“Too much of everything is detrimental,” says an old saying. This is certainly true with foods, too. There are many super healthy foods, but eating too much of them could be seriously harmful.
Here are 8 incredibly healthy foods that can harm you if you eat too much of them.
1. Coffee
Attention coffee-lovers: While coffee is a wonderful beverage that is loaded with antioxidants and is linked with numerous health benefits (e.g. reduced risk of type 2 diabetes, neurodegenerative diseases, and liver diseases).
Caffeine is coffee’s active ingredient. Each cup of coffee contains an average of 80-to129 mg. The amount of caffeine considered to be safe is 400 mg a day.
On the other hand, consuming more than 500–600 mg per day can be excessive. This may overwhelm the nervous system, causing insomnia, nervousness, irritability, stomach cramps, heart palpitations, and muscle tremors.
2. Omega-3 and Fish Oils
Omega-3 is an essential fatty acid. They fight inflammation in the body, play an important role in brain development and reduce the risk of heart disease, to name a few.
Most of our diets are low in Omega-3. Hence, supplements have gained popularity. These include Omega-3 capsules produced from fish, fish liver, and algae.
The usual dose of Omega-3 considered safe ranges from 1–6 grams per day, but taking as much as 13–14 grams per day may have blood-thinning effects in healthy individuals.
Taking high amounts of fish liver oil may result in excessive vitamin A intake. Excess vitamin A may cause vitamin A toxicity. This is of particular concern for children and pregnant women.
3. Tuna
Tuna is a fish, a fatty fish. Aside from being extremely delicious, it’s super healthy. Tuna is a fatty fish that is usually considered to be very healthy. It is a good source of Omega-3 and protein.
The bad news, however, is tuna may also contain high levels of an environmental pollutant called methylmercury (especially those caught in the Pacific Ocean).
Methylmercury is a neurological toxin if taken in higher levels. It can pose adverse effects like developmental delays in children, and affect neuropsychological dysfunctions like vision problems, lack of coordination, and impaired hearing and speech.
The larger the tuna, the more mercury it has. Larger tunas are usually served as steak, sushi, or sold in the wet market. Smaller tunas are usually canned.
There are two main types of canned tuna, and their mercury content differs:
- White tuna: Light in color and usually comes from albacore fish. White tuna contains 4–5 times the amount of mercury found in light tuna.
- Light tuna: Light tuna contains much less mercury than white tuna. It is darker in color and usually doesn’t come from albacore fish.
The upper safety limit of methylmercury for humans is 0.1 micrograms per kilogram of body weight. Meaning, a 25 kg (55 lb) child could only eat one 75 g (2.6 oz) serving of canned, white tuna every 19 days. So, limit intake of seafood containing mercury to no more than two times per week.
There are several other types of fish that are also rich in omega-3 fatty acids, but less likely to be contaminated with mercury. These include salmon, mackerel, sardines, and trout.
4. Cinnamon
Cinnamon is a widely-used spice and herb. It is high in antioxidants and has been shown to fight inflammation, can lower blood sugar levels, and reduce the risk of heart disease, diabetes, cancer, and neurodegenerative diseases.
However, cinnamon contains high amounts of a compound called coumarin, which may be harmful in large doses.
There are two main types of cinnamon, with different amounts of coumarin:
- Cassia: Also known as regular cinnamon, Cassia cinnamon contains a relatively high amount of coumarin.
- Ceylon: Known as the true cinnamon, Ceylon is the less common of the two. It is much lower in coumarin.
The tolerable daily intake of coumarin is 0.1 mg per kg of body weight. Consuming much more than that may cause liver toxicity and cancer.
5. Nutmeg
Nutmeg is a spice that contains a compound called myristicin – a psychoactive substance. Taken in large doses, nutmeg may cause myristicin poisoning.
Eating more than 10 grams of nutmeg in one sitting is not recommended as it may lead to myristicin poisoning. The effects of myristicin poisoning include seizures, heart arrhythmias, nausea, dizziness, pain, and hallucinations.
6. Liver
The liver is the most nutritious organ of all. It is very rich in many essential nutrients, such as iron, B12, vitamin A, and copper. However, a 100 gram portion of beef liver contains more than six times the recommended dietary intake (RDI) of vitamin A, and 7 times the RDI of copper.
As you know already, too much vitamin A can cause vitamin A toxicity. Eating too much copper may cause copper toxicity. This can lead to oxidative stress and neurodegenerative changes and may increase the risk of Alzheimer’s disease.
Eat liver once a week only.
7. Cruciferous Vegetables
Cruciferous vegetables are a family of greens that include broccoli, brussels sprouts, kale, cabbage, and collard greens. These veggies have been linked with many health benefits, such as a reduced risk of cancer and heart disease.
However, compounds in these vegetables called thiocyanates can interfere with the body’s ability to absorb iodine. This may contribute to a condition called hypothyroidism.
People who are sensitive to thyroid problems should avoid consuming these veggies in very large amounts.
8. Brazil Nuts
Brazil nuts are very rich in selenium, an essential trace element that can also be toxic in high amounts. Symptoms of selenium toxicity include loss of hair and nails, digestive issues, and memory difficulties.
The recommended daily intake of selenium is 50–70 micrograms/day for adults. Additionally, the upper tolerance level for safe intake is about 300 micrograms/day for adults.
Read: Tolerable Upper Intake Levels for Vitamins and Minerals
One large Brazil nut may contain up to 95 micrograms of selenium. Eat only 4–5 Brazil nuts a day. It’s not recommended that you eat more than that.
A Word to the Wise
Remember that not because a food is healthy in small amounts, it’ll be healthier in greater quantity. When it comes to nutrition, more is not always better. Be mindful of your health. Stay informed.