Intermittent Fasting For Dummies
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The myriad health benefits that come from simply refraining from eating for short periods of time are extensive. Read on to see exactly how and why the act of intermittent fasting has such an extraordinarily salutary effect on the body, a truly fascinating phenomenon.

The diseases/disorders affected

Fast forward to present day and scientists are truly excited about the data — intermittent fasting is proving to be effective at preventing and improving markers of disease, reducing oxidative stress (an imbalance between the production of damaging free radicals and the ability of the body to counteract or detoxify their harmful effects through neutralization by antioxidants) and enhancing learning and memory functioning.

A century of laboratory research links the practice of intermittent fasting with the prevention of age-related disease, including tumors, cardiovascular disease, diabetes, and dementia, to name a few. However, much of that research was conducted in animal models, so the evidence that intermittent fasting holds miracle health benefits for humans is still in its infancy. However, intermittent fasting was prominently featured in a recent review article in the New England Journal of Medicine, touting the extraordinary power of intermittent fasting to heal.

The following figure depicts many of the remarkable health benefits derived from following an intermittent fasting plan.

The health benefits of intermittent fasting. The health benefits of intermittent fasting

The following list touches on many of these benefits in greater detail:

  • Promotes weight and fat loss: Intermittent fasting can help you lose weight and belly fat, without having to consciously restrict calories. Intermittent fasting also amplifies enzymatic fat breakdown (lipolysis).
  • Reduces insulin resistance: Intermittent fasting can sensitize cells to insulin, reducing harmful insulin resistance and lowering blood sugar by 3 to 6 percent. Fasting insulin levels have been lowered by 20 to 31 percent with intermittent fasting, all of which protect against type 2 diabetes. Insulin secretion from the pancreas goes up due to an increase and regeneration of the beta cells of the pancreas (the cells that produce and secrete insulin).
  • Regulates blood sugar: When your blood sugar is constantly high, your insulin levels are constantly high. This leads to type 2 diabetes, which is a huge epidemic. Consistently high blood sugar levels (also known as hyperglycemia) cause damage to the insides of the arteries. Hyperglycemia harms the vessels that supply blood to vital organs, which can increase the risk of heart disease and stroke, kidney disease, vision problems, and nerve problems.
  • Reduces inflammation: Research shows that a program of intermittent fasting reduces blood markers of inflammation, a key driver of many chronic diseases. Oxidative stress is one of the factors that accelerates aging and predisposes you to developing disease. Several studies show that intermittent fasting boosts the body’s resistance to oxidative stress. Intermittent fasting strengthens immune function and enhances the body’s ability to repair cells and DNA.
  • Promotes cardiovascular health: Intermittent fasting improves multiple indicators of cardiovascular health in both overweight and normal weight individuals. Intermittent fasting reduces resting heart rate, blood pressure, bad LDL cholesterol, blood triglycerides, inflammation, blood sugar, and insulin resistance — all risk factors for heart disease — the leading cause of death in American men and women. In addition, intermittent fasting lowers inflammation and oxidative stress, both causative factors associated with heart disease.
  • Prevents and treats cancer: Some research suggests that intermittent fasting helps fight cancer by lowering insulin resistance and levels of inflammation. Intermittent fasting may also reverse the effects of chronic conditions such as obesity and type 2 diabetes, which are both risk factors for cancer. Researchers believe that intermittent fasting suppresses tumor growth and extends survival in patients with cancer. Intermittent fasting may make cancer cells more responsive to chemotherapy while protecting other cells. Intermittent fasting also boosts the immune system to help fight cancer that is already present.
  • Promotes brain health: Intermittent fasting increases production of brain-derived neurotrophic (BDNF), an anti-aging protein thought to protect against Alzheimer’s disease by helping the brain produce new healthy cells and strengthen existing ones, improving cognition. Intermittent fasting causes the cells in the body to initiate the cellular cleanup process called autophagy.
  • Promotes psychological benefits: Intermittent fasting improves eating behavior and mood. Intermittent fasting increases BDNF, the protein that aids in the growth of new nerve cells. A deficiency of BDNF has been implicated in depression and various other brain problems. BDNF is food for the brain cells, keeping them flourishing, strong and healthy.
  • Treats asthmatics and multiple sclerosis: With weight loss comes improvement in asthma symptoms and a reduction in airway resistance. Multiple sclerosis (MS) is an autoimmune disorder characterized by degeneration of the nervous system. Recent studies in people with MS adhering to intermittent fasting programs saw reduced symptoms in as short a period as two months.
  • Fights aging: Intermittent fasting can extend lifespan in rodents. Studies showed that fasted mice lived 36 to 83 percent longer! Although it’s a far cry from mice to men, intermittent fasting has become very popular among the anti-aging crowd. In fact, the health benefits of intermittent fasting on aging, oxidative stress, metabolism, and cardiovascular disease have been demonstrated in both human and animal studies alike.
  • Promotes a healthy gut: The gut microbiome refers to all the microbes in your intestines, which act as another organ, crucial for your health. More than 1,000 species of bacteria are in the human gut microbiome, and each of them plays a different role in your body. Most of them are extremely important for your health, whereas others may cause disease such inflammatory bowel disease, liver cirrhosis, and colorectal cancer. Scientific research has shown that intermittent fasting restores microbe health and diversity in the gut by increasing the good microbes, augmenting tolerance against bad gut microbes, and rebuilding the integrity of the intestinal wall.
  • Regulates sleep: Experts have recommended that adults get about seven to nine hours of sleep per night for good health. Intermittent fasting positively affects your circadian clock, which exerts a powerful influence over your sleep. Intermittent fasting strengthens the 24-hour circadian clock. A stronger, more synchronized circadian clock means an easier time falling asleep, staying asleep, and waking feeling refreshed on a regular basis. A good night’s sleep will help you function at your best, and to protect your health over time, and with age.

