Tea

In recent years there has been an ongoing effort to promote the use of tea with birds, primarily by an individual who has a business selling tea products aimed at birds.  This article will take a look at whether there is a good basis for the claims quoted from sources like the In Your Flock tea article, the Bird Channel tea article, and the In Your Flock raw foods article.  The raw foods article suffers from a variety of defects, but I will not discuss them here except to say that there is a general lack of evidence for effectiveness and a disregard for potential risks with the tea claims, and the same statement could be made about the oil claims.  I have a separate article on coconut oil and why it doesn't seem like an appropriate thing to feed to a bird.

Claim:  "What birds drink in the wild is far from sterile. Many species of birds visit water sources like tree hollows into which these plant components leach tannins, other compounds and minerals. We have all seen wild birds drinking from what appears to be "dirty” puddles and other water sources. However, many contain a type of "tea” from the leaves that have fallen into the water."

It is certainly true that birds drink impure water in the wild, but it's nonsensical to equate this with tea drinking. It's as logical as saying we should dip our birds' drinking water out of a fish tank because wild birds drink from ponds and streams containing fish. The quantity and type of plant material and other contaminants in the water is expected to vary considerably from place to place depending on local conditions, and it can't be assumed that this is beneficial or that the chemical content is similar to the teas that are being sold. 

I couldn't locate any research on the factors that guide a bird's choice of where to drink, but it's likely that in many cases safety or convenience is a higher priority for the bird than the exact content of the water. Birds need to drink, but they also need to avoid predators and aggressive rivals, and some birds need to guard their own territory against competitors. Any water that isn't acutely toxic will meet the bird's physical needs.

There is no evidence that birds intentionally seek out tannin-laced water in preference to any other type, but there is evidence that some birds might avoid such water when possible. A study on cockatiels found that they preferred pure water over water containing plant tannins, and they were much more sensitive to the taste of tannins than the taste of salt and sugar (Matson et al). This sensitivity to tannins is probably protective; according to Cornell University, small quantities of tannins in the diet can cause adverse effects in poultry.  Levels from 0.5% to 2% can cause depression in growth and egg production, and levels from 3-7% can be fatal.

Tannins/polyphenols are a large class of natural plant compounds that are generally considered to be antinutrients or toxins. They help protect the plant from being eaten and also play a role in regulating the growth of the plant. Some of these compounds may have health benefits for humans, particularly as antioxidants, but there are concerns about toxicity even with the "good" polyphenols (Galati & O'Brien).

Claim:  "Blended teas offer countless benefits for parrots"

The purported benefits of most of the teas being promoted haven't been studied well in humans, let alone birds.  There have been a considerable number of human studies on widely used black and green teas, with findings of potential benefits.  But the evidence isn't strong enough for the FDA to allow sellers to make marketing claims about health benefits (CBS News, FDA), and there is also evidence of potential harm from habitually drinking these same teas (for example BBC News, Molinari et al, Fluoride Alert).  In fact all the teas being promoted for birds are associated with warnings about human health risks, but this is never mentioned in the bird-magazine articles.  The risks associated with specific teas will be discussed at the end of the article.

I have been able to find only one scientific paper on the use of tea with birds.  It involved starlings and black tea, and found that the use of tea did reduce the amount of iron stored in the liver (Seibels et al). Some bird species like toucans and lories are highly susceptible to hemochromatosis (iron storage disease), and it is desirable to inhibit iron absorption in these species.  Most pet bird species are much less sensitive to iron, and inhibiting iron absorption in these species could potentially result in iron deficiency. 

It is possible to construct a logical rationale for offering tea in specific circumstances when a strong body of evidence is not available. For example the Riverbanks Zoo Toucan Manual and their separate article on toucan diet explain the basis for their decision to feed black tea to their toucans in an effort to prevent iron storage disease. Private communication with the zoo indicates that they subsequently discontinued this practice because a low-iron pellet became available (reducing the need for preventive measures), and the zoo veterinarian did not feel that the data demonstrated a benefit from the tea.

