and rapid weight loss,” Popiolek-Kalisz wrote.
Should heart patients consider the keto diet?
One of the key takeaways from this new analysis is that heart patients appear to be poor candidates for the keto diet.
From a nutritional perspective, keto diets are typically high in saturated fatty acids, red meat and processed foods, which heart-healthy diets limit. Keto diets are also typically low in wholegrain products, fruits and vegetables, three things that heart-healthy diets make a priority.
In addition, Popiolek-Kalisz wrote, individuals on a keto diet typically discontinue the use of SGLT-2 inhibitors, which are regularly prescribed to heart failure patients.
“The last concern, also important for elderly patients, is initial dehydration due to elevated diuresis resulting from ketosis,” Popiolek-Kalisz added. “In elderly patients, this could lead to orthostatic hypotonia, which should be also taken into consideration.”
Click here to read the full analysis.
Michael has more than 16 years of experience as a professional writer and editor. He has written at length about cardiology, radiology, artificial intelligence and other key healthcare topics.