As well as being fascinating and beautiful, mushrooms have a range of intriguing nutritional properties that makes them a very valuable dietary addition.
1) Rich in copper and other minerals - a true "superfood"
The ancient Egyptians called mushrooms “sons of the gods” and “plants of immortality” and thought that the storm god Set created them by hurling lightning bolts coated in mushroom-seed to earth. Consuming mushrooms was the exclusive privilege of the pharaoh and his dining companions. In the 400s, an Egyptian scholar even described a recipe called "mykai", in which mushrooms were recommended as a healthy main course.
The Egyptians were right - mushrooms are rich in B vitamins and they also contain iron, phosphorus, copper, potassium and selenium. In fact, shiitake mushrooms are one of the best non-meat sources of copper available. Some species of mushrooms do contain vitamin B12, although a very large amount per day would be required to meet requirements.
2) Delicious umami flavour
Mushrooms can be really helpful to add a delicious savoury flavour to recipes where protein restriction is required for therapeutic reasons. Dried shiitake mushrooms, in particular, can add a beefy flavour to stock, which can improve palatability.
3) Production of vitamin D with exposure to UV light
Mushrooms are extremely unusual, in that they can produce vitamin D when exposed to UV light, rather like people can. No plants can do that.
In a paper by Urbain and Jakobsen (2012), "Dose-Response Effect of Sunlight on Vitamin D2 Production in Agaricus bisporus Mushrooms", the authors found that after just 15 minutes of sun exposure and an UV-B dose of 0.13 J/cm, the vitamin D2 content increased significantly to 2.2 ± 0.5 mcg/g DW, which is equivalent to 17.6 mcg (704 IU) vitamin D2 per 100 g of fresh mushrooms and comparable to levels found in fatty fish like the Atlantic salmon.
Other authors recommend slicing mushrooms and laying them plate on a board or plate. The mushrooms can then be placed in the sun for 30 minutes. More exposure is not better, with research demonstrating that the vitamin D content declines after several hours in the sun.
4) Excellent source of the antioxidants ergothioneine and glutathione
It has been well-established that mushrooms are the highest dietary source for the unique sulfur-containing antioxidant ergothioneine. However, they are also an excellent source of glutathione as well. These two antioxidants are believed to have the potential to help ward off diseases that come with ageing, such as heart disease and Alzheimer’s disease, however much more research is needed on this. The fat and handsome porcini mushroom was found to have much higher concentrations of these antioxidants - another reason to eat a lot of delicious risotto ai funghi porcini.
5) Significant immunomodulatory effects
One of the best-studied types of medicinal mushroom is the beautiful turkey tail or Trametes versicolor (pictured above), so named because it grows in autumn-color rings resembling feathers. Studies in humans and animals suggest that a component of turkey tail, polysaccharide-K (PSK), may stimulate the immune system. In clinical trials, the supplement appeared to improve survival for people with gastric or colon cancer and, although the evidence is not as strong, may also benefit those with other types of cancer.
"I'm Yunity" is a polysaccharopeptide supplement derived from turkey tail, that has been specifically developed for dogs on the basis of Brown and Reetz's 2012 paper, "Single Agent Polysaccharopeptide Delays Metastases and Improves Survival in Naturally Occurring Hemangiosarcoma". The authors found, in a double-blind randomized multidose pilot study, that high-dose polysaccharopeptide significantly delayed the progression of metastases and afforded the longest survival times reported in canine haemangiosarcoma.
Several clinical trials show that a similar compound, lentinan, extracted from shiitake mushrooms, extends survival in patients with stomach, prostate, colorectal and liver cancers when combined with chemotherapy. Both PSK and lentinan are approved in Japan as an addition to conventional therapies for treating cancer. Much more research is needed on the safety and efficacy of medical mushrooms for veterinary patients, however there seems to be some promising results in other species.
So, plenty of reasons to add mushrooms to home-prepared diets for dogs (and to your own diet as well!) If you would like any more information: firstname.lastname@example.org