From the Guidelines
Frying with oil and consuming the oil is generally acceptable when done in moderation and with the right types of oils, as it can be part of a healthy diet when considering morbidity, mortality, and quality of life outcomes. For everyday cooking, choose oils with high smoke points like avocado oil (520°F), refined olive oil (465°F), or canola oil (400°F) for high-heat frying, as these oils remain stable and produce fewer harmful compounds when heated 1. Extra virgin olive oil is better for low to medium-heat cooking or raw applications. Limit consumption of fried foods to 1-2 times per week, and avoid reusing cooking oils multiple times as this increases harmful compounds. When frying, maintain proper temperatures (350-375°F) to minimize oil absorption into food. Healthier alternatives include air frying, which uses significantly less oil, or cooking methods like baking, grilling, or steaming. The health concerns with fried foods relate to their high calorie content and potential formation of compounds like acrylamide and aldehydes during high-heat cooking, particularly when oils are heated beyond their smoke points or reused repeatedly.
Some key considerations for healthy frying practices include:
- Choosing the right oil for the job, with high smoke points for high-heat frying
- Limiting the frequency of fried food consumption
- Avoiding the reuse of cooking oils
- Maintaining proper frying temperatures
- Exploring alternative cooking methods that use less oil
It's also important to consider the broader dietary context, including the overall balance of nutrients and the types of foods being consumed. A diet rich in whole, unprocessed foods like fruits, vegetables, whole grains, and lean proteins can help support overall health and well-being, while also minimizing the risks associated with fried foods 1.
In terms of specific oils, some studies suggest that polyunsaturated oils may be associated with a lower risk of cardiovascular disease when consumed in moderation, while others highlight the importance of choosing oils with high smoke points to minimize the formation of harmful compounds 1. Ultimately, the key is to find a balance that works for individual needs and preferences, while prioritizing overall health and well-being.
From the Research
Safety of Consuming Oil Used for Frying
- The safety of consuming oil used for frying is a complex issue, with various studies suggesting potential health risks associated with the consumption of fried foods 2, 3, 4, 5.
- Research has shown that the process of frying can lead to the formation of toxic compounds, such as aldehydes and epoxy-fatty acids, which can be harmful to human health 3, 5.
- A study published in 2021 found that the compounds produced during the process of frying in different vegetable oils can be identified and used as markers of oil used for deep-frying food 2.
- Another study published in 2020 suggested that the ingestion of dietary lipid oxidation products (LOPs) in fried foods may contribute to enhanced risks of chronic non-communicable diseases (NCDs), such as cancer, cardiovascular, and neurological diseases 3.
- However, a systematic review published in 2015 found that the use of vegetable oils for cooking may not necessarily increase the risk of chronic diseases, and that the type of oil used may modify the association between fried food consumption and health risks 4.
- A study published in 2007 found that used frying oils did not contain acrylamide, a potential carcinogen, and that the recovered oil was safe for use as a component of animal feeds 6.
- Overall, the evidence suggests that consuming oil used for frying can pose potential health risks, and that further research is needed to fully understand the effects of fried food consumption on human health 2, 3, 4, 5.