I was on a television talk show recently, and I had brought along something for the other guests to taste: branch tips from spruce and Douglas-fir. The spruce, the most common tree in Germany these days, is relatively well known. The Douglas-fir, less so. It is a conifer native to the west coast of North America, where these trees grow into impressive, ancient giants. In recent decades, more and more of them have been planted in Germany, but that was not the focus of the program. I had chosen the Douglas-fir branch tips because, in my opinion at least, they have the pleasantly tangy taste of candied orange peel. My fellow guests, the actor Axel Prahl and the cabaret performer Ilka Bessin, con-fidently bit into the soft, green tips—and quickly spat them out. They did not like the taste at all. A reaction they share with most people.
The flavours of the forest are mostly variations on tart and bitter and all the nuances in between. Those things we find delicious—that is to say, ripe nuts and berries—are usually in short supply and available for only a few weeks of the year. In spring, fresh growth and new leaves are tart, turning bitingly bitter and tough later in the season. A tree’s cambium, a crystal-clear layer just under the bark that you can peel off with a pocketknife, is highly nutritious. It contains sugar and other carbohydrates, and tastes a bit like carrots, but on the whole, I would say it, too, tastes bitter. And that is the case for just about all the food you can find in the forest.
I’m fairly certain that in the dim and distant past, the majority of the meals our ancestors ate tasted completely different from the meals we eat today. Our food and drink, just like the environment in which we live, have under-gone evolutionary change. The only products that survive on supermarket shelves are the products people buy. And so, manufacturers develop foods that appeal most to our sense of taste. Their methods get ever-more sophisticated and match our desires ever-more precisely, which is also one of the reasons we find it so difficult not to reach for those particular foods. Sugar, salt, and fat—enrich that combination with other flavour enhancers, and we end up eating more than our body needs. In the process, we increasingly forget what natural, unprocessed food tastes like. I don’t mean fruits and vegetables, because even these are being similarly transformed through selective breeding: always sweeter, always with fewer bitter compounds. In comparison with the rich variety of flavours available in nature, the food we eat all tastes more or less the same. Only certain particularly bitter or sour foods stand out, such as coffee or pickles.
Luckily, you can never completely spoil your sense of taste or dull your papillae, the taste centres on your tongue. A single papilla contains one hundred taste buds, and each taste bud contains one hundred sensory cells. These cells are not particularly long lived; they are renewed every ten days.16 This means if you damage one of them when you are eating—for example, if you drink something that is too hot—your tongue heals relatively quickly.
If there are about one hundred papillae, that means we have about 10,000 taste buds. If that seems like way too many to you, just take a look at a horse’s tongue, where you will find about 35,000 taste buds. Why do horses need this many? There are hundreds of different kinds of grasses and weeds in every meadow, and quite a few of them are poisonous. A horse also has difficulty seeing anything that is directly in front of its lips because its huge, elongated head gets in the way. And if you can’t see what you’re eating, you have to rely on your tongue. If you’re going to do this, the plant in question has to get into your mouth and then be removed quickly if it turns out it’s not good to eat. Horses have mastered this perfectly. Miriam and I own two mares, and we never tire of watching them eat. If a bit of greenery is not to a horse’s taste, it carefully moves it to the side of its mouth as it chews and from there the offending slip of green is eventually released back into the outside world by way of the horse’s lips.
While we are on the subject of the tongue: it’s not the only body part we taste with. First, let’s return to our nose. Currently, we know of about eight thousand substances in food that evaporate easily so we can smell them. Amazingly, we do most of this smelling as we exhale. Three-quarters of our sensation of taste is based on what our nose picks up. You might know this from when you have a cold: food immediately tastes bland, and you no longer enjoy what you are eating. And so it makes perfect sense when you are out on your next walk in the woods to figure out the differences between tree species not by investigating the shape of their needles and leaves, but, like Ilka Bessin and Axel Prahl, by biting into a spruce tip to see which taste and scent compounds are to be found in the needles.
As I mentioned earlier, our search for taste sensors doesn’t end in the mouth. We need to travel farther down the alimentary canal, into the gut. Just as the gut joins the nose in smelling things, it also joins the tongue in tasting things. It, too, contains sensors that were once thought to belong only in the nose. These cells are less easily tricked by sugary things than the cells in our palates. Normally, sugar, which the small intestine recognises, triggers a release of hormones. Our consciousness registers this as a signal we are full. When we eat artificial sweeteners, however, this signal malfunctions and becomes weak and intermittent, which means our body craves more food. For this reason alone, “lite” products manufactured with sugar substitutes are not particularly effective if you want to lose weight.
Thanks to modern cosmetics—and perfumed laundry products, fragrant candles, and the like—not only our noses and our palates, but also our guts are swamped with scents. Wait a moment. Who eats cosmetics, laundry products, and candles? The answer is simple: we don’t need to eat them for them to get inside us, because we absorb them through our skin and airways not only into our guts but also into every other corner of our body. And when we ingest flavour – enhanced foods, a veritable armada of artificial compounds drifts down our alimentary canals to overwhelm our sensory receptors.
According to the German Federal Institute for Risk Assessment, 2,700 (overwhelmingly artificially synthesised) aromas are added to food products. That doesn’t seem like very many when you compare them with the smells that are present in nature: to date we have identified about ten thousand of those. But numbers alone are deceiving. In our daily lives, we would encounter very few of these natural smells. After all, we don’t taste every fruit in the world, only the ones that grow close to where we live—or at least that used to be the case before the advent of global trade.
Nowadays, our gut is overwhelmed by an unbelievable number of alien aromas. That can cause it to act up occasionally and lead to all sorts of intestinal complaints, because sensing aromas, depending on which ones they are, can, as I mentioned earlier, trigger the release of chemicals and change the way our gut moves.
What has all this got to do with the forest? Well, we’ve adapted to the smells and tastes of this natural ecosystem, and we’re just fine with them. Artificial additives, however, stress our systems unnecessarily. Therefore, it’s a good idea to give your nose, palate, and gut a break every now and again by going out into the forest and spending a good long time there. Everything that flows over your senses when you are in the forest is exactly the kind of compound your body is made for. If you take along a snack of natural, minimally processed food without additives, then your time spent forest bathing will be even more beneficial.
PETER WOHLLEBEN is a forester and author of numerous books, including the international bestseller The Hidden Life of Trees which has sold more than 150,000 copies in the UK alone, over 3 million worldwide and has been in the Top 10 bestseller lists in 13 different countries. He also manages a sustainable forest in Germany and runs a forest academy. ‘Nature Doesn’t Always Taste Good’ is an extract from his new book The Heartbeat of Trees.