In This Article
When the Heat is On…
According to Ayurveda, honey is one of the most powerful medicines. However, honey lovers should beware: it can become a harmful toxin if heated. Heating or cooking with honey is a major source of ama: indigestible substance. Ama is linked to the cause of most health issues.
This article will answer the following questions:
- How does heating honey make it toxic?
- How much heat is needed to damage the honey?
- What happens to bees when fed heated honey?
- What does science say about heated honey?
- Do I need to store honey in the refrigerator?
What Ayurveda Says about Heated Honey
Ayurveda’s main text, Caraka Samhita, says, “There is nothing so severe as the ama (indigestible substance) caused by the improper intake of honey. Honey, if heated, can be fatal due to its association with poisons.”1 The text goes on to describe the medicinal properties of honey and its ability to act as a carrier or “yogavahi” agent that potentiates the properties of other foods or nutrients taken with honey.1
Experts interpret this to mean that when honey is heated, its properties are changed and should be avoided. Fresh raw honey is a medicine, used most effectively to reduce kapha and congestion and, in small amounts, to balance vata.
How Do Bees Handle Heated Honey?
Many years ago, I read stories about how heated honey was toxic to bees. Beekeepers spray honey water on the hives to calm the bees before tending to the hive or harvesting honey. This is a regular practice and successful technique that de-stresses the hive, but, when pasteurized (heated) honey was used, all the bees died in the following days. If this is true and bees die when they consume heated honey, then how does heated honey affect humans? Let’s dig into the science.
When honey is heated or cooked, the sugar and fructose in the honey change their chemical composition as a result of a browning effect called the Maillard Reaction. Heating or storing honey for long periods of time will increase the production of a toxic substance called 5-hydroxymethylfurfural (HMF).
To see if this chemical is toxic to bees, a handful of studies have been done where HMF was fed to bees in a controlled hive. One study fed bee larvae varying concentrations of HMF while monitoring mortality rates. Higher concentrations of 7500ppm and above showed a 100% death rate of honey bee larvae. In this study, lower concentrations did not cause death.3
In another study, a solution containing 30–150 mg/kg of HMF was used to feed honey bees and was found to cause 15–58.7% of deaths of caged bees within 20 days.2
Note: Safe levels of HMF for Humans is below 40 mg/kg.
In a Belgium study, abnormal losses of honeybee colonies were observed in colonies fed with syrup of inverted beet sugar, containing high concentrations of HMF (up to 475 mg/kg). These losses suggest HMF could be implicated in bee mortality.4
HMF naturally occurs in honey, but at very low concentrations that are safe for the bee. Storing honey for long periods of time or heating it can raise toxic HMF levels.2
If Bees Die, What About Humans?
HMF is not just in heated honey; it is a toxic chemical formed whenever sugars are heated or caramelized, which is why baking with honey is bad idea.
It is found in sugary or honey-baked breakfast cereals, breads, dairy products, fruit juices, and liquors at different concentrations. Heated honey, molasses, and processed protein and whey protein powders are high sources of HMF.
Let’s start with some mice science. In one study, when mice were given a dosage of 250 mg/kg of HMF, most animals died after 5-11 days due to massive kidney damage. Later, the living mice developed kidney complications and liver damage.5
In humans, HMF has been reported to cause a host of health concerns, such as cytotoxicity in the mucous membranes, skin, and upper respiratory tract; mutagenicity; chromosomal aberrations; and carcinogenicity in humans and animals.2 In both bees and humans, HMF seem to first damage and weaken the epithelial protective layers of the body in the lungs and intestinal tract.2
HMF May Not Be the Whole Story!
While decades of science suggests HMF is a formidable toxin, emerging research finds HMF may also have a variety of health benefits, including anti-inflammatory, anti-allergy, and anti-oxidant properties. One of the more comprehensive studies concludes, “HMF has both profoundly adverse and beneficial effects on human and bee health. Some effects of HMF on human health and its carcinogenic as well as anti-carcinogenic properties remain inconclusive”2
It is very possible other factors besides HMF make cooked honey indigestible, toxic, and to be avoided. Ayurveda is a study of nature and perhaps when early Ayurvedic doctors saw bees die when fed with heated honey, they decided better to avoid heating honey altogether!
Studies show that in addition to cooked honey, old honey, processed honey, and honey stored at higher temperatures will build up HMF and become toxic. Studies report honey stored at low temperatures and/or under fresh conditions has low or minimal HMF concentrations, while aged and/or honey stored at comparatively higher or medium temperature has high HMF concentrations.2
Studies show honey stored at 68-86°F for more than a year has HMF levels ranging from 118.47–1139.95 mg/kg. In another study, when honey was stored at room temperature for over a year, HMF levels ranged from 3.18 to 703.10 mg/kg.2
How Hot Can Honey Get Before it Becomes Toxic?
The Codex Alimentarius Standard commission has set the maximum limit for HMF in honey at 40 mg/kg (with a higher limit of 80 mg/kg for honeys originating from tropical regions) to ensure the product has not undergone extensive heating during processing and is safe for consumption.2
Honey processed at 203°F for 90 minutes and 194°F for 75 minutes shows HMF levels lower than 40 mg/kg, the established safe limit of HMF in honey. Water boils at 212°F, so putting honey in your tea will be within safe levels. Cooking, baking, or frying with raw honey will exceed the HMF limits.
- Avoid honey that has been heated during processing
- Avoid honey that has been stored for any length of time.
- Store honey in your refrigerator to protect it from HMF damage.
- Caraka Samhita. Sutrasthana XXVII. Verse 243-248