1. Fish oil without antioxidants
Fish oil is one of the more popular supplements due to its great benefits, such as reducing inflammation and lowering triglycerides. However, experts say that if you’re taking fish oil and it doesn’t contain antioxidants, it can be pretty risky for your cardiovascular health.
"While fish oil is very beneficial for cardiovascular health, it can be harmful," Iafelice says. Fish oil that isn't preserved with antioxidants like vitamin C, E, or astaxanthin poses a risk, as "fish oil is extremely susceptible to rancidity and the production of toxic byproducts." Yikes!
For this reason, Iafelice says, you should "always be sure that your fish oil has antioxidants in it to protect it from rancidity."
2. Ephedra
Ephedra has actually been banned in dietary supplements since 2004 by the FDA. This ingredient is known to increase your heart rate, blood pressure, and other cardiovascular complications.
But Dr. Sambyal warns, “Despite this ban, some products may still have ephedra or its derivatives, like ma-huang in traditional Chinese medicine.”
He further adds that "this stimulant can increase blood pressure, heart rate, and metabolism. Ephedra can interact with blood pressure medications and other drugs such as caffeine and decongestants."
3. Green Tea Extract
Green tea extract is renowned for its antioxidant properties, primarily due to its high concentrations of catechins like epigallocatechin gallate (EGCG).
However, Dr. Geiga warns that, while there are many benefits to green tea, "high concentrations of catechins in green tea extract can induce oxidative stress in the liver, leading to hepatotoxicity." This oxidative stress may manifest as elevated liver enzymes and, in severe cases, acute hepatitis.
To mitigate these risks, it is recommended to limit intake to no more than 300 mg per day and consider brewed green tea as a safer alternative.
4. Turmeric
A recent study that was published in JAMA Network Open has revealed that drug-induced liver injury is on the rise in the U.S., with supplements like turmeric being a few of the common culprits. The ease of accessing these supplements, either through a quick online purchase or over-the-counter availability, has significantly added to this increase.
Turmeric supplements are popular because of the active compound curcumin. Curcumin has strong anti-inflammatory and antioxidant properties. However, the study claimed that if taken in excessive amounts, it could put you at risk of liver damage, kidney stones, and even liver failure.
5. Iron
Love says that a lot of people take iron supplements, but the truth is they don't really need it.
"High levels of iron can lead to memory loss as well as loss of cognition. And iron in excess actually increases aging," he reveals.
Love says that unless you've undergone a blood test that shows significant low levels of iron in your body, "you probably don't need iron supplements." However, this supplement can benefit those who are on a vegan diet, he notes.
6. Copper
Taking copper supplements in excess can negatively affect your brain due to copper’s role in oxidative stress and its impact on brain health.
Love says that high levels of copper “actually increase free radicals, and this can cause oxidative stress and damage in your brain.”
Instead, he says to make sure you're taking plenty of zinc, either in a supplement form or food. "Zinc counteracts the free radicals of copper, and that helps protect your brain," he explains.
7. Calcium Carbonate
Another supplement to take cautiously is calcium supplements. Best known for its bone health benefits, they can also cause constipation, bloating, and gas, as they can slow down the digestive process.
McKinney elaborates on this and notes that "calcium is an essential element for the development of bones; however, calcium carbonate supplements produce a constipating effect and may be uncomfortable in the digestive system. This type of calcium is less soluble and may bring disturbances in the intestines, so it becomes difficult for the digestive tract to become healthy."