Egg white protein and metabolic syndrome in rats and people
What it found
In rats, egg white protein reduced body fat and cholesterol absorption, and in people with high cholesterol or belly fat, a fermented egg white drink lowered total and LDL cholesterol and cut visceral fat.
The authors say it may help prevent or ease metabolic syndrome.
What they found
Studies in people
Cholesterol in people
Men with mildly high cholesterol who drank a fermented egg white drink with 8 grams of protein daily for 8 weeks had lower serum total cholesterol and LDL cholesterol levels. The 4 and 6 gram doses did not show this effect.
Visceral fat in people
Adults with visceral fat obesity who drank a fermented egg white drink with 8 grams of protein daily for 12 weeks had a reduced visceral fat area and a better ratio of visceral to subcutaneous fat, compared with those who drank a whey drink.
Animal and lab studies
Fat and protein in rats
Rats fed egg white protein for 4 weeks had less body fat and more body protein than rats fed casein. Their abdominal fat pads were smaller and their fat cells were smaller.
Fat burning in rats
In rats, egg white protein increased the activity of liver enzymes involved in fatty acid breakdown, which may help explain the lower body fat.
Lipid absorption in rats
In rats with a lymph duct cannula, egg white protein decreased the amount of cholesterol and triglycerides absorbed into lymph, compared with casein.
Lab tests on digestion
In lab tests, egg white protein broken down by pepsin reduced the solubility of cholesterol in micelles and its transfer into oil, and formed a gel that may trap micelles. Ovalbumin, the main protein in egg white, was resistant to pepsin digestion.
What the authors conclude
- They conclude that dietary egg white protein and lactic-fermented egg white would be useful for preventing or alleviating metabolic syndrome.
- They suggest that the consumption of egg white protein could improve the quality of life of patients with metabolic syndrome.
- They note that if lactic-fermented egg white is produced commercially, it could provide a good source of protein and help reduce visceral fat and prevent metabolic syndrome.
How it was done
Abdominal fat accumulation causes metabolic syndrome, a cluster of conditions that raises the risk of diabetes and heart disease. The authors note that the quality of dietary proteins may affect the risk of this syndrome, and they wanted to test egg white protein.
They reviewed their own studies in rats, lab tests, and two human trials. In one trial, 88 Japanese men with mildly high cholesterol drank a fermented egg white drink with 4, 6, or 8 grams of protein daily for 8 weeks. In another, 37 Japanese adults with visceral fat obesity drank a fermented egg white or whey drink with 8 grams of protein daily for 12 weeks.
What it can’t tell you
- The animal and lab results may not apply to people.
- The human trials were small and lasted only 8 or 12 weeks, so they cannot show long-term effects.
- The trials tested lactic-fermented egg white, not ordinary egg white powder or fresh egg white.
The paper
- Title
- Alleviation of Metabolic Syndrome with Dietary Egg White Protein
- Type
- ReviewThe authors read earlier studies and describe what they found. It isn’t a new study.
- Evidence
- Studies in people · animals · lab
- Summarised from
- Full text
- Cite
- Shirouchi B, Matsuoka R (2019). Alleviation of Metabolic Syndrome with Dietary Egg White Protein. Journal of oleo science. doi:10.5650/jos.ess19084Free full textPubMed 31168041DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error