Too much of a good thing – tea overdosing

The harmful banana diet (Photo: Joey Yee)

The harmful banana diet lacks nutrient balance (Photo: Joey Yee)

We get inundated with claims of superfoods that will cure your every ailment. Dietary advice is abundant and often provides skewed food intake. One day you are supposed to avoid saturated fats at all cost, but the next fat is the best thing since sliced bread and you should actually avoid the bread since you need to limit carbohydrate intake.

Fad diets

In the Morning Banana Diet you eat bananas to breakfast, lunch and as an evening snack, but fortunately you are allowed a normal dinner. It was popular in Japan in 2008 and caused a banana shortage. You might lose weight, but it is a harmful fad diet due to lack of nutrient balance.

In the Cabbage Soup Diet, also a weight loss diet that was proposed in the 1930s, you only eat a low-calorie cabbage soup. Fortunately it only lasts for seven days, but can still cause considerable damage. You are allowed to consume as much cabbage soup as you like, but still the number of calories per day is lower than what is considered safe and the extremely high sodium content used to make the soup palatable is dangerous. Many people report feeling weak and light-headed during the course of the diet.

The Master Cleanse Diet, revived in 1976, is a modified juice fast allowing no food but only tea and lemonade made with maple syrup and cayenne pepper. Proponents claim that the diet detoxifies the body and removes excess fat, but there is no scientific evidence that this is the case. It achieves nothing beyond a temporary weight loss and can be harmful over the long run. Short term side effects include fatigue, nausea, dizziness, and dehydration, while long term harm includes loss of muscle mass.

The benefit and potential downside of drinking tea

And that leads us into discussing tea in general. Research about green tea’s health benefits over the years has claimed that it has potential to fight cancer and heart disease, and that it can lower cholesterol, burn fat, prevent diabetes and stroke, and stave off dementia. Pretty impressive stuff, but probably far from the real truth. Sure the catechins in tea act as free radical scavengers and might prevent DNA damage. However, it is more likely that the theory that drinking green tea is good for memory is true. Researchers have actually shown that epigallocatechin-3 gallate, a key property of green tea, can affect the generation of brain cells, providing benefits for memory and spatial learning.

A few cups of tea are fine but avoid excessive consumption.

A few cups of tea are fine but avoid excessive consumption.

But as usual, too much of a good thing can turn bad. A middle-aged female in the USA experienced pain in her lower back, arms, legs and hips for five years before visiting a doctor. X-rays revealed areas of very dense bone on the spinal vertebrae and calcifications of ligaments in her arm. According to reports the doctor suspected that the female had skeletal fluorosis, a bone disease caused by consuming too much fluoride (a mineral found in tea as well as drinking water). On questioning her the doctor learned that she had consumed a full jug of tea made from at least 100 tea bags daily, for 17 years. Her blood levels of fluoride were four times higher than what would be considered normal. Excess fluoride is typically eliminated from the body by the kidneys, but with extreme consumption the fluoride accumulates and forms crystal deposits on bone.

A few other cases of skeletal fluorosis caused by tea drinking have been reported in the USA. In these cases, patients typically drank 3-4 L of tea a day. On reducing fluoride exposure the fluoride deposits will gradually go away as the bone repairs itself.

Go for a balanced diet

Typically too much of a good thing. The old adage to eat a little of everything and have a balanced diet is still very true despite what all the diet gurus are trying to convince you to do.

Post script

By the way it might be handy to know that skeletal fluorosis is endemic in regions of the world with naturally high levels of fluoride in drinking water, including some parts of India and China, but is rare in Europe and North America. And don’t confuse the low levels of fluoride added to drinking water in many parts of the world to prevent cavities with those high levels. Deliberate water fluoridation is a good thing (despite some misinformation) and not high enough to cause fluorosis.


One thought on “Too much of a good thing – tea overdosing

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s