If we are what we eat, we're in big trouble, studies say.

Food safety is important, but it seems Americans wake up every week to another food scare.

Even things that were once considered healthy are now raising red flags. Fish used to be safe, but now some studies say that shark, swordfish, mackerel and tuna may cause mercury poisoning (search). There's news that eating farmed salmon more than a few times a year isn't good for you, and that tofu is made from genetically modified soybeans.

But some are skeptical about the reports.

"Food phobias make news and I think anything that gets people panicked about the food supply is going to get on the news," said Susan Bowerman of the UCLA Center for Human Nutrition. "But the bottom line really is that in most cases the things we're most panicked about are completely overshadowed by the benefits we get from eating the foods in question."

Lately, even fruits and vegetables have been called into question. The Environmental Working Group (search) says that lettuce contains excessive levels of rocket fuel, and that pesticides contaminate apples, bell peppers, celery, cherries, grapes, nectarines, peaches, pears, potatoes, raspberries, spinach and strawberries.

The group recommends eating only organic varieties of these fruits and veggies.

"It's not putting artificial pesticides or harmful toxins in ground water. It's healthier soil and we think a tastier product," said Elizabeth Carovillano of Whole Foods markets.

And, if you got milk, some say it could kill you. Cows today get a hormone — bST — that can be bad for people. Tap water has arsenic and toxic chemicals like perchlorate. Bottled-water bottles may leach plasticizers and petrochemicals. Bread can contain potassium bromide, a carcinogen.

Reports say problems with grains, fertilizers, herbicides and pesticides linger in the food supply, and that our bodies contain toxic residue of 258 industrial pollutants — 76 causing cancer, 79 causing birth defects.

Cookies and crackers' hydrogenated oils clog the arteries; chips, fries and baked goods contain cancer-causing acrylamide. Soda leaches calcium from your bones. Coffee causes osteoporosis and heart disease.

The mad-cow scare is making some people steer clear of beef. Chicken may be contaminated by the bacteria salmonella. The preservatives in bacon, ham and hot dogs — meant to stop bacteria — may cause cancer.

It used to be question of what can't we eat ... but now it's what can we eat?

Ken Cook, president of the  Environmental Working Group (search), says some studies are just warnings.

"We're not saying people should never eat farm-raised salmon just because it has PCBs — we're just saying be aware the contamination is there."

But for every study that says a food will kill you, another says it's fine. And often these studies are paid for by groups who oppose industrial food production and agribusiness, or by companies who produce organic or free-range products.

So take this stuff with a grain of salt, but not too much, because salt can cause high blood pressure.

Click here to watch a fair and balanced report by Fox News Channel's William La Jeunesse.

William La Jeunesse joined FOX News Channel (FNC) in March 1998 and currently serves as a Los Angeles-based correspondent.