The wave of reported illnesses has provoked outrage among consumers, but also has flummoxed nutritionists and health experts, since liver damage from food is rare. As Daily Harvest tries to figure out what has caused such severe symptoms, it’s unclear which ingredient could have triggered them. “I can’t figure out what’s going on with this,” said Marion Nestle, a professor of nutrition, food studies and public health at New York University who is not affiliated with the investigation. “It looks like they don’t have a clue.”

Higher levels of enzymes indicate that your liver is injured and can point to a wide range of issues, said Dr. Laura Kulik, a hepatologist at Northwestern Memorial Hospital. Up to 30 percent of tests showing elevated liver enzymes are related to dietary supplements, she said, including unregulated vitamins and herbal medications. Antibiotics can also cause liver enzymes to rise, as can excessive alcohol consumption, hepatitis and viral infections.

It’s rare that eating food would cause damage to the liver, Dr. Nestle said. Toxins that are found in wild mushrooms can cause acute liver poisoning, but beyond that, foods typically don’t raise enzyme levels. “This is very unusual, which is why it’s so important to figure out what’s going on,” she said.

This past spring, organic strawberries were linked to an outbreak of hepatitis A, a virus that may cause liver disease.

“Any time you’re in the emergency room and someone’s complaining of nausea, they get a liver test,” Dr. Kulik said. Abdominal pain, fatigue, fevers and itching — particularly when it’s accompanied by a rash — can point to liver damage, she said. Jaundice, a condition that causes the skin or eyes to turn yellow, is also one of the main symptoms.

Other signs of liver injury that doctors said to watch for include darker urine and stool that becomes pale in color. People experiencing these symptoms and the above should seek medical attention.



This story originally Appeared on Nytimes.com