I haven't seen any evidence that the tea promoter has constructed a science-based rationale of this sort.  In a direct online conversation, he said his rationale for offering tea to birds was "why not" (in addition to the dubious contention that birds drink tea in the wild).  His response to a question about potential risks was "I haven't seen any problems".  It's unlikely that he's monitoring the health of all his customers or that it would be easy to identify tea as the culprit in a situation where it did cause a problem, so I wouldn't consider his personal observations to be serious evidence that there aren't any risks.

A bird isn't likely to be harmed by an occasional sip of tea just for fun, and there may be circumstances where a specific tea might help solve a specific problem.  The indiscriminate, frequent use of teas without seriously considering the evidence about the benefits and risks is irresponsible and potentially dangerous, but that is what is being recommended:

Recommendations:  "The use of tea is yet another way to incorporate items into the diet thereby increasing vitamins and minerals in your bird’s daily regimen. They also serve as a great enrichment tool; use a different kind each day to keep tea stimulating and engaging. ...   When cooking for your bird, it is quite easy to substitute water for tea when preparing egg foods, beans, rice, pasta and other items that are prepared in hot water. Baking is another opportunity to incorporate tea by replacing water with tea in the recipe for bird bread, crumble, muffins or another concoction your birds prefer. Offering certain teas without steeping them is another option, as small birds love to eat flowers, for example, within their dry food mix. For our softbills, we also roll items like chamomile or calendula flowers into our daily fresh fruit mixture for our birds to increase and diversify the nutritional content of every bite. ... Many herbal teas may be fed dry or mixed with dry and fresh food mixtures, but we do recommend steeping for the full benefits."

The Bird Channel article says "Check with your avian veterinarian for guidance in regard to the frequency, amount and types of tea you might offer your bird before incorporating giving tea to your pet bird." The other two articles have no such warning, and the general impression created by all three articles is that tea is a marvelously healthy, risk-free food that will cure or prevent a long list of ailments and can be used without restraint or moderation. Miracle claims like this usually turn out to be at least 90% quackery and hype and that appears to be the case here.

The recommendation to feed tea leaves to birds is particularly disturbing. With brewed tea we have centuries of human experience to shed some light on the possible results, although there is no guarantee that birds will respond to tea chemicals the same way humans do.  Humans do not normally eat tea leaves, and as mentioned earlier these leaves are expected to contain the insoluble compounds that were not released by the brewing process. The leaves haven't been studied to see what compounds remain in them, so we don't know what these compounds are and can't predict the long term consequences of habitually eating them. Many plants are toxic. The tea producing nations generally have a long history of poverty and hunger, and the fact that they do NOT normally eat these leaves suggests that there is a good reason not to do it.

The pro-tea articles recommend a few specific herbs to mix directly into a bird's food, but there's also a nonspecific statement that "many" teas can be added to the food, with no mention at all of whether there are any teas that should NOT be added to the food.  I can find no evidence that wild birds eat tea leaves or are considered to be crop pests on tea plantations.  Insects and fungi are the crop pests for black and green tea, and the only mention of birds I could find in connection with crop pests was a site saying that birds were beneficial to the crop because they ate insects.  The two specific teas that were recommended for mixing in food were chamomile and calendula.  The crop pests for both are insects not birds, and calendula actually repels many insects - it's recommended to plant it in gardens to help keep the bugs away from more palatable plants.

One of the articles includes a recommendation to bathe birds in aromatic teas.  Birds have very sensitive respiratory systems so the safety of this is questionable.

It appears that tea is generally a poor source of vitamins and minerals, despite the claim above.  It's difficult to even find sources talking about the vitamin and mineral content of tea, although it's said that black tea contains some vitamin C, E, and K (Livestrong) and green tea apparently contains at least C and K. It appears that the only noteworthy mineral in green and black teas is fluoride, which is beloved by the dental community but generally damned by the "health food" community as toxic (which is true if you ingest enough of it). Tea plants take up fluoride much more readily than most other plants, and green and black teas contain the highest fluoride level of any food source (FluorideAlert, FoodInfo).  

