Understanding the Causes of the “Old Person Smell”

As we age, our bodies undergo a variety of changes. One of these is the emergence of a distinct body odor often referred to as the “old person smell.” This odor is usually considered a natural phenomenon that appears as we get older, but its causes are complex and multifaceted. In this post, we will explore the main causes and biological mechanisms behind this scent, as well as ways to reduce and manage it.

 

The “old person smell” is a natural phenomenon that arises as we age, but it has various physiological causes.

 

Understanding and Recognizing the “Old Person Smell”

The term “old person smell” refers to a distinctive body odor that begins gradually in the late 40s and becomes more prominent after the 60s. Scientifically, it is associated with a compound called “nonenal.” In the West, it is referred to as the “old person smell,” and in Japan, it is widely known as “kareishu.” This odor is generally described as a slightly sour scent reminiscent of animal fat.

 

The “old person smell” is not simply a matter of personal hygiene but rather a natural part of the aging process. So, what causes this specific body odor?

 

Main Causes of the “Old Person Smell”

Formation of Nonenal Compounds

Nonenal (specifically 2-Nonenal) is the primary compound associated with age-related body odor. It is produced through the oxidation of unsaturated fatty acids in the body, and its generation becomes increasingly active with age.

• Characteristics of Nonenal: Nonenal forms as unsaturated fatty acids oxidize, and the unstable structure of these fatty acids makes them highly susceptible to oxidation. As we age, the body experiences greater oxidative stress, which leads to increased nonenal production.
• Mechanism of Oxidation: Reactive oxygen species generated during metabolism oxidize unsaturated fatty acids, producing nonenal. This process becomes more pronounced when the body’s antioxidant defenses weaken, as oxidative stress is closely related to aging.

Changes in Sebum Production

Sebaceous gland activity also changes as we age. In younger individuals, these glands actively produce various fatty acids. However, as we age, sebum production decreases, and the proportion of unsaturated fatty acids increases, which are more prone to oxidation.

• Changes in Sebum Composition: The levels of triglycerides and neutral fats in sebum decrease, while the proportion of cholesterol and wax esters rises, making it more susceptible to oxidation.
• Relationship Between Sebum and Nonenal: Oxidized sebum remains on the skin surface, forming body odor. When nonenal combines with other oxidized fatty acids, it creates a distinctive scent.

Weakening of the Skin Barrier Function

Aging weakens the skin's protective barrier, increasing water loss and exacerbating skin dryness. This creates an environment that allows external pollutants, which can cause unpleasant odors, to penetrate the skin more easily and worsen the scent.

• Relationship Between Skin Dryness and Odor: Dry skin makes it easier for bacteria to remain on the skin. Pollutants decomposed by bacteria can turn into unpleasant smells.
• Keratin and Body Odor: As keratin accumulates and breaks down, microbial action can also contribute to body odor.

Hormonal Changes

Hormonal decline, especially in sex hormones, affects both sebum production and body odor. For men, testosterone levels decrease, while for women, estrogen levels drop after menopause, leading to changes in body odor.

• Hormones and Sebum Production: Hormones influence the body’s fat metabolism, so imbalances in hormones can alter the composition of fatty acids, affecting body odor.

Decline in Metabolic Function

Aging results in a decline in the body’s metabolic functions, making it harder to expel waste products. As a result, odor-causing substances may accumulate in the body.

• Increase in Reactive Oxygen Species: Reactive oxygen species are a major factor in oxidizing cells and tissues, which hinders the effective removal of waste products and toxic substances. This contributes to age-related body odor.

 

Managing and Reducing the “Old Person Smell”

The “old person smell” is a natural part of aging, but there are ways to mitigate it. Here are effective methods for managing body odor that can be easily implemented in daily life.

Consuming Antioxidant-Rich Foods to Prevent Oxidation

Consuming foods rich in antioxidants is important to reduce oxidative stress. Antioxidants such as vitamins C and E, polyphenols, and selenium help lower oxidative stress in the body and reduce the formation of oxidized by-products like nonenal.

• Recommended Foods: Blueberries, green tea, walnuts, and salmon.
• Benefits of Antioxidant Consumption: Antioxidants reduce reactive oxygen species in the body, inhibiting the production of oxidized by-products and positively impacting odor reduction.

Hydration and Adequate Water Intake

Staying hydrated helps maintain healthy skin and facilitates the removal of waste, which helps reduce body odor.

• Recommended Water Intake: It is advisable to drink around 2 liters of water daily to support metabolism and promote the efficient expulsion of waste.

Skin Care and Regular Cleansing

Regular skin hygiene and exfoliation are essential for removing oxidized oils on the skin. Pay special attention to areas prone to body odor, such as the underarms, back of the neck, and torso.

• Recommended Products: Use pH-balanced, mildly acidic cleansers.
• Shower Routine: Use lukewarm water instead of hot water to avoid stimulating the sebaceous glands.

Proper Clothing Care

Nonenal produced on the skin can linger on clothes, worsening body odor. Therefore, regular washing and wearing fresh clothes is essential.

• Washing Tips: Wash fabrics prone to retaining odor regularly, and consider wearing natural, breathable fabrics.

Regular Exercise

Exercise promotes waste elimination and supports metabolism, reducing the buildup of odor-causing substances in the body.

• Exercise Recommendations: Walking and light aerobic exercise are effective in reducing body odor. Be sure to stay hydrated and shower after sweating to maintain skin cleanliness.

 

Conclusion

The “old person smell” is a natural phenomenon that arises as we age, but it has various physiological causes. The production of nonenal, changes in sebum, hormonal decline, and metabolic slowdowns all contribute to body odor. Effective methods for managing this include consuming antioxidant-rich foods, maintaining skin hygiene, keeping clothes clean, staying hydrated, and exercising regularly. By adopting these small habit changes, it is possible to reduce body odor and maintain a more pleasant living environment throughout the aging process.

 

The “old person smell” is a natural part of life, but managing it can improve quality of life.