ID 598 -
Białko sojowe
PL: Białko sojowe
EN: Soy protein
Pdf: soy protein
1. Charakterystyka żywności / składnika
The food constituent that is the subject of the health claims is soy protein.
Soy protein is an edible component derived from the soybean Glycine max (L) Merr. Soy protein may be consumed as part of whole soy bean products that have undergone minimal processing or can be prepared from soybeans by various separation and extraction processes. Food products containing soy protein usually also contain variable amounts and types of phenolic compounds, such as isoflavones, and variable amounts of fatty acids and fibre, which could contribute to the claimed effects. Neither the food constituent nor the conditions of use for these claims provide consistent specifications regarding other components in soy besides protein. Therefore, this evaluation will apply to the protein component in soy. Protein can be measured in soy foods by established methods.
The Panel considers that the food constituent, soy protein, which is the subject of the health claims, is sufficiently characterised.
2.1. Udział w utrzymaniu lub osiągnięciu prawidłowej masy ciała (ID 598)
The claimed effect is “weight control”. The Panel assumes that the target population is the general population.
Weight control can be interpreted as contribution to the maintenance of a normal body weight. In this context, a moderate weight loss in overweight individuals even without achieving a normal body weight is considered to be a beneficial physiological effect.
The Panel considers that contribution to the maintenance or achievement of a normal body weight is a beneficial physiological effect.
3.1. Udział w utrzymaniu lub osiągnięciu prawidłowej masy ciała (ID 598)
Eight references were provided for the scientific substantiation of this claim. These include a narrative review (Velasquez and Bhathena, 2007) and an intervention study investigating the effects of soy isoflavones on body composition (Moeller et al., 2003). The Panel considers that no conclusions can be drawn from these references for the scientific substantiation of the claimed effect.
Three references reported on the effects of soy protein or soy protein-based diets on long-term weight control in humans (Allison et al., 2003; Deibert et al., 2004; Liao et al., 2007).
In a prospective randomised controlled clinical trial, Allison et al. (2003) randomised 100 obese subjects to either a weight loss diet (n=50; about 1200 kcal/day; 33 %, 52 % and 15 % energy as protein, carbohydrates and fat, respectively) using soy protein-based meal replacements (providing 90 grams of soy protein, 75 grams of carbohydrates, 15 grams of fat and 30 grams of fibre daily) or to a control diet (n=50; about 1200 kcal/day; 23 %, 56 % and 21 % energy as protein, carbohydrates and fat, respectively; dietary fibre not reported) for 12 weeks. Only the soy protein group was checked for compliance at four-week intervals and only 74 subjects (26 % drop-out) completed the study. The Panel notes that this study was designed to assess the effects of meal replacements (and not of the protein component of soy) on body weight, and that differences in body weight changes between the intervention and control groups owing to the different macronutrient composition of the two diets (including dietary fibre), and/or to the behavioural regime of a meal replacement programme, cannot
be excluded. The Panel considers that no conclusions can be drawn from this study for the scientific substantiation of the claimed effect.
The study by Deibert et al. (2004) was a randomised controlled clinical trial on weight loss where participants were randomly assigned to one of three dietary regimens for six months: a) a lifestyle education programme which aimed to provide 1200-1500 kcal/day for women and 1500-1800 kcal/day for men, with approximately 60 % energy from carbohydrates, 25 % energy from fat and 15 % energy from protein; b) a low-fat diet (maximum of 60 g/day fat) where subjects were asked to replace two daily meals by a commercially available soy yogurt honey preparation for the first six weeks (energy intake aimed at 1000 kcal/day for women and 1200 kcal/day for men), followed by the replacement of only one meal for 18 weeks (energy intake aimed at a maximum of 1500 kcal/day for women and 1700 kcal/day for men); c) the same low-fat diet and meal replacement programme plus an endurance physical activity programme. Eighty-three overweight and obese subjects completed the study. The Panel notes that the energy and fat intakes prescribed to the control group (i.e. lifestyle education programme) were higher than those prescribed to the soy groups and that the composition and protein content of the soy yogurt honey preparation used was not reported. The Panel considers that no conclusions can be drawn from this study for the scientific substantiation of the claimed effect.
In the study by Liao et al. (2007) 30 overweight and obese subjects (24 women) were randomised to consume a soy protein-based (100 % protein from soy) low-calorie diet or a mixed protein-based (2/3 animal protein and 1/3 vegetable protein) low-calorie diet for eight weeks. Both diets were comparable in energy (1,200 kcal/day) and macronutrient composition (60 % energy from carbohydrates, 25 % energy from fat and 15 % energy from protein). Body weight changes during the study were not significantly different between the soy protein and the mixed protein groups.
Three of the references provided reported on animal studies that investigated the effects of soy protein or soy protein isolates on body weight (Aoyama et al., 2000) and gene expression (Iritani et al., 1996; Nagasawa et al., 2002). The Panel considers that the evidence provided in animal studies is not sufficient to predict the occurrence of an effect of soy protein consumption on the maintenance or achievement of a normal body weight in humans.
In weighing the evidence, the Panel took into account that the only study that allowed conclusions to be drawn for the scientific substantiation of the claim showed no effect of soy protein on body weight when compared to other protein sources.
The Panel concludes that a cause and effect relationship has not been established between the consumption of soy protein and contribution to the maintenance or achievement of a normal body weight.
Warunki i możliwe ograniczenia stosowania oświadczenia
Soy protein - At least 14 g per day