Top Surprising Foods That Might Be Making You Sick

When trying to narrow down the reasons for your digestive upset, consider these lesser-known food intolerances and allergies that might be making you sick.
Top Surprising Foods That Might Be Making You Sick
June 5, 2014

As more convenient, processed foods inundate our supermarket shelves, more people are becoming aware of how food allergies, intolerances and sensitivities affect our bodies.

When trying to narrow down the reasons for your digestive upset, consider these lesser-known food intolerances and allergies that might be making you sick.


If you are plagued by seasonal allergies such as pollen, fruits such as apples can also disrupt your immune system. This is because pollens have similar proteins to some fruits, which can confuse the body into thinking it is encountering the pollen allergy. If you suffer from this condition, eat your fruits cooked instead, such as in an apple crumble, because the allergy-causing proteins in fruit can be destroyed by heat.


Red and black grapes contain resveratrol, an antioxidant believed to help against coronary disease, some cancers and viral infections. However, as grapes are high in fructose, a natural sugar that can cause gas, and also contain a lot of tannins that can lead to stomach upset, grapes might be giving you nausea and diarrhoea. If this is the case, try swapping grapes for other fruits rich in resveratrol such as blueberries.

Dried Fruit

To prevent natural discolouration, dried fruits are sometimes treated with sulphur dioxide. This compound can lead to discomfort, headaches and nausea when digested. If you have asthma, it may also trigger a serious attack.


To avoid getting sick when eating vegetables, always wash the produce first and avoid cross-contamination by washing your hands and using separate cutting boards when preparing salads with meat.


While all potatoes contain low levels of natural toxins called glycoalkaloids, which are produced by the potato in response to stress, potatoes with a greenish tint beneath the potato's skin can contain higher levels of these toxins through exposure to UV light. Such potatoes might taste bitter, exhibit a lot of bruising, and also grow little sprouts or 'eyes'.

Glycoalkaloids can cause severe stomach aches, diarrhoea and vomiting for one to six days, and even death in rare cases. You can make these potatoes safe to eat by cutting off the sprouts and peeling off any green layers or damaged parts. To prevent exposing your raw potatoes to these toxins, always store your spuds in a dark, cool place.

Kidney Beans

Raw kidney beans can be disastrous for your stomach, causing severe stomach aches, vomiting and diarrhoea, because of toxins called lectins. These poisons can also disrupt cellular metabolism. To eliminate the toxin, soak raw kidney beans for five hours, discard the water, boil them for ten minutes, and strain them before eating. Alternatively, you can eat canned kidney beans.

Lima Beans

While lima beans are a great source of protein, folate, and fibre, in their raw form, they can contain a toxin called limarin, which can cause nausea, vomiting and abdominal pain. To keep them in your diet, cook them for at least ten minutes.


The high fibre and fat content of nuts slow their movement through the digestive tract, which increases the risk for gas and bloating. Nuts also contain stomach-irritating tannins. Some alternatives to whole nuts include nut butters or oatmeal with berries.

Peanuts and Peanut Butter

While nuts like almonds and walnuts have strong, hard shells, peanuts are actually legumes that grow underground as part of a root system. When the environment surrounding the peanut becomes warm, humid and wet, a fungal growth occurs in the peanut's soft and porous skin. This fungus is not dangerous. However, the poison it releases, called 'aflatoxin', can cause cancer, attack the liver, and is one of the more deadly food-borne toxins in existence. Choose organic peanuts grown in a place where the soil is dry to hedge your bets.

Ham and Bacon

Smoked meats such as ham and bacon are high in histamines, naturally occurring compounds that can trigger an onslaught of allergy-like symptoms in people whose bodies can’t properly process them. That might mean headaches, a stuffy nose, stomach discomfort, and skin woes. According to a recent study, histamines can prompt rashes, itchiness, eczema, acne, and even rosacea. To see if you’re sensitive, see how you feel after switching to fresh meats rather than aged or smoked varieties.


Eggs are notorious for having the Salmonella bacteria lurking inside the egg, so proper cooking of eggs to kill the germs is advised. Avoid eating any products containing raw eggs, including cookie dough.


Aged or fermented foods such as sauerkraut are high in the enzyme tyramine, which can trigger migraines in people who can't metabolise it properly.


If fresh tuna is stored at improper temperatures after being caught, it can release a toxin called scombrotoxin, which causes flushing, headaches and cramps. This toxin cannot be destroyed by cooking.


If served raw or undercooked, oysters can trigger viral gastroenteritis. They can also contain a bacterium known as Vibrio vulnificus, which can cause nausea, vomiting and diarrhoea.


Cheese can be contaminated with bacteria like Salmonella or Listeria. To ward against devouring cheese that might harbour bacteria, keep an eye on the use-by dates.

Artificial Sweeteners

Artificial sweeteners, such as Splenda (sucralose), Equal (aspartame) and Sweet‘N Low (saccharin), can be difficult for the body to break down, leading to bloating, nausea and headaches. These artificial sweeteners can be found not only in diet sodas and sugarless gum, but also in other processed foods such as yoghurts, snacks, sugary cereals and juices.