Do you eat seasonally? We have evolved to eat with the seasons, and while autumn brings comfort food for cold days such as squashes and roots, spring brings a certain amount of bitter tastes! In spring, we start to see an increasing availability of fresh greens. There are wild plants that can be foraged, such as wild garlic or even humble dandelion leaves, as well as cultivated crops like spring greens and spinach. Then salad leaves come into season as we move into summer.
Many people today have become so used to sweet tastes that they shy away from bitter tasting foods. However, I would encourage you to give bitter tastes a try, as they have potent health benefits. And whilst many greens are certainly bitter tasting, there are other foods and drinks that are bitter too.
Physiological Effects of Bitter Tastes
Bitter is one of 5 tastes, the others being sweet, sour, salty and umami. We have bitter taste receptors on our tongue, but also in our digestive tract, our brain and even in immune cells(1). There are substantial genetic variations in the perception of bitter taste between individuals, with some people being bitter supertasters. A supertaster ability in detecting bitter tastes would have been beneficial for our ancestors, as it would have enabled them to avoid eating poisonous plants, which tend to be bitter. Some of the same mechanisms that protect us against the effects of bitter poisons paradoxically benefit our health when we eat bitter plants that are not poisonous.
When you eat something bitter, a hormone called cholecystokinin (CCK for short) is released in your gut(2). CCK is an important hormone when it comes to digestion; it stimulates the pancreas to release digestive enzymes, it increases the liver’s production of bile, it regulates the movement of food through the gut, and it increases satiety (the feeling of fullness after eating)(3). This means that eating bitters helps with:
- good digestion
- removing toxins from the body, as many are removed via the bile
- absorption of dietary fats and fat-soluble nutrients, as bile breaks down fats so that they can be absorbed
- preventing gallstone formation, as it is sluggish bile rather than free-flowing bile that encourages their formation
- appetite control
Many cultures around the world have long recognised that bitters improve digestion. Small salads are often served as antipasti or entrées in Europe to prepare the digestive system for heavier foods to follow. Of course, there are also bitter “digestif” drinks. Rich foods typically require bile to break down the fats they contain, and bitters pave the way for this to happen smoothly. The pancreatic enzymes that are released in response to bitter tastes also help with breaking down fats, as well as protein and carbohydrates.
It’s thought that the upregulation of liver function and bile production that occurs when we taste something bitter developed in order to get toxins out of the body efficiently and thus reduce risks from poisoning!
Appetite and Blood Sugar
Given the health implications of the obesity epidemic, the fact that bitters increase satiety and therefore can help regulate appetite has clear benefits. This is in direct contrast to the effects of ultra-processed foods, which are often engineered to be “hyperpalatable”, so that we eat (and buy) more of them(4). The contrast between the two is just one example of how eating unprocessed foods, in their natural state, has health benefits that go beyond the amounts of fat, sugar or salt on food labels.
Of course, many of us have taste buds that have become accustomed to sweet tastes rather than bitter. Even if we avoid refined sugar, sweeteners and ultra-processed foods, many fruits and vegetables have been selectively bred to increase their sweetness. This means that if we do not actively seek out bitter foods, our taste buds are exposed to fewer strong bitter tastes than our ancestors would have been. If you are very accustomed to sweet tastes, it might at first seem difficult to eat bitter foods. However, if you persist with bitter tastes they might help reduce your sweet tooth. Animal studies suggest that bitter tastes might shut down receptors in the brain that drive sugar cravings(5). When bitter taste receptors are activated, it helps keep blood glucose levels regulated(6), (7).
Examples of Bitter Foods
Some examples of bitter foods that you can include in your diet are:
- dandelion leaves (yes, really, but pick from an unpolluted spot and wash thoroughly)
- kale and other cruciferous vegetables
- radicchio (my personal favourite)
- extra virgin olive oil
- bitter Melon
- dark chocolate
- apple cider vinegar
So now that you know some of the health benefits of bitter tasting foods, which are you going to introduce into your diet first?
- Lu, P., Zhang, C.-H., Lifshitz, L. et al. (2017). ‘Extraoral bitter taste receptors in health and disease’, Journal of General Physiology, 149(2), pp181-197. Available at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5299619/ (Accessed 22 March 2023).
- Jeon, T.-I., Seo, Y.-K. and Osborne, T.F. (2011). ‘Gut bitter taste receptor signalling induces ABCB1 through a mechanism involving CCK’, Biochemical Journal, 438(1), pp33-37. Available at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3319131/ (Accessed 22 March 2023).
- Tack, J., Verbeure, W., Mori, H. et al. (2021). ‘The gastrointestinal tract in hunger and satiety signalling’, United European Gastroenterology Journal, 9(6), pp727-734. Available at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8280794/ (Accessed 22 March 2023).
- Great Britain. Department for Environment, Food & Rural Affairs (2021). National Food Strategy Independent Review: The Plan. [Online]. Available at https://www.nationalfoodstrategy.org/the-report/ (Accessed 22 March 2023).
- Lvovskaya, S. and Smith, D.P. (2013). ‘A spoonful of bitters helps the sugar-response go down’, Neuron, 79(4). Available at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3806211/ (Accessed 22 March 2023).
- Dotson, C.D., Zhang, L., Xu, H. et al. (2008). ‘Bitter taste receptors influence glucose homeostasis’, PLoS One, 3(12), e3974. Available at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2597743/ (Accessed 22 March 2023).
- González-Castejón, M., Visioli, F. and Rodriguez-Casado, A. (2012). ‘Diverse biological activities of dandelion’, Nutrition Reviews, 70(9), pp534-547. Available at https://academic.oup.com/nutritionreviews/article/70/9/534/1835513?login=false (Accessed 22 March 2023).