OPINION
Mums are repositories of home-spun wisdom, including “early to bed and early to rise…”, and “don’t go swimming straight after eating!” The latter was a particular bane of my childhood summers. There was nothing more frustrating than watching the clock after lunch, waiting until the statutory time limit was up and we could jump back in the pool. (The round, Clark Rubber, above-ground frame job, of course: only posh people had in-ground pools, or a fancy deck around their above-ground one.)
But was Mum’s medical wisdom on the money? After all, she also told us that if we swallowed chewing gum, we’d gum up our heart, so…
Turns out at least one bit of homespun health advice was off the money.
A study from Imperial College London suggests night owls – those who feel more alert and productive in the evening – tend to outperform their early rising counterparts on brain tests.
Researchers analyzed data from more than 26,000 participants and found evening people scored up to 13.5% higher than morning people on cognitive assessments. Even those without a strong preference for morning or night still performed better than early risers.
As a lifelong night-owl (Mum fairly soon stopped even trying to enforce a 9pm bedtime), I feel vindicated.
The study accounted for age, gender, smoking, drinking, health conditions and other factors. Younger people and those without chronic illnesses generally did better on the tests. Healthier lifestyle choices were also linked to better brain performance.
But don’t stay up all night just yet. The study also found that getting the right amount of sleep is crucial for everyone. People who slept between seven and nine hours a night had the best brain function. Those who slept too little or too much showed decreased cognitive performance.
So, sitting up all night and sleeping till midday isn’t “lazy”, it’s smart. So there.
But what about the no-swimming-after-eating thing? Also busted.
In most cases, there’s no need to wait at least 30 minutes after eating to go for a swim, doctors say.
That old warning stems from worry that people might drown or struggle because blood will be diverted to their full stomachs instead of their muscles.
Which is, in fact, exactly what Mum warned us about.
In reality, people still have plenty of blood flowing to their muscles after eating, said Dr. Matthew Badgett of the Cleveland Clinic. A former high school swimmer, Badgett used to eat a couple of bananas and drink some water or Gatorade before he raced.
He worries that the old warning can actually cause complications. It’s important to quench your thirst before swimming, especially on sunny days. People often don’t realize they can still get dehydrated, which can lead to muscle cramps.
“We sweat when we are in the water, we just don’t appreciate the water loss,” he said.
Wait, you cry. What was that about cocaine sharks?
Unlike the no-swimming-after-eating thing, this is totally real.
In what sounds like the plot of a low-budget movie, scientists have discovered cocaine inside sharks caught off of Brazil, and they are concerned it may be changing their behaviour.
Because when you’re swimming after a good lunch, the last thing you want to worry about is that the sharks might be wired.
Tests on 13 Brazilian sharpnose sharks taken from waters off Rio de Janeiro revealed they all had high levels of the recreational narcotic in their livers and muscles.
Marine biologists, who published their findings in the journal Science of the Total Environment, said the drug likely came from the city’s sewerage system.
They said it may have come from illegal cocaine factories or from the excrement of drug users, through untreated sewage.
A less likely source was from the sharks feeding on bales of cocaine that were lost or abandoned in the sea by drug smugglers.
So, that’s why they call them “great white” sharks.
