Your voice box (larynx)

 I got the following information from Mary Roach’s review of a book called This is the Voice. I thought it was interesting.

“Infants begin life with the larynx tucked up into the back of the mouth. This makes possible nonstop suckling: unlike adults, babies can swallow and breathe at the same time. The price they pay for such highly efficient nutrient intake is that, temporarily, their speech sounds are limited. With no resonating chamber in the throat, they can manage little beyond mama, dada, gaga. As babies transition to solid food—and the risk of choking increases—the larynx begins to drop to a safer and less vocally limiting position.” The larynx of infants moves! Apparently, it drops down at about three months. Who knew? Not me.

Here's more: as we all know, during puberty men’s vocal cords thicken and their voices get lower. From an evolutionary standpoint, the author believes that a deeper voice made men seem larger and scarier, giving early human males an edge in competition for mates. On this topic, the book’s author has this to say about Donald Trump’s signature speaking behavior: “For a person like Trump, so consumed by the need to dominate and be the alpha male in every circumstance, it seems likely that…he intuitively hit on the expedient of rounding and pushing out his lips to lower his pitch slightly.”

Icky.

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Our virus friends

 As nasty as some viruses can be, we can’t live without them. Living within us are types of viruses called phages, meaning bacteria eaters. Our bodies are home to trillions of them. So far, scientists have identified 21,000 species of phages living in our guts. Most of them infect the bacteria, fungi, and other single-celled organisms that live inside us. Some studies suggest that our resident viruses help keep our bodies in balance, preventing any one species from getting out of control and making us sick. 

About two years ago I wrote a blog post about a man whose life was saved by treating him with a phage. He had been infected with a “superbug” (bacteria) that no antibiotic could kill. A phage did the job instead.

In the ocean, phages invade microbes at the rate of 100 billion trillion times a second, killing 15 to 40 percent of bacteria in the world’s oceans every day. The shredded bacteria spill billions of tons of carbon for other marine creatures to feast on. Some ocean phages carry genes for photosynthesis, making the microbes they infect do better job of  harnessing sunlight. In the photosynthetic process, the microbes release oxygen. This means that the oxygen we breathe is brought to us in part by viruses. (Incidentally, a quart of seawater holds more viruses than all the human beings on the planet.)

Remnants of a virus that invaded our shrew-like ancestors more than 100 million years ago live within us today. In other words, the DNA of viruses are part of our own DNA. Today we carry about a hundred thousand fragments of viral DNA, which make up eight percent of the human genome. That means you.

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Prediabetic? Probably no need to worry

 My husband was diagnosed with prediabetes decades ago. He’s never gotten diabetes. Prediabetes is diagnosed through a blood test that measures blood sugar levels over the past two to three months. The test is called A1C and the results are given as a percentage. Normal is 5.7. Prediabetes begins at 5.8. Diabetes is defined as 6.5. (My husband doesn’t know what his percentage is.)

Anyhow, the point is that new studies have shown that older people who were diagnosed as prediabetic were far more likely to have their blood sugar levels return to normal than to progress to diabetes. A study of 3,412 people, which began in the 1980s, found that prediabetes was rampant—three-quarters were given that diagnosis—but, when looking at the now 71- to 90-year-old people, only 8 or 9 percent developed diabetes. Because we old people often produce less insulin later in life, we often have slightly above normal blood sugar readings, so being prediabetic isn’t unusual.

As one of the researchers noted, “in most older adults, prediabetes probably shouldn’t be a priority. We’re not seeing much risk in these individuals.” Getting a diagnosis of prediabetes creates needless anxiety for us and “medicalizes” a normal part of aging. If you want to become more anxious, go to the website doihaveprediabetes.org and take the test. I did that. It asks your age, your weight, whether you’ve been diagnosed with high blood pressure, and so forth. My results: “You are at risk and are likely to have diabetes.” You’d probably get the same results. Don’t worry about it.

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

Autism and gut bacteria

According to the CDC, about one in every 59 children in the U.S. is diagnosed with autism, up from one in every 150 in 2000. Alarming numbers! No one really knows why the numbers are escalating in this way. (It’s not from vaccinations!) Among other things, researchers have found that 30-50% of all people with autism suffer from gastrointestinal problems, such as diarrhea or constipation. They have also found that children with autism have lower diversity of microbiota in their intestines as well as a nearly-depleted strains of helpful bacteria.

For years, scientists have been looking at the ways in which gut bacteria affect brain communication and neurological health. In the words of one, “We are finding a very strong connection between the microbes that live in our intestines and signals that travel to the brain.” To test the relationship between the gut microbiome and autism, 18 children were given fecal transplants to alter the makeup of their gut microbiome. The transplant regimen (Microbiota Transfer Therapy) was rather rigorous: first, pre-treatment with an antibiotic to kill existing intestinal bacteria followed by a bowel cleanse, a stomach acid suppressant, and finally fecal microbiota transfer every day for seven to eight weeks.

Amazingly, this treatment reduced autism symptoms, such as social communication difficulties and repetitive behaviors, by 45%, and the effects seem to be lasting. At the start of the trial, 83% of the participants were rated as “severe” autism. At the end, only 17% were severe, 39% were mild/moderate; and 44% were below the cut-off for mild autism.

Interestingly, many of the participants share common history, including birth by C-section, reduced breastfeeding, increased antibiotics, and low fiber intake by both mother and child—conditions that lead to limited biodiversity in gut bacteria.

Much remains to be done, including understanding which microbes and chemicals produced by the microbes are driving the behavioral changes in autistic children. It can’t happen soon enough. 

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