Monounsaturated fatty acid (MUFA)
Monounsaturated fatty acid is ingested from foods and synthesized by Δ9 desaturase in the body. The median intake of MUFA in Japanese based on the National Health and Nutrition Survey in 2010 and 2011 are 20.8 g/d (9.0 %E) in male and 17.3 g/d (9.5 %E) in female, respectively.
MUFA-rich diet does not increase LDL cholesterol, does not decrease HDL cholesterol and does not increase neutral fat. If carbohydrate has been replaced with MUFA or polyunsaturated fatty acid (PUFA), it has been shown that PUFA has stronger effect of LDL cholesterol lowering than MUFA.
It is not consistent the association the coronary artery disease and MUFA. Although Seven Countries Study has reported the risk reduction of coronary death, Nurses’s Health Study has reported no association. Framingham Study，Cohort study in Denmark，Lipid Research Clinics Prevalence Follow-Up Study and Strong Heart Study have reported the risk increase of coronary artery disease. Although the association with obese and insulin sensitivity and insulin resistance have been reported, it is not concluded.
Trans Fatty Acid
It has been reported that it is the risk of coronary artery disease to intake fat containing trans fatty acids from industrial. However, trans fatty acids exist in nature, that are included in the meat and dairy products, does not pose a risk of coronary artery disease. Based on the National Health and Nutrition Survey form 2003 to 2007, the median intake of trans fatty acids from industrial are 0.292 g/d (0.13 %E) in male and 0.299 g/d (0.16 %E) in femal, respectively. Typical trans fatty acids is shortening.
In meta-analysis in 2011, it has been shown that the relative risk of the maximum intake group of trans fatty acids from industrial increases 1.3 times compared to the minimum intake group. It is not consistent with the relationship with diabetes risk. There are reports of positive correlation between coronary artery disease and trans fatty acid intake and positive correlation between serum CRP levels and trans fatty acid intake.
For conjugated linoleic acid, diacylglycerol, medium-chain triacylglycerols and plant sterols, because epidemiological studies is insufficient and the estimation of intakes is difficult, it has not been considered.
Cholesterol
Cholesterol is produced in the body. Its production is 12-13 mg/kg/d. The 3-7 times of cholesterol is produced in the body compared with the cholesterol that is taken orally. The cholesterol production in the liver is regulated by cholesterol intake.
Cholesterol is rich in eggs. Therefore, there are some reports of relationship between egg intakes and arteriosclerosis. In meta-analysis in 2013, it has not been shown of relationship between egg intakes and coronary artery disease and stroke. In cohort study for Japanese, it has not been shown the relationship between egg intakes and the mortality due to ischemic heart disease and stroke. In JPHC study, the association with coronary artery disease has not been shown.
There are some reports associated with cancers. In NIPPON DATA 80, Cancer mortality relative risk in the two or more eggs intake group was doubled compared to one egg intake group in female, but it was not statistically significant. On the other hand, there are reports of the relationship between cholesterol intake and ovarian cancer, endometrial cancer. There is a report that hazard ratio of liver cancer or cirrhosis is 2.45, significantly high.
References:
The Dietary Reference Intakes for Japanese (2015 edition) Lipids (pdf)
The Dietary Reference Intakes for Japanese (2010 edition) Lipids (pdf)