04/18/2012 01:55 EDT | Updated 06/18/2012 05:12 EDT

Cook fresh or frozen fiddleheads properly to avoid illness: Health Canada

OTTAWA - Fiddleheads are one of nature's earliest gifts for those who love the edible shoots of the ostrich fern. But it's best to be safe when preparing the young sprouts — which look like the curled heads of miniature violins — to avoid getting sick.

Fiddleheads are collected along the banks of rivers and streams and sold as a seasonal vegetable at farmers markets, roadside stands and in some grocery stores.

Fresh fiddleheads must be cooked properly and should never be eaten raw. There have been cases of temporary illness in Canada and the United States associated with eating raw or undercooked fiddleheads. Studies so far have not determined the cause of these illnesses, Health Canada says in a release.

Prior to cooking, the agency recommends removing as much of the brown husk as possible from the fiddleheads. Fresh fiddleheads should then be washed in several changes of clean cold water. Cook them in boiling water for 15 minutes or steam them for 10 to 12 minutes. The water used for boiling or steaming fiddleheads should be discarded.

Fiddleheads should also be boiled or steamed prior to sauteing, frying or baking.

Due to their short growing season, many people freeze fiddleheads. Be sure to use the same cooking methods when preparing fiddleheads that have been frozen.

Preserving fiddleheads with a pressure canner is not recommended, as safe process times have not been established for home-preserved fiddleheads.

Symptoms of illness usually begin 30 minutes to 12 hours after eating raw or undercooked fiddleheads and may include diarrhea, nausea, vomiting, abdominal cramps and headaches, Health Canada says. Illness generally lasts less than 24 hours but can result in dehydration, particularly among the elderly and in infants. There have been no reported cases of illness associated with eating fully cooked fiddleheads.

Anyone experiencing symptoms after eating fiddleheads should consult a health-care professional and contact their local public health unit.