While you may think your smoothies
are always healthy, research has found some adverse side effects.
Sometimes all you need for motivation before a morning workout is
a smoothie. It's a reliable way to have some fruits, veggies, and your favorite
nut butter into your diet, and it's also quick and straightforward to make.
However, while smoothies can help you in several ways, such as adding more
vitamins and protein to your diet, they can also have harmful side effects.
Although it's not fun being the bearer of bad news, it's time we
look at some of the potential adverse side effects of drinking smoothies. Read
on to learn how smoothies may affect our health.
1. You might weaken your teeth
Fruit is a healthy part of any balanced diet. But the acidity
found in fruit, especially in a smoothie that is consumed as a meal
replacement, can weaken our teeth over time.
Contact with too many naturally occurring acids, like the ones
found in fruit, has been proven to cause dental erosion, which can lead to
things like an increase in tooth sensitivity and pain, as well as loss of
surface area. For example, smoothies containing fruits like strawberries,
bananas, cranberries, blueberries, and cherries increased the erosion of
surface hardness on tooth samples, according to a 2013 study published in the
British Dental Journal.
Because of the higher levels of calcium, phosphates, and
gut-healthy probiotics in smoothies containing dairy in the form of milk or
yogurt, this research suggests that they are healthier for our dental health.
2. You might increase your risk of kidney stones and inflammation
Another possible side effect of smoothie consumption is the formation of oxalate crystals in the body, which can cause kidney problems. Oxalic acid is a compound found in many different foods but is exceptionally high in certain leafy green vegetables like spinach. Although this is a natural compound, it can cause kidney stones to form if consumed in excess. Oxalic acid is known to produce kidney stones, but it has also been linked to inflammation, chronic pain, increased fibromyalgia symptoms, and a hormonal imbalance in the stomach.
If you want to continue drinking smoothies but avoid getting too
many oxalates, use less spinach or take it out entirely. A 2015 study in the
Nutrition and Food Science Journal created two green juice combinations that
were similar in everything except spinach. They found that the green juice with
less spinach came back with significantly fewer oxalates.
3. You might decrease the effectiveness of your medication
Certain leafy greens that are popular choices for smoothies, like
kale or spinach, are often high in vitamin K. This vitamin is essential for
developing blood clots, which allow wounds to heal. Too much vitamin K, on the
other hand, can be a problem for those who have a history of blood clots or who
need to take blood thinners for different reasons.
According to a study published in Nutrition Reviews, taking
700-1500 micrograms of vitamin K from one serving of vegetables can cause
problems for individuals who take blood thinners. To put this in perspective,
just 1/2 cup of kale is already around 531 micrograms. So if you're using kale
as the main vegetable in your green smoothie, you may want to monitor the
amount you're using.
The Cleveland Clinic also points out that while you may want to
watch your intake of vitamin K, you don't want to cut it out of your diet
completely. It's still a necessary part of a healthy diet and is a nutrient our
bodies need to heal from injury properly.
4. You might slow the function of your thyroid
Our thyroid gland is in control of a lot more than we realize. It
makes the hormones that regulate our levels of energy, which impact our brain
development, digestion, heart health, and several other vital functions...
Iodine levels must be enough for our thyroid to function correctly and produce
these hormones.
The natural compound glucosinolate found in cruciferous vegetables
(think kale, broccoli, cabbage, etc.) has been shown to block the production of
thyroid hormones in studies. As a result, these reduce iodine uptake in the
thyroid, potentially contributing to thyroid disorders. So by drinking
smoothies packed with kale, we could run the risk of interrupting the function
of our thyroid gland.
If you're a green smoothie lover, it may be essential to monitor
your consumption of kale and note how it may be affecting the way your body
feels over time.
5. You might ingest some toxic metals
Before you fill your blender to the brim with kale, you should
learn about thallium, a toxic metal found in soil. This heavy metal is commonly
found in soil near industrial activity such as power plants or coal-fired
plants. Thallium thrives on cruciferous vegetables such as broccoli,
cauliflower, bok choy, and kale, most notably for green smoothie lovers.
According to the Journal of Environmental Geochemistry and Health, consuming thallium regularly, even in trace amounts from a daily green smoothie, can offer a lengthy health risk, especially to our nervous systems. Of course, this doesn't mean we need to throw out our beloved kale, but it may encourage us to shop organic when we can. Much current research supports sticking to organic vegetables because organic farms often use soil rich in carbon, which can stop the transfer of thallium to our favorite green veggies.