The Bird Channel article included a quote from a 'holistic' veterinarian who encourages the use of teas with birds, saying that tea enriched a bird's life experience and introduced additional nutrition, while saying nothing at all about any other health benefits or potential risks. This is odd.  Antioxidants and plant tannins are not considered to be nutrients and tea doesn't seem to contain much in the way of "official" nutrients.  The value as an enrichment experience looks pretty minimal to me.  These teas are touted for human use because of their purported health benefits, not for their nutritional value or entertainment value. 

Claim:  "Teas: Another Raw, Whole Foodstuff"

Tea isn't a whole raw food unless you're eating fresh raw tea leaves.  Otherwise it's best described as a cooked processed food.  Tea leaves are dried in a multistage process that often includes the use of heat (Wikipedia).  The tea promoter recommends decaffeinated tea for birds, which involves more heat and a chemical process to remove the caffeine (Wikipedia). Despite the claims about "Select teas that are decaffeinated via a natural process using CO2 and/or water", soaking tea leaves in carbon dioxide under pressure to make the CO2 act as a solvent is not a natural process.  Neither is the more common process of "natural decaffeination" with ethyl acetate (Arbor Teass, Amazing Green Teas).

In the hands of the consumer, the tea is processed again in water (usually hot water) to extract the water soluble compounds in it, then this water is drunk and the actual tea leaves are thrown away.  Imagine doing all this with broccoli and trying to convince someone that it's a serving of whole raw food.

Claim:  "Brewing releases beneficial compounds that may not otherwise be readily available to our birds."

Brewing releases water soluble compounds without regard to whether they are beneficial or not. Brewing does NOT release compounds that aren't water soluble whether they are beneficial or not. The hydrochloric acid in the digestive tract and other digestive processes are very efficient at releasing water soluble compounds from foods without any assistance from brewing, and it also extracts a good many of the insoluble compounds including important vitamins and minerals.

Credentials claim:  "[Name of promoter] is a degreed biologist."

The internet indicates that he's a full time high school biology teacher and part time college instructor.  It's customary to describe people in this line of work as a teacher or instructor unless they are a full-fledged tenure-track university professor engaging in funded research. The term 'biologist' is traditionally reserved for professional researchers and people who are actively engaged in wildlife monitoring and management.

Credentials claim:  Statement by the promoter on this Avian Answers Facebook thread: "I have done years of peer-reviewed medical research on these teas so I'm well versed in the research."

The link is an open, public Facebook group, so anyone who is logged into Facebook can view the thread without being a member of the group.  I have a screen capture of this comment in case a non-Facebook member is interested.

For those unfamiliar with the research world, research itself isn't peer reviewed; it's the scientific papers reporting the results of the research that go through a strict evaluation by other researchers in the same field, for possible publication in a scientific journal.  Publication in a peer-reviewed journal is the highest, most prestigious level of publication for a scientific paper, and the majority of scientific papers are published at a lesser level (mostly scientific conferences).

So a claim that one has "done years of peer-reviewed medical
research" carries a considerable amount of weight - if it's true.  It's easy to look up scientific papers and their authors on science-oriented venues like Google Scholar, and peer-reviewed journal publications in particular are expected to be there.  A search for the promoter's name on Google Scholar turns up NO publications in peer-reviewed journals, scientific conferences, or any science-related publication, nor is there any reason to believe that he is remotely qualified to publish in such a venue. Scientific papers are mostly authored by professional researchers, to present conclusions based on evidence and logical analysis. It's unacceptable to make unsupported assumptions or accept the claims of others at face value.  The bird magazine articles discussed here don't display any of the required qualities. 

An Australian researcher with the same name published a small number of papers related to topics like weather forecasting and water flow in Australian agriculture, but this is clearly not the same person.

