So, why is it that more than half of the population suffers from hay fever in Japan? In this article, I talk about the reasons why the number of hay fever patients is increasing from the viewpoint of oxidative stress.

Diabetes and Pre-diabetes

As some of you may know, there are more pre-diabetics in Japan than actually diagnosed diabetics.

There is a study called the Hisayama Study, which was conducted by Kyushu University on residents of the town of Hisayama from 1961, and the data showed that about 40% of the residents of the town had diabetes or pre-diabetes.

It is thought that the number of diabetics and pre-diabetics in Japan is actually double the estimated 20 million people announced by the Ministry of Health, Labor and Welfare.

In other words, 40 million people in Japan have diabetes or are pre-diabetic, which means that many of them have elevated blood sugar levels and oxidative stress. This is thought to be the case. Naturally, there is a causal relationship between these people and their susceptibility to hay fever. I think that the reason why hay fever is so common in Japan is because of the lack of adequate countermeasures against diabetes.

Reference

Hisayama Town Research Institute: Research theme "Diabetes"
http://www.hisayama.med.kyushuu.ac.jp/research/disease05.html

Ministry of Health, Labour and Welfare: Results of the National Health and Nutrition Survey, 2016
https://www.mhlw.go.jp/stf/houdou/0000177189.html

Oxidative Stress and Radical Treatment of Allergic Rhinitis (Hay Fever)

I believe that the reason why allergic rhinitis (hay fever) is so common among Japanese people is because many of them have very high levels of oxidative stress, that is, as mentioned above, many of them are diabetic or pre-diabetic.

By suppressing oxidative stress, the symptoms of allergic rhinitis (hay fever) can be considerably alleviated. However, even if the symptoms are alleviated, it is not a fundamental measure.

For example, cedar in Japan is an indigenous species of cryptomeria and japonica, but this cedar pollen is said to be extremely allergenic.

As a countermeasure, we are trying to plant other species of cedar, but it takes hundreds of years to grow, so it is highly unlikely that you will be able to hear about it in your lifetime.

So, why is it that cedar pollinosis does not occur where there is no cedar, but cedar pollinosis does occur where there is cedar?

There is a very clear answer to this.

In fact, deep in the mountains of the Himalayas, only cedar grows. It is a type of cedar called Himalayan cedar, and during the spring flowering season, pollen falls like a waterfall.

However, there are no hay fever sufferers among the people living there.

Why is that? Because they breathe very good air and eat only local food. They don't have exhaust fumes that can damage the mucous membranes of their throats and noses, and they don't eat foods that are bad for them. In other words, oxidative stress is not elevated.

In other words, there is no oxidative stress. This is why people living deep in the Himalayas are said to have no hay fever.

From this point of view, it is not that cedar causes cedar pollinosis, but that reducing oxidative stress is the most direct way to prevent hay fever.