Zhu and Hollis (2013) found that soup consumption is associated with a reduced risk of overweight and obesity.
Another study conducted by Farzana et al.(2017) to develop a healthy vegetable soup powder supplemented with soy flour, mushroom, and moringa leaf and compare its nutritional facts with locally available soup powders. The study found that the developed soy–mushroom–moringa soup powder is nutritionally superior to locally available soup powders and sufficient to meet day‐to‐day nutritional requirements as a supplement.
Appiah et al.(2020) study explores the proximate composition of selected Ghanaian soups from defined recipes and photographically present quantities of the soups, measured with common Ghanaian household food measures, equivalent to servings of protein and carbohydrates. Two types of each conveniently selected soup (light soup, groundnut soup, kontomire (cocoyam leaves) soup, and palm nut soup) were prepared; one with animal protein and the other without. The soups prepared include; LS1- light soup with garden eggplant (African eggplant); LS2- light soup with garden eggplant and chicken GS1- groundnut (peanut butter) soup without animal protein; GS2- groundnut soup with chicken; PS1- palm nut soup without animal protein; PS2- palm nut soup with smoked catfish and herrings. Proximate analysis was done to determine the macronutrient content of all the soups. Each soup was measured using a household food measure (150 ml soup ladle) to obtain a 15 g carbohydrate and 7 g protein equivalent and then photographed.
The carbohydrate content of the soups ranged between 1.18 g-8.43 g, protein was between 0.34 g-4.31 g and 0.14 g-7.78 g for fat per 100 g of edible portion. Palm nut soup with animal source protein had the highest carbohydrate (8.43 ± 0.86 g) and fiber (1.99 ±0.22 g) content. Soups with the highest protein and fat content were GS2 (4.29 ± 0.14 g) and PS1 (20.39 ± 3.54 g) respectively. Serving sizes of the soups prepared ranged approximately between 1-8½ soup ladles (using 150 ml soup ladle) per 15 g carbohydrate equivalence and 1-13 soup ladles (using 150 ml soup ladle) per 7 g protein equivalence. It took variable quantities of the prepared soups to obtain the target serving sizes with PS2 having the least quantity (~1 soup ladle) for 15 g carbohydrate serving and PS1 having the least amount (~1 soup ladle) for 7 g protein serving. The large serving size of most of the soups required to meet a serving of protein implied that those soups should be eaten together with food sources rich in protein, to appreciably enhance the protein intake of individuals.
Another interesting review by Ito K(2020) found that despite the higher consumption of salt by Japanese than Westerners. It has been reported that miso soup was one of the major sources of daily salt intake in Japanese people. Adding salt is indispensable to make miso, and therefore, in some cases, refraining from miso soup is recommended to reduce dietary salt intake. However, recent studies using salt-sensitive hypertensive models have revealed that miso lessens the effects of salt on blood pressure. In other words, the intake of miso does not increase the blood pressure compared to the equivalent intake of salt.
Miso is a traditional Japanese soybean paste made from fermented soybeans. It is often prepared into a soup and is one of the major components of Japanese-style cooking. One serving of miso soup contains 1–2 g of salt, and the addition of salt is indispensable to miso preparation. Okada et al.(2018) reports have demonstrated that a Japanese-style diet reduces total mortality and is associated with a longer survival time(Zhang et al. 2006).
In exploring their diets, Suzuki et al.(2018) study separated Japanese dietary constituents into 16 categories and revealed that the top 3 categories are soybeans/soybean-derived products, seafood, and vegetables, followed by rice and miso soup. Miso is also a soybean product. Therefore, soybean products are considered to contribute to the health benefits of Japanese-style diets.
This is just one aspect, miso is a fermented soybean product. Jayachandran et al(2019) study found that fermentation is reported to improve the quality of soybeans, resulting in increased digestibility, enhanced nutrition, and increased isoflavone content. Therefore, fermented soybean products are expected to have greater health benefits than nonfermented soybean products.
Another study by Nozue et al.(2017) revealed that the intake of fermented soy products, but not nonfermented soy products, is inversely associated with developing high blood pressure in subjects with normal blood pressure.
A more recent study by Li et al.(2022) compares the immunomodulatory effects of chicken soups prepared with native free-range chickens and commercial caged broilers in immunosuppressive mice. The chicken soups promoted the recovery of immunosuppressive mice, but the expression mechanisms were different. The study concluded that soups from the native free-range chickens and the commercial caged broilers showed distinctly different mechanisms in promoting immunity, both could be used as potential immunomodulators.
Prof. Raphael Nyarkotey Obu is a full professor of Naturopathic Healthcare. E-mail: [email protected] . This article is for educational purposes and awareness only.