Sleep update: some new information

I have written several posts about sleep (see the Topics menu for a list), the gist of which is not to worry if you don’t get eight hours of uninterrupted sleep. New research, published in Current Biology, underscores that message and adds new information.

Researchers studied the sleep habits of three hunter-gatherer societies, two in Africa (The Hadza and San tribes) and one in Bolivia (the Tismane people). These tribes live much as their ancestors have for tens of thousands of years. By studying these people, the researchers could determine how early humans were “programmed” to sleep, and, by extension, what normal sleep might be for us. (Of course, manufacturers of Ambien and Lunesta would have you believe that less than eight hours of sleep will have dire consequences.) Like early humans, the hunter-gatherer people sleep outside or in crude huts and their only light at night comes from fire.

What the researchers found is that, on a typical night, these people sleep slightly less than the average American. In the US, most adults sleep seven hours or more a night--although many sleep significantly less. Members of these hunter-gatherer tribes slept just six and a half hours. About like me. Researchers also found that the presence or absence of daylight is not the primary factor in their sleep patterns.

The conventional thinking has been that the artificial light throws off our biological clocks and that if we could live like early humans, going to bed when the sun goes down and getting up when the sun comes up, we’d be much better off. It turns out that the people in all three of these tribes do not follow that sundown/sunup scenario. Instead, they stay awake several hours after the sun goes down and do not wake at sunrise. What does determine their sleep habits is temperature. They almost always fall asleep as the temperature begins to fall at night and wake up as the temperature rises in the morning. This habit suggests that humans may have evolved to sleep during the coldest hours of the day, perhaps as a way to conserve energy.

From what I can observe, most of us modern humans like sleeping in a cool bedroom. In the 20 years we have lived in our house, we have never turned the heat on in our bedroom (it has its own heat zone). We also open windows at night. Most people I know do the same thing. We seem to have figured it out ourselves.

Next week: A dose of radiation for health?

For an introduction to this blog, see I Just Say No; for a list of blog topics, click the Topics tab.

Messing with your microbiome

As I discussed last week, your microbiome consist of the trillions of microorganisms that live in and on your body (three pounds of them). These resident microbes exert a powerful influence on our health, including training and modulating our immune systems. Because of our war on bacteria, we have impoverished our microbiomes in a way that has led to the rise of chronic diseases that were virtually unheard of 75 years ago.

Researchers are now trying to figure out ways to refurbish our microbiomes. So far, there’s not been much progress on that front. Fecal transplants (transplanting fecal matter from a healthy donor to a sick patient) have been successful in treating people who have been infected with the Clostridium difficile bacteria, a life-threatening condition. Unfortunately, C. difficile is the only disease for which fecal transplants are approved by the FDA. Plenty of people with intestinal problems (count me in) would like to try this therapy. Many have tried to do it at home (count me out). You can find instructions for this on the internet.

“Probiotics”—substances containing “good” bacteria—don’t actually help much. In fact, most scientific studies have not found any health benefits from consuming probiotics—either in supplements or in foods such as yogurt and sauerkraut. Considering that 99 percent of our gut bacteria are anaerobic (they function in an oxygen-free environment) and that probiotics are exposed to oxygen, it’s not surprising that the probiotics we eat don’t easily colonize our guts. However, there is some indication that consuming probiotics may help with some kinds of diarrhea. This may be because the one percent of gut bacteria that are aerobic live in the cecum, a cul-de-sac at the beginning of our large intestines where bacteria work on the partially digested food that become feces.  For myself, I can say that probiotics haven’t done anything for me, and I’ve tried lots of them.

A company called AOBiome sells a spray containing live cultures of Nitrosomonas eutropha, an ammonia-oxidizing bacteria commonly found in dirt. Before we started washing it away, it occupied our skin, feeding on the ammonia in our sweat and, in the process serving as a built-in cleanser, deodorant, anti-inflammatory, and immune booster. Studies have shown that restoring N. eutropha populations has helped people clear up acne, rosacea, and eczema.

Here’s my favorite do-it-yourself story: a man suffered from ear infections in one ear and had been treated with antibiotics in that ear. One day, he inserted ear wax from his good ear into his bad ear. He was cured (this is true).

In the future, scientists may discover therapies that will reinvigorate our feeble microbiomes. Until then, you might try playing in the dirt.

Next week: Sleep update: some new information

For an introduction to this blog, see I Just Say No; for a list of blog topics, click the Topics tab.

Your microbiome: it's who you are

You may already know that about 90 percent of the cells on your body are not your own. They belong to the more than 100 trillion microorganisms—such as bacteria and fungi—that live in your gut, mouth, skin and everywhere else. Your gut alone contains about 40,000 species of bacteria. For every one of your own genes you have 100 genes from the microorganisms. It’s kind of a creepy idea, but in fact these microbes help you digest food, synthesize essential nutrients and vitamins, and prevent disease-causing pathogens from invading your body. Together, these organisms are called your microbiome and it is unique to you.

Your microbiome plays a critical role as a filter between the environment and our body’s own cells. Substances must first pass through layers of microbiota on the skin, gut, and airways at which point they may be sequestered, excluded, or metabolized before they enter our cells. At the same time, the microbiota are training our immune systems.

