How air pollution affects your brain

Scientists at the University of Pennsylvania have been studying the effects of pollution on brains for more than twenty years. Among other things, they perform autopsies on the brains of people with dementia. What they learned was that people who had been exposed to air pollution were more likely to have Alzheimer’s disease than those who did not. As Dr. Edward Lee, who directs the brain bank, concludes, “The quality of the air you live in affects your cognition.”

For example, an 83-year-old man who died with dementia had lived near a freeway. At autopsy, his brain showed large amounts of the plaques and tangles associated with Alzheimer’s disease. In contrast, an 84-year-old woman, who died of brain cancer, lived in an area surrounded by woods. As one of the researchers attested, her brain autopsy showed that she had “barely any Alzheimer’s pathology. We had tested her year after year and she had no cognitive issues at all.”

Because of their different home locations, the amount of air pollution that the woman was exposed to was less than half that of the man’s exposure. Increasing evidence is showing that chronic exposure to fine particulate matter—called PM2.5 (it has a diameter of 2.5 micrometers or less)—is likely associated with dementia. It’s a neurotoxin that can be inhaled deeply into the lungs. It not only affects brains, but it also damages lungs and hearts.

Sources of PM2.5 include vehicle emissions, industrial activities, wildfires, and household activities, such as cooking and burning candles. 

We’ve been cooking with our gas (propane) stove for decades. No wonder I’m having memory problems! All this time I’d been thinking it was just old age.

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Your hair can reveal your body’s secrets

The New York Times article from which I got this information says, “hair sits at the boundary between biology and identity.” Also: It serves as a “sensor for your brain and an archive of your body’s secrets.” Goodness! Really?  Here’s the explanation:

Hair is made mostly of keratin, a tough protein also found in your nails. You have about 100,000 hair follicles on your scalp and many more across your body. Each follicle cranks out the strands as well as the pigment that gives it color. Bacteria, viruses and fungi live within the follicles—a microbiome that keeps out harmful germs, reduces the risk of infections, and helps your hair grow. Your hair follicles also help heal wounds by sending stem cells to the wound where they create new skin cells.

As for your brain, your hair acts like motion detectors. Because the follicles are wrapped in nerve endings that fire at the slightest touch, if an insect drifts near your eyes, for example, your lashes sense it and you blink. The nerves also feed into your brain’s emotion centers, which is why a gentle caress can feel pleasant. In addition, hair follicles contain smell and bitter-taste receptors that influence hair growth. Some research indicates that certain fragrances seem to stimulate hair growth while others might inhibit it. Like your brain, the follicles also have an internal clock with a resting and shedding cycle. (Hair grows faster in the morning than in the evening.)

As the second-fastest growing tissue in the body—after bone marrow—hair serves as an archive of your health, signaling when something’s wrong. Follicles suck up toxic compounds and deposit them in your dead hair shaft. A centimeter of your hair captures a month’s worth of biological data: drug use, poisons, chronic stress, and even medication adherence.

Because keeping the pace of growth takes a lot of energy, rapid hair loss can serve as a sign of illness or stress. Of course, some hair shedding is inevitable—we lose about 50 to 100 strands of hair each day.

The article didn’t explain what happens when you lose a lot of hair in old age. Inquiring minds want to know!

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

What your tongue tells you

Traditional Chinese medicine includes studying the tongue to detect illness. A healthy tongue appears pink with a thin white film. Not-so-healthy tongues may look white (lack of iron), bluish yellow (diabetes), purple (certain cancers), and so forth. Now, some researchers are working to adapt this diagnostic method by using AI technology. 

Because color perception is very subjective and varying light conditions can affect color perception and analysis, researchers created a kiosk with a standardized lighting system. Patients would put their heads in the kiosk where images of their tongues could be collected.

Next, they trained an AI program to detect illnesses by showing it 5,260 images of healthy and unhealthy tongues, after which it was able to classify and predict conditions such as diabetes, asthma, COVID, and anemia, with 96.6 percent accuracy. After this training, the researchers tested it with 60 tongue images they’d collected with their kiosk at two hospitals. AI correctly identified patients’ conditions—based on their medical records—in 58 out of 60 images.

According to the article in Scientific American, researchers at the University of Missouri have launched an AI application, called BenCao, where users can upload tongue images and receive personalized health guidance. The app is designed and marketed as a “wellness” tool.

As you can imagine, the scientific community is wary about studying the tongue to assess a patient’s health. On the other hand, tongue examination is often part of a routine screening for oral cancer by dentists and hygienists.

I’m guessing you’ll soon be sticking out your tongue in front of a mirror.

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

The emergency room

I went to the emergency room recently. The head of a tick was embedded in my arm, and I couldn’t get it out. My arm was swollen, red and sore. My GP’s practice—taken over by a conglomerate—doesn’t take “walk-ins.” Heading for the ER, I was aware that this wasn’t an emergency, but what was I to do?

In 2022 there were 155 million visits to emergency rooms, up from 130 million in 2018. With Trump’s cuts to Medicaid, that number is expected to increase. A third of Americans have no primary care physician, up from a quarter ten years ago. In the past, the ER was used for last-resort care. Now it’s become the doctor’s office for millions of people (like me!). Some patients sit in the ER for days—a situation called “boarding”—while they wait for hospital admission.

I read an article about a Columbia University student who fell ill with headaches and chills and went to the ER. The best diagnosis they could come up with was “acute viral syndrome.” They sent him home. He returned to the ER the next day, and after careful examination, they stuck with that diagnosis and sent him home again. Two days later he died in his dorm room. (The cause of his death, according to the autopsy, was “pulmonary hemorrhage of unknown etiology.”) The father sued Mount Sinai Morningside hospital for medical malpractice.

I’ve read lots of books by ER physicians. They work hard. They’re conscientious. They do their best. As one ER doc said, “The spectrum of disease is just unbelievable.” The first job of an ER physician is to treat patients in need of resuscitation. More difficult is determining which patients are in imminent danger, neither obviously dying nor obviously well.

In their high-volume, fast turnover environments, should doctors be expected to follow mysterious blood results over days or phone patients after discharge to check up on them? As one doc said, “Our job is kind of perilous…bad things can happen. It’s on you to be extremely vigilant, and to some extent, lucky.”

Maybe I should buy some lidocaine and instruments and take care of future tick heads myself.

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