Whether you're roasting a chicken in the oven, browning onions in a skillet, or choosing a spread for your toast, oil is at the heart of our culinary endeavors.
The choices are dizzying. Around 30 different oils are currently used in cooking, from sunflower to flaxseed, avocado to coconut. Deciding which one to use can have a big impact on your health, including your cholesterol, blood pressure, and risk of cardiovascular disease.
If the headlines are to be believed, palm oil is obsolete, sunflower oil is in limbo, and there seems to be no end to the benefits extra virgin olive oil can bring to our plates. But are these claims backed by solid science, and how do the health impacts of these products compare to their environmental costs?
Saturated or unsaturated?
First, let's talk about chemistry. Edible oil contains fat, which is made up of long chains of carbon atoms. Saturated fats found in red meat and dairy products are so named because each carbon atom is connected to the next carbon atom by a single bond. The remaining electrons of each carbon atom are available to form bonds with hydrogen atoms, and the molecule becomes completely “saturated” with this element. This structure makes these fats very hard and stable, which is why butter and lard are solid at room temperature.
Unsaturated fats, which are commonly found in plants and fatty fish, have at least one double bond between adjacent carbon atoms, which reduces the number of bonds.
Source: www.newscientist.com
Study Confirms the Health Benefits of Vegetable Oils
New dietary intervention studies Published in the journal Nature MedicineSwitching from a diet high in saturated animal fats to one high in unsaturated plant fats affects the composition of fats in your blood, which can affect your long-term disease risk.
Eichelmann othersThis shows that it is possible to accurately measure diet-related changes in blood fats and directly link them to the risk of developing cardiovascular disease and type 2 diabetes. Image courtesy of Tung Lam.
The World Health Organization (WHO) highlights the importance of a healthy diet in preventing chronic diseases and recommends replacing saturated fats with unsaturated fats from plant sources to reduce cardiometabolic risk.
However, limitations in existing research mean these guidelines are of moderate certainty.
The new study addressed these limitations by conducting a detailed analysis of fats in the blood, also known as lipids, using a technique called lipidomics.
These highly detailed lipid measurements have allowed researchers to innovatively combine different types of studies to link diet and disease.
This approach combines dietary intervention studies (using highly controlled diets) with previously conducted cohort studies with long-term health follow-up.
“Our collaboration provides conclusive evidence that diets low in saturated fat and high in unsaturated vegetable fats have health benefits and may help to provide targeted dietary advice to people who would benefit most from changing their eating habits,” said Professor Julie Lovegrove, from the University of Reading.
“Our study provides further conclusive evidence that diets high in unsaturated vegetable fats, such as the Mediterranean diet, are beneficial for health,” added researcher Dr Clemens Wittenbecher from Chalmers University of Technology.
The study included 113 participants from the DIVAS trial, a single-blind, randomized, controlled, parallel trial.
For 16 weeks, one group ate a diet high in saturated animal fats and the other group ate a diet high in unsaturated vegetable fats.
The blood samples were analyzed using lipid analysis techniques to identify specific lipid molecules that reflected the different diets consumed by each participant.
“We summarized the effects on blood lipids in a Multi Lipid Score (MLS),” said Dr Fabian Eichelmann, researcher at the German Institute of Human Nutrition in Potsdam-Rehbrücke.
“A high MLS indicates a healthy blood fat profile, and such good MLS levels can be achieved by consuming more unsaturated vegetable fats and less saturated animal fats.”
“These MLS results from dietary intervention studies were statistically associated with incident cardiovascular disease and type 2 diabetes in previous large observational studies.”
“These large cohort studies followed initially healthy participants for several years.”
Analysis of data from both studies showed that participants with a higher MLS, indicating a beneficial dietary fat composition, had a significantly reduced risk of developing cardiometabolic diseases.
Additionally, the scientists investigated whether people with lower MLS levels, indicative of a higher saturated fat content in their diet, particularly benefited from a healthier diet.
The Mediterranean diet, which focuses on consuming more unsaturated vegetable fats, was used in one of the large intervention trials known as the PREDIMED trial.
From this study, the authors found that the diabetes prevention effect was most pronounced in individuals who had low MLS levels at the start of the study.
“Because diet is so complex, it's often difficult to draw conclusive evidence from a single study,” Dr. Wittenbecher said.
“Our approach of combining a highly controlled dietary intervention study with lipid analysis and a prospective cohort study with long-term health follow-up can overcome current limitations in nutrition research.”
_____
F. Eichelmann othersLipid changes through improving the quality of dietary fats can aid in cardiometabolic risk reduction and precision nutrition. National MedPublished online July 11, 2024; doi: 10.1038/s41591-024-03124-1
This article is a version of a press release provided by the University of Reading.
Source: www.sci.news
