Are Ginkgo nuts really edible?

Last week I posted on some various nuts we’ve considered growing. We also took a deeper look at chestnuts, and I shared our latest video:

In the list of nuts, I wrote:

Ginkgo makes good nuts, but it’s sure hard to find fruiting ones since people hate the female trees because of the fruit’s rancid odor. They also take decades to fruit.

In response, Tonya emailed me to say:

I would use caution when ingesting ginkgo nuts. They are known to inactivate vitamin B6 in the body. See the following article. Asians use ginkgo nuts as a tonic and not in large quantities.

She links to this article from the Hong Kong Centre for Food Safety, which states:

MPN is found in the food storage tissue of the ginkgo seeds.  It has an antivitamin B6 activity and inhibits the formation of 4-aminobutyric acid (GABA) from glutamate.  GABA and glutamate play a role in transmitting nerve signals from one nerve cell to another. The dual effect of a decrease in GABA and an increase in glutamate is believed to induce seizures and convulsions. Cooking cannot inactivate MPN; however, it can reduce the toxicity of the seeds, probably by inactivating heat-labile toxins such as cyanogenic glycosides.  It is worth noting that immature and uncooked ginkgo seeds are more toxic. 

Yet earlier in the article, it also states:

The ginkgo seeds (Bai Guo in Chinese) are commonly consumed as food in Asia (especially China, Japan and Korea); they are used as an ingredient in congee, soups, dinner dishes and desserts.  It is also not uncommon to see food premises serving Japanese-style grilled ginkgo seeds and street hawkers selling fried/roasted seeds.

And Green Deane reports:

People with a vitamin B6 shortage should not eat cooked Ginkgo seeds. Children under six should not eat more than five (5) cooked seeds a day. No one should eat cooked Ginkgo seeds every day. Skipping a day is recommended.  In a well-fed society eating a few cooked seeds in season is not a problem. But if you eat 50 cooked seeds AND have a poor diet (and or you’re a kid, thus less seeds needed) it can be an issue. There is a chemical in Ginkgo seeds (4-methoxypyridoxine) that is anti vitamin B6. Thus if you are experiencing a famine and are low on B6 and you eat a lot of Ginkgo seeds it’s a combination for misery. 4-methoxypyridoxine is thought to be related to the chemical that makes China Berries non-edible. Also some people get contact dermatitis from handling fresh Ginkgo fruit. The fruit have some urushiol, the active chemical in poison ivy which is why you wear gloves when collecting them.

Yet Greene Deane also says they are worth harvesting and eating, as they are delicious.

We’ve only seen them fruiting in the “wild” once, and that was at an Interstate rest area in Georgia. The stinky fruits were all over the ground.

Since then, we haven’t ever found any, and we don’t have any on our property. Considering the potential health problems associated with the seeds, it’s probably not worth planting them on purpose as a nut tree.

It rather reminds me of the problems with cashews. Down in Grenada there were cashew trees here and there, scattered around the island.

Some of the locals would harvest the fruit and take the “nuts” off the bottoms to clean and roast over a fire to make them edible. They called it “burning dem,” and it had to be done in the open as the smoke could really mess you up.

Cashew “nuts” before processing

The fruits themselves were also supposed to be good for juicing, but when we tried drinking the juice the high oxalate content burned our mouths and throats.

Overall, not worth planting except as a curiosity, unlike friendlier nuts like monkeypot, pecan and chestnut.

From now on, we’ll put Gingko in the same category. I had read about them being tasty, but hadn’t done any real research into their potential side effects since we’ve never really had the opportunity to do anything with them.

So are they edible? Yes, technically, but with some important caveats.

1. Don’t eat them raw
2. Don’t eat very many of them
3. Don’t eat them every day

The trees are still beautiful, however, so I wouldn’t mind planting them just as an ornamental.

*Image at top via Blue Record on Pexels.