Even "good" foods can cause havoc in your life. Here are a few to keep your eye on.

DRIED FRUITS

Problem: Exaggerate symptoms of candida and other yeast-feeding infections.

What happens: Jackie Keller, founder of NutriFit and author of "Body After Baby: A Simple, Healthy Plan to Lose Your Baby Weight Fast," says, "Dried fruits are a concentrated source of naturally occurring fruit sugars that can exaggerate symptoms of candida and other yeast-feeding infections."

These infections can lead to symptoms like constipation, diarrhea, colitis, abdominal pain, headaches, memory loss, mood swings, prostatitis, persistent heartburn, severe itching, bad breath, and kidney and bladder infections. The disorder is often misdiagnosed, since there are so many symptoms, says Keller. Symptoms often worsen after eating foods containing sugar and/or yeast, including all forms of fruits and grains.

How much do you have to eat? "Everyone is different, so it's impossible to generalize, but I would think that since a 'normal' serving size is (about 1 ounce), having any more than twice what a serving size is supposed to be is having too much," says Keller.

FLAXSEED

Problem: Increased risk of prostate cancer.

What happens: Its high content of alpha-linolenic acids has made the ancient flaxseed our modern miracle food, says dietitian Gloria Tsang of www.HealthCastle.com. "It offers a vegetarian alternative to provide omega-3 fatty acid and has been shown in many studies to offer heart-healthy benefits by lowering total cholesterol and low- density lipoprotein (LDL or "bad") cholesterol levels. Flaxseed may also help lower triglycerides and blood pressure and keep platelets from becoming sticky, thereby reducing the risk of a heart attack," adds Tsang.

However, a few studies have also linked high concentrations of ALA to a higher risk of prostate cancer. Until more is known, men who are not vegetarians are urged to choose fish sources for heart-healthy omega-3s instead, says Tsang.

How much do you have to eat? As ALA is concentrated in oil form, it's OK for men to eat the actual seeds, but until more studies are done, they should completely stay away from the oil form (flaxseed oil and flaxseed oil pills), says Tsang.

CARROTS

Problem: Eating too many carrots may result in hypercarotenemia.

What happens: According to Maurice A. Ramirez, a Florida-based emergency room physician and founder of High Alert, "Excess beta carotene ingestion can cause yellow or orange discoloration of the skin and eyes that mimics jaundice and liver disease."

How much do you have to eat? It depends on your size. Originally, this condition was seen only in infants transitioning to pureed foods. In the 1950s, '60s and '70s, parents were told to introduce only one food at a time and feed it to the baby six times a day for a week. Since the first food was carrots with the next being sweet potatoes and the third butternut squash, by the fourth week the child was orange. Just about the time this became a rare problem in babies, adults started using beta carotene pills as a way to tan without sitting in the sun. The problem with using large doses of beta carotene as a "tanning pill," however, is that your tan is orange, says Ramirez.

POPPY SEEDS

Problem: Opiate positive drug test.

What happens: Poppy seeds come from the poppy plant, which is the source of opium and other opiate drugs. According to Ramirez, "Sub-therapeutic amounts of opiates in the poppy seeds are metabolized in the same way as larger drug doses and excreted in the urine."

How much do you have to eat? "Contrary to popular belief, the amount of poppy seeds on a bagel or a loaf of bread will not result in a positive drug test, nor will it excuse such a result. Poppy seed strudel, if the poppy seeds are ground and sauteed in butter for several hours to make the strudel paste and then eaten in large quantities, may result in a positive screening exam. However, confirmation with a 2-monoamino-morphine test will make a drug-abuse source evident. In short, enjoy your bagel, but don't expect it to protect you from a positive drug test," says Ramirez.

BARLEY, RYE, WHEAT AND SOMETIMES OATS

Problem: Gluten sensitivity or celiac disease.

What happens: "People who are sensitive or allergic to gluten, a protein found in barley, rye, wheat and sometimes oats, may experience diarrhea, lactose intolerance, iron deficiency and other malnutrition-related problems. Nongastro-intestinal symptoms include a dermatitis rash typically found on the elbows and knees," says Lona Sandon, a professor of nutrition at the University of Texas Southwestern Medical Center at Dallas.

How much do you have to eat? Any amount of gluten is a problem. "People who are sensitive to gluten may have a reaction to food that simply touched other food with gluten in it," says Sandon.

ASPARAGUS

Problem: Urine smells odd and takes on a slight green tinge.

What happens: "Asparagusic acid and thioesters in asparagus are excreted in the urine, creating the odor change and, when combined with other urine components, changing the color of the urine," says Ramirez.

How much do you have to eat? Even small amounts of asparagus can cause this effect. "This effect can be disconcerting, but is harmless and resolves in a few hours," says Ramirez.

Charles Stuart Platkin is a nutrition and public-health advocate, and author of "Breaking the FAT Pattern" (Plume, 2006). Sign up for the free Diet Detective newsletter at www.dietdetective.com.