This article is transferred from | China Biotechnology Network
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As we all know, cardiovascular disease is the number one disease in the world in terms of morbidity and mortality. According to the latest data, the number of patients in China has exceeded 330 million, and 2 out of every 5 deaths have died of cardiovascular disease.
To promote cardiovascular health, for many years, countries have recommended reducing the intake of saturated fats, including milk, in dietary guidelines, which has led many people to choose low-fat or skim milk instead.
While consuming more milk fat is expected to increase low-density lipoprotein (LDL) cholesterol, recent human clinical studies have found that this effect varies depending on dairy type and processing method. That said, the health effects of dairy products depend more on the type (e.g., milk, yogurt, cheese, and butter) than on fat content. Because dairy products are a major source of human nutrition and are increasingly consumed worldwide. Therefore, a better understanding of the effect of milk fat intake on the risk of cardiovascular disease is essential.
On September 22, Beijing time, in a study published in PLOS Medicine, an international research team from Johns Hopkins University in the United States, Harvard University, the University of New South Wales in Australia, and Uppsala University and Karolinska Institutet in Sweden found that consuming milk fat in products such as whole milk, yogurt and cheese can prevent heart attacks. This means that people who consume more milk fat are at less risk of cardiovascular disease, and higher milk fat intake is not associated with an increased risk of death. The study provides the most comprehensive evidence for the idea that native full-fat dairy products are good for heart health.
Previously, many studies relied on participants' diet questionnaires, which were affected by recall biases that greatly compromised the accuracy of the data, plus dairy products were often added to a variety of diets. Therefore, it is even more difficult to accurately grasp the intake of milk fat.
Fatty acid composition in tissues or circulation is used as a biomarker for dietary fats. Among them, pentadecanic acid (15:0) and heptadecanic acid (17:0), as well as a trans fatty acid, trans palmoleic acid (t16:1n-7), are increasingly being used as biomarkers for dairy fat intake because they are mainly found in ruminants' foods, such as milk, and are not strongly affected by genetic variation.
In the study, the researchers measured milk fat intake using serum pentadecanic acid (15:0) without relying on the quality of participants' memories or food databases. A more objective measure of dairy fat intake is provided.
They surveyed a cohort of health studies in Stockholm, Sweden, involving 4150 participants with an average age of 60 (51 percent were women). During the average 16.6-year follow-up period, there were 578 cardiovascular disease events (coronary heart disease and ischemic stroke) and 676 deaths.
After adjusting for risk factors such as age, income, lifestyle, eating habits, and other diseases, the researchers found that people with higher intakes of milk fat had a lower risk of cardiovascular disease; and that higher intake of milk fat did not increase the risk of all-cause death.
Therefore, those who choose low-fat or skim milk can consider whole milk. In fact, the fat content of whole milk is only about 3%.
The researchers believe that the findings highlight the uncertainty of the evidence in this area.
They say the health effects of dairy products depend more on the type, for example, milk, yogurt, cheese and butter; than on fat content. So, it's important to choose specific dairy products, for example, yogurt instead of butter, or avoid sweet dairy products with added sugar.
Although the findings may be influenced in part by factors other than milk fat, the researchers stress that the study did not show any harm in the milk fat itself.
Dr Kathy Trieu, lead author of the study and from the George Institute for Global Health In Australia, said: "Previous studies have shown that eating some dairy products, especially fermented products, is good for the heart. Our research suggests that reducing milk fat or avoiding dairy products altogether may not be the best option to protect heart health. Taken together, these relationships are very interesting, but we need further research to better understand the overall health effects of dairy fats and dairy foods. ”
Thesis Link:
https://doi.org/10.1371/journal.pmed.1003763