Making a case for bitter foods

Not every flavour needs to comfort us,” says Prateek Sadhu, 40, founder and executive chef of Naar, the Himalayan speciality restaurant in Kasauli, Himachal Pradesh. He describes bitterness as one of the more misunderstood flavours, often sidelined, minimised by curing it down, rather than celebrated for the story it tells of its location, time and context.

Our foraging ancestors used bitterness to identify toxicity. Research, including on neem flower toxicity by Thailand’s National Cancer Institute, and the Gut Peptide Research Lab at KU Leuven, Belgium, shows an excess of bitters activates gut receptors to trigger nausea and warn you off potential toxins, intake of which can affect liver function and weight. However, to avoid all bitters as toxic would be a mistake.

Chinese philosopher Confucius likened bitter foods to unpalatable advice, both healing in role. Traditional food systems such as Ayurveda have propagated the inclusion of bitter foods in meals. Homely wisdom has perceived it as a balance on the plate and palate. However, researchers probing the gut-brain axis today are pin-pointing the role of bitters beyond taste alone, in hormone signalling with applications in weight loss, infertility, wound healing and cancer treatment. These findings are what have sparked the Semaglutide era, the creation of compound drugs and supplements that exploit bitter receptors to curb overeating.

On the food side, as sustainable farming movements provoke a rediscovery of wild varietals, heirloom seeds and foraged foods, and moving away from over-farmed genetically modified variants, bitters are coming back to the table.

Research in The American Journal of Clinical Nutrition by Adam Drewnowski and Carmen Gomez-Carneros (2000) shows that fruit and vegetables rich in polyphenols, flavonoids, isoflavones and other compounds offer anti-oxidant and anticarcinogenic properties. But since all such compounds are astringent and bitter, consumers are averse to them—so growers and producers consciously keep produce sweeter at the cost of nutrient value. A local example would be sweet corn varietal replacing the less appealing desi corn.

Professor Anil Gupta, founder of the Gujarat Grassroots Innovation Augmentation Network (GIAN), set up in 1997 in collaboration with IIM Ahmedabad and the Honey Bee Network that documents and disseminates grassroots knowledge, offers the example of the jungli bitter gourd. The vegetable was documented by Prof. Anamika Dey and her GIAN team at Pelling, Sikkim, under a department of biotechnology project (DBT) between 2022-24. They found that local villagers have been using the varietal in curries, juices and herbal drinks, during the turn of the harsh winters as a liver detox and to control blood sugar.

The project also documented bitter foods such as hog plum, a bitter used in pickles, and the acerbic seeds of the timur fruit, also known as grapefruit pepper. Timur is used locally to relieve a toothache or to cure a cough or cold, while the lapsi (hog plum) aids digestion and is used for gut health. Since these are still wild foraged plants, their uses have not yet been scientifically corroborated by any study, it’s the ongoing documenting of such folk wisdom that is our primary resource to knowing bitters.

Systematic efforts to commercialise farming of the wild bitter melon, known as jhaar karela in Punjab, have been on at the Punjab Agricultural University, Ludhiana since 2008. Sustained efforts to document and revitalise wild varietal are why some variants are now available in grocery stores.

With the rising focus on sustainable, organic farming and the documentation of indigenous food systems, knowledge that was once highly localised and regionalised, native wisdom is now becoming accessible. India has a plethora of bitters that are well-used in regional cuisine but remain outside the scope of commercial farming. Pharmacological research is only beginning to test and exploit the impact of compounds in local and wild varietals, and bitters are quickly becoming valuable in the way extracts of curcumin and the wild gooseberry have shown to be, with a flurry to extract value for medicinal application mainly in weight-loss drugs du jour. The bitter pill is only offering at a higher cost and with expensive side effects what the bitter fruit of the vine in your grandmother’s stew may be offering you for free.

A SEASONAL PALATE CLEANSER

The first foray of bitters is seasonal. In early March and April, before the rains start trickling in, the bitters in leaf, root, berry, flower are budding and become part of regional delicacies everywhere.

