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The Deleterious Health Effects of Partially Hydrogenated Vegetable Oils

Partially hydrogenated vegetable oils (PHVOs) are formed when vegetable oils undergo a chemical process called partial hydrogenation. This process adds hydrogen atoms to unsaturated fatty acids in the oil, making it more stable and solid at room temperature. PHVOs are widely used in the food industry due to their longer shelf life, texture-enhancing properties, and heat stability. However, numerous studies have linked PHVOs to several health issues, primarily due to the formation of trans fatty acids (TFAs) during the hydrogenation process. This article examines the deleterious health effects associated with PHVO consumption and the importance of seeking healthier alternatives.

Cardiovascular Diseases

The consumption of PHVOs has been strongly linked to an increased risk of cardiovascular diseases (CVDs). TFAs can raise low-density lipoprotein (LDL) cholesterol levels, also known as "bad" cholesterol, while simultaneously lowering high-density lipoprotein (HDL) cholesterol or "good" cholesterol. This imbalance contributes to the build-up of plaque in the arteries, which can eventually lead to heart attacks, strokes, and other cardiovascular complications. A meta-analysis of several studies revealed that a 2% increase in energy intake from TFAs corresponds to a 23% increase in the risk of coronary heart disease.

Inflammation and Endothelial Dysfunction

PHVO consumption has also been associated with increased inflammation and endothelial dysfunction, both of which are critical factors in the development of atherosclerosis. TFAs are known to trigger inflammatory responses by activating pro-inflammatory cytokines and increasing C-reactive protein (CRP) levels. In addition, they can impair the functioning of the endothelium, the inner lining of blood vessels, by reducing the bioavailability of nitric oxide, a vasodilator essential for maintaining vascular health.

Type 2 Diabetes

A diet high in PHVOs may contribute to the development of type 2 diabetes by negatively affecting insulin sensitivity. In several observational studies, higher TFA intake has been linked to a higher risk of type 2 diabetes. The mechanism underlying this relationship is not entirely understood, but it is suggested that TFAs may alter cell membrane structure and function, disrupt insulin signaling, and promote inflammation, which can impair glucose metabolism.


Although the relationship between PHVO consumption and obesity remains inconclusive, some studies have suggested that TFAs may contribute to weight gain and abdominal fat accumulation. A potential explanation for this effect is that TFAs may disrupt the activity of key enzymes involved in lipid metabolism, such as lipoprotein lipase and hormone-sensitive lipase, which could lead to increased fat storage.


Some research has indicated that high TFA intake may be associated with an increased risk of certain cancers, such as breast, colon, and prostate cancer. While the exact mechanisms are not yet fully understood, it is hypothesized that TFAs may promote inflammation, disrupt cell signaling pathways, and interfere with the normal functioning of cell membranes, which can contribute to the development and progression of cancer.

The deleterious health effects of PHVOs can no longer be ignored. Due to the extensive evidence linking their consumption to a wide range of health issues, many countries have implemented policies to reduce or eliminate TFAs from the food supply. As consumers, it is essential to be aware of the risks associated with PHVO consumption and opt for healthier alternatives, such as unhydrogenated vegetable oils, which contain fewer TFAs and have been associated with more favorable health outcomes.