Scientific Update
By Reed Mangels, PhD, RD
Eat Your Vegetables!
Dark green leafy vegetables like kale and collards are good sources of nutrients, including calcium and iron. They can have a bitter taste that may make them less popular with young children.
Studies have shown that infants and young children like sweet tastes and dislike bitter flavors at first. This dislike can wear off with repeated exposure to foods. This initial dislike of bitter flavors may be reflected in the limited numbers of toddlers eating dark green vegetables—only 12% of 1- to 2-year-olds in the United States ate a dark green vegetable on any given day. Researchers wondered if adding a small amount of salt or sugar to puréed kale would make it more acceptable to 6- to 24-month olds.
More than 100 babies and toddlers were given steamed, puréed kale, either plain, with a small pinch of salt, with about a quarter teaspoon of sugar per cup, or with a half teaspoon per cup, in random order. The babies were observed to see which preparation of kale they preferred. The plain (unflavored) kale was most likely to be accepted suggesting that salt or sugar do not need to be added to foods for babies and toddlers. Children under a year old were more likely to accept kale than were toddlers, age 1 year and older.
There may be a time period during which infants are more likely to accept somewhat bitter foods like dark green vegetables. Perhaps this acceptance will continue as the baby gets older. Since dark green vegetables are important sources of nutrients, foods like kale and other greens should be introduced after age 6 months but before a baby's first birthday to increase the likelihood of acceptance. The strong flavor of kale and other greens, which may be off-putting to some babies, can be diluted by puréng the greens with bland foods like avocado or tofu.
Johnson SL, Moding KJ, Grimm KJ, et al. Infant and toddler responses to bitter-tasting novel vegetables: findings from the Good Tastes Study. J Nutr. 2021;151(10):3240-3252.
Octopuses, Squid, Crabs, Lobsters, and Shrimp are Sentient Beings
Sentience is described as the capacity to have feelings, including feelings of pain, harm, and/or distress. Determining that a category of beings has the ability to experience pain and suffering has implications for laws related to animal welfare and may influence people's food choices.
Currently, in the United Kingdom, all vertebrates (animals with backbones) are covered under animal welfare laws. A recent report from the London School of Economics and Political Science examined more than 300 published studies evaluating sentience in invertebrates, namely cephalopod mollusks (including octopuses and squid) and decapod crustaceans (crabs, lobