8 Foods That Can Be Deadly If Overconsumed: Fact or Myth? - Nutrition

Dr. Xie Huimin reply Nutrition

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Hello William: Generally, processed foods contain food additives to extend shelf life and enhance flavor.
Normally, the Department of Health has established usage standards.
If the production does not exceed these standards and our consumption frequency is low, there is no need to worry about food additives! Regarding your questions, here are some references:
(1) The traditional method of making century eggs involves coating duck or chicken eggs with an alkaline paste for curing, which causes the yolk and white to gel and develop a matured flavor.
The alkaline paste typically consists of two types: (a) quicklime, wood ash, sodium carbonate, salt, and water; (b) black tea, lime, salt, wood ash, and water.
The most challenging part of making century eggs is the gelling process.
Producers may add lead salts or copper salts to prevent liquefaction after gelling or to maintain the tea-brown color of the eggs.
(If added, the Department of Health stipulates that the allowable lead content in century eggs must not exceed 2 ppm.) To avoid selecting century eggs with lead salts, one should pay attention when choosing; generally, lead-free century eggs have a cleaner, whiter shell and interior without black spots, and the contents (egg white) should be a reddish-brown green rather than a deep black-green.
Additionally, look for century eggs labeled as high-quality.

(2) The production methods for stinky tofu vary by vendor, and the government may not be able to monitor them, so it is advisable to consume this type of food sparingly.

(3) The chemical composition of MSG (monosodium glutamate) is sodium glutamate.
In terms of nutrition, we recommend using it sparingly, especially for patients with certain conditions, such as hypertension.
If using MSG, it can be added after cooking when the heat is turned off, allowing the flavor to be released without producing toxic substances (generally, heating above 120 degrees Celsius for extended periods can produce harmful substances).
Consuming large amounts of MSG or free glutamate (≥3g) at once may trigger a temporary physical reaction known as "Chinese Restaurant Syndrome."
(4) Many plant-based foods contain oxalic acid or phytic acid, which can reduce calcium absorption when combined with calcium.
When supplementing with high-calcium foods, it is advisable to avoid consuming them with vegetables high in oxalic or phytic acid.

(5) Cholesterol has its functions, but for patients with hyperlipidemia, foods high in cholesterol should be consumed in moderation.
Foods high in cholesterol include animal organs (brain, liver, kidneys), shrimp and crab roe, and other animal fats.

(6) Cooking meat over charcoal can produce carcinogenic mutations in proteins, so it is recommended to avoid consuming grilled foods.

(7) Generally, pickled foods come with safety labels, so when purchasing, avoid those with unknown origins or incomplete packaging labels.
Additionally, pickled foods typically contain high levels of salt and should not be consumed in excess.

(8) Alum is classified as a leavening agent among chemical additives and is commonly used in making Taiwanese fried dough sticks.
It acts as a slow-reacting acidic agent, promoting the production of carbon dioxide gas from baking soda in the dough (baking soda is an alkaline powder that reacts better in acidic environments than in neutral ones), aiding in the expansion of the fried dough sticks and making them crispy, especially on the surface.
Furthermore, fried foods should be consumed sparingly; it is generally recommended to limit consumption to 1-2 times a month to reduce cumulative harm to your health.

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Reply Date: 2004/08/12