(CBSNews)--For many, the New Year is a time to get back on track with health goals, making it a period ripe for marketers to tout unfounded claims about the benefits of “detox” diets.

Methods that promise to “rid your body of toxins” can include anything from an all juice or liquid diet to pumping your body with multiple herbal supplements and even taking laxatives.

But in a new paper published online in the journal BMJ Case Reports, doctors warn that not only do such detox diets not have scientific evidence behind them, they can also be life threatening.

The report describes the case of a previously fit 47-year-old woman who was hospitalized after following a New Year’s “detox” last year that involved drinking lots of fluids and taking various herbal remedies. She was admitted after a brief period of confusion and repetitive behavior such as grinding her teeth. She then collapsed and suffered a seizure.

According to the woman’s family, she had been drinking more water and tea in the previous few days, but they did not think it was excessive. However, she had also been taking herbal remedies, including milk thistle, molkosan, l-theanine, glutamine, vitamin B compound, vervain, sage tea, green tea and valerian root.

The doctors concluded that her initial confusion and seizures were caused by a condition called hyponatraemia, which occurs when the level of sodium in the body is abnormally low, typically brought on by drinking too much fluids. However, they were unsure what exactly caused the condition in this patient’s case.

After researching the herbal remedies that the woman used, the doctors came across another case of a man who had suffered from seizures due to severe hyponatraemia after consuming large amounts of herbal remedies that contained valerian root, along with lemon balm, passion flower, hops and chamomile.

In the report, they explain that both patients didn’t seem to drink enough excess fluid to bring on hyponatraemia (typically more than 10 liters per day for someone with healthy kidneys). But they hypothesize that the valerian root may have played a role, potentially altering the body’s threshold and allowing for hyponatraemia to occur at an earlier stage.

However, they caution that more scientific evidence is needed in order to draw definitive conclusions that valerian root was to blame.

Still, they say the two cases highlight the fact that “despite marketing suggesting otherwise, all-natural products are not without side effects.”

Dr. Nieca Goldberg, cardiologist and director of the Joan H. Tisch Center for Women’s Health at NYU Langone Medical Center, notes that while “detoxing” can be a necessary process for people addicted to drugs and alcohol, the average person does not need to take extreme steps to cleanse so-called “toxins” out of their system. In fact, the body detoxes naturally. 

“That’s the function of your kidneys,” Goldberg told CBS News.

The author of the case report, Dr. Oliver Toovey of the Milton Keynes Hospital NHS Foundation Trust in the U.K., also said that he would not recommend such a detox regimen to patients.

“The liver plays an important role in breaking down toxins in the body and getting rid of them,” he told CBS News. “There is no way to artificially enhance this, nor should anyone need to.”

Toovey also points out that the notion of drinking excess water as a way to “purify and cleanse the body” can be dangerous.

“The best policy is to rely on your body’s own senses,” he said. “If you’re thirsty, drink, and if you’re not, don’t. And bear in mind though that some of your fluid requirement will be in your food so you don’t need to drink all of that amount in glasses of water.”

Goldberg recommends that if you’re interested in achieving better health, stick to old-fashioned methods like a diet rich in fruits and vegetables.

“The best way you can keep your body toxin free is living a healthy lifestyle and getting your nutrients from food,” she said.

As for the woman in the case study, doctors said she was released from the hospital after treatment and did not appear to suffer lasting neurological damage.