I really have no need to get this question answered but I’m inquisitive. I went down a google rabbit hole just seeing if birch can be used for bbq wood. I learned about black birch and the wintergreen oil in it.

So this led me to an article about birch sap toxicity and all it said was it must be diluted before drinking. This is because it has methyl salicate which is toxic but is basically an NSAID.

Anyhow this is contradicted by numerous articles on making birch syrup and also drinking birch sap for health. I read the low amounts of methyl salicate needed to kill a person but nothing I found mentions the concentration in black birch sap.

So is the sap and syrup safe for consumption? Anyone?

Oh and I also learned why wintergreen lifesavers spark.

Never heard of consuming Birch but Willow bark is a potent nsaid.

Willow Bark: Nature’s Aspirin

https://www.healthline.com/hea...bark-natures-aspirin

What is willow bark?

Willow bark, the bark of several varieties of willow tree, has been used for centuries as a pain reliever. The active ingredient in the medicine made from willow bark is called salicin.

Some people use willow bark as an alternative to aspirin, particularly those that experience chronic headaches or back pain. Willow bark is also used in some products to aid weight loss.

It comes from the branches of 2- to 3-year-old willow trees. Willow trees and shrubs grow all over the world, except for Australia and Antarctica. The white willow and black willow are two of the most common willows that are used medicinally.
Side effects

When taken in moderation, willow bark does not appear to have negative side effects. The salicin in willow bark converts to salicylic acid. Some believe that this makes it gentler on your stomach than lab-created aspirin. Too much willow bark, however, can cause stomach cramping and bleeding.
Forms and dose of willow bark
Capsules

Willow bark can be purchased from many drugstores and almost any health food store in a powdered, encapsulated form. The recommended dose for pain relief is 240 milligrams a day.
Bark

The active ingredient in willow bark is salicin, but the accompanying flavonoids and plant particles might be part of what make willow bark effective. For this reason, some people prefer to actually chew on the unprocessed bark of the willow tree. It is difficult to determine how much salicin you are getting from each piece of bark, so this method of consumption should be approached with caution.
Liquid

Willow bark can also be found in a distilled tincture form. Taking a drop or two per day for pain relief (up to 2 milliliters) can work as an anti-inflammatory and pain relief substitute for aspirin.
Tea

Some health food stores sell willow bark tea, advertising it as a pain reliever and anti-inflammatory. Steep willow bark tea for two to three minutes in hot water. When consuming willow bark in this form, it’s hard to tell how much salicin you are getting in each serving of tea.
Topical

Willow bark can be used topically. Since it isn’t absorbed digestively, topical willow bark is a good alternative for those who commonly experience stomach ulcers. However, topical use can be harsh and cause skin irritation.
Potential benefits

When used on people with lower back pain, willow bark was foundTrusted Source to be more effective than placebo in a recent herbal medicine review. Conclusive data that contrasts willow bark to traditional aspirin is needed. However, if you’re looking for an alternative to aspirin, you could consider willow bark.

Willow bark can also be used to relieve menstrual cramps and bring down a fever. The salicin inside willow bark works the same way as aspirin, by reducing inflammation and pain as it enters your bloodstream. Because of the anti-inflammatory properties of willow bark, it may be especially effective in combatting joint painTrusted Source as well.
Potential risks of willow bark

There are some people who should not use willow bark. If you have an allergy to aspirin, it’s possible to have a reaction to willow bark as well. Willow bark can also interact with certain medications, like blood thinners and beta-blockers.

Children and adolescents up to the age of 16 are generally discouraged from taking willow bark for any reason. This is because of the risk of Reye’s syndrome, a rare condition that causes brain and liver damage. Pregnant and breast-feeding women are also discouraged from taking any medication that contains salicylates. People with gastric ulcers should be especially careful with willow bark, in the same way that they would be cautious with aspirin, because too much could cause stomach bleeding.
Current research

Even though it is used widely, very few clinical trials have been done to verify the effectiveness of willow bark. Preliminary studiesTrusted Source do show that there are some health benefits, and that certain species of willow contain higher concentrations of salicin and flavonoids than others.

In the studies that have been done, the risks and side effectTrusted Sources seem fairly minimal. And there are centuries of study and use of aspirin, which gets its active ingredient from willow bark.

Basically the same compound. Methyl salicylate in birch and salacin in willow break down to salacylic acid (the nsaid). In birch the methyl salicylate is what smells like wintergreen (it is wintergreen oil).

Methyl salicylate is potentially deadly, especially for young children. A single teaspoon (5 ml) of methyl salicylate contains approximately 6 g of salicylate,[22] which is equivalent to almost twenty 300 mg aspirin tablets (5 mL × 1.174 g/mL = 5.87 g). Toxic ingestions of salicylates typically occur with doses of approximately 150 mg/kg body weight. This can be achieved with 1 ml of oil of wintergreen, which equates to 140 mg/kg of salicylates for a 10 kg child (22 lbs).[23] The lowest published lethal dose is 101 mg/kg body weight in adult humans,[24] (or 7.07 grams for a 70 kg adult). It has proven fatal to small children in doses as small as 4 ml.[14] A seventeen-year-old cross-country runner at Notre Dame Academy on Staten Island died in April 2007 after her body absorbed methyl salicylate through excessive use of topical muscle-pain relief products.[25]
Most instances of human toxicity due to methyl salicylate are a result of over-application of topical analgesics, especially involving children. Salicylate, the major metabolite of methyl salicylate, may be quantitated in blood, plasma or serum to confirm a diagnosis of poisoning in hospitalized patients or to assist in an autopsy.

https://en.wikipedia.org/wiki/Methyl_salicylate

“ when a Wint-O-Green Life Saver is crushed between your teeth, the methyl salicylate molecules absorb the ultraviolet, shorter wavelength light produced by the excited nitrogen, and re-emit it as light of the visible spectrum, specifically as blue light -- thus the blue sparks that jump out of your mouth when you crunch on a Wint-O-Green Life Saver.”
https://recipes.howstuffworks.com/question505.htm

Fearsome I appreciate that but it is what I already read and doesn’t really answer my question. It doesn’t say how much of the oil is actually in the sap or if it is destroyed by heat (making syrup safe).

Icabod: that is a slightly different description than I read although the science is probably the same. Interesting stuff.