General Health

Effect of ketogenic diets on insulin-like growth factor (IGF)-1 in humans: A systematic review and meta-analysis

During aging, the body’s nutrient-sensing systems, especially the growth hormone and IGF-1 pathways, can become disrupted. While these pathways promote cell growth, elevated levels are also linked to increased risks of cancer and other diseases. Evidence shows that diets like severe calorie restriction or fasting can reduce IGF-1, but these approaches are unsustainable and pose risks, especially in older adults or cancer patients.

Recent findings suggest that ketogenic diets, which induce ketosis by limiting carbohydrates and increasing fats, can lower IGF-1 levels safely without calorie restriction, showing potential in aging and cancer management.

A systematic review and meta-analysis assessed the impact of ad-libitum ketogenic diets on serum levels of insulin-like growth factor-1, glucose, and insulin across various adult populations, including those with cancer and other health conditions, examining studies that measured compliance through blood or urine ketone levels.

Results:

→ IGF-1: A 20% reduction in IGF-1 levels was observed in participants following ketogenic diets, with consistent results across both cancer and non-cancer groups.

→ Glucose: Fasting glucose decreased by an average of 6% in nine studies, although there was considerable variation among the results.

→ Insulin: Fasting insulin levels were reduced by an average of 29%, with significant decreases reported in most studies.

This study highlights the potential of the ketogenic diet as a viable alternative to calorie restriction for reducing IGF-1, glucose, and insulin levels, potentially benefiting metabolic health, cancer treatment, and healthy aging. Further research is recommended to explore long-term effects and optimize dietary protocols for broader applications.