Lactic-fermented egg white reduced serum cholesterol concentrations in mildly hypercholesterolemic Japanese men: a double-blind, parallel-arm design

Health Functions of Egg Protein

Egg protein is a remarkably abundant source of protein, with an amino acid score of 100 and the highest net protein utilization rate. However, there have been relatively fewer studies investigating the health benefits of egg protein. In this review, we have summarized the available information regarding the health benefits of egg proteins based on human studies. In particular, studies conducted on the characteristics of egg whites, as they are high in pure protein, have reported their various health functions, such as increases in muscle mass and strength enhancement, lowering of cholesterol, and visceral fat reduction. Moreover, to facilitate and encourage the use of egg white protein in future, we also discuss its health functions. These benefits were determined by developing an egg white hydrolysate and lactic-fermented egg whites, with the latter treatment simultaneously improving the egg flavor. The health benefits of the protein hydrolysates from the egg yolk (bone growth effect) and eggshell membrane (knee join pain-lowering effect) have been limited in animal studies. Therefore, the consumption of egg protein may contribute to the prevention of physical frailty and metabolic syndromes.

Property of Phytosterols and Development of Its Containing Mayonnaise-Type Dressing

Phytosterols are functional ingredients with known efficacy and safety. Phytosterols are found as free sterols or as their esters with fatty acids. Although phytosterol esters are soluble in oil and have been used in many commercial foods, it has been difficult to similarly use free phytosterols since they are insoluble in water and practically insoluble in oil. We have developed mayonnaise-type dressing materials using free phytosterols since people who are conscious about cholesterol intake are likely to be conscious about oil. In this review article, we summarized pieces of evidence for the development of phytosterol-containing mayonnaise-type dressing materials.

Nutritional Viewpoints on Eggs and Cholesterol

Although most current epidemiologic studies indicate no significant association between consuming one egg daily and blood cholesterol levels and cardiovascular risk, arguments still persist with a positive association. Since the diet is one of the most influential factors for this association, we illustrate characteristic features in Japanese people whose dietary pattern is distinct from that, for example, the US (United States) population. Available epidemiologic studies in healthy Japanese people show no association between consumption of one egg daily and blood cholesterol level, consistent with those observed in the US population. However, when consumption of major nutrients and food sources of cholesterol are compared to the US population, Japanese people may have an extra-reserve against the influence of eggs on cardiovascular risk markers, despite consuming relatively more eggs. Further discussion on the influence of nutrients contained in the egg and dietary pattern, including interaction with gut microbes, is necessary. In addition, special consideration at the personalized level is needed for judgment regarding dietary cholesterol not only for hypercholesterolemic patients but for hyper-responsive healthy persons. Although randomized controlled trials with long-term follow-up are required to evaluate the association between consumption of eggs and human health, available information, at least from the nutritional viewpoint, suggests that egg is a healthy and cost-efficient food worldwide.

Egg White Hydrolysate Retains the Nutritional Value of Proteins and Is Quickly Absorbed in Rats

Egg white protein has a high net protein utilisation, with a score of 100 in the amino acid rating system. Although the enzymatic breakdown of egg white yields hydrolysates that are rapidly absorbed and various physiological activities can be expected from them, flavouring egg white to meet taste requirements as a food has been a difficult challenge. Herein, we developed a high-molecular-weight egg white hydrolysate and compared the absorption rate and nutritional value of the hydrolysate with those of egg white proteins obtained from raw materials, whey proteins, and hydrolysates, also known as high-quality proteins. The absorption rate of egg white hydrolysates was faster than that of egg white and whey proteins in portal vein cannulated rats, and their bioavailability values were higher than those of whey proteins and hydrolysates. According to the protein digestibility-corrected amino acid score and digestible indispensable amino acid score, the scores for egg white hydrolysates were equivalent to those of egg white and whey proteins but higher than those of whey hydrolysates. Our results show that egg white hydrolysates maintain the nutritional value of egg whites and are rapidly absorbed by the body.

Minimal effective dose of lactic-fermented egg white on visceral fat in Japanese men: a double-blind parallel-armed pilot study

Background

We previously reported that the consumption of 8 g of protein per day in the form of lactic-fermented egg white (LAFEW) improves visceral fat obesity. In this study, we investigated the minimum effective intake of LAFEW for visceral fat reduction in the Japanese males with mild obesity.