Bitterness is not a flaw in the food. It’s a story in the food that needs to be understood, Sadhu says. “The first leaves of wild herbs and flowers that emerge from the thawing ground of winter carry bitterness with them as a cleanser for the digestive system that needs to release the fatty warmth stored during the cold months. Bitter resets the palate during seasonal change and carries with it a story of time and place.” It tells a story of seasons, earth, climate, nutrition, and a philosophy of intensification through a process of constraint.

In the month of Chaitra, which falls in April-May, tender neem leaves called limbdo are added to buttermilk-based kadhis and curries in Gujarat and Rajasthan. Gupta says iskus ko paat or chayote leaves, kaancho ningro or young fern tips, kaalo saag or local wild greens, fermented bamboo shoot, farsi ko paat or pumpkin leaves, and radish leaves are used in Sikkim. Karnataka, Tamil Nadu and Andhra Pradesh take to neem flowers for their new year festivals. Why now? Tenderness is key.

Shruti Tharayil, 37, founder of Goa-based Forgotten Greens, conducts urban wild food walks all over the country to reintroduce people to edible wild greens through foraging. Often, she says, she will ask participants to taste the greens, and there are few takers for the bitter ones, such as bhui amla, though these are often the ones with the most nutritional value. The mistake, she notes, is in assuming all leaves have a linear bitterness. “Traditionally, we have always eaten the tender leaves, precisely because as the plant fruits and flowers, the leaves become increasingly bitter.”

Sadhu points out that all bitters are not the same in nature. Watercress lends a gentle undertone, while walnuts add an earthy bitterness. You have to find the bitter tone that works for you.

Research scholar Palanivelmurugan Mohanasundaram at the Vellore Institute of Technology has been working on extracting bioactive wound-healing properties of neem flowers. Mohanasundaram’s research, co-authored with his guide Mary Saral Antoneyraj, professor and former dean of the School of Advanced Science’s chemistry department, has found the flowers to be anti-oxidant, anti-bacterial, anti-fungal, and anti-tumour. “Bitter compounds in excess do trigger toxicity, so extraction of properties is a safer way to utilise their healing benefits,” he says. Bitter ingredients, he warns, are seasonal for a reason. While they can be dried and used throughout the year, in everyday consumption, moderation and proportion is advised.

When and how to use bitters is a kind of native wisdom however that is increasingly being lost, warns chef Thomas Zacharias, 40, who left The Bombay Canteen in 2020 and founded The Locavore in 2022, which champions local foods and food traditions. He is just back from guiding a group trip centred on the food culture of the Idu Mishmi tribe in Lower Dibang Valley in Arunachal Pradesh. “Food wisdom is documented orally, in the way it is passed on. That’s a link that is breaking as people relocate and food becomes more convenient and adaptable,” he notes.

Where the wild greens grow, bitter is well-understood and adapted to, he points out. “Forest greens have strong bitter undertones, and that’s considered normal across Indian indigenous communities.” A variety of local citruses, the bamboo, the scarlett eggplant and the Thai brinjal are used in Idu Mishimi cooking; hemp seeds and the bichu buti or stinging nettle in Uttarakhand; and the country cousin of bitter gourd, the cantola, and young sweet potato leaves are well-used in Meghalaya’s Khasi food traditions.

When we do not use bitters with this native wisdom of what, when and how to use them—seasonally, long-term and in proportion to the rest of our meal—weight loss supplements step in to the gap mimicking their effect.

BITTER TRUTH

Each individual tastes bitterness differently. The BitterDB database at the Hebrew University of Jerusalem holds over 2,400 bitter molecules and analyses a range of bitterness by chemical structure and how over 66 species take to them (i.e. triggers on one end and receptors at the other). All bitters are not the same nor do we react to them the same.

The variation offers a clue to how Semaglutide, the obesity-curbing injectable drug work. The patent for Semaglutide expired in India in March, and the market is gearing up for affordable versions of the drug. It works by doing what including bitter foods on a regular basis would do for you, if you let them.