We pick up the critters that make up our microbiomes beginning at birth with our trip through the birth canal. From that point on, we are “seeded” with microorganisms through our continuing contact with our home environment. Apparently, our microbiomes becomes stabilized at about age three.

Recent advances in DNA sequencing has brought much of this information to light. Scientists are now looking at the ways in which our microbiota affect our health. Some have suggested that changes to our microbiomes over the last 75 years account for the rise in diseases such as diabetes, heart disease, asthma, autism, inflammatory bowel disease, obesity, and many more. Many—if not most—of these diseases were virtually unknown 75 years ago.

For example, a bacterium called Heliobacter pylori once occupied the stomach of nearly every person in the world, having been intertwined with our species for at least two hundred thousand years. Now it is found in just five percent of children born in the US. H. Pylori plays a role in regulating stomach acid and in quieting the inflammatory response. While it can cause ulcers, the near-eradication of this bacterium has now been shown to have a serious downside. Many Americans now suffer from acid reflux, and the rate of a certain type of esophageal cancer has soared. What’s more, researchers have found the lack of H. pylori to be implicated in the rise of asthma and allergies.

The heavy use of antibiotics may be the main culprit. Also, scientists believe that moving from dirty rural environments to clean urban environments also account for the change in our microbiomes. Because we are less exposed to microbes than in the past, our immune systems are not being challenged in the ways they once were.

There’s not a lot you can do to change your microbiome, although some efforts are being made in that regard. I’ll discuss this next week.

Next week: Messing with your microbiome.

For an introduction to this blog, see I Just Say No; for a list of blog topics, click the Topics tab.

Stress and illness

Recently several people close to me have become ill as a result of stress. Depending on the person, the illness has taken the form of skin rashes, sore joints, swollen eyelids, and the flu. Each of these people have been in long-term stressful situations. Even though the relationship between stress and illness is common knowledge, it seem that people who get sick don't usually make the connection. I think many--if not most--illnesses are stress-related.

When stressed your body releases cortisol and other hormones that cause a complicated cascade of bio-chemical events that suppress your immune system. In the words of one scientist, “the immune cells are being bathed in molecules which are essentially telling them to stop fighting.” Normally cortisol regulates inflammation—lowering or raising inflammatory responses depending on the circumstances. But if you are undergoing a prolonged stressful event, your immune cells lose their ability to respond to the signals that regulate inflammation. Consequently, they produce levels of inflammation that promotes disease.

As you’ve probably heard, cortisol is the “fight or flight” hormone. It surges when you’re in potentially harmful situations and promotes short-term inflammation to fight infection. After the onslaught, all returns to normal. Your body can deal with the kinds of short-term stressful situations that come and go. After all, you don’t fall ill after being stuck in traffic or rushing to meet a deadline. It’s the long-term or chronic stress that gets you.

Recent research has shown that genes are also involved in suppressing your immune system. In this case, scientists study people with long-term psycho-social stress, such as loneliness or facing the death of a loved one. Chronic stress affects whole networks of immune-related genes, such that genes that promote inflammation are over-expressed and those that are anti-inflammatory and anti-viral are suppressed. As reported in The Scientist Magazine, “Social stress seems to reach deep into cellular control centers to shape key aspects of the immune system—and, as a result, can impair one’s ability to avoid or fight off disease and psychiatric disorders.”

Next week: Your microbiome: it's who you are

For an introduction to this blog, see I Just Say No; for a list of blog topics, click the Topics tab.

Public toilet seats: have no fear

This is a rather indelicate subject. It’s about one of my pet peeves: coming into a bathroom stall and seeing that the toilet seat is spattered with pee. You see, I choose to sit on an uncovered seat. But before doing so, I must take some toilet paper and wipe the seat until it’s dry. Studies vary, but one study found that 85 percent of women said they crouched over public toilets, and 12 percent papered the seat. Only 2 percent sat all the way down. I’m one of the minority who is not afraid of toilet seats.

There’s no reason to be afraid. As Dr. William Schaffner, professor of preventive medicine at Vanderbilt University Medical Center says, “toilet seats are not a vehicle for the transmission of any infections agents—you won’t catch anything.” There’s no medical evidence that anyone has ever picked up a venereal disease from a toilet seat. Any bacteria found on toilet seats are common skin microbes that we all carry around on our bodies. In fact, when studying bacteria on various surfaces in the bathroom, the toilet seat proved to be the cleanest surface.

Some experts define a sanitary surface as something clean enough to eat off of, with no more than 1,000 bacteria per square inch. On a 20/20 news program, Dr. Schaffner measured the bacteria on various surfaces, including those in a nearby bathroom as well as in the newsroom. They found that the toilet seat passed the sanitary test, but the anchorman’s desk did not.

Dr. Chuck Gerba, professor of microbiology at the University of Arizona measures bacteria in a variety of household objects. His studies found that the average toilet seat contains about 50 bacteria per square inch. “It’s one of the cleanest things you’ll run across in terms of micro-organisms. It’s our gold standard—there are not many things cleaner than a toilet seat when it comes to germs.” A sponge, for example, has about 10 million bacteria per square inch.

You can’t avoid bacteria—they’re part of you and part of our environment. I don’t worry about sponges or toilet seats. I wish other women didn’t.

Next week: Stress and illness

For an introduction to this blog, see I Just Say No; for a list of blog topics, click the Topics tab.