Methods

Twenty-two Japanese adult males with a Body mass index (BMI) ≥24 and a waist circumference ≥ 85 cm were included in this study. The subjects were divided into three groups, that is, control group, LAFEW 6 g group, and LAFEW 8 g group. The LAFEW 6 and 8 g groups consumed 6 and 8 g, respectively, of egg white protein (EWP) in a drink at breakfast for 8 weeks, whereas the control group consumed a drink containing 8 g of milk whey protein. Body weight, body fat percentage, abdominal circumference, and visceral fat (VF) area around the navel were measured at 0 and 8 weeks after initiating the consumption.

Results

No changes in body weight or body fat percentage were observed in any of the groups. No significant differences between the pre- and posttreatment measurements were found in the VF area around the navel in the control group and the LAFEW 6 g group. In the LAFEW 8 g group, the VF area had decreased significantly after 8 weeks of consumption, when compared to that before consumption, and the average observed decrease (Δcm²) was 13.2 ± 4.7 cm². Among the subjects with an initial BMI > 25, the VF area was significantly smaller in the LAFEW 8 group, when compared to the week 0 values and those in the control group. Visceral fat/subcutaneous fat values in the LAFEW 8 group were also significantly smaller than those in the control group or at week 0.

Conclusion

The results suggested that the minimum effective intake of EWP in the LAFEW to reduce the VF area in the Japanese men is 8 g.

Trial registration

This clinical trial was retrospectively registered with the University hospital Medical Information Network (UMIN) Center, (UMIN000031681; registered on 12/03/2018).

Egg white hydrolysate improves fatigue due to short-term swimming load test in mice

We studied the effect of egg white hydrolysate (EWH) on swimming endurance in mice. 7-week-old male ddY mice (28-30 g) were divided into three groups and fed an AIN-93G diet supplemented with casein (n = 8), EWH (n = 7), or egg white protein (EWP, n = 8) for 14 days. From day 11, the mice underwent a swimming test daily with a weight load equivalent to 10% of their body weight, and the lengths of time they swam were recorded. Blood was sampled for testing on the last day of the study. We observed that increases in the swimming duration through day 14 were significantly greater in the EWH group than in the casein group (p = 0.049). As a factor underlying this, the hexanoyl-lysine level in blood was confirmed to be decreased in the former group (p = 0.013). These findings indicate that consumption of EWH extended the swimming duration and suggest the mechanistic involvement of an antifatigue effect mediated by its antioxidant activity.

Lactic-fermented egg white improves visceral fat obesity in Japanese subjects-double-blind, placebo-controlled study

BACKGROUND

It was reported that egg white protein (EWP) reduced body fat in rats. We developed a lactic-fermented egg white (LE) that facilitates the consumption of egg whites by fermenting them with lactobacillus, and were able to study their intake in humans. In this double-blind, placebo-controlled design, we evaluated the effect of LE on visceral fat area (VFA).

METHODS

Participants included 37 adult males and females aged ≥40 years (VFA at navel ≥100 cm2). They were divided into two groups: the control group and the LE group. The control and LE groups consumed drinks containing whey and LE, respectively, for 12 weeks (providing 8 g protein/day). VFA was measured at baseline and at week 12 of intake. Abdominal girth was measured at baseline and at weeks 6 and 12.

RESULTS

LE intake decreased VFA significantly compared with baseline (-8.89 cm2, p < 0.05), and VFA was significantly lower than that in the control group (+1.71 cm2, p < 0.05). The LE group showed significant improvement in the ratio of visceral to subcutaneous fat area compared with baseline and the control group (p < 0.05).

CONCLUSIONS

The results demonstrated that LE reduces VFA and improves the ratio of visceral to subcutaneous fat area. As other measurement items were not influenced, we concluded that LE improves visceral fat obesity.

TRIAL REGISTRATION

This clinical trial was retrospectively registered with the University hospital Medical Information Network (UMIN) Center, ( UMIN000026949 ; registered on 11/04/2017; http://www.umin.ac.jp /).