Can you remember how your favorite grandma smelled? If you think back to a beloved elder, you might be able to summon up the memory of a scent that’s been described as a blend of stale oil and musty cardboard. It might remind you of opening up old books or unpacking a box of vintage clothing. And while it’s much more subtle than the sweaty body odor of youth, it’s definitely noticeable and probably filed away in your memories as “old person smell.”
As it turns out, that smell is an actual biological phenomenon, caused by an epidermal change that happens to everyone as they age. According to skin experts, every birthday after age 40 increases the likelihood of these changes in the way skin smells. Research has identified the culprit as something called 2-nonenal (pronounced noh-neh-nahl), an organic compound known as an aldehyde.
That “aging odor” is caused by increased production of this aldehyde in older people, which is the source of a distinctive, dusty “granny” smell. Not all aldehydes smell the same, by the way, and another example is cinnamaldehyde, the organic compound that gives cinnamon its characteristic flavor and aroma, explained Dr. Delphine J. Lee, chief of dermatology and residency program director at Harbor-UCLA Medical Center.
We spoke with dermatologists and other experts to get to the bottom of why this happens.
Here’s what changes in your skin to produce the scent.
The compound 2-nonenal has its own unique scent, and it proliferates as people get older. “As we age, several things happen simultaneously in our skin,” said Dr. Sonal Choudhary, a dermatologist from the University of Pittsburgh School of Medicine. “Antioxidant defenses in the skin decline, the composition of our sebum changes, and our cumulative UV exposure and environmental stress increase oxidative damage in the skin.” As these things are weakening the skin, 2-nonenal has an opportunity to make its presence known.
“Research suggests measurable increases in 2-nonenal typically begin after age 40, with more noticeable accumulation in the 50s and beyond,” Choudhary said. “It’s a gradual process, not an instant switch. The intensity of the smell varies significantly from person to person depending on genetics, skin type, lifestyle and environmental exposure.”
It’s something that happens to most people, said dermatologist Dr. Naana Boakye, founder of Bergen Dermatology. “Evidence suggests that 2-nonenal production is a common age-related phenomenon, not something limited to a small subset of people,” she noted. “Studies consistently detect this grassy, greasy scent in older adults of both sexes. While levels vary between individuals, there is no evidence that only certain people produce it.”
Betsie Van der Meer via Getty Images
You may not be able to smell it yourself if you’re producing it.
Since so many factors, including genetics and lifestyle, contribute to the condition of your skin, you may get lucky and avoid the 2-nonenal odor altogether. And even if that distinctive smell does show up, remember that it’s all in the nose of the beholder. “People can exaggerate that this smell is unpleasant or disgusting,” Lee said. “It may even be more neutral or pleasant than the body odors of younger and middle-aged people.”
As Choudhary mentioned, this process happens gradually, and that gives your brain an opportunity to become accustomed to the new scent, thanks to something called olfactory adaptation. You might not notice a prevalent scent after a while, since brains often filter out familiar odors, while staying alert for new information. An example of this “nose blindness” is that we might notice a friend’s house always smells a certain way but are probably unable to detect our own home’s unique scent.
Unlike sweat, it doesn’t wash off easily.
Since 2-nonenal is a fatty acid, it won’t easily dissolve in soap and water, the way sweat does. “It’s hard to get rid of this molecule, because it’s very sticky,” said Danielle Reed, chief science officer at Monell Chemical Senses Center, a nonprofit research institute that studies taste and smell. “It loves to stick to your skin and it loves to stick to fabrics. You’ll remove some of it when you bathe, but your body is constantly making it, so washing isn’t a cure.”
Boakye suggested it might be helpful to use antioxidant-based cleansers. She also said products with ingredients that bind aldehydes, like tannins, may help reduce odor persistence in some people. “Persimmon soap, which contains tannins, has a plausible mechanism and a long history of use, though large randomized trials are lacking,” she noted. While none of these experts recommended specific products, Mirai’s clinical persimmon soap, with Japanese persimmon and green tea extract, is popular and highly rated.
Recent research has looked at the potential role eggplant extract might play in reducing the oxidative stress that contributes to 2-nonenal formation. In a study published last year, researchers said the fruits, leaves, stems and roots of eggplant, along with their active ingredient N-trans-feruloylputrescine, exhibited excellent 2-nonenal scavenging activity. But that’s a “someday” option, Lee said: “Human clinical data remain limited, so this should not be positioned as a cure.”
An older study was initially positive about how the consumption of white button mushroom extract could alleviate body odor in subjects aged 50 to 79, but there have not been large clinical trials to follow up on that.
So there’s still no sure-fire way to completely eliminate it from your skin, experts agreed. “If you could figure this out, you’d be very rich, but so far there’s nothing that’s truly helpful,” Reed said.
And also? It’s all natural and perfectly OK.
If you’re noticing this scent on yourself or someone you love, don’t be ashamed or judgmental. Choudhary noted that it’s not a sign of poor hygiene, nor is it inevitable or unmanageable. “This is a normal biochemical change of aging skin, similar to wrinkles or dryness,” she said. “With thoughtful skin care, antioxidant support and proper laundering, it can often be minimized significantly.”
Another consideration is that smell is a subjective area for humans. “We’ve decided we don’t like the odor of old people, but we love the odor of babies’ heads,” Reed said. “Perhaps, as a society, we could learn to love the smell of aging. Not everyone finds this smell unpleasant, and there’s always something for everybody when it comes to smell.”
There’s also the opportunity to lean into this and other age-related changes, because they’re going to happen whether we like them or not.
“As a dermatologist, I emphasize that aging is a natural, lifelong biological process experienced by us all,” Lee said. “We should focus on promoting health and well-being across our lifespans, while recognizing and valuing the wisdom, resilience and lived experience that accompany advancing age. I’d like us to place less emphasis on cosmetic or physiological changes such as body odor or wrinkles, which are often part of a life fully lived.”
The original version of this story was published on HuffPost at an earlier date.