Lee Flynn thought she had a healthy lifestyle. She was thin and active and she ate well -- with lunches of tuna and fresh vegetables and dinners of halibut, sea bass or swordfish.
Yet she spent over a decade plagued by fatigue, stomachaches and headaches, as if she had "a wicked hangover." Her hair started falling out. Memory lapses made her think she was losing her mind.
"I really felt something was poisoning me, but I couldn't find the source," said Flynn, 59.
The Sausalito anthropologist and documentary filmmaker eventually ended up in the office of Dr. Jane Hightower, a San Francisco internist. When Hightower heard that Flynn was eating fish nine times a week, she immediately ordered a blood test for mercury. A heavy metal that accumulates in the flesh of fish, especially the popular predatory varieties, mercury can also accumulate in people who eat those fish.
The test's stunning result: Flynn's mercury level was 20.6 micrograms per liter of blood. A safe level is about 5, according to the federal Environmental Protection Agency.
Like Flynn, many adults and children may be unwittingly overdosing on mercury, say Hightower and some public health activists, and it's likely that most of them are going undiagnosed.
In recent years, fish has become the food of choice for millions of Americans trying to eat more healthfully, with per capita consumption at about 15 pounds, a 20% increase since 1980.
People on weight-loss diets turn to fish as a lean alternative to beef. Bodybuilders go for the protein; it's not unusual for them to polish off entire cans of tuna. Others are drawn to the cardiovascular benefits of Omega-3 fatty acids in fish. Restaurants, meanwhile, are expanding their portions, often serving as much as a pound at a time (a normal portion is 3 or 4 ounces).
The health benefits are undeniable -- and some people may suspect the warnings are overblown. This past week, researchers at the American Psychiatric Assn. meeting announced that fish rich in omega-3s may prevent depression late in pregnancy and after childbirth. A study a week earlier in the Lancet found that children in the Seychelles Islands whose mothers ate a lot of fish during pregnancy showed no signs of health problems.
