If you see fresh shiitake mushrooms on sale, snap them up quick. Not only do they taste delicious, but Shiitake mushrooms (Lentinula edodes or Lentinus edodes) have been used medicinally for over 3,000 years to treat high blood pressure and raised cholesterol levels. In ancient Japan, shiitake was considered an ‘elixir of the life’ and they were eaten to increase energy and vigor, and to protect against heart disease and infections. You can buy shiitake fresh, dried to add to soups and sauces, or as powder or capsules if you prefer to take them in supplement form.
Nutritional benefits of shiitake
Shiitake is the second most popular edible mushroom worldwide, after the common white button mushroom (Agaricus bisporus) but have a far superior nutritional value.
Shiitake provide all essential amino acids, vitamins B1, B2, B12 and C and have the highest content of vitamin D of any plant foods (679 mcg per 100g). Shiitake also provide magnesium (200mg per 100g), calcium (127mg per 100g) which have direct blood pressure lowering actions, and a substance called eritadenine which lowers cholesterol levels and blood pressure.
How shiitake mushrooms lower blood pressure
The eritadenine found in high concentration in shiitake, and some other edible mushrooms (eg oyster mushrooms, enoki, porcini, Reishi and Maitake) lowers blood pressure by blocking angiotensin-converting enzyme (ACE) in a similar way to the ACE inhibitor class of antihypertensive drugs. This reduces blood vessel constriction so that arteries and veins can dilate to lower a high blood pressure.
Of all the edible mushrooms tested, Lentinus edodes, or shiitake, contained the highest amounts of eritadenine, providing as much as 642.8 mg per 100g, and tests showed it was a strong, competitive inhibitor for ACE. Preclinical studies also suggest that shiitake extracts stimulate the removal of excess sodium via the kidneys to reduce fluid retention.
It’s therefore not a surprise that people with the highest intake of mushrooms have a blood pressure that is around 5 mmHg lower than those who eat the least.
In one study, a group of overweight people who substituted mushrooms for red meat for one year lowered their blood pressure by an average of 7.9/2.5mmHg compared with a similar group who continued on their standard diet, as well as losing 7lbs (3.2kg) in weight.
Shiitake mushrooms lower cholesterol
Extracts from shiitake mushrooms also block the activity of an enzyme, HMG-CoA reductase, so that cholesterol production in the liver is reduced. This inhibitory activity is not due to the presences of natural statins (like those found in red yeast rice) but to the presence of α-glucans, β-glucans and fucomannogalactans, and eating shiitake mushrooms can help to improve cholesterol balance as well as lowering a raised triglyceride level which often accompanies high blood pressure.
Other health benefits of shiitake mushrooms
Shiitake is the source of a unique beta-glucan, called lentinan, which boosts immune function. Leninan stimulates the activity of white blood cells, increases your production of natural anti-viral agents (interferons) and boosts the activity of a group of antioxidant enzymes, called superoxide dismutases. Lentinan is even an approved immunotherapy treatment for stomach cancer in Japan where it is used to prolong survival.
Substituting mushrooms such as shiitake for at least half the meat in familiar dishes such as lasagne and chilli, can halve the calorie content of a meal and increases its filling power without reducing palatability or satisfaction. Because of the ‘umami’ factor of mushrooms, it even improves the savouriness and flavour. See how to make shiitake that tastes like bacon below!
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