Introduction

Recent research on mice has shed light on how ketogenic diets may affect internal body organs. A ketogenic, or keto, diet typically involves eating foods high in fat and low in carbohydrates. While this diet often leads to rapid weight loss, medical experts are worried about its potential risks. Scientists found that mice on keto diets showed increased cellular aging in their organs.

Study Overview

Researchers from UTHealth San Antonio conducted a study to examine the effects of ketogenic diets on mice. They published their findings in Science Advances. With obesity rates rising in the United States, many people turn to diets like keto, traditionally used to treat epilepsy, to lose weight. The keto diet emphasizes high fat intake while reducing carbohydrates.

The Research Process

The scientists conducted experiments to see how ketogenic diets impact health. They were particularly interested in whether the diet causes cellular senescence, a process where cells stop dividing but don’t die. The study compared a group of mice on keto diets to a control group. The mice on keto diets experienced higher rates of aging in their organs.

Characteristics of the Keto Diet

People on the keto diet focus on specific macronutrients:

• 55 to 60% of calories from fats
• 30 to 35% of calories from protein
• 5 to 10% of calories from carbohydrates (20 to 50 grams of carbs)

In contrast, the Food and Drug Administration (FDA) recommends:

• Fewer than 10% of calories from saturated fats (found in beef, butter, pork)
• Higher intake of unsaturated fats (found in fish, avocado, walnuts)
• 275 grams of carbs per day, much higher than the keto diet allows

The Experiment

In the study, one group of mice ate a control diet with 17% fat, 25% protein, and 58% carbohydrates. Another group ate mostly Crisco, which contains 84% unsaturated fat and 14% saturated fat. This Crisco group got 90.5% of their calories from fat, 9.2% from protein, and 0.3% from carbohydrates. The mice started their diets between 35 and 42 days old and continued for either 7 or 21 days. After this period, researchers euthanized the mice to evaluate them.

Findings: Keto Accelerates Cellular Aging in Mice

The researchers monitored various health markers like ketones, glucose, insulin sensitivity, triglycerides, and cholesterol levels. They examined samples of the heart, liver, and kidneys for damage. They found that the ketogenic diet led to increased cellular aging in these organs. The mice in the Crisco group had a buildup of senescent cells, which are old cells that stop dividing but don’t die. This can lead to inflammation, organ damage, and tumors.

Comparing Different Keto Diets

Researchers also tested another group of mice with a different ketogenic diet using cocoa butter, which has more saturated fat than Crisco. The cocoa butter group also showed organ damage and cellular senescence. The researchers discovered that the cellular aging process was linked to proteins AMPK and p53. Blocking these protein pathways reduced cellular aging in the mice.

Reversibility of Cellular Senescence

The scientists wanted to know if cellular senescence was reversible. They tested more mice on a ketogenic diet and found that cellular aging markers decreased after quitting the diet. This suggests that while ketogenic diets may cause damage, it is possible to manage this either through medications or by following the diet intermittently.

Implications for Humans

Scott Keatley, a dietician not involved in the study, commented on the findings. He emphasized that the study provides important insights into how long-term ketogenic diets might lead to cellular aging and organ dysfunction. Keatley noted the need for careful consideration of diet duration and composition, especially for people with existing organ concerns or chronic diseases. He called for long-term human trials to confirm these effects.

Long-Term Studies Needed

Steve Gendron, a specialist in immunology and endocrinology, also stressed the need for long-term human studies. He likened short-term studies to short movies, suggesting that only long-term studies can give a complete picture of how keto diets impact health. Gendron also highlighted the need for studies among diverse populations and comparisons with other diets.

Conclusion

This study on mice indicates that ketogenic diets may accelerate cellular aging in the heart and kidneys. While keto diets can help with weight loss and managing epilepsy, their long-term effects are not fully understood and could pose significant health risks. Anyone considering a ketogenic diet should do so under medical supervision. More research is needed to understand the long-term impacts of ketogenic diets on human health.