September 3, 2024 – You probably already know that a eating regimen high in fruits, vegetables, and other plant-based foods is healthier for you than one which relies on meat and dairy. But to this point, dietary research has not been in a position to explain the precise influence of certain kinds of dietary fats on health.
A new study examined how the consumption of vegetable fats in comparison with animal fats affects people's life expectancy. Researchers found what we already suspected: A eating regimen higher in fruits, vegetables, grains, and vegetable oils provides higher protection against death from all causes and diseases of the guts and blood vessels (heart problems).
And it also matters how much you devour. People who ate more fats from plants had a 9% lower risk of dying from all causes and a 14% lower risk of dying from heart problems than those that ate significantly less of those foods took in.
On the opposite hand, individuals who ate plenty of animal fat, including fat in meat, dairy and eggs, had the next risk of dying from all causes and heart problems than those that ate less. When the highest consumers of animal fats were compared with the bottom consumers, it was found that the highest consumers had an overall 16% higher risk of death and a 14% higher risk of heart problems.
Data from a long-term health study
The greater than 400,000 people within the study were a part of the National Institutes of Health-AARP Diet and Health Study. In the group used for dietary fat research, there have been barely more men than women, and the typical age of the topics was 61 years. They were enrolled in 1995 and followed until 2019.
When enrolling, study participants accomplished a questionnaire that included questions on their dietary habits, broken down into 124 dietary items and portion sizes. Total dietary fat intake included each plant sources (reminiscent of grains, nuts, legumes, and vegetable oils) and animal sources (reminiscent of red and white meat, dairy products, and eggs).
During the 24-year follow-up period, 185,111 deaths were recorded, including 58,526 from heart problems (45,634 from heart disease and 10,877 from stroke). The researchers linked these deaths to the dietary information within the baseline questionnaire to calculate the diet-related risk of death, after making an allowance for quite a lot of other aspects that will have contributed to the general deaths.
In addition, the authors examined fats in specific food groups to find out their association with the chance of death. For example, on the plant side, they found that higher intake of fat from beans and legumes was not related to any of the mortality results.
Higher consumption of fat from dairy and eggs showed an increased risk of all-cause mortality, including from heart problems, while consumption of greater amounts of fat from white meat was related to a lower risk. Fat from beef carries the next risk of mortality; In contrast, higher fat consumption of fish was not significantly related to a rise in the chance of death overall or of death from heart and blood vessel diseases.
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The researchers also examined whether dietary changes affected the chance of death. The answer? A convincing “yes”.
Replacing just 5% of calories from animal fat, beef fat, dairy fat, or egg fat with the identical amount of total vegetable fat was related to a 4 to 24% lower risk of overall death and a 5 to 30% lower risk of death from disease of the guts and blood vessels, researchers said.
Another finding: Replacing vegetable fats with fish and white meat fat didn't reduce the chance of death, they said.
Because of the fatty deposits that may construct up in human arteries over time, dietary changes can have very different effects on heart health depending on when in life an individual makes the change, Dr. Walter Willett, professor of epidemiology and nutrition on the Harvard TH Chan School of Public Health. It takes a protracted time for these plaques to vanish. So the earlier you turn to a more plant-based eating regimen, the higher, he said.
Study co-author Demetrius Albanes, MD, senior investigator within the Division of Cancer Epidemiology and Genetics on the National Cancer Institute, agreed with Willett. “Cardiovascular plaques probably take a long time to clear,” he said. “Therefore, it is better to change your diet earlier under the guidance of doctors and at the same time avoid drastic and extreme diets.”
Possible limitations of the study
A significant drawback of the paper, Willett said, is that the underlying NIH-AARP study only asked people about their eating regimen within the baseline questionnaire. Some of the people within the study, he said, undoubtedly modified their diets through the 24-year follow-up, but those changes weren't included in the info utilized in the study on dietary fats. Because of this, he said, an increasing number of errors were introduced into the info utilized in the evaluation, weakening the connection between the participants' diets and the deaths of a part of the study group.
“If we only use the baseline survey, we only see a weak signal in the random noise,” he said.
Another problem with the study's results, Willett said, was that within the Nineteen Nineties, when participants were enrolled, trans fats began to be faraway from foods that contained vegetable oils. The FDA banned Partial hydrogenation of vegetable oil, a sort of food processing that produces trans fats, in 2018. Since most plant-based foods aren't any longer partially hydrogenated, he said, “This contributes to errors as it contains up to 30-40% of the plant .” Fats [in the baseline diets] were trans fats, and these significantly increase the chance of heart problems, which might greatly underestimate the advantages of vegetable fats.”
Although the study authors say they statistically controlled for the decline in trans fats, Willet says they didn't do it thoroughly “because food composition databases didn't keep up with the changes.”
He said that between these two problems and problems with the validity of the questionnaire “are the connections that they describe.” [in the study] results in an roughly twofold underestimation of the effect of nutrition [on mortality]. When you place all of the sources together, they probably underestimate the consequences of eating regimen by 4 times or much more.”
Albanes responded that the study's methodology was valid and that the majority studies of this kind “can only collect dietary data at baseline.” All dietary changes through the years
“They may have biased our estimates somewhat,” but if that's the case, their estimates of the risks from animal fats “may have been underestimated.”
“The problem with trans fats is real and there are questions about how this would have affected our tracking and mortality in our population. This continues to be researched as it is a recent development.”
In any case, Albanes said, if the study underestimates the impact of consuming more vegetable or animal fats on the chance of death, it only underscores the importance of its key findings.
Nutritional recommendations
Albanes believes the study's data on the mortality risks of various food groups is solid enough to be utilized in dietary recommendations. In addition to vegatables and fruits, the vegetable fat sources he would recommend include fats from grain products (bread, pasta, etc.) and vegetable oils, including olive, rapeseed and corn oil.
Willett emphasized that grains don't contain much fat except within the germ. “Almost all plants have fat to protect their seeds, and this fat is full of antioxidants.”
Albanes agreed. “When we discuss fat from grains, that refers to all of the grain foods that were asked about in the unique questionnaire. “That will be different whether it's a whole grain bread with sprouted content or a refined wheat or white bread.” While the study didn't highlight the consequences of whole grain bread in comparison with more processed bread, he said the previous is healthier for health.