Cooking Oil - Health and Nutrition

Health and Nutrition

The appropriate amount of fat as a component of daily food consumption is the topic of some controversy. Some fat is required in the diet, and fat (in the form of oil) is also essential in many types of cooking. The FDA recommends that 30% or fewer of calories consumed daily should be from fat. Other nutritionists recommend that no more than 10% of a person's daily calories come from fat. In extremely cold environments, a diet that is up to two-thirds fat is acceptable and can, in fact, be critical to survival.

While consumption of small amounts of saturated fats is essential, initial meta-analyses (1997, 2003) found a high correlation between high consumption of such fats and coronary heart disease. Surprisingly, however, more recent meta-analyses (2009, 2010), based on cohort studies and on controlled, randomized trials, find a positive or neutral effect from shifting consumption from carbohydrate to saturated fats as a source of calories, and only a modest advantage for shifting from saturated to polyunsaturated fats (10% lower risk for 5% replacement).

Mayo Clinic has highlighted oils that are high in saturated fats, including coconut, palm oil and palm kernel oil. Those of lower amounts of saturated fats, and higher levels of unsaturated (preferably monounsaturated) fats like olive oil, peanut oil, canola oil, avocado, safflower, corn, sunflower, soy, mustard and cottonseed oils are generally healthier. The National Heart, Lung and Blood Institute and World Heart Federation have urged saturated fats be replaced with polyunsaturated and monounsaturated fats. The health body lists olive and canola oils as sources of monounsaturated oils while soybean and sunflower oils are rich with polyunsaturated fat. Results of research carried out in Costa Rica in 2005 suggest that consumption of non-hydrogenated unsaturated oils like soybean and sunflower are preferable to the consumption of palm oil.

Not all saturated fats have negative effects on cholesterol. Some studies indicate that Palmitic acid in palm oil does not behave like other saturated fats, and is neutral on cholesterol levels because it is equally distributed among the three "arms" of the triglyceride molecule. Further, it has been reported that palm oil consumption reduces blood cholesterol in comparison with other traditional sources of saturated fats such as coconut oil, dairy and animal fats.

Saturated fat is required by the body and brain to function properly. In fact, one study in Brazil compared the effects of soybean oil to coconut oil (a highly saturated fat) and found that while both groups showed a drop in BMI, the soybean oil group showed an increase in overall cholesterol (including a drop in HDL, the good cholesterol). The coconut oil group actually showed an increase in the HDL:LDL ratio (meaning there was more of the good cholesterol), as well as smaller waist sizes (something that was not shown in the soybean oil group.

In 2007, scientists Kenneth C. Hayes and Pramod Khosla of Brandeis University and Wayne State University indicated that the focus of current research has shifted from saturated fats to individual fats and percentage of fatty acids (saturates, monounsaturates, polyunsaturates) in the diet. An adequate intake of both polyunsaturated and saturated fats is needed for the ideal LDL/HDL ratio in blood, as both contribute to the regulatory balance in lipoprotein metabolism.

Oils high in unsaturated fats may help to lower "bad" LDL cholesterol and may also raise "good" HDL cholesterol, though these effects are still under study.

Peanut, cashew, and other nut-based oils may also present a hazard to persons with a nut allergy. A severe allergic reaction may cause anaphylactic shock and result in death.