WHY WE AVOID IT:

Those long brown strands of seaweed on your mixed Japanese salad are often pushed to the edge of your plate because they smell like the ocean floor. A species of kelp, arame can readily absorb minerals from the water, so can become toxic with heavy metals such as arsenic, lead and cadmium if they’re harvested from polluted waters.

WHY WE SHOULD EAT IT:

Their ability to take up minerals is precisely why sea vegetables like arame should be considered one of the healthiest foods on the planet. They contain a good amount of calcium, copper, iron, magnesium, manganese, molybdenum, phosphorus, potassium, selenium, vanadium (a mineral that may help with blood glucose control) and zinc. As for iodine, a nutrient essential for thyroid function, you cannot find a more concentrated source. Compounds in arame called fucoidans seem to have important anti-inflammatory, anti-viral and anti-thrombotic properties. Scour the Asian markets for certified organic brands to avoid heavy metal contamination.