Caffeine gives Bees a Buzz

Writers, as well as lots of other folk, believe they need to be caffeinated to discover their creative side and help burn the midnight oil. The downside of drinking coffee and other caffeine-rich drinks is physical dependence, with withdrawal symptoms starting at surprising low levels of consumption of one cup of strong coffee per day, or equivalent to 100 mg of caffeine.

Bees too get hooked on caffeine, because it boosts their memory.  Caffeine is found in many flowering plants where it can affect bee behavior at much lower concentrations than are present in coffee, tea, cacao, and yerba mate.Comb+ bees

When researchers at the University of Sussex at the University of Sussex offered nectar feeders to honey bees, the insects remembered the ones that contained tiny traces of caffeine and returned again and again. At first sight, it’s an odd finding because the compound is thought to be present in some plants as a deterrent against animals that might eat them, because it has a bitter taste and is somewhat toxic. The bees that found the caffeinated nectar performed the famous waggle dance when they went home to their hive, which was a coded navigation instruction for their sisters to find the source. But the bees returning from control feeders danced less and persuaded fewer of their sisters to find their food, even though the nutrients and energy in the nectar sources were identical.

The difference between the experimental and control nectar was like comparing a “sports energy drink” like Rockstar Energy Shot, which contains a whopping 230 mg caffeine and only 10 calories per serving according to Consumer Reports, with Crush Orange soda, which is caffeine-free but has 160 calories. The first drink provides the sensation of energy while the second provides real energy.

Our lesson is that plants can fool bees, because when flowers offer more caffeine they get more attention, and better pollination services. The bees get nothing out of it, and might even be losers if the caffeine-rich nectar they prefer is nutritionally inferior. Of course, a bee brain is so tiny it is easily fooled, but caffeine-rich plants are duping big brains too.

Caffeine boosts human attention and memory by potentiating neural traffic in the synapses of the hippocampus and neocortex. We enjoy its effects, but the coffee plant and other caffeinators are coercing us into helping them to proliferate, just as they do with the bees. Coffee plants probably originated in the Ethiopian Highlands, but our liking of the caffeine kick has made us propagate the plants across three continents, now generating over seven billion kilograms of coffee beans for our habit. That is the second most valuable traded commodity in the world, and has zero nutritional benefit.

Out of Africa
Out of Africa

Next Post: My Microbiome

Honey Health

A neighbor asked for local honey to treat her allergy so I gave her some from our hives. She wanted a natural alternative to anti-histamines.

South-east Virginia has a miserable reputation for hay fever sufferers, and pollen is suspect as soon as our cars are dusted apple-green from pine trees in early spring. Pollen levels remain high and in the 8 to 9 range throughout the summer because of a succession of grasses flowering after the pine. But some people are symptomatic the year round or mainly in the fall. Pollen sometimes gets the blame for culprits like dust mites, molds and animal scurf. Maybe our neighbor is wasting her time by self-medicating on honey.

But at least the theory of educating her immune system with antigens is sound, and obviously analogous to vaccination. Someone in our family has an allergy to birch pollen and is getting relief from graded doses of the same pollen by subcutaneous shots. Would it work if he took it orally, like her trial with honey? Perhaps!

Time for Medicine

The oral mucosa has a sophisticated immune system with Langerhans cells and patrolling dendritic cells involved in tolerance. A defense system is needed in the mouth because food and drink are not necessarily sterile until they are mixed with stomach acid. If honey lingers under the tongue before it is swallowed there may be time for its cargo of antigens to be presented to these cells. Whether pollen creates an immune response during passage through the gut is more dubious, because it encounters there a fury of enzymes, although pollen grains have been found in the evacuated products at the rear end. Ahem.

Since I was both ill-equipped and disinclined to test that theory, I decided to ask a more practicable question. Is there any pollen in our honey? I dusted off a microscope to focus on a glass slide where I smeared a sample.

Aha! I saw several types of grain. They were clear or dark spheres ranging in size from about 0.01 to 0.1 mm, but I had no idea what trees or herbs they came from. And I wondered if they were sufficiently abundant to alert the immune system, but that wasn’t the most serious doubt.

When a hay fever sufferer is tested for hypersensitivity, trees and grasses are top of the pollen list. Note: they are wind-pollinated species. I can’t discount them in our honey, but if any of their pollen is present it is an “accidental” minority because bees don’t visit those species. Insect-pollinated flowers rarely cause hay fever, but it is their pollen grains that rub off bees when depositing nectar in the comb to make honey. I haven’t expressed these doubts to my neighbor since there’s a chance that she will feel better from the placebo effect!

Honey has an ancient and honorable history in medicine: it was used to dress wounds and made foul tonics and potions palatable. Moreover, it doesn’t need refrigeration because it has natural antiseptic properties. The concentration of sugars is so high that bugs are dehydrated by osmosis, and without water there can be no life.  Archaeologists have even found edible honey in Egyptian tombs thousands of years old. One of the oldest elixirs, it is still useful.

I tested honey as an antiseptic barrier on a skin wound. Easy to apply and always in the pantry, I was excited when it seemed to be working – until my dog licked it off. She knows its other virtues.

Next Post: Notes from the hive

Where the Bee Sucks

There are compensations of being cooped up indoors in wintertime. Bilbo Baggins looked forward to the long evenings in his hole at Bag End when he could relax in an armchair toasting his feet in front of a blazing fire. It’s a time of greater idleness and harder to rouse oneself even for a few steps from a comfort zone to the pantry for a snack. And bee colonies are likewise.

As the outside temperature falls below freezing, they huddle deep inside their hive to maintain a remarkable 90 °F. (32°C.). The workers who labored so hard on warm days earlier in the year are now idlers that rarely bother to snack, and no longer share their precious honey stores with drones that died off in the fall. The queen is at the quiet center of the bee-ball. She has stopped laying eggs, and won’t resume until February when the colony must expand rapidly for the coming nectar flow.

Cosy-up in the comb

Honey stores gradually run down over the cold season. On warm days, a few workers head out to forage for the few hours before sundown, but it is a risky business because if nectar and pollen are scarce the flights may have a negative energy balance. Bee colonies often perish from starvation at the end of winter, just a few days or weeks before food is plentiful again.

The beekeeper who stole most of the honey hoarded last summer must replace it. Trading sugar for honey seems good to him. But the sugar-water that was welcome in warmer months needs lots of energy from beating wings to evaporate it, and can increase the danger of condensation inside the hive. So we give candy to the bees, and why not at Christmas?

On a warm Christmas Day like today there was no danger of chilling the bee-ball when I lifted the inner cover to check the girls. I took a bar of candy out of Santa’s sack and rested it on the frames of empty honeycomb. The candy was home-made by boiling concentrated sugar with a few drops of essential oils until it caramelized and set into solid bars. It’s toffee for bees. A few lethargic workers crawled from their warm place to inspect the treat. Last year, I tested whether they could tell the difference between refined sugar and non-caloric artificial sweetener, because some people find it difficult. Of course bees aren’t so easily fooled. They know that real sugar is vital for survival, but it’s a different story for our species.

Next Post: Pure and Poisonous

A Merry Christmas to my readers