During an extended period of travel last year, my husband and I lent our house in the Ozarks to an older couple who were having work done on their own house.

We returned after a month away to a spotless house and two hostess gifts. But there was also a distinctive smell in the air: slightly stale and sweet, like the musty first whiff of strawberries in a cardboard box.

I wiped countertops and mopped floors. Still, the odor remained. Not terrible, but strange and cloyingly human. Late that night I guiltily Googled, “Do old people smell?”

The answer I found was yes. Then no. And maybe …

I mentioned my question to a group of female writers, ranging from 40 to 70, and got drastically different responses. The younger women said yes, there’s an odor associated with aging. But to the older women it sounded like ageism, and a few took offense.

At 52 I felt a little prickly about it myself, but also in need of information. If there was anything I could do to improve my personal scent, now and in the future, I wanted to know. So I consulted two scientists from a renowned research lab and ran into the same split.

Johan Lundstrom, a 46-year-old biologist with the Monell Chemical Research Center, says his studies confirm what Japanese researchers found in 2001: An unsaturated aldehyde called 2-nonenal is more concentrated on the skin of older people, often producing a distinctive grassy, waxy or fatty odor.

His study — admittedly small — used samples from the underarms of people from the ages of 20 to 95 and presented them to 41 participants who ranked them on intensity and unpleasantness. In addition, Lundstrom and his co-authors found that “participants were able to correctly assign age labels to body odors originating from old-age donors but not to body odors originating from other age groups.”

But George Preti, a 74-year-old analytical organic chemist, also with the Monell Chemical Research Center, says his studies did not match the results found by either the Japanese group or Lundstrom’s team. Preti’s team used upper back and forearm samples and submitted them to gas chromatography and mass spectrometry, concluding that “no method of analysis” revealed the presence of 2-nonenal in older subjects.

“Old people actually smell less than younger ones,” Preti said. “Unless you go to a nursing home, where there are hygiene issues in the mix, you’re not going to find this musty, unpleasant odor everyone is talking about.”

“I know what George told you,” Lundstrom said. “He’s wrong. His study was too narrow. He’s just sensitive about this topic because he’s old,” he said in a tongue-in-cheek manner.

Universally, studies show that in blind “smell tests,” the odor of middle-age men is judged to be the worst — more offensive than samples from younger individuals and older ones. (Middle-age women, despite all our fears to the contrary, smell the best.) Chemical analysis bears this out, with lower levels of sebaceous secretions in the very young and very old.

Lundstrom’s study affirmed the existence of “old people smell” but stated that on average participants found it “neutral” and “not unpleasant.” He believes the odor is perceived as negative largely due to context. It’s similar, Lundstrom says, to the smell of fresh manure: Smelled in a stable, it’s perceived as natural. But in one’s bedroom it becomes disturbing and bad.

“In the Japanese study, when researchers did not tell participants what the odor was, they rated it as ‘inoffensive,’” Lundstrom says. “But when they said it was from an old person, it was rated as ‘nasty.’”

The bias in Japan is clear. They have a name for older-person odor — “kareishu” — and it has a definitively negative association. A Japanese company called Mirai Clinical sells a $16 persimmon soap bar that promises to eliminate the “offensive” smell.

Preti distrusts the science of the 2001 study. “I was 57 when the original Japanese study came out, and I remember being quite offended,” he said. “The group they sampled as being ‘old’ included people in their 40s. That’s insane.”

Lundstrom endorsed the Japanese findings but was leery of the industry around kareishu; he said expensive creams and soaps will not provide a fix.

“Smell has a very large subconscious component,” Lundstrom said, “so masking it will not do any good. Each odor binds to a particular chemical receptor in the nose, and this information will travel even through heavy perfume.”

Instead, he’s advised his own aging parents to stay active, air out their house frequently and wash linens and clothing regularly, even if they don’t appear dirty. Other factors are harder to control, such as genetic predisposition and general health.

Preti — despite his conviction that older people smell less and better than younger ones — made many of the same recommendations.

The scientists agree that people with chronic diseases are more likely to give off odor, no matter what their age. Preti attributed this more to diet, metabolism and self-care, Lundstrom to the possibility — which he is investigating — that ongoing inflammation leads to odorous cell decay.

“Yes, that’s actually somewhat reasonable,” Preti said affably when presented with Lundstrom’s theory. “We didn’t talk about inflammatory disease, and all the subjects in my study reported they were healthy.”

Both researchers mentioned that the sense of smell tends to decrease as people age, so systems of self-monitoring — such as breathing into cupped hands, or sniffing under our arms — often fail around the seventh decade of life.

For now the best advice for combating age-related odor is simply to take care of yourself and your home: Exercise, stay healthy and hydrated, eat clean food, open windows, launder clothing and sheets.

And don’t worry about it.

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