B.M.I. is out B.R.I. is in

As you probably know. B.M.I. stands for body mass index, which is the ratio of height to weight. The B.M.I. began as an index developed by Adolph Quetelet (1796–1847), a statistician who studied the distribution of weight in a population—mostly 5,738 Scottish soldiers. It’s been used as a medical screening tool since the 1970s.

I’ve always thought this measurement was problematic. Consider this: Arnold Schwarzenegger, in his prime, was in the “obese” category. So is American Olympic rugby player Ilona Maher. (Muscle weighs more than fat.) A study of 500,000 U.S. adults found that those with a B.M.I. between 25 and 29.9 (“overweight”) had a 5–7% lower risk of death than those with a "healthy" B.M.I. And so forth. For most of my adult life, including now, I’ve been in the “overweight” range.

Because of its obvious shortcomings as a measure of health, it is now being replaced by the B.R.I., the body roundness index. This metric measures how round or circlelike you are to get an estimate of abdominal fat, which is supposedly linked to an increased risk of developing Type 2 diabetes, hypertension, and heart diseases. That’s because fat stored in the abdominal cavity surrounds internal organs such as the liver and contributes to insulin resistance and glucose intolerance as well as high blood pressure and lipid abnormalities.

Apparently, it’s a complicated formula, but you can avoid the math by using a calculator. You’ll need to include more measurements than with a B.M.I. calculator, which looks at only height and weight.

I’m not bothering with it myself. Plus, I’m not sure that I trust this metric either. Just leave me alone.

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Statistics on the value of exercise

I rarely write about exercise, a topic that gets plenty of coverage elsewhere. However, thanks to a friend, I got some eye-opening information I’d not seen before. The information comes from Euan Ashley, who is a professor of cardiovascular medicine and genetics and data science at Stanford, where he is the Chair of Genomics and Precision Health. (He helped establish the field of medical genomics.)

In a podcast interview with Derek Thompson, he states that “Exercise is just the single most important intervention you can think of for your health.…you name the system in your body and exercise improves it and makes your chance of disease in that system less.” Here are the statistics he offers on the effect of exercise on a variety of diseases:

• 60 percent less likely to have atrial fibrillation.
• 50 percent less likely to have diabetes.
• 70 percent less likely to fracture your hip.
• 50 percent less likely to have colon cancer.
• 25 percent less likely to have breast cancer.
• 25 percent less likely to get depression.
• 70 percent of people who are active in their daily lives report better sleep.

The data is based on a population of more than half a million people who were followed for over ten years. In the interview he doesn’t mention how much exercise or what kind. You have to figure that out for yourself.

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

America's oversized death rate

Our mortality rates from non-Covid causes have been rising for years. Among 18 high-income countries, America’s life expectancy ranks dead last. A million more Americans died each year than would have if our overall mortality matched those of peer countries in Europe.

• In a quarter of American counties, death rates among working-age adults are higher than they were 40 years ago.
• Homicide rates involving a firearm are 22 times higher here than in the European Union.
• The death rate among children grew more than 15 percent between 2019 and 2021, with little of that attributable to Covid.
• For the first time in half a century, all-cause mortality in children ages 1-19 years began to increase, due primarily to homicide, suicide, vehicle injuries, and drug overdoses.
• Our maternal mortality rate is more than three times as high as that of other wealthy countries, and our newborns have the highest infant mortality rate in the rich world.
• Life expectancy among America’s poorest men may be 20 years shorter than their counterparts in the Netherlands and Sweden.

Whatever accounts for this decrease in life expectancy appears to be uniquely American. Something systemic to the U.S. is limiting survival. “Deaths of despair,” such as opioid overdoses, alcoholic liver disease, and suicides, account for some of the increased death rates. But mortality from other causes has also increased, including Alzheimer’s, diabetes, kidney failure, heart failure, vehicle collisions, and firearms. In addition to deaths of despair, experts posit a number of other possible causes for our decrease in life expectancy, including obesity, limited access to health care, health care affordability, loss of social support systems, chronic stress, and an increase in high school dropouts.

On the other hand, it looks like we do pretty well at keeping old people alive: the chances that an American 75-year-old makes it to 90 or 100 are about the same as in other wealthy countries. In the U.S., the trick is to make it to 60.

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

Being left-handed

I am right-handed, but for ten days my right hand was in a cast, so I was forced to use my left hand for everything. Boy was that hard! Even if you’re naturally left-handed—as only ten percent of people are—the engineered world makes it hard to do ordinary things. My sister is left-handed. Here are some of her examples:

• If you approach big heavy doors with a single handle, it’s always on the right, so you must open it with your right hand, or make an awkward crossover.
• At the bank, the pens-on-chains aren’t convenient for the left-handed.
• In the ladies room the drying towels are on the right. So are the nozzles of gas pumps.
• Travel mugs with lids on them don’t work for lefties. If you hold the handle with your left hand, the opening on the lid is on the wrong side.
• “How to” instructions are written for right-handed people.

On the plus side, lefties seem to be overrepresented in terms of special skills and accomplishments. Albert Einstein and Isaac Newton were left-handed. So were Leonardo da Vinci and Ruth Bader Ginsburg. Six of the last 12 presidents were/are left-handed, including Reagan, Clinton, and Obama. Studies have shown that 20 percent of students enrolled in art programs were left-handed, and that left-handed men who attended a year of college are 15 percent richer than similarly educated right-handed men. 

Some researchers theorize that lefties are more likely than righties to use both sides of their brains at the same time. But nobody really knows why the percentage of especially accomplished lefties is unusually high. Maybe it’s from persevering in a world designed to thwart you.

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

The complexity of taste

Taste is a multisensory experience in which smell, texture, and pain receptors all play a role in determining how something tastes.  It’s also a complex process that starts with our tongues, where a variety of sensors in taste buds send signals to our brains. The taste buds are located in the bumps you can see on your tongue.

Depending on their location, your tongue’s taste buds vary in their receptivity to the different tastes we can sense: sweet, salty, sour, bitter, savory (umami), and more recently, fat (“oleogustus”). The taste receptors at the back are most sensitive to bitter taste, those at the tip are most sensitive to sweet and savory tastes, and those on the sides are most sensitive to salty and sour tastes. The bumps on the remaining portions of the tongue don’t contain taste buds. Rather, their rough texture aid in gripping food and transferring it down to the esophagus as well as in cleaning our mouths and spreading saliva. Taste buds also reside on the pharynx, larynx, soft palate, and epiglottis (the little flap that keeps food from going into your bronchial tube). 

Signals sent by taste buds go to other organs besides our brains. Taste receptors are also found in the gastrointestinal tract, liver, pancreas, fat cells, muscle cells, thyroid, and lungs. Receptors in these organs pick up the presence of various molecules, metabolize them, and use them to prepare the organs for work. For example, when your gut notices sugar in food, it tells your brain to alert other organs to get ready for digestion. Taste wakes up the stomach, stimulates salivation, and sends a little insulin into the blood, which in turn transports sugars into the cells.

In 1904 Ivan Pavlov showed that lumps of meat placed directly into a hole in a dog’s stomach would not be digested unless he dusted the dog’s tongue with some dried meat powder to start things off. Looks like he was onto something.

I don’t know what we can do with this information. I just thought it was interesting.

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