GLP-1 (Glucagon Like Peptide-1) is a natural hormone secreted in the enteroendocrine cells, that regulates gut-brain signalling, appetite, metabolism and satiety. Dr Shashank Joshi, endocrinologist at Mumbai’s Lilavati hospital, explains that humans have seven documented type of tastes, and there are 25 kinds of known bitter Taste 2 receptors (TAS2Rs). “Bitterness begins in the taste bud. Specialised proteins on taste cells, the TAS2R receptors detect bitter compounds, binding to thousands of different molecules. When a bitter compound, like say amla juice binds to a TAS2R receptor, it triggers gustducin, a G-protein that sparks a signalling cascade: calcium levels rise in the cell, ATP (Adenosine Triphosphate, which is an energy signal) is released, and the nerve is stimulated, producing the sensation we experience as bitter.”

These receptors, he explains, are ancient. Evolutionarily, bitterness developed as a genetic early warning system for toxins when our ancestors were foraging plants. This ancient wiring also explains why the same food tastes different to different people. Kale or broccoli may taste intensely bitter to one person and mild to another because genetic variation in bitter receptor genes produces real differences in sensitivity.

The thing is, some people just don’t take to bitter tastes as easily as others. A 2025 study of 210,000 UK Biobank adults conducted at Harvard Medical School found that TAS2R38 is a haplotype, a version of a gene you inherit. It comes in two versions: PAV (sensitive) and AVI (blunted). If you inherit two copies of PAV, your gut bitter receptors detect bitter compounds strongly and release more GLP-1, resulting in lower blood sugar spikes after a meal. If you inherit two copies of AVI, receptors barely respond. Which bitter plants your ancestors ate has written the code of how well your gut manages appetite and blood sugar today.

What science has more recently established, Dr Joshi explains, is that bitter taste receptors are not confined to the tongue. They have now been found in the lungs, airways and gut and this opens up an entirely different set of questions. If GLP-1 is produced in the gut, can bitter compounds alter not just oral taste sensation but the entire GLP-1 axis, including the gut microbiome, appetite suppression in the hypothalamus, and craving behaviour? “Indians especially love to eat. And we all know the right thing to do, but most people can’t control their cravings. This ‘crave’ in itself is something that is the subject of research. We are looking at whether commercially available bitter drops, for instance, ‘bitterize the mouth’, which is a concept derived from the Sushruta Samhita,” Dr Joshi says.

Dr Joshi’s team at his clinic is working on questions that bridge the research gap, such as whether Semaglutide alters bitter receptors, a process of integrative science that includes looking at the native wisdom.

Prof. Inge Depoortere leads the Gut Peptide Research Lab at KU Leuven, Belgium, and is the world’s foremost independent researcher on extraoral bitter taste receptors. Over 15 years, her lab has established that bitter taste receptors lining the gut wall trigger the release of satiety hormones, and that bitter compounds can delay gastric emptying and reduce hunger. Her 2024 paper, working with obese patients, showed that bitter compounds also activate GDF15, a satiety signal in the brain. This is the same pathway that creates the nausea that users of Semaglutide experience. Bitter tastes trigger GLP-1, but the gut is reading the whole meal, the balance of flavours and elements, not just sugars or bitterness, i.e. eating bitter foods isn’t as targeted as a drug that only targets bitter receptors. “Semaglutide activates satiety in a way that bitter foods will never replicate to achieve the same weight-loss magnitude,” she warns.

The value of eating bitter foods regularly is preventative and it sustains satiety in a balanced way. Because of the difference in how we receive bitter foods, simply piling bitter foods on our plates is not going to counteract obesity in the way the drugs that mimic the effects of bitter foods do. Understanding the compound and how it affects us is a two-pronged approach.

