As a college undergraduate, I learned about a fascinating anti-aging trick for mice: a significant calorie restriction.
Restrict the caloric intake of a mouse by about one-third, and they live about 30 percent longer.
Calorie Restriction
Calorie restriction (CR) extends life span and retards age-related chronic disease in numerous species, including mice, rats, fish, flies, worms, and yeast.
The concept of calorie restriction likely wasn’t formally described until the 1930s, based on available information.
Here’s a breakdown of the timeline:
- 19th Century: The concept of the calorie was developed during this time. Calorie restriction as a practice wasn’t widely explored.
- Early 20th Century: In 1935, researcher Carlo Moreschi described how restricting calories (without malnutrition) prolongs mean and maximal lifespan in rats compared with ad libitum feeding.
It’s important to note that while the idea might have been brewing earlier, the term “calorie restriction” and its wider use likely emerged in the late 1930s.
Did You Know?
Almost all organisms undergo aging and senescence.
Senescence is the physiological deterioration resulting in an increase in mortality and a decline in fertility with age.
Some animals do the aging thing better than others.
Here are some species that seemingly defy aging, at least to a large degree:
- Lobsters
- Perennial plants
- Tortoises
- Rockfish
- Hard-shelled clams (quahogs)
But Does Calorie Restriction Work for Humans, Too?
The groundbreaking work of Carlo Moreschi laid the foundation for significant research in aging and nutrition.
Here’s the thing:
Calorie restriction (CR) remains the only non-genetic intervention that can extend lifespan across various species.
CR has lengthened the lives of species ranging from yeast to worms, flies, and rodents and is even showing promise in primates.
And humans?
Human Trials on Calorie Restriction
If calorie restriction can slow biological processes in mice, worms, and flies, can it extend a healthy lifespan in humans?
A Columbia University (New York City) study tested if calorie restriction also slows biological aging in humans.
This randomized controlled clinical trial — the CALERIE (Comprehensive Assessment of Long-Term Effects of Reducing Intake of Energy) — analyzed 220 healthy men and women in three sites in the U.S.
Researchers randomly assigned participants to one of these two approaches for two years:
- calorie-restricted diet (with a 25 percent reduction in intake)
- normal diet
What do you think the scientists discovered? Did calorie restriction slow human biological aging?
Study Details
The participants in the calorie restriction group had an average 12 percent drop in calorie intake (from 2467 to 2170 kcal).
Of this drop in weight, 71 percent was a fat mass loss.
The control group sustained an average increase of 0.1 kg.
Study Results
Here are the study results of the two-year study on calorie restriction:
Cutting back a moderate amount of calories can significantly improve heart health for young and middle-aged adults, even if they aren’t overweight.
The study found that people who cut back on calories saw lasting improvements in many important markers of heart health over the two years.
Calorie Limitation Improves Health Markers
Improved markers include:
- “Bad” LDL cholesterol.
- The ratio of total cholesterol to “good” HDL cholesterol.
- Both systolic and diastolic blood pressure (the top and bottom numbers in a blood pressure reading).
Those in the calorie restriction cohort also saw benefits in inflammation (measured by C-reactive protein).
They improved how well their bodies used insulin (insulin sensitivity) and had a score that indicated metabolic syndrome (a group of risk factors for heart disease, stroke, and type 2 diabetes).
These improvements happened even when accounting for weight loss, meaning the calorie restriction had a positive impact beyond just shedding pounds.
My Take: Eat Food. Not Too Much. Mostly Plants.
I am impressed that just two years of calorie restriction significantly reduced several cardiometabolic risk factors.
This study reminds me of the potential of moderate calorie reduction.
While the study focused on young and middle-aged healthy individuals, I suspect we all could benefit from staying reasonable regarding calories.
My personal goal?
Eat food. Not too much. Mostly plants (the last is a work in progress).
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