(NaturalNews) In a culture that feasts 21 times a week, fasting is almost a heretical idea. Yet amidst escalating rates of heart disease, obesity, diabetes and cancer, emerging research on animals and humans suggests that planned, regular fasting may decide whether your twilight years are long and healthy or cut short. The crux of the issue is surprisingly simple: insulin-like growth factor, or IGF-1, levels of which largely determine the rate at which the body ages.
IGF-1 and age-related disease
Insulin-like growth factor is produced in the liver and released according to activity of Human Growth Hormone (HGH), produced in the pituitary gland. Levels of both naturally decline with age, which is desirable: high levels of IGF-1 encourage the body to focus on producing new cells rather than existing repairing ones. As cellular and DNA damage continues to go unchecked, aging and disease take hold. What's more, cancerous cells usually mutate to take advantage of both insulin and IGF-1, using them as fuel. The reverse is also true: in mice genetically engineered to have low levels of IGF-1, lifespan increases to the human equivalent of 120 years, and among the few hundred people worldwide with low IGF-1, cancer and diabetes are virtually unknown.
Fasting's impacts on IGF-1 and other disease markers
In the recent BBC documentary "Eat, Fast and Live Longer," Michael Mosley fasted for three days and four nights. The result? Halved levels of IGF-1, slashing his risk for age-related disease. His blood glucose levels also fell, indicating improved sensitivity to insulin and lessened risk of developing diabetes. As is typical, after returning to his normal diet Mosley's IGF-1 levels rose to what they were before. To maintain lower levels of the hormone, Mosley adopted the practice of intermittent fasting, taking up what is known as the 5:2 diet. Followers of the 5:2 diet eat whatever they want five days a week and about 500 calories twice a week. Amazingly, following this simple formula is known to lower blood pressure, HDL cholesterol and blood lipids and sustain weight loss no matter what kind of food is consumed. After five weeks on the diet, Mosley lost almost 15 pounds.
Additional promising research on mice suggests that intermittent fasting protects against mental illnesses including Alzheimer's, Parkinson's and dementia.
Two simpler dietary interventions also promise some dampening of IGF-1: lowering protein intake, which for most people is higher than is optimal, and refraining from milk. Hormone-rich milk contains an abundance of IGF-1 and is known to contribute to the risk of cancer, particularly fatal prostate cancer.