When New Zealand’s Plant and Food Research set out to develop Amarasate, a hops-derived extract marketed as a natural GLP-1 activator, they screened over 900 plant compounds for “bitter brake” activity. Edward Walker, the research lead, explains in an email that the gut bitter system is less sensitive than the tongue. “Something that tastes somewhat bitter on the tongue, probably won’t be bitter enough for the gut bitter taste systems to respond to it.” Thus a bitter-tasting item may not always satiate appetite. The gut cannot detect all the bitter compounds that the tongue can. “The tongue expresses 25 bitter taste receptors, whereas the gut expresses 17-18 in the majority of people, and this means the gut may not respond even if the tongue tastes it as bitter,” he notes. Karela or bitter gourd, one of the only Indian bitter compounds they tested, Walker suggests, likely stimulates enough GLP-1 to improve glucose control, which may be why it has been used as a traditional treatment for diabetes and elevated blood sugar.

Research shows that bitters like chocolate and coffee also activate polyphenols which curb sugar cravings, regulate metabolism and insulin sensitivity. Regular consumption of bitter foods keeps this system activated. “Including bitter foods in the diet is important as they play a role in regulating appetite. In that context, the food industry’s development of bitter-masking compounds is not necessarily beneficial, since reducing bitterness may counteract these natural regulatory effects. Such compounds are most appropriately used for medications, where suppressing the bitter taste is helpful,” Depoortere says.

EMBITTERING IS A PROCESS

Indian cuisine thankfully has a plethora of preparation techniques that give us a taste for the bitter.

In West Bengal, bitter gourd is part of the opening gambit in shukto, made with potato and poppy seeds. In Rajasthani, Maharashtrian and Gujarati kitchens, it’s stuffed and fried as chips, into pickles, or made into a sweet-sour curry or shak. In Keralam, Kannada or Tamil cuisine, it is used in tamarind preparations like theeyal, sambar, and fries called poriyal or vathal, a tradition of sautéing bitter ingredients like turkey berry or black nightshade to build the layers of a complex bitter, sweet and sour gravy.

Drying brings out the bitter. This includes a salt-cured citron rind or a dry-ground citron leaf with chilli, that are used as pickles in Tamil Nadu. Konkan foods use pomegranate rind in chutneys, and the rind is sun-dried and in powdered form for a coconut and yogurt-based regional delicacy, the thambli.

“Few people realise that bitter pairs very well with fat,” says Sadhu, who renders the simplicity of the versatile dandelion greens in cultured butter and salt to bring out their natural intensity of flavour. Fermentation has been a traditional way across cultures to bring out the bitterness of ingredients that are not inherently bitter, such as in pulses, he notes.

Fermentation is well-used in Meghalaya cuisine where fermented bamboo and fish are celebrated carriers of bitters in a dish. Chef Nambie Marak, 37, first runner-up of MasterChef India, season 8 (2023) and culinary ambassador for Meghalaya, specialises in Garo cuisine. “Bitter flavours are well integrated in Garo village food traditions, not merely as medicinal preambles, but as main meals, widely eaten even by children,” she notes. Apolka, a wild bitter berry, turkey berries, chambil fruit, bitter eggplant, bitter gourd, kimka, a wild bitter berry cooked in simple stews, titaful, delicate bitter flowers added to broths, and many wild greens carry the bitters in the meal.

“Bitterness is a respected taste. Bitters are distinctively paired with dried or fermented fish, a flavour combination that brings deep umami and intensity to the dish that is both nourishing and deeply satisfying,” Marak says.

Apart from choosing an ingredient at a certain stage of its growth, one may also select the parts of the fruit or ingredient that holds most of its concentrated pith. When you leave the rind in, either by adding the unpeeled vegetable, or by pickling, dehydrating, sun-drying or powdering, you can adjust the range of bitterness. “Two ways to add bitterness to any ingredient are: char-roast it, especially over coals or a live fire or to smoke it,” explains Zacharias.

In Karaikudi (Tamil Nadu), the cooking begins with the frying of the gundu milagu (a GI- tagged fat pepper from Ramanathapuram also called the mundu chilli) in oil to the point of charring it, which sets the base as slightly bitter, he notes. Doing this to spices is also a way of adding a subtle and balanced base bitter flavour profile in Chettinad cuisine. The slight burning of butter or garlic creates an earthy flavour to it, popular in barbecues or coal-seared foods such as baingan ka bharta and tandoori preparations that contribute to the effect of heartiness.

