Shiitake (Lentinula edodes)

Shiitake mushrooms are far more than a delicious edible mushroom. They're also part of the functional mushroom family. Hailing from Japan, they're commonly called sawtooth oak mushrooms, black forest mushrooms, or oakwood mushrooms. 

The earliest record of their cultivation was in 1209 during the Song dynasty in China, and over the centuries, they have earned a reputation for their health and nutritional benefits. These include:

1. Skin and hair health
2. Immune system support
3. Liver support
4. Brain power

Skin and hair health

Your hair and skin require the right balance of vitamins, minerals, and nutrients to do their job. If you've got a nutritional deficiency, you'll notice brittle, dry hair and flaky skin.

Luckily, shiitake contains many of the essential ingredients for optimal skin and hair growth. First, it contains 1 gram of protein for every 4 dried shiitake mushroom⁶⁵. These amino acids are similar to meat⁶⁶ and can support keratin production, the key protein in hair and skin.

Moreover, it also contains a healthy dose of vitamin B5, vitamin D, zinc, and selenium⁶⁵. Together, they form the key building blocks of hair and skin. Your outer layer of skin has five times more zinc than the layer beneath it, and, alongside selenium, helps protect against UV damage⁶⁷.

Vitamin B5 helps relieve itchiness and promotes healing from skin conditions like eczema and insect bites⁶⁸. Vitamin D deficiency, meanwhile, is associated with hair loss as it's a critical compound in its growth⁶⁹.

Immune system support

In addition to its nutritional profile, shiitake also contains polysaccharides that support your immune functioning. One study identified a particular polysaccharide (L2) that enhanced immune responses by altering gene expression⁷⁰.

Another study of 52 people aged 21 to 41 years old found daily shiitake intake for 4 weeks boosted immune cell proliferation and activation and improved cytokine production. The result was an overall uptick in immune performance and lowering of inflammation⁷¹.

In one mouse study, shiitake mushrooms even appeared to reverse some age-related immune function decline⁷².

Combining its effect on skin and the immune system, a 2019 study reported an antibacterial effect against acne bacteria⁷³. In fact, it's even been used in some cosmetic products⁷⁴.

Weight loss

Shiitake mushrooms are a perfect addition to a weight loss diet with a high protein and fiber content and low calories. Indeed, a common problem for overweight individuals is maintaining adequate nutrition while losing weight. In rats fed a high-fat diet, shiitake mushrooms prevent excess fat in the liver and lower cholesterol levels compared to a no-mushroom diet⁷⁵.

Moreover, there's some indication they boost heart health. These fungi contain three compounds associated with lower cholesterol: eritadenine, sterols, and β-glucans^66,76,77. They've also been observed to prevent blood pressure increases in rats: a risk factor for heart disease⁷⁸