The brightest take on this week’s science
Happy holidays!
Unwrap this edition of Spark, and you’ll find exciting research on diet and longevity.
Plus, wacky findings that suggest Earth’s seasons are out of sync.
Also in this issue:
🤯 A mind-blowing fact about reindeer eyes
🧀 The link between cheese and dementia
🔬 A microscope mystery
Enjoy the gift of science!
LOOK IN
The Amino Acid Linked to Mouse Longevity
(Vladyslav Varshavskiy/Getty Images)
Research in mice shows that cutting back on just one amino acid can increase lifespan by up to 33 percent.
The amino acid is called isoleucine.
It’s an essential component our bodies use to make proteins, but our cells can't produce it from scratch, so we have to eat it in food like eggs, dairy, soy protein, and meats.
But everything in moderation, as they say.
Mice that cut back on isoleucine in experiments became leaner and stronger, with better blood sugar control.
Whether the same benefits exist for humans remains to be seen…
HEADLINES
What Else We're Watching
🏅This week’s most read: Most People Develop Diverticulosis in Their Gut by Age 80… So What Is It?
LOOK OUT
Earth’s Seasons Are Surprisingly Out of Sync
(NASA/JPL-Caltech)
Spring, summer, winter, and fall are surprisingly out of sync.
That’s what scientists at the University of California, Berkeley, have discovered after watching our planet’s seasonal cycles from space.
The map they’ve created is based on 20 years of data, and in some regions, seasonal patterns appear strangely out of sync.
Take two cities in Arizona: Phoenix and Tucson, which are only 160 kilometers (99 miles) apart.
Tucson experiences its highest amount of rainfall during the summer monsoon season, whereas Phoenix receives most of its rain in January.
Most climate models, however, lump this whole region together…
ZOOM ZONE
Microscope Mystery: What Do You See?
(Clouds Hill Imaging Ltd./Getty Images)
A) Soap bubble
B) Scots pine
C) Candle wax
D) Cholesterol
Answer at the bottom.
GOOD NEWS GRAPH
Cheese And Dementia
Dementia diagnoses were more common among people who rarely or never ate cheese, but only slightly. (Jeong et al., Nutrients, 2025)
The Japanese food company Meiji Co. commissioned a study on 7,914 people aged 65 or over.
What does it show?
A small increase in the risk of developing dementia among those who did not eat cheese at all, compared to those who ate cheese at least once a week.
In the details: Those who abstained from cheese had just over a 1 percent increased relative risk of developing dementia.
That’s not much for an individual, but at a population level, diets that include more cheese may meaningfully contribute to dementia prevention.
WOW FACTOR
Science Fact of The Week
The color of a reindeer’s eyes changes with the seasons.
In summer, their eyes reflect gold-turquoise, and in winter, they turn a deep blue. This switch makes them over a thousand times more sensitive to light.
Reindeer are the only known mammal to adapt their eyes to the Arctic’s extended winter twilight.
DOPAMINE HIT
Before You Go…
Hop into the holidays!
Microscope answer: Scots pine
The Scots pine is a very popular Christmas tree, and the most widespread pine species in the world. The plant’s tissues survive freezing winters by precisely controlling where ice forms.
That’s all for today… see you next week!
- Carly