DEFINING THE TASTE

The process that calibrates bitterness in foods through roasting is the Maillard reaction. As sugars reduce when a food is heated, it reacts with the amino acids at temperatures above 140-165 degrees Celsius. This is exactly how coffee roasters define the bitterness on the roast of their beans, explains Homi Appachoo, 31, a fourth-generation coffee farmer, roaster, quality grader and Speciality Coffee Association instructor from Kodagu. A coffee that has a balance of sweet, sour and bitter is what gets it a good score. “The essence of coffee is its bitterness,” Appachoo explains. When either the sweetness or the bitterness is imbalanced, south Indian coffee roasters balance it out with a sweet or a bitter root of the blue-flowered chicory plant, which is roasted and powdered into the coffee. All instant coffee in India uses chicory blends, he explains.

The prevalence of a palate for the bitterness of coffee is deeper in the south where the British colonial plantations were established in the hills of Wayanad, Chikkamagaluru and Kodagu. From here they were sold through Chettiar traders of Tamil Nadu. By contrast, in the North-East, which was a tea-growing region, the palate for bitterness is different and lighter, Appachoo points out. Even the southern tea is heavier and bolder than its north-eastern counterpart. There is now a growing market for speciality coffees expanding in the north, he says, espresso and manual brews being the largest growing base. Thus the palate for bitterness has been stretched through a variety of influences, including exposure, local soil, frost, varietals, usage, cost, war and geography.

A SHARP SIP

Beverages, both fermented and not, also play with bitter flavours quite well. Hops were traditionally used to embitter and stabilise the flavours of beers, before which dandelion root, marigold, ivy and heather served as bittering agents. Fay Baretto, 39, founder of Mr Bartender and The Crew, India’s first LGBTQ+ inclusive bartending company, explains that bitters in alcohol derived from apothecaries that used extracts medicinally. This was the basis of liquors like Jägermeister and the bitters—most famously Angostura, which has only made its re-entry into India in January due to licensing issues. These bitters were originally tinctures. As the cocktail was born in the pre-war pre-depression era, bitters became popular as cocktail bases.

Baretto began experimenting with making his own bitters out of sarsaparilla, angelica root, karela, cherry bark, apricot bark, walnut, citrus peels, raisins, and fish scales. “I’d go to Ayurvedic shops and ask them for ingredients to experiment with,” he says. That’s how he discovered long pepper and mugwort. The Campari will give you a long-drawn bitter, but the chirata—a bitter herbal leaf—hits hard closer home.

Finding the bitters that work for you is a long-drawn process. “You have to keep experimenting. You have to spend time with the bitterness, for it to begin to reveal its nature to you in the way that Alexander Fleming spent time with penicillin. There are some bitters that the longer you sit with them, you realise they are so bitter they are sweet,” he says. Baretto uses sous vide techniques as well as fermentation and steeping. “Composing a bitter flavour is alchemy, it’s about nose and aroma, about which part of the palate you want to hit, and about creating a body,” he says, like the layering of an expensive perfume. “Bitter is not just bitter,” Baretto says. It expands, and shrinks, and mutates. You have to allow it to evolve.

In the Dharmasamgraha, a Buddhist philosophical glossary attributed to the scholar Nagarjuna, bitterness is classified among the six tastes not as a dietary observation but as a phenomenological one. Consuming a bitter is less about liking it and more about working against a dislike of it. It is an acceptance of a variety of experiences, sitting with, a developing, a rounding of taste and thus a seeing of all that life provokes in us.

“Bitterness is an answer in nature,” Sadhu says. “Including bitters is about honesty and authenticity in cooking; toning them down or masking them is a cover-up. If you’re not tasting bitters, you’re not tasting fully.”

Tara Das is a Mysuru-based therapist and author.