노랑느타리버섯, 노화억제, 에르고티오네인, ergothioneine, Yellow oyster mushroom, anti-aging

 

 

노랑느타리버섯은 일반 느타리버섯과 생김새는 비슷하지만 갓 색깔이 노란색을 띠는 것이 특징이다.

농촌진흥청 국립원예특작과학원에 따르면 일반 느타리버섯보다 항산화 작용은 3.1배, 혈전 용해 작용은 약 3.3배 높다. 면역력을 높여주는 베타글루칸 함량도 느타리버섯 가운데 가장 높고 혈압을 떨어뜨리는 데도 한몫을 한다. 버섯에서 항산화제 역할을 하는 물질이 에르고티오네인(ergothioneine)이란 아미노산이다.


스웨덴 룬드대 연구진은 2020년 수천명의 건강 데이터를 장기간 추적한 결과, 에르고티오네인의 높은 수치와 심혈관 질환과 조기 사망 위험 사이의 상관관계를 확인했다. 그러나 둘 사이의 인과관계를 규명하지는 못했다.

일본 구마모토대 연구진이 생쥐 실험을 통해 이를 확인한 연구 결과를 공개학술지 ‘NPJ 노화’에 발표했다.

연구진은 생후 8주로 중년에 들어선 생쥐 10마리에게 매일 노랑느타리버섯 분말을 먹이고 심장 건강 상태를 추적했다. 먹인 양은 몸무게 1kg당 9g이었다.

1년 후 확인한 결과 노랑느타리버섯을 먹은 생쥐들은 그렇지 않은 생쥐들보다 심장 기능이 상당히 좋은 것으로 나타났다. 이 생쥐들은 심장이 수축할 때마다 평균적으로 20% 더 많은 혈액을 분출했다. 또 다른 생쥐들보다 더 빨리, 더 멀리 달릴 수 있었고, 심부전과 관련한 유전자 발현이 더 낮았다. 나이가 더 들면 이런 생체 활력 지표가 더 나빠지는 것이 일반적인 것과 다른 현상이 나타난 것이다. 노화와 심부전으로 인한 심근비대 현상도 상대적으로 덜했다.

연구진은 이는 노랑느타리버섯이 심혈관 노화를 억제하는 효과가 있음을 보여주는 것이라고 설명했다. 연구진은 추가로 분석한 결과 이 버섯이 심장과 혈관의 세포를 활성산소의 공격으로부터 막아주는 걸 확인했다.


펜실베이니아주립대 로버트 빌먼 교수는 과학전문지 뉴사이언티스트에 “에르고티오네인에 강력한 항염증 효과가 있다는 건 알려진 사실이므로 이번 연구의 결론은 타당하다”며 그러나 생쥐 연구 결과가 사람한테 그대로 적용되는 건 아니라고 말했다. 또 생쥐에게 먹인 버섯의 양은, 사람(몸무게 80kg 기준)으로 치면 하루에 720g이나 되는 엄청난 양이라고 덧붙였다.

연구진에 따르면 에르고티오네인은 열과 산에 강해 가열조리에도 파괴되지 않고 장기보관도 가능해 실용적 가치도 높다. 연구진은 “에르고티오네인 보충제만으로도 비슷한 효과를 볼 수 있지만 버섯 자체에 함유된 다른 생리활성 화합물이 에르고티오네인의 효과를 높일 수 있으므로 버섯으로 섭취하는 것이 더 바람직하다”고 밝혔다.


농촌진흥청에 따르면 노랑느타리버섯은 우리나라에는 비교적 덜 알려져 있지만, 일본에서는 노랑느타리버섯을 활용한 다양한 가공식품이 시판되고 있고, 화장품 소재로도 쓰인다. 국립원예특작과학원은 노랑느타리버섯의 보급을 위해 지난해 향은 줄이고 감칠맛은 높인 ‘온누리’ 품종을 개발했다.

 

 

 

Yellow oyster mushrooms are similar in appearance to ordinary oyster mushrooms, but are characterized by a yellow color.

According to the National Institute of Horticultural Science under the Rural Development Administration, the antioxidant activity is 3.1 times higher than that of ordinary oyster mushrooms and the thrombolytic activity is 3.3 times higher. Beta-glucan, which boosts immunity, is also the highest among oyster mushrooms and also contributes to lowering blood pressure. The substance that acts as an antioxidant in mushrooms is an amino acid called ergothioneine.


Researchers at the University of Lund in Sweden conducted a long-term follow-up of health data from thousands of people in 2020 and determined a correlation between high levels of ergothionein and the risk of cardiovascular disease and early death. However, they have not been able to establish a causal relationship between the two.

Researchers at Kumamoto University in Japan published the results of the study confirming this through mouse experiments in the open academic journal 'NPJ Aging'.

The researchers fed yellow oyster mushroom powder every day to 10 mice that entered middle age at eight weeks old and tracked their heart health. The amount fed was 9 grams per kilogram.

A year later, the mice who ate yellow oyster mushrooms showed significantly better heart function than those who did not. These mice released an average of 20% more blood each time their heart contracted. They were able to run faster and farther than other mice and had lower heart failure-related gene expression. This vital index worsens with age, which is a different phenomenon from the norm. There were relatively less myocardial hypertrophy due to aging and heart failure.

The researchers explained that the yellow oyster mushroom is effective in suppressing cardiovascular aging. The researchers further analyzed the mushrooms and confirmed that they protect the cells of the heart and blood vessels from free radicals.


Professor Robert Bilman of Pennsylvania State University told The New Scientist that the conclusion of the study is valid because it is known that ergothionein has a strong anti-inflammatory effect. However, the results of the mouse study do not apply to humans. He added that the amount of mushrooms fed to mice was as much as 720 grams per day (based on their body weight of 80 kilograms).

According to the researchers, ergothionein is resistant to heat and acid, so it is not destroyed by heating and can be stored for a long time, which has high practical value. "Eggothionein supplements alone can have similar effects, but other physiologically active compounds contained in mushrooms themselves can increase the effectiveness of ergothionein, so it is more desirable to eat them as mushrooms," the researchers said.


According to the Rural Development Administration, yellow oyster mushrooms are relatively less known in Korea, but various processed foods using yellow oyster mushrooms are on the market in Japan and are also used as cosmetic materials. The National Institute of Horticultural Science developed a "Onnuri" variety last year that reduced the scent and increased the taste of yellow oyster mushrooms.