One of these new studies was published recently in the Journal of the American Heart Association. Researchers set out to add evidence of an association between diets high in red meat and cardiovascular disease risk. The data on this topic thus far is sparse and inconclusive about specific types of proteins.
For the study, researchers analyzed data from more than 100,000 postmenopausal women aged 50 to 79. All had participated in the National Women’s Health Initiative study between 1993 and 1998 and were followed through February 2017. At the start of the study, participants completed questionnaires about their diet detailing how often they ate eggs, dairy, poultry, red meat, fish/shellfish, and plant proteins, including tofu, nuts, beans, and peas.
During the study period, a total of 25,976 deaths occurred; 6,993 deaths from cardiovascular disease; 7,516 deaths from cancer; and 2,734 deaths from dementia.
The women were divided into groups to compare those who consumed the least amount of protein to the highest protein consumption level. The median percent intake of total energy from animal protein in this population was from 7.5% to 16.0%, and plant protein was between 3.5% and 6.8%.
It was found that compared to postmenopausal women who had the least amount of plant protein intake, those with the highest amount of plant protein intake had a 9% lower risk of death from all causes, a 12% lower risk of death from cardiovascular disease, and a 21% lower risk of dementia-related death.
A higher consumption of processed red meat was also associated with a 20% higher risk of dying from dementia. Unprocessed meats and dairy also showed a relationship to a higher risk of dying from cardiovascular disease.
The Associations of Eggs
An interesting association with eggs was found. A higher consumption increased the risk of dying from cardiovascular disease and cancer. However, consuming more eggs also lowered the risk of dying from dementia.
“It is unclear in our study why eggs were associated with a higher risk of cardiovascular and cancer death,” said lead study author Wei Bao, M.D., Ph.D. “It might be related to the way people cook and eat eggs. Eggs can be boiled, scrambled, poached, baked, basted, fried, shirred, coddled or pickled or in combinations with other foods.
In the United States, people usually eat eggs in the form of fried eggs and often with other foods such as bacon.
Although we have carefully accounted for many potential confounding factors in the analysis, it is still difficult to completely tease out whether eggs, other foods usually consumed with eggs, or even non-dietary factors related to egg consumption, may lead to the increased risk of cardiovascular and cancer death.”
It is important to note that dietary proteins are not consumed in isolation, so interpreting the findings could be challenging. The population involved in the study were also more likely to have Type 2 diabetes at the start of the study, a family history of heart attacks, and a higher body mass index, all risk factors for cardiovascular disease. However, the outcomes do support the need to consider dietary protein sources when looking at dementia risk.