Overcooking Your Vegetables Until They’re Mush
Boiling vegetables led to the most substantial reduction in ascorbic acid content, from nearly ten percent to over seventy percent, with spinach experiencing the greatest decline. When you throw veggies into boiling water for too long, you’re basically washing away all the good stuff. In terms of total polyphenol content and total flavonoid content, boiling had a higher negative effect on most vegetables than the other two cooking methods, with losses of up to about seventy percent and over eighty percent, respectively. In contrast, microwaving had the mildest effect on ascorbic acid, preserving over ninety percent of the initial content. The fix is simple: steam or microwave your vegetables for shorter periods instead of drowning them in water.
Cooking at Dangerously High Temperatures
Exposure to higher temperatures and lower moisture levels coincided with higher advanced glycation end product levels, thus frying, broiling, grilling, and roasting yielded more AGEs compared to boiling, poaching, stewing, and steaming. These AGEs are nasty compounds that form when you cook foods at extreme heat, especially meats. Excessive consumption of advanced glycation end products, harmful compounds that stem from cooking foods at high temperatures and accumulate in the body as people age, are a major cause of inflammation that can increase the risk of insulin resistance and type two diabetes. Low AGE generating cooking methods such as boiling and steaming decrease serum AGEs and improve lipid profiles. Think about switching from that blazing hot grill to gentler cooking methods more often.
Using the Wrong Cooking Oils at High Heat
Let’s be real, not all oils are created equal when it comes to heat. When an oil exceeds its smoke point, harmful compounds called polar compounds may be released as a byproduct of the breakdown of that oil as it’s exposed to heat, and these compounds have been linked to cellular damage thought to lead to health issues like Alzheimer’s and Parkinson’s disease. Smoke point does not predict oil performance when heated; oxidative stability and UV coefficients are better predictors when combined with total level of polyunsaturated fats, and of all the oils tested, extra virgin olive oil was shown to be the oil that produced the lowest level of polar compounds after being heated. Here’s the thing: you need to match your oil to your cooking temperature or risk creating harmful oxidation products.
Reusing Cooking Oil Over and Over
Repeated heating of oils at high temperatures over a long period of time predisposes the oil to thermal oxidation, hydrolysis and polymerization, and repeated heating changes the physical appearance of the oil with increase in its viscosity, darkening in color, foaming and decrease in smoke point making it harmful for human consumption. I know it sounds crazy, but many people regularly reuse frying oil to save money. When oils are heated at high temperatures repeatedly and for a long time, the organic matter within breaks down more quickly, which decreases the oil’s smoke point and forms compounds that are potentially harmful to health, including polycyclic aromatic hydrocarbons and aldehydes which, when consumed, increases the risk of cancer and cardiovascular diseases. Rats fed diets with reheated cooking oils exhibited significantly higher levels of neurodegeneration compared to rats consuming a standard diet, and reheated oil may increase neurodegeneration by disrupting the liver gut brain axis. Replace your cooking oil frequently, not just when it looks nasty.
Not Adjusting Cooking Times for Nutrient Preservation
In general, cooking for shorter periods at lower temperatures with minimal water gives the best results when you’re trying to keep nutrients intact. Water soluble vitamins such as vitamin B complex and vitamin C can leach out of foods into the cooking water which is often discarded after cooking is done, and vitamin C and folate are also heat sensitive, meaning that they can be destroyed when foods are cooked at high temperatures. Steaming is one of the best cooking methods for preserving nutrients including water soluble vitamins, and steamed broccoli retains more of its beneficial glucosinolate compared with boiled or fried broccoli. The vast majority of us are cooking our foods way longer than necessary, which destroys vitamins before they even reach our plates.
Skipping Acidic Marinades Before Cooking Meat
Cooking meat with acidic ingredients such as vinegar, tomato juice, or lemon juice can reduce AGE production by up to fifty percent. This is one of those simple tricks that almost nobody uses but makes a huge difference. Decreased cooking times, using moisture while cooking, the use of lower temperatures, and the addition of acidic marinades like vinegar help to prevent the formation of new dietary advanced glycation end products. Microwaving produces less AGEs than other dry heat cooking methods, and marinating meat in an acidic solution like vinegar or lemon juice before cooking also reduces AGE production. Adding lemon juice or vinegar to your meat before cooking isn’t just about flavor; it’s genuinely protective.
Ignoring the Smoke Point Warning Signs
At the moment an oil hits its smoke point, changes begin to occur including oxidation, polymerisation, and hydrolysis, and oxidation will cause harmful free radicals to form in the oil. When you see that thin blue smoke rising from your pan, you’ve already crossed into dangerous territory. Aldehydes have the potential to be carcinogenic and increase oxidative stress, and free radicals are harmful and play a key role in the aetiology of many degenerative diseases such as cardiovascular disease and type two diabetes. An especially toxic aldehyde called acrolein is produced when vegetable oils are heated to their smoking point, and acrolein is quite toxic; although it has not been classified as to carcinogenicity, the US Occupational Safety and Health Administration has set a workplace limit in air at point one parts per million. Turn down the heat immediately when you see smoke, period.
Cooking Everything on Maximum Heat
Cooking methods have an enormous effect on AGE production; cooking eggs in an open pan over low or medium heat generates only half the AGEs produced when cooking over high heat, and poaching or steaming generates only one fourth of the AGEs of roasting or broiling. Honestly, most home cooks think higher heat equals faster and better cooking. Wrong. Eggs scrambled in an open pan on high heat, compared to eggs that were scrambled on low to medium heat, doubled the amount of dietary AGEs, and when chicken was baked or broiled instead of steamed or poached, the amount of dietary AGEs increased seventy five percent. Eating processed foods promotes inflammation, weight gain and risk of various health conditions including heart disease, type two diabetes and mental health disorders. Lower heat preserves more nutrients and creates fewer harmful compounds.
Forgetting That Raw Isn’t Always Best
Many of the nutrients contained in foods are not readily accessible prior to cooking and thus cannot be easily digested by the body, and cooking foods containing starch prior to consumption initiates the breakdown of the polysaccharide, thus aiding the action of amylase and the consequent digestibility of the carbohydrate component of the food. Some people get obsessed with raw food diets thinking everything cooked is destroyed. The nutrient content of food is only half the equation; we also need to know how much we can extract from the food through digestion, and this is the main advantage of cooking as it weakens cell walls and breaks down proteins so they are easier to digest, enabling us to extract more nutrition. Cooking of foods could increase the extraction of carotenoids by softening plant walls and disrupting carotenoid protein complexes, and it is assumed that an increased extractability may be associated with improved bioavailability. Balance is key here; some foods need cooking to unlock their nutrients.
Using Old or Improperly Stored Oils
When oil oxidizes it may develop an unpleasant smell, taste bitter, or even produce harmful compounds that are not beneficial for health. That bottle of oil sitting on your counter near the stove for months? It’s probably rancid. Light and air negatively affect the oils and can cause them to become rancid, rancid oils are a major source of destructive free radicals in our diet and they shouldn’t be consumed, so store your oils in a cool dry place away from direct light. Glycation oxidation reactions, although at a slower rate, continue to occur over time even at cool temperatures, resulting in large accumulation of dietary advanced glycation end products in the long term. Buy smaller bottles of oil, store them properly in dark cool places, and replace them regularly to avoid oxidation.
