Why doctors do not recommend consuming blended oil

Doctors generally do not recommend consuming blended oils, mainly due to unclear labeling of ingredients, unbalanced nutritional composition, possible inclusion of low-quality oils, poor heat stability, and the risk of long-term fatty acid imbalance. The detailed analysis is as follows:

1. Unclear ingredient labeling: Some blended oil products fail to clearly indicate the specific proportions of each type of oil used. Consumers thus cannot determine whether large amounts of inexpensive oils (such as genetically modified soybean oil or palm oil) have been added, making it difficult to assess oil quality and increasing the risk of unintentionally ingesting components that do not meet health requirements.

2. Unbalanced nutritional composition: Blended oils are typically mixtures of various plant oils. However, some manufacturers, in an effort to reduce costs, may heavily favor one particular type of oil, leading to an imbalance in unsaturated fatty acids (such as Omega-3 and Omega-6). Long-term consumption cannot meet the body’s diverse fatty acid needs and undermines overall nutritional balance.

3. Possible inclusion of low-quality oils: A small number of unscrupulous producers may use inadequately refined low-grade oils in their blends. These oils may contain residual harmful substances (such as trans fats or heavy metals), which can increase the liver's metabolic burden over time and potentially lead to health risks.

4. Poor heat stability: Some blended oils incorporate oils with low smoke points (such as flaxseed oil or sesame oil), reducing the overall smoke point. During high-temperature cooking (e.g., frying or sautéing), these oils easily produce fumes and harmful compounds, which not only degrade nutrients but may also negatively affect the respiratory system and overall health.

5. Long-term use may cause fatty acid imbalance: Prolonged and exclusive consumption of a single brand of blended oil—especially one with a narrow fatty acid profile—can lead to an imbalance in dietary fatty acid intake, potentially increasing the risk of cardiovascular diseases and disrupting normal lipid metabolism.

For daily cooking, it is recommended to choose single-source plant oils with clearly defined compositions (such as olive oil or rapeseed oil), or to rotate among different types of oils.