Hello everyone,
Dr. Chuma here again.
Frying, and in particular deep frying, is a common cooking method used across the globe. Restaurants and fast-food chains often use it as a quick and inexpensive way to prepare foods. Popular fried foods include fish, french fries, chicken strips, and cheese sticks, although you can deep-fry just about anything. Carnivals, especially in the south where deep frying is a way of life, can have such odd fried offerings as fried strips of butter and even ice cream. But even healthy foods like Brussels Sprouts and green beans are fried these days.
Fried foods are typically coated in batter, often made up of flour, eggs and butter, already a calorie bomb, before being fried. And when foods are fried in oil, they lose water and absorb fat, which further increases their calorie content.
For example, as compared with one small baked potato, which contains only 128 calories and less than 1g of fat, the same amount of fried french fries contains almost 500 calories and 20 g of fat.
They are addictive because, in addition to the fat we crave, they are usually also loaded with salt and sugar, increasing their craveability.
Fried foods are typically high in trans fats, which form when unsaturated fats undergo a process called hydrogenation. Food manufacturers often hydrogenate fats using high pressure and hydrogen gas to increase their shelf life and stability, but hydrogenation also occurs when oils are heated to very high temperatures during cooking. The process changes the chemical structure of fats, making them difficult for your body to break down. Trans fats increase the risk of many health conditions, including heart disease, cancer, diabetes, and obesity.
In addition to forming trans fats, fried foods are often cooked in poor quality, processed vegetable or seed oils, which contain trans fats even before heating. When these oils are heated to high temperatures, their trans fat content increases. Each time an oil is reused for frying, its trans fat content increases. These superheated oils also are packed with various harmful chemicals which accumulate each time they are re-heated.
In addition to oils, other foods naturally have trans fats in them, in particular meat and dairy products.
The more fried foods you consume, the greater the risk of developing many diseases including type 2 diabetes, dementia, heart disease, and obesity. Let’s look at a few of these.
Heart disease
Eating fried foods contributes to high blood pressure, low HDL, the “good” cholesterol, and obesity, all of which are risk factors for heart disease. Although some fish consumption is part of the healthier Mediterranean diet, a 4-year study with 16,479 participants concluded that eating 2 servings of fried fish per week is associated with a significantly higher risk of cardiovascular disease. Meanwhile, those who ate a diet high in fruits and vegetables, and low in fried foods, had a significantly lower risk.
Diabetes
Several studies have found that eating fried foods increases the risk of developing type 2 diabetes.
Consuming them just twice per week doubles the risk of developing insulin resistance, leading to diabetes. 4-6 servings of fried food per week increases the risks by 40% and 7 or more times a week increases risks by 55%.
Obesity
As already mentioned, fried foods contain more calories than their non-fried counterparts, so eating a lot of them can significantly increase your caloric intake, which obviously contributes to weight gain.
Studies also indicate that the trans fats in fried foods affect the hormones that regulate appetite and fat storage, further contributing to weight gain.
Regardless of whether it’s due to high calorie content or high trans fat content, multiple observational studies have shown a significant association between fried food intake and obesity.
Fried foods also contain harmful chemicals like acrylamide, a toxic substance that can form in foods during high temperature cooking such as frying, roasting, or baking. It is formed by a chemical reaction between sugars and an amino acid asparagine. Many foods, including some plants like potatoes, contain asparagine, but they are particularly high in meat and dairy. Acrylamides are linked to kidney, endometrial, and ovarian cancers.
Cooking oils that contain large amounts of polyunsaturated fats are far less stable and are known to form acrylamide when exposed to high heat. Examples include oils made from:
- Canola, also known as rapeseed
- soybean,
- corn,
- sesame,
- sunflower,
- safflower,
- grapeseed.
Restaurants commonly use these oils because they tend to be cheaper. But you should avoid these oils for deep frying at home.
Although frying in any kind of oil is less healthy than alternative cooking methods like sautéing and baking with water or vegetable broth or air frying, there are safer frying oils if you must use them.
Some oils can withstand much higher temperatures than others and are therefore safer to use. Generally speaking, oils that consist mostly of saturated and monounsaturated fats are the most stable when heated.
Coconut, olive, and avocado oils are among the safest and most stable for frying:
- Olive oil contains mostly monounsaturated fats, so it’s relatively stable for high temperature cooking.
- Avocado oil is similar in composition to olive oil. It also has an extremely high heat tolerance, which makes it a great choice for deep frying.
- Coconut oil: More than 90% of the fatty acids in coconut oil are saturated, which means this oil is very resistant to heat. Saturated fat is terrible for you, but coconut is better than some other oils.
Using these healthier oils may decrease some of the risks associated with eating fried foods. But note that these are the most stable oils for frying, not necessarily the most nutritious ones in general. There is also a quality issue. You should always choose cold pressed, extra virgin oils as they are the least processed and don’t use as many chemicals to refine, deodorize and color them.
The Beef Tallow Controversy
In recent years, seed oils have been villainized to the point where frying and cooking in beef fat, or tallow, has been promoted as being healthier. There is such a craze in this regard that some fast food chains are jumping on the bandwagon, announcing that they have switched from vegetable and seed oils to beef fat. This is completely insane. Although frying, and in particular deep frying, is not particularly healthy, some plant oils are healthier than others and ALL of them are healthier than animal fats.
Until next time, enjoy the beautiful fall weather.