5 supplements you should avoid if you have metabolic syndrome

Supplements can be a great way to get important nutrients into your diet — but they aren’t for everyone. 

Those with metabolic syndrome, a group of health conditions that include high blood pressure, high blood sugar, abnormal cholesterol or triglyceride levels and excess body fat around the waist, should be especially careful about supplementation.

For EatingWell, registered dietitian Isabel Vasquez revealed the five supplements you shouldn’t take if you have metabolic syndrome — chromium, niacin, green tea, bitter melon and milk thistle.

Chromium

Chromium is an essential trace mineral found in foods such as grape juice and broccoli. Some people take chromium to regulate blood sugar and cholesterol or to improve athletic performance despite limited evidence of effectiveness.

“While some studies suggest [the supplement] chromium picolinate may improve insulin sensitivity, evidence is inconclusive and inconsistent,” Michelle Routhenstein, a preventive cardiology dietitian at Entirely Nourished, told EatingWell.

Chromium may also interact with insulin and antidiabetic medications, causing unwanted side effects.

“Excessive intake may lead to negative side effects such as kidney damage and GI issues,” Routhenstein explained. 

Niacin

Niacin, also known as vitamin B3, helps your body turn food into energy and keeps your nervous system, digestive system and skin healthy, according to the Mayo Clinic. 

People take prescription niacin to lower their cholesterol or to reduce their risk of heart attack.

Vasquez warned people not to take a niacin supplement if they have metabolic syndrome. 

“A recent study found that for participants taking statin drugs, which lower cholesterol, adding a niacin supplement increased HDL,” Vasquez wrote.

“This is usually good — after all, HDL is the ‘good’ kind of cholesterol,” she added. “In this case, however, HDL levels skyrocketed so much it actually increased the risk of atherosclerosis (plaque buildup in the arteries).”

Green tea

People can typically safely drink six to eight cups of green tea a day, but supplementation may bring health risks, especially for those with metabolic syndrome, Vasquez warned. 

Green tea extract can be found in various supplements that promote weight loss and metabolic health, but it’s important to know that green tea has been shown to interact with some medications used to treat cardiovascular problems.

Some people who have taken green tea extract supplements for weight loss have developed a rare liver injury, the National Center for Complementary and Integrative Health reports. 

Bitter melon 

Bitter melon has been linked to lower blood sugar levels, according to Healthline. 

The fruit contains chemicals that seem to mimic insulin. Vasquez said that cooking with bitter melon is fine, but taking a bitter melon supplement may not be safe or effective in treating diabetes, especially in the long term.

Vasquez referenced a study that found bitter melon helped lower blood sugars in patients with type 2 diabetes who took it over 12 weeks. However, that study was only tested in the short term. 

Milk thistle

Milk thistle is another supplement advertised to people who have diabetes or high blood sugar.

However, there isn’t enough data to support the theory that it’s helpful. 

“There is simply no evidence on its effectiveness to treat metabolic syndrome or aid in liver health,” registered dietitian nutritionist Lauren Mahesri told EatingWell.

Furthermore, people who are allergic to plants like ragweed, marigold or daisy may experience an allergy to milk thistle since it’s a similar plant. 

Health recommendations

The experts support a healthy, well-rounded diet consisting of plenty of fruit, vegetables and healthy grains as well as exercising and regularly checking in with a doctor.

“Monitoring your cardiometabolic risk factors by going to regular physical checkups and checking your blood pressure at home can help you monitor your progress, make adjustments as needed and tailor your plan to help manage metabolic syndrome,” Routhenstein said.