Summary: Fasting has been a tradition in many cultures and many religions for thousands of years. But, like many ancient traditions, there are biological reasons to do it. Fasting alters our chemistry in ways that can be managed to induce desired changes. Calorie restrictions have been shown to add to lifespans of mice in research labs. There are good reasons to consider adding it to our lifestyle practices. But there are risks if not done correctly, so it's important to learn to do it right. I intend to test Longo’s diet over the next six months.
Famines have caused misery and death throughout history. But no longer. A hint of mismanagement by incompetent third world dictators and the world assembles airlifts to force the victims to accept donated food. Incompetent individuals who lack money for food have many charity kitchens to choose from, or panhandling generous drivers in SUVs. Hunger is optional. But it's worthwhile to consider fasting as a therapeutic activity.
There are two kinds of people who should consider the benefits of fasting -- those who want to live longer, and those who want to avoid dementia. Which should be a lot of people. For the rest of you, there are more general benefits, such as weight management without muscle loss, tumors, skin inflammatory disorders, rejuvenated immune system, and improved cognitive performance. And you save a little grocery money.
The dementia benefit was what introduced me to fasting. I have a genetic predisposition for Alzheimer's (APOE4), along with about 25% of the population, meaning I'm likely to get it earlier than others, expected in my 70s without intervention. Everyone has similar brain degradation processes, but most are slower than those with the gene.
But genes aren't destiny. We can manage our genes. We just have to be smarter than our genes. We're in charge.
My blood tests indicated elevated homocysteine, which my cardiologist interpreted as a risk for heart and brain, and prescribed vitamin B12 supplements and daily fasting. Homocysteine is a marker of inflammation and loss of synapse supporting factors, and is linked to onset of Alzheimer's.
I have followed a practice of time restricted eating for three years, with no food for around 15 hours between supper and breakfast. It has worked to reduce my homocysteine and insulin resistance. It hasn’t seemed uncomfortable. I have also eliminated most sugars from my diet, being vegan for two years with very low fat and high complex carbs. For the last year I’ve been a carnivore, with high fat and protein and very low carbs. I miss cakes and candies more than I miss my midnight snacks. Daily fasting is easy. And it seems to be working.
Dale Bredesen in "The End of Alzheimer's" describes it in more detail. The short version is the body engages in either operations or repair. Lots of food in the system tells the body to work on building and performing. Between meals, or in famines, and especially during sleep, the body changes to repair mode. Extending that repair period improves the maintenance.
Bredesen recommends a "12/3" cycle, with 12 hours between feeding cycles and 3 hours fasting before sleeping. That maximizes the repairs which, in the brain, includes clearing out the amyloid tissues that slowly clog our neurons with disruptive plaques. For those with the gene (APOE4) this is even more important so he recommends 12 to 16 hours. The process of clearing out undesired cells is called autophagy, which operates throughout the body, not just the brain. It also fights infections and cancer — and aging.
Fasting also benefits insulin resistance, which causes unhealthy levels of insulin in the system, driven by chronic glucose overloads. Insulin is essential for some processes, but is a powerful enzyme which can cause detrimental reactions when we have too much. One such reaction is the insulin degrading enzyme (IDE) which clears out unused insulin but also clears amyloid. Insulin comes first, so insulin resistance accelerates Alzheimer’s. So the fasting effect on insulin reduction is important, especially for those with the Alzheimer’s gene.
For the longevity goal, I would refer you to Valter Longo, one of the most experienced researchers in aging science, and author of "The Longevity Diet." Longo has studied aging for decades, using a variety of test subjects from yeast to people. Lots of mouse testing, which he somewhat apologetically defends. The important discovery is that all living organisms share some genes that control our health and lifespan, so tests on lower life forms are often instructive. And they’re necessary precursors for human interventions.
After suggesting a general diet based on what theoretically could work, he wisely states "One of the major mistakes of guidelines on nutrition is blurring the line between what theoretically could work and what actually does work." Then he moves into the evidence his research has shown regarding his fasting diet.
Longo’s focus is the biology. He determined the dietary detriments to our health are predominantly sugar and protein. Both are useful in moderate amounts, but high levels create chemical imbalances which can cause imbalances.
High protein intake causes activation of growth hormone receptors, which in turn increases the levels of insulin and insulin-like growth factor 1 (IGF-1) whose altered concentrations are associated with diabetes and cancer, respectively. Proteins can activate TOR-S6K, a set of genes that accelerate aging. Sugar activates the PKA gene which plays a key role in aging. Mice with reduced PKA live longer and are protected against age related diseases.
