Differences in Body Odor between Japanese and Foreigners: Surprising Relationship between Genetics and Culture


Are you concerned about body odor from foreigners? Different countries and cultures show great differences in how they perceive and respond to body odor. Here, we delve deeper into the differences between Japanese and non-Japanese body odor and examine the causes of these differences.

There are trends in body odor by country, but there are great individual differences.

Causes and Types of Body Odor

Body odor is mainly caused by sweat and sebum and their mixing with bacteria on the surface of the skin. Sweat and sebum themselves are odorless, but when decomposed by bacteria, they produce a variety of odors. These odors vary from person to person and depending on the environment in which they live. There are two main types of odor: Eccrine odor and Apocrine odor.

Eccrine Odor

Eccrine odor is caused by sweat secreted from the entire body to regulate body temperature. This sweat consists mainly of water and salt and is originally odorless, but if left untreated, it will emit a sour odor due to bacteria. This odor becomes stronger if left unattended after sweating.

Apocrine odor

Apocrine odor is caused by sweat secreted by apocrine sweat glands. Apocrine sweat glands are abundant in the armpits, nipples, and anus and are active when stressed or sexually aroused. This sweat contains fat and protein and is odorless, but when decomposed by bacteria, it produces a strong odor. This odor is sometimes referred to as Wakiga in Japan.

While foreigners are often unconcerned about apocrine odor or cover it with perfume, Japanese people are said to have a relatively small number of apocrine sweat glands to begin with. This is one of the reasons why Japanese people have relatively light body odor. There is also research showing that Japanese people have genetically low activity of enzymes that produce substances that affect body odor.

However, since there are individual differences, some Japanese have armpit odor, and many foreign nationals are odorless.

Rates of armpit rash by region

Rates of armpit rash (medically known as armpit odor) is a distinctive and strong body odor caused by secretions from the apocrine sweat glands.
The condition is strongly influenced by genetic factors and varies in incidence by specific regions and ethnic groups. The following table shows the rates of armpit odor by region of the world.

Region Rates of armpit rash
Europe and America 50 – 60%
Africa 95%
East Asia (including Japan) 10 – 20%
Middle East 30 – 40%
South Asia 70 – 80%

As can be seen from this table, it can be said that many people in regions such as Europe, the United States, Africa, and South Asia have arachnidism. On the other hand, there are fewer people with armpit rash in regions such as East Asia and the Middle East.

Japanese people may have a strong aversion to armpits because there are few people with armpits, but in some countries, armpits are a natural part of the body and are not particularly bothersome.