As mentioned earlier, there are a considerable number of peer-reviewed papers on black tea and green tea, but the results weren't conclusive enough for the FDA to allow medical claims to be made about these teas. There's also a fair amount of research on chamomile and calendula, but many of the other teas have little in the way of published research.  Reading peer-reviewed papers is NOT "doing peer-reviewed research". That terminology is reserved for people who actually write and publish peer-reviewed papers.

The health risks of specific teas  

The bird magazine articles cited at the top of the article go into detail about the claimed benefits of a wide variety of teas, with no mention of possible health risks.  This section of the article will correct that omission.

The risks listed below mostly relate to exacerbating an existing condition, but in some cases tea consumption may actually cause a health problem that didn't previously exist. In the case of green and black tea, some but not all of the listed risks are related to caffeine and can be reduced or eliminated by using decaffeinated tea. Many of the herbal teas are reputed to have estrogenic/hormonal effects, which is not something to play around with lightly. It is wise to carefully research a specific tea prior to use to determine whether the potential benefits appear to outweigh the potential risks.

Green tea: anemia, anxiety disorders, bleeding disorders, heart disorders, diabetes, diarrhea, irritable bowel syndrome, glaucoma, high blood pressure, liver damage, osteoporosis, skeletal fluorosis (WebMD, Tea Talk)

Black tea: anemia, anxiety disorders, bleeding disorders, heart disorders, diabetes, diarrhea, seizures, glaucoma, hormone-sensitive cancers, high blood pressure, irritable bowel syndrome, osteoporosis, overactive bladder, skeletal fluorosis (WebMD, Tea Talk)

White tea: there's little in the way of individual reporting on this type, but it comes from the same plant as green tea and black tea, so it's likely that it would have similar properties.

Chamomile tea: anticoagulant, allergic reactions, drug interactions, sedative effects. May increase risk of miscarriage. (Livestrong, Herbal Resource, Tea Talk)

Calendula tea: Likely unsafe for pregnancy and breastfeeding, with possible increase for risk of miscarriage. Allergic reactions, drug interactions, sedative effects, fertility and menstrual cycle disruption (WebMD, Herbal Resource)

Rose hip tea: not recommended for pregnancy and breastfeeding. Bleeding conditions, diabetes, glucose-6PD deficiency, kidney stones, iron-related disorders, sickle cell disease, anticoagulant, nausea, headache, dizziness (WebMD, Rosehips Tea)

Peppermint tea: not recommended for pregnancy or breastfeeding. GERD (reflux disease), drug interactions, muscle tremors, diarrhea, heart palpitations, reduced heart rate (Tea Talk, Steady Health)

Ginger tea: drug interactions, insomnia, gallstones, stomach upset, anticoagulant, menopausal hot flashes. Use in pregnancy is controversial (B4tea, Tea Talk)

Anise seed tea: Not recommended for pregnancy.  Allergic reactions, estrogenic effects.  (The Right Tea, WebMD)

Raspberry leaf tea: drug interactions, loose or dark stools, nausea and vomiting, low blood pressure, estrogenic effects. (Livestrong, Healthwalaa)

Rooibos tea (aka Red Bush): little is known about this tea. Not recommended for pregnancy and breastfeeding. Estrogenic effects, liver damage, allergic reactions (WebMD, Livestrong, Buzzle)

Red clover tea: estrogenic effects, anticoagulant, headaches, upset stomach (WebMD, Tea Talk)

Hibiscus tea: possibly unsafe in pregnancy with some evidence that it can cause miscarriage. Estrogenic effects, drug interactions, diabetes, low blood pressure, intoxication/hallucenogenic (WebMD, Tea Lovers, SFGate

Lavender tea: Estrogenic effects, allergic reactions, sedative effects with possibly dangerous depression of nervous system when combined with anesthesia (Livestrong, WebMD)

Jasmine tea: little is known about this tea. Not recommended for pregnancy and breastfeeding. Green tea is the primary ingredient, so see green tea warnings. Contains caffeine which can trigger insomnia, irritability, dizziness, heart palpitations, and numerous other problems.  (WebMD, Livestrong, SFGate)