The mechanics behind the results

Each of the body’s systems is positively affected from undergoing repetitive fasted states. The heart, for example, becomes a more efficient machine. Intermittent fasting lowers resting heart rate and blood pressure and promotes a decrease in inflammation and an improvement in resistance to debilitating oxidative stress. The following figure displays just how intermittent fasting affects each body part.

Effects of intermittent fasting This figure shows the effects of intermittent fasting on the body that contribute to disease prevention and treatment.

Cells can become damaged when they encounter oxidative stress, so preventing or repairing cell damage from oxidative stress is helpful against aging. This stress happens when there is higher-than-normal production of free radicals (unstable molecules that carry highly reactive electrons). When free radicals encounter other molecules, a rapid chain reaction occurs forming more and more damaging free radicals. Oftentimes, this process occurs in faulty mitochondria (the energy production centers of the cells). Excessive free radical chain reactions cause stress and damage to cellular membranes, essential proteins, and DNA, accelerating aging and promoting disease.

The onslaught of free radicals is oxidative stress, the detrimental condition arising from the imbalance between harmful oxidants species and antioxidant defenses. Intermittent fasting boosts internal production of natural free radical–stabilizing antioxidants. The metabolic switch causes cells to turn on survival processes to remove the unhealthy mitochondria and replace them with healthy ones, thus reducing the production of free radicals in the long term. The fasting state also programs cells to cope better with more severe stresses that may come in the future.

The positive effects on the brain

Intermittent fasting heightens the senses, memory, and ability to learn, sharpening cognitive skills. Fasting gets rid of brain fog (a lack of mental clarity) by improving your ability to focus and improving memory. The increase in BDNF observed with intermittent fasting protects your brain from stress and slows brain aging.

Intermittent fasting triggers a dramatic switch in the body’s metabolism, flipping the metabolic switch — the state where the body switches fuel from blood sugar to ketones (fat). The use of ketones to feed the hungry brain might help explain several mysteries surrounding brain benefits. From an evolutionary perspective, the brain power that intermittent fasting generates makes sense. Humankind’s ancestors typically went days without food, often hunting on an empty stomach. This period of semi-starvation resulted in a brain adaptation, allowing the brain to live off its less preferred fuel, ketones. The use of ketones for brain fuel enhanced cognitive ability and energy so humans would be more likely to obtain food and live another day.

The benefits for longevity

In today’s world, the relationship with food is different than at any other time in human history. Humans evolved over many thousands of years with food as a scarce resource. Today, for many people, the problem isn’t food scarcity, but food overabundance — a situation that poses a serious threat to health. High calorie food is everywhere combined with extensive marketing geared toward getting people to eat more. The result? An epidemic of type 2 diabetes and heart disease — chronic illnesses that shorten a person’s life span — and are inextricably linked to a person’s eating habits and automated, sedentary lifestyle.

After nearly a century of research investigating the effect of calorie restriction on lifespan in animals, the jury is in. Intermittent fasting robustly increases life span. One of the earlier studies on rats placed on a program of alternate day fasting (ADF) showed the average life span of rats increased by up to 80 percent.

Whether intermittent fasting has a similar life-extending effect in humans has yet to be proven. However, many effects of intermittent fasting appear to contribute to a longer life, such as a reduction in unhealthful inflammation and a boost in the body’s ability to protect itself against oxidative stress, a major contributor to aging and disease.

Renew your body with autophagy

Perhaps you may have heard all the buzz about this term, autophagy, known by some as the cell regenerative diet. In fact, Yoshinori Ohsumi, a Japanese cell biologist, was awarded the Nobel Prize in Physiology or Medicine in 2016 for his discoveries of mechanisms for autophagy. Autophagy is Greek for self-eating, which is accurate: Your system ingests the old or damaged proteins and mitochondria and replaces them with brand new ones. So, autophagy is like spring cleaning in your cells.

Intermittent fasting causes extreme autophagy in your body’s cells. Autophagy makes your cells younger and more powerful and bolsters antioxidant defenses and DNA repair, which slows aging. The autophagy process not only refers to your body’s ability to recycle damaged cells, but also, in some cases, kills cells that no longer serve a purpose. The igniting of autophagy has been linked with promotion of a longer life span. These pathways are untapped in sedentary, overweight people — believed to be one of the many reasons why obesity shortens life span.

With intermittent fasting — during the fasting period — the cells enter autophagy, the stress-resistance mode. Cells are regenerated, damaged molecules are recycled, and all the maintenance and repair work is performed promoting cell survival — all of which support improvements in increased longevity.

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