We've all heard the admonitions about how keeping mentally active boosts overall health and longevity. A new study suggests that busy brains might mean shorter lifespans, and excessive brain activity could be a risk factor for dementia.

Researchers documented the phenomenon across multiple species — from humans to mice to roundworms (!) — and said it appears people who live longer may have a regulatory gene that more effectively quiets unnecessary nerve activity.

They concede their findings appear counterintuitive and the full story in humans is likely to be much more complicated. So don't stop just yet taking those foreign language lessons, doing Sudoku and reading this column.

Body of Knowledge

Adults have approximately 20,000 pores on their faces.

Get Me That, Stat!

Of the 195 countries around the world, 119 were found to have an insufficient supply of blood units for health care and emergency use in 2017, according to a new study published in The Lancet Haematology.

Higher income countries were largely able to meet demand, but poor countries were not. South Sudan, for example, had a need 75 times greater than the country's supply.

It's estimated that 10 to 20 donors can supply enough blood to help 1,000 people.

Stories for the Waiting Room

The 1992 book "Sharks Don't Get Cancer" spawned a huge increase in shark hunting as people sought shark parts as a treatment for various malignancies. In fact, sharks do get cancer, and multiple studies have found no evidence that using shark cartilage or other tissues is an effective treatment for any type of cancer.

Doc Talk

Cachexia: A complex syndrome associated with an underlying illness, such as cancer or AIDS, that results in ongoing muscle and weight loss that cannot be entirely reversed with dietary supplementation.

Phobia of the Week

Nephophobia: Fear of clouds

Never Say 'Diet'

The Major League Eating record for poutine is 28 pounds in 10 minutes, held by Joey Chestnut. Poutine is a Canadian dish consisting of French fries and cheese curds topped with brown gravy. In Quebec, where it is believed to originate, a plate of poutine is routine cuisine.

Observation

"A man's health can be judged by which he takes two at a time — pills or stairs." — Joan Welsh

Medical History

This week in 1974, Dr. Christiaan Barnard performed the world's first "twin heart" operation, implanting a second human heart alongside the old one in a 58-year-old man. In the procedure, Barnard removed only the diseased portion of the patient's heart — one-third of the left ventricle. Barnard then joined the left atrium to the atrium of a second donor heart. The operation was considered less radical than total heart replacement and was conducted without a heart-lung machine. With both hearts beating, the second acted as a booster for the first. The patient died four months later, however, of unrelated causes.

Perishable Publications

Many, if not most, published research papers have titles that defy comprehension. They use specialized jargon, complex words and opaque phrases like "nonlinear dynamics." Sometimes they don't, and yet they're still hard to figure out. Here's an actual title of actual published research study: "Stimulae Eliciting Sexual Behavior."

In this case, the specific topic was the sexual behavior of turkeys, in which a pair of researchers at Pennsylvania State University in the early 1960s wanted to know just how minimal turkey stimulae might be to still do the job. So they created a mock female bird and progressively removed parts of the model, assessing when a male turkey lost interest.

Finally, they got to just a stick-mounted head and neck, which the male turkey found just as appealing a mate as a whole bird.

Self-Exam

Q: What does your spleen do?

A: The spleen is an organ located between the stomach and diaphragm. It makes new white blood cells and cleans old ones out of the body. It's also a place where immune cells congregate. Though these cells are spread throughout the body, they sometimes need to talk with one another, which they do when meeting in the spleen or in lymph nodes.

A person can live without a spleen, but their immune system is substantially impaired. Some people have a second spleen, called an accessory spleen, that is very small but may grow and function when the main spleen is removed.

Fit to be Tried

There are thousands of exercises, and you've only got one body — but that doesn't mean you can't try them all:

It's called the Superman, an easy exercise to strengthen back, buttocks, hips and shoulders. Lie prone (face down) on a floor mat, legs extended, arms extended overhead with palms facing each other. Relax head to align with spine.

Exhale, contract abdominal and core muscles and slowly and simultaneously raise both legs and arms a few inches off the floor. Avoid any rotational movement. Maintain head and torso position. Don't arch back or raise head. Hold this position briefly.

Gently inhale, and lower legs and arms to starting positions without any movement in lower back or hips. Repeat.

Med School

Q: How many kinds of tonsils are there?

A: Four. The palatine tonsils are the ones seen at the back of the throat. But there are also lingual tonsils (base of the tongue), tubal tonsils (around the opening of the Eustachian tube in the nasopharynx, which is the upper part of the cavity behind nose and mouth) and adenoid tonsils (high up in the throat behind the nose). All together, these tonsils form Waldeyer's ring, which serves as a gatekeeper to all things entering the airways and digestive tract, grabbing pathogens and warding off diseases.

Last Words

"I will see you tomorrow, if God wills it." — Pope John Paul I (1912-1978).

Apparently, God didn't. Pope John Paul I suffered a heart attack and was found dead in bed with reading material and his bedside lamp still lit. He had been pope for just 33 days.

To find out more about Scott LaFee and read features by other Creators Syndicate writers and cartoonists, visit the Creators Syndicate website at www.creators.com.