Digesting New Discoveries Inside the Human Body

There was a moment during the Lewis and Clark expedition of 1804 when, after months of deprivation, hardship, and arduous climbing, the party finally scaled the eastern face of the Continental Divide. Standing exhausted on that peak, they hoped to gaze down on gentle meadows and the gateway to the sea, but instead they saw…more mountains. It was mountains as far as the eye could see.

In some ways, modern biology has followed the same trajectory: in the 70’s we believed we were within striking distance of the cure for cancer, steps away from enlightenment about our own internal processes. Now we know it’s a much bigger expedition than we ever anticipated.

When it comes to understanding the body, the complexity we face is mind-boggling, a thick and tangled web of feedback loops and inner dependencies. Take, for example, the human gut.

For years, it’s been relegated to the back bench of physiological study. Recently, we’ve begun to see that the digestive tract is, in fact, a star in its own right. Those less glamorous organs are rising to costar status with the brain. The two are sometimes described as a team: the brain/gut axis. According to Giulia Enders in her new book, Gut: The Inside Story of Our Body’s Most Underrated Organ, there is incredible crosstalk between the two.

The human brain contains about 86 billion neurons. The gut, meanwhile, contains only 100 million neurons—on par with the brain of a cat. So, in the neuron department, the brain generally calls the shots. But the gut calls more than a few plays of its own.

Your gut houses a teeming microbiome of bacteria that affects your daily life in myriad ways. What goes on in your gut shapes your immune system, nutrition absorption, vitamin production, muscle function, hormone levels, libido, whether you’re hungry or full, and how you break down your food intake into proteins, carbohydrates, and fats. Your gut’s microbiome weighs in at about 4.5 pounds and Enders says some scientists are beginning to refer to it as a separate body organ.

Gut-related chronic health problems include allergies, cancer, Type II diabetes, mood swings, and anxiety. The bottom line: your gut is far more auxiliary brain than mere food dumpster.

Your vagus nerve, the longest of the twelve cranial nerves, is the superhighway connecting the brain to the gut. The gut also produces 95% of the neurotransmitter serotonin. Sometimes called the “feel-good” hormone, serotonin is strongly linked to your levels of happiness and depression. Your gut also makes GABA, an amino acid that calms the nervous system and smooths out brain waves, and a neurotransmitter called glutamate, involved in cognition, learning, and memory.

Your food choices have a direct effect on your gut’s microbiome. For that reason, Enders says it’s probably a good idea to eat a diet rich in probiotics (although more research is needed to confirm healthful benefits.) These are bacteria and yeast that support digestive health, found in fermented foods like kim chi, sauerkraut, kefir, pickles, and plain unsweetened yogurt.

According to Enders, these foods may help maintain the integrity of the gut lining, and that they serve as natural antibiotics, antivirals, and antifungals. They also play a role in regulating your body’s immune system. This in turn helps control inflammation and improve nutrient absorption.

There are many more summits to climb before we have a clear map of what goes on inside the belly’s hidden kingdom, but like Lewis and Clark, the discoveries we make continue to amaze. And yet for all our newfound knowledge, we’ve only begun to gain a tenuous foothold—and there are still mountains as far as the eye can see.

The Siren Call of Convenience

We Americans are proudly and hugely into our conveniences. We buy pre-washed lettuce and pre-cut chicken pieces because it’s more convenient than washing our own vegetables or slicing up our own birds. We use our remotes because it’s more convenient than getting up to change the channel. We navigate the drive-thru at Starbucks because it’s more convenient than actually walking into a coffee shop. And we email the person in the cubicle next to us because who has the time for a conversation these days?

Entire technologies are built around the idea of convenience. Since our GIs returned from the rather massive inconvenience of fighting World War Two, we’ve been obsessed in sparing ourselves extra toil wherever possible. Remember TV dinners? In minutes, you could enjoy nicely diced chicken parts with presorted peas and carrots and a little peach cobbler on the side. Usually at least one of those things was still crunchy with ice on the inside, but who could complain? It seemed a small price to pay.

So why do we demand this unending cascade of convenience? The cynics might argue we’re inherently lazy, propping ourselves up in our Barcaloungers like a generation of Jabba the Huts, waiting for life to be spoon fed to us (preferably pre-chewed). The more thoughtful might frame it differently. Convenience begets time saving.

