Danger in Fruits & Veggies

Ever since we were little kids, our parents have been drilling it into our heads: "Eat your fruits and veggies, they're good for you." We can't even count how many times we've heard the saying "an apple a day keeps the doctor away."

But what if we told you that some of these produce items might be dangerous? While eating an apple may give you much needed vitamins, the seeds could actually make you feel sick.

We're not telling you to stay away from the very nutritious fruits and vegetables. And we're not trying to fill you with fear or make you wonder if every meal that's on your plate is safe to eat. But we do want to better inform you on which foods you should be cautious of when preparing, and which ones have leaves or seeds you need to steer clear of.

Yuca

Yuca, also known as cassava, is a starchy root and a major source of carbohydrates in subtropical areas. It should never be eaten raw because yuca contains linamarin and lotaustralin, which is very toxic. Improper preparation of yuca can also lead to cyanide intoxication, which in some cases affects one's ability to walk.

Kidney beans

Kidney beans have the highest level of the toxin phytohemagglutinin (PHA) than any other bean. And they contain enough of this toxin to cause acute symptoms, even if only a few raw beans are consumed. To be safe, the beans should be soaked for a few hours first, the water discarded and then cooked for at least 10 minutes before being consumed.

Cherry Seeds

As you probably know, the flesh of the cherry fruit is not harmful, but the seed inside the pit, when crushed, chewed, or even slightly injured, produces prussic acid (hydrogen cyanide). With this in mind, try to refrain from chewing on the seeds.

Green Potatoes

It's true, our favorite starch can make us sick. But not just any old potato, only green potatoes. Green spots indicate that concentrations of solanine, a nerve toxin, are present. If ingested in large amounts, it can make you feel sick and can even cause paralysis of the central nervous system.

Elderberry

The flower of the elderberry isn't poisonous, but the leaves, stems and seeds are. They contain a bitter alkaloid and glycoside that can make you ill. Be sure to stay clear of the bush, just grab the flowers to make some soda syrup.

Apples Seeds

There's a reason that you don't eat the seeds of the apple (besides the fact that they don't taste good); it's because they're poisonous. Those little seeds contain amygdalin, and if you consume enough of them (which is pretty unlikely considering the quantity you'd need to ingest) you could be in trouble.

Lima Beans

Raw lima beans contain limarin -- only a handful can be enough to make some people violently ill. These beans are very nutritious otherwise, just be sure to cook them through before adding them to your next meal.

Tomatoes

While in the 1800s, the entire tomato was thought to be poisonous, it's now known that just the leaves of the tomato plant should be avoided. The leaves and stems of the tomato plant contain a chemical called "Glycoalkaloid" which causes extreme nervousness and stomach upsets.

Rhubarb

It's known that the leaves of the rhubarb plant are poisonous, yet it's still unclear as to what exactly makes them dangerous for consumption. The leaves contain oxalate and anthraquinone glycosides, so it's thought that the combination of both compounds could be responsible.

Peaches Pits

There's about eighty-eight milligrams of cyanide in the average peach pit. But luckily, if you did swallow a peach pit, the hard shell covering the seed would protect you from ingesting the poison. And if you were to become contaminated from a seed, it would give you a stomach ache at worse.

(Courtesy of forwarded mail from David Chen)  

Comments from Dr. JB Lim:  

Thursday, 24 January, 2013 7:42 PM

Thanks for giving me a lesson on Food & Nutrition Toxicology.

Correct, I give my nod on these info, except that the toxin in tomato leaves is called tomatine which is actually an alkaloid conjugate with glycosides (glycoalkaloid).

This toxin is little bitter in taste, but this is only found in the stems and leaves of tomato plants, and not in the ripe tomatoes. It is safe to eat even uncooked, but ripe tomatoes which is rich in lycopene against prostate cancer.

Even then, tomatine is heat labile (destroyed by adequate cooking), and should not be a problem.

Another misinformation in this article is that amygdalin containing cyanide is not exactly eighty-eight milligrams of cyanide per peach pit. This is just an average. The levels can range from 5 - 100 mg per pit, but again this depends on the variety of the peach, ripeness, and length of post-harvest storage.

Other than that, I can give an 'okay' to the rest of the information.

Thanks for your nutrition advice.

jb lim

Formerly, Research Food and Nutrition Toxicologist

Massachusetts Institute of Technology

Former Member, Expert Technical Committee on Food Standardization, Quality Control and Food Safety

SIRIM - Ministry of Health Malaysia