Longo concludes that the necessary maintenance of a healthy body includes a fast of several days every few months. The benefits last about 3 months, so monthly is fine, less frequent is okay, more frequent is not recommended. Extended fasting risks numerous deficiencies that can be detrimental to health, so medical supervision is important for true fasting.
The protected state of fasting requires four changes in the blood. (1) lower levels of growth factor IGF-1; (2) lower levels of glucose; (3) higher levels of ketone bodies, the byproduct of fat breakdown; and (4) higher levels of growth factor inhibitor (IGFBP1). He achieves this with a diet low in proteins and sugars and high in healthy fats. Mouse tests showed lifespan extension 11 to 18 percent, weight loss without muscle loss, lower loss of bone mineral density, half the rate of tumors, half the skin inflammatory disorders, rejuvenated immune system, regeneration of the liver, muscle and brain, increased stem cells, and improved motor coordination, learning and remembering. Lucky mice. Again, mouse genetics are similar to humans in many ways. Mouse results are not conclusive, but definitely interesting.
But mice aren’t absolutely predictive of human results. Mice with calorie reductions of 40% fewer calories live longer and develop half the tumors and disease of normally fed mice. But reductions as much as 20% in humans can reduce wound healing, immune response, and cold temperature tolerance. We’re not mice, just distant cousins.
But Longo has isolated the mechanisms of fasting responses and determined it is mainly the reduction of sugar and protein that produces the fasting benefits. He found a diet that provides the benefits seen in calorie restrictions in mice without the risks in humans. He calls it the fasting mimicking diet, designed to provide sufficient nutrients while subsisting on a reduced calorie diet for five days. It is safe for use without medical supervision.
Day 1 - 1100 Calories:
500 calories from complex carbohydrates (vegetables such as boccoli, tomatoes, carrots, pumpkin, mushrooms, etc)
500 calories from healthy fats (nuts, olive oil)
Multivitamin and mineral supplement
Omega 3/Omega 6 supplement
Sugarless tea (up to 3-4 cups a day)
25 grams of plant based protein, mainly from nuts
Unlimited water
Day 2-5 - 800 calories
400 calories from complex carbohydrates
400 calories from healthy fats
Multivitamin and mineral supplement
Omega 3/Omega 6 supplement
Sugarless tea (up to 3-4 cups a day)
Unlimited water
Day 6 - Transition Diet
For 24 hours following the end of the five day fastoing mimicking diet, patients should follow a diet based on complex carbohydrates (vegetables, cereals, pasta, rice, bread, fruit, etc) and minimize the consumption of fish, meat, saturated fats, pastries, cheses, milk, etc.
He tested this diet in a small (100 subjects) human trial at USC with monthly 5-day fasts for three months. Results showed weight loss in obese subjects, increased muscle mass, reduced blood glucose, reduced cholesterol and triglycerides, decrease in blood pressure in subjects with moderately high blood pressure, decrease in IGF-1, and decreased C reactive protein. These benefits were maintained for three months.
I haven't tried it yet, but I intend to soon. I'll report my observations here. For three years, I have followed a diet with fewer calories than I had been accustomed to. I adapted comfortably. I have used the daily 16 hour fast the last three years, and for several months I skipped eating for a day, once a week, producing a 40-hour fast. That also was easily accommodated, though it didn't produce identifiable results. But I'm enticed by Longo's analysis for the longer "mimicking" fast and want to try it, after my next consultation with my doctors.
Longo is Italian, raised with a sort of Mediterranean diet, which he favors, and recites several popular press accounts of increased longevity of people in several regions. These are more comprehensively refuted by Paul Saladino in his book "Carnivore Code," which I follow. But Longo's research of fasting seems better supported and I intend to test that on myself. My main unresolved question is whether the basic Longo objective is shifting metabolism from sugar burning mode to fat burning mode, doesn't the Saladino carnivore diet already accomplish this? I want to find out if the periodic fasting makes a difference. My next blood tests are planned for March, so I'll report my results then.
Fasting is an artifact of every culture and religion, and is likely a persistent factor in the existence of our ancestors due to their unreliable food supply. It's reasonable to assume it's a standard adaptation in our genes. Worst case I'll save a few bucks on groceries while improving my self discipline. I don't expect it to be fatal, but just in case, I have left instructions for my gravestone to read "That Didn't work."
Slowing the onset of dementia is certainly an incentive! I do a similar fast (no eating between breakfast and dinner) but not nearly so often as you. It's more for religious reasons for me (Mark 9:29) but has the added bonus of keeping off the eight or nine pounds I tend to gain if I'm eating whatever I want.