Are your greens toxic? greens toxic?

Are your greens toxic?
Green, healthy, sometimes toxic (Getty Images)
Over-consumption of certain toxins in vegetables and fruit could mar their wholesome goodness Medical literature is replete with the goodness of fruit and vegetables.

Science credits these food items with nutrients, antioxidants and fibre. In fact, there is even medical evidence to suggest that vegetarians live longer.

But is everything about them good? The world of medicine chooses to turn a blind eye to the toxic substances present in them, given their safe-for-consumption tag. Few know that these toxic substances could prove fatal if consumed in large quantities.

Solanine is a glycoalkaloid present in vegetables like potatoes, tomatoes and brinjals. Genetic factors, exposure to light and bruises sustained during harvesting can significantly increase the solanine content in vegetables.

This substance is usually not perceptible to human taste buds, but a bitter or burning sensation should make one suspect the presence of an unusually high level of solanine. A small amount of solanine in plants helps them defend themselves against fungus, and also has inherent pesticidal properties.

The National Institutes of Health (NIH), the US health regulatory body, says potatoes high in solanine content are green below the skin and should never be eaten. The NIH believes its consumption in large quantities by an expecting mother results in birth defects.

Cases of solanine poisoning have also been recorded in history, one of them in a UK school.Solanine poisoning causes nausea, vomiting, cramps, hallucination, paralysis, jaundice and even death.

Symptoms usually show within eight to 12 hours of consuming solanine but may start as early as within 30 minutes, so potatoes that are green under the skin must be avoided. However, the presence of solanine in tomatoes and its harmfulness is a matter for debate.

In 1948, erstwhile East Berlin was struck by a bout of food-poisoning, thought to have been caused by food items airlifted into the region, especially beans.

Beans contain a toxic substance called lecithin that is capable of making the red and white blood cells stick together. Lecithin also gets at tached to the internal lining of the intestine.Symptoms of abdominal pain and diarrhea are manifest within one to three hours of consumption.

Cyanide-like substances are found in apricots, peaches, bitter almonds and bambooshoot. They contain amygdalin, which is converted into cyanide by the gastrointestinal track.

Agitation, confusion, convulsion, disrupted cardiac rhythms, disturbances, shock and death are known to occur an hour after consumption. This can happen after consuming 20 to 30 apricot kernels or even after eating six to 10 bitter almonds.

Oxalic acid is found in high concentrations in rhubarb, spinach and peanuts. The average lethal dose of oxalate is 2 to 30gm. These can be toxic for the kidney and lead to hypocalcemia, which may cause convulsions.

Chillies contain capsaicin. Wilbur Scoville measured the sharpness of chillies on a scale known today as the Scoville Scale. Chillies have been anecdotally deemed aphrodisiacal, invigorating and anti-bacterial. Capsaicin finds use in pepper sprays as well. In large quantities, capsaicin is known to cause an elevated blood pressure level.

A doctor hardly comes across problems caused directly by high consumption of vegetables and fruit, but one must keep in mind that the consumption of certain substances present in them might have adverse effects that could leave even the best physician surprised.