Original Bio Valley Bio Valley
2024-07-20 19:59 Zhejiang
In today's society, healthy eating has become a hot topic for the whole country, from "light food" to "plant-based", from "sugar-free" to "whole grains", people are paying more and more attention to the impact of food on the body. And among them, there is a delicacy that we may have loved eating since childhood, but when we grow up, we gradually resist eating it for fear of causing obesity and three highs - lard! Now, we may need to re-evaluate it.
Legend has it that almost every household used to have a lard enamel bowl, picture from: photo network
As we all know, cardiovascular disease is the number one killer of global health, and hyperlipidemia, which is an abnormal increase in lipids such as cholesterol and triglycerides in the blood, is one of the important factors that cause cardiovascular disease. Previous studies have confirmed that controlling the type and amount of fat in the diet is essential for the prevention and treatment of cardiovascular disease. And lard, which contains a higher content of saturated fatty acids, increases low-density lipoprotein (LDL, or "bad cholesterol") in the blood. Therefore, the conventional wisdom is that eating lard not only induces obesity, but also increases the risk of cardiovascular disease.
然而，一篇由来自泰国国立法政大学、卜蜂食品企业有限公司等研究人员撰写的，发布于International Journal of Food Science上题为“Effects of Omega-3-Rich Pork Lard on Serum Lipid Profile and Gut Microbiome in C57BL/6NJ Mice”的论文却反驳了“吃猪油不利于健康”这一观点，研究表明：富含Omega-3的猪油不仅能改善血脂水平，降低心血管疾病的风险，还能通过调整肠道微生物组，促进肠道健康，进而可能对整体健康状况产生积极影响。
Introduction to Omega-3 fatty acids and the experimental design of this study
Omega-3 fatty acids are polyunsaturated fatty acids that have important effects on human health, especially for heart health. They are called "essential fatty acids" because the body cannot synthesize them on its own and must be consumed through the diet. The main Omega-3 fatty acids include:1. α-linolenic acid (ALA), which is a short-chain omega-3 fatty acid found mainly in vegetable oils such as flaxseed, rapeseed and walnut oil, as well as some green leafy vegetables and legumes; 2. Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), two long-chain omega-3 fatty acids mainly derived from deep-sea fish such as salmon, mackerel, herring and sardines.
In this study, 23 16-week-old male C57BL/6NJ mice were randomly divided into three groups: one group received a standard diet (control group), one group was fed high-fat coconut oil, and the other group was fed omega-3-rich lard. After a four-week feeding cycle, the researchers analyzed the mice's serum lipid levels and fecal microbiome.
Eat lard, but the right kind!
After testing, the researchers found that mice in the Omega-3 lard diet group had the largest increase in body weight, with a 35% increase, followed by mice in the high-fat coconut oil diet group, with a 22% increase, and the control group with an increase of about 6%.
Although the weight of the mice fed with Omega-3 lard increased, the percentage of liver weight in the mice in the Omega-3 lard diet group decreased significantly compared to the control group and the mice on the high-fat coconut oil diet, and the relative weight of visceral fat increased.
Supplementary note: The decrease in liver weight indicates that the probability of fatty liver disease in mice may be lower, visceral fat has a protective effect on viscera, and the increase in visceral fat indicates that mice have better visceral protection. Although Omega-3 lard increases weight and fat, it is actually beneficial to the health of mice.
Figure 1: Differences in body weight, dietary intake, and organ weight between the three groups
Omega-3 fatty acids can protect against cardiovascular disease
The results of the study showed that the levels of cholesterol, triglycerides, low-density lipoprotein (LDL) and urea nitrogen in the Omega-3 lard diet group were significantly lower than those in the high-fat coconut oil diet group, suggesting that Omega-3 has a positive effect on blood lipid regulation. This finding has important implications for the prevention of cardiovascular disease.
Figure 2: Differences in serum lipid profiles and liver and kidney functional enzymes
Omega-3 fatty acids can improve blood lipids by regulating gut microbes
In addition, the researchers explored changes in the gut microbiome during this process. Compared with the control group, the relative abundance of Lachnospiraceae in the high-fat coconut oil diet group was significantly decreased, while the relative abundance of Bacteroidaceae and Burkholderiaceae was significantly increased.
而与对照组相比，在Omega-3猪油饮食组小鼠中，Bacteroidaceae, Peptococcaceae, 和Burkholderiaceae相对丰度增加；与高脂椰子油饮食组相比，Omega-3猪油饮食组小鼠Lachnospiraceae相对丰度显著增加。
Spearman correlation analysis showed that the relative abundance of Bacteroidaceae and Burkholderiaceae was significantly positively correlated with serum lipid content. However, there is a significant negative correlation between the relative abundance of Lachnospiraceae and cholesterol, triglycerides, LDL, and HDL levels, and the bacteria of the Lachnospiraceae family are generally associated with a healthy intestinal environment, and their proliferation contributes to the maintenance of intestinal barrier function and metabolic health.
These results suggest that omega-3 fatty acids may indirectly improve blood lipid levels by regulating the composition of gut microbes.
Figure 3: Mouse gut microbiota analysis
Figure 4: Correlation between gut microbiota and serum lipid content
summary
In the past, all saturated fats were often considered unhealthy sources, but this study suggests that omega-3-rich sources of saturated fats, such as specially raised lard, may have unique health benefits. For individuals pursuing a healthy diet, especially those who need to control their blood lipid levels, moderate intake of foods rich in Omega-3 may be a choice worth considering (not recommended products, not advertisements~).
This discovery gives new health value to the traditional ingredient of lard, emphasizing the importance of dietary diversity and nutritional balance, and also providing new ideas for future nutritional therapies.
Bibliography:
Koontanatechanon A, Wongphatcharachai M, Nonthabenjawan N, et al. Effects of Omega-3-Rich Pork Lard on Serum Lipid Profile and Gut Microbiome in C57BL/6NJ Mice. Int J Food Sci. 2022;2022:9269968. Published 2022 Nov 22. doi:10.1155/2022/9269968