For most of us, that seems like a strange and perhaps unproductive question. Of course not, should be the obvious answer. Time goes on, we age along with every other living thing (and even non-living things if you consider phenomenon like erosion a sign of aging). But one group, the National Institute on Aging (NIA), part of the federal government’s National Institute of Health, felt that asking the question, “Can we prevent aging?” was indeed worthwhile and, in 2012, they released a report on just that topic.
People are living longer than ever, the report pointed out. The average life expectancy for women in 1900, according to numbers gathered by UC Berkeley, was 48 years, 46 for men. By 1950, life expectancy had jumped to 71 for women, 65 for men, and life expectancy is projected to continue rising. The U.S. Census Bureau expects that by 2020 the average American will be living to the age of 79.5.
Now, I don’t want to get into an argument in semantics—whether longer life spans are synonymous with slower aging, but the National Institute on Aging is not just concerned with helping people reach another birthday: The group is actually trying to support longevity and healthy aging, or what they call “active life expectancy,” and their 2012 study promotes one surprising lifestyle habit for longer living: fasting.
“Scientists are discovering that what you eat, how frequently, and how much may have an effect on quality and years of life,” the report pointed out. “Of particular interest has been calorie restriction, a diet that is lower by a specific percent of calories than the normal diet but includes all needed nutrients. Research in some animals has shown calorie restriction [and intermittent fasting or reduced meal frequency has] impressive positive effect on disease, markers of aging, and, perhaps, life span…and may also help with heart function and regulation of sugar content in the blood.”
Long before fasting was considered a health practice it was used by people of various faiths as a means of prayer and purification, as a sign of discipline and spiritual strength. Many Mormon households forgo two consecutive meals on the first Sunday of every month (and donate to charity the money that would have bought that food) in a practice that they believe brings them closer to God. During the month of Ramadan, Muslims fast each day until sunset; for Jewish peoples Yom Kippur, the Day of Atonement, is a time to abstain from eating. Until 1964, Catholics fasted before receiving Holy Communion. Buddhist, Hindu, Christian—almost every faith and culture —has a tradition of fasting, but it wasn’t until the 19th century that science finally made its way into how humans approached the act of fasting.
The coupling of science and fasting began with an attempted suicide-turned health-experiment conducted by Henry S. Tanner, a doctor from Minneapolis. In Starving Your Way to Vigor (Harper’s Monthly, 2013) journalist Steve Hendricks recounts the unusual story of Tanner who, in 1877, after being left by his wife, resolved to kill himself in a manner neither painful nor messy by starving himself to death. The common wisdom at the time indicated that a man would not live more than 10 days without food —only Christ, whom the Bible says fasted for 40 days, yet was more than a mere man, could live so long without food. But as the days and eventually weeks passed, Tanner found that, not only was he still alive, he felt strong and vigorous. He no longer felt hungry, chronic ailments he had once suffered from disappeared, and on his fourth foodless week Tanner celebrated with a 10-mile walk about the city. On the 41st day, Tanner finally broke his fast.
Tanner’s feat was not greeted with much enthusiasm or interest by either the general public or the scientific community of his day, but half a century later nutritionist Clive McCay of Cornell University began studying the effect of calorie restriction on rats and found the animals that lived on a low-calorie diet were less likely to develop cancer and other age-related illnesses and diseases. Intermittent fasting showed similar effects in subsequent studies by other groups. Since then, studies have indicated that fasting has positive effects on cardiovascular health and mental health (reducing depression), and lowers the risk of Alzheimer’s, Parkinson’s and other neurological diseases that usually appear later in life.
When I tried my first fast I was 22 years old and living on a farm in Sicily doing low-intensity manual labor, picking oranges and mandarins, along with half a dozen other youth from across Europe and the United States, all of us eager for new experiences and connections. My first fast began as a curiosity. Another young man was fasting and I decided to do the same.
It was much like the time I had, one summer as a teenager, forced myself to stay awake as long as I could – three days it turned out – to see if I could actually hallucinate from sleep deprivation. (I didn’t.)
The fast wasn’t about health, or longevity, or faith, it was simply to experience how hunger felt, how it affected my mind and body. To tell the truth, it wasn’t that much fun, and the hunger pangs never fully subsided, coming in waves throughout the day, but I found that I could carry on easily with the work around the farm and after five days I was satisfied with the experiment and began reincorporating simple, whole foods back into my diet.
Now, fasting sounds like a good idea until about 10 a.m. when I start looking around the teacher’s lounge for anything to snack on—as my co-worker says, it’s no good trying to teach kids when you’re hangry (hungry/angry). Weekends, my time, are on principle off limits to acts of self-denial, especially of food. So I haven’t fasted in years. But occasionally it still sounds like a good idea.
Most Americans, myself included, aren’t any good at self-denial and look where it’s gotten us. We live in houses that are too big for our needs; our addiction to cars makes us the second largest contributor to greenhouse gas emissions in the world; we have the world’s third highest rate of diabetes. It might be good to take a break, to step back. It might be good to fast, and not just to slow our patterns of consumption, or out of some youthful curiosity; maybe we really are designed to fast.
Some scientists have theorized that our bodies, our very genome, are still wired to react beneficially to the feast and famine environment experienced by our Late-Paleolithic ancestors. In a 2005 paper on the effects on intermittent fasting, published in the Journal of Applied Physiology, Danish researchers concluded that “cycling between feast and famine, and thus oscillations in energy stores, as well as between exercise and rest, might have driven the selection of genes involved in the regulation of metabolism. Thus our genotype selected centuries ago to favor an environment with oscillations in energy stores still exists with few if any changes. The modern sedentary lifestyle common in the westernized countries is characterized by constant high food availability and low physical activity, and it has led to an imbalance between our genotype and the environment in which we live today. This may predispose our potential ‘thrifty’ genes to mis-express metabolic proteins, manifesting in chronic diseases (e.g., Type 2 diabetes) in the industrialized part of the world.”
The tests conducted by the Danish group also showed that fasting was not exclusively useful to the middle-aged, elderly or even the out-of-shape or overweight. Conducted on eight healthy Caucasian men in their mid-20s, the Danish study examined the subjects before and after the test period during which they fasted every second day for 20 hours (with a total of seven fasting periods). After the test, the men showed changes to their metabolic status with an increased sensitivity to insulin almost sevenfold, a highly desirable outcome for overall health.
The link between insulin and fasting is critical to understanding why fasting, in moderation, throughout our life, might help us live longer, more vigorous lives and, in the end, age more gracefully. Insulin is the body’s blood sugar-regulating hormone. It allows the body to use sugar from carbohydrates while maintaining steady blood sugar levels—avoiding spikes or drops in energy and cell function. A well-functioning body responds quickly to insulin and does not have to produce much of the hormone and in studies of both animals and humans those with naturally low levels of insulin tend to live longer. When bodies are resistant or less responsive to insulin, sugar (glucose) builds up in the blood instead of being absorbed by the cells. Such build-up is often accompanied with obesity and can lead to complications such as type 2 diabetes and heart failure. So it’s no great surprise then that a simple act such as fasting, shown to increase insulin sensitivity by sevenfold, is recommended by the National Institute on Aging.
I don’t know if I need to live until I’m 80 to have a full and satisfying life. And I’m not particularly worried, at this point, in age prevention as discussed by the National Institute on Aging, but I do want to live mindfully and to treat my body well. Every day we are aging, whether we’re 22 or 60. Aging gracefully can start now, at any age. So maybe I’ll start tomorrow with a tall glass of water for breakfast.
Katherine Pioli is CATALYST’s associate editor and teaches at the Salt Lake Arts Academy.