Time, as famed psychologist Daniel Kahneman points out, is one of our most precious commodities. We can’t renew it or restore it; we can only watch as it continually leaks away with the slow and steady drip of a desert canteen.

But do the cynics have a point? Even though I’ve stolen a few seconds by not traversing the living room floor to change the channel, or not getting out of the car to buy my coffee, what I am doing with my newfound bounty?

I—drum roll—am surfing the web. I’ve managed to scrimp and save my minutes only to blow my hard-won currency on a little Facebook, a little YouTube, chasing some bit of trivia or checking the latest poll data on “The Donald” and pondering the big questions. If, as The Donald has posited, ‘Heidi Klum is no longer a ten,’ then what number is she? (And what number does he think he is?)

Without vigilance and careful stewardship of my time (no small task given the strum and drang of daily life), I wouldn’t be able to keep track of the important things. Where would we be without convenience?

Suicide: A Stark Truth

Suicide: the word itself is sobering.

In the U.S., there are 38,000 suicides a year. This makes it one of the top ten causes of death in the country; twice as common as homicide, which in recent years has declined.

Roughly 38,000 people also die annually on U.S. highways, but that number is on its way down as well; we’ve experienced a 50% drop in highway fatalities since the seventies.

Unfortunately, the suicide rate has not followed suit. In fact, overall it is ticking upwards.

So why do people kill themselves?

Experts on suicide are among the first to admit that their own understanding is limited. It’s not something people feel particularly comfortable talking about, which makes research tough.

Big Pharma has offered no solution; there are no anti-suicide drugs for sale. In fact, it’s almost the opposite: a number of drugs list suicide as a possible side effect.

From looking at the statistics, we do know some factors increase chances of suicidal behavior. These include mental illness (especially mood disorders such as clinical depression or bipolar disorder), substance abuse, poverty, discrimination (for instance, rates are much higher in transgender people), a history of trauma (including veterans and survivors of childhood sexual abuse), unemployment, homelessness, cancer, chronic pain, or a traumatic brain injury.

Of course, many encounter these conditions without attempting suicide. Some research suggests that what sends people over the tipping point might be genetic. Autopsies show that people who commit suicide have reduced levels of BDNF in their brains. BDNF is a protein involved in forming new neural connections, nerve regeneration, building neurotransmitters, and maintaining brain plasticity. The less of it a brain has, the harder it is to adapt to one’s surroundings. Stress can lower BDNF levels (and exercise can raise them) but there is a hereditary aspect as well.

In general, women are more likely to attempt suicide, but men are more likely to succeed, in part because they tend to choose more violent methods. In the Western world, roughly 75% of all suicide fatalities are men. However, this isn’t true across the board: in China, more women commit suicide than men. This seems to imply that the gender difference is a result of culture, and not some inborn Y chromosome issue.

One interesting find: it seems that people who attribute their troubles to some external source—the government, for instance—are less inclined to kill themselves. The risk of suicide goes way up when an individual begins to blame themselves for their circumstances.

Emotional despair in some cases might be seen as part of an elaborate self-preservation system, where the brain tries to send an alarm to move back to a more neutral feeling. In this way, depression could be a survival strategy gone awry.

In Parerga and Paralipomena, Arthur Schopenhauer writes, “Suicide may also be regarded as an experiment—a question which man puts to Nature, trying to force her to answer. The question is this: What change will death produce in a man’s existence and in his insight into the nature of things? It is a clumsy experiment to make, for it involves the destruction of the very consciousness which puts the question and awaits the answer.”

Schopenhauer sees suicide as a gamble, albeit poorly made. But his suggestion, that there is at least some reasoned thought behind the act belies the possibility that it represents a complete fraying of the brain’s rational safety net.

Mental illness remains very much a taboo subject. When it comes to ailments of the body, we know better than to blame the patient, but we don’t always grant the same leniency to a malfunctioning brain. And yet neuroscience makes it clear that the brain vs. body distinction has been overturned.

Since physical pain and emotional pain share the same circuitry in our heads, there’s a danger of a vicious cycle, one which overwhelms any logical response. It’s similar to how the immune system can fall apart in the face of some cancers. In that regard, perhaps saying a person chose take their own life makes no more sense than saying they chose to succumb to leukemia.

For all of the progress that has been made to keep humans alive—diseases cured, water purified, seatbelts installed—suicide remains a runaway train, carrying the likes of David Foster Wallace, Robin Williams, Sylvia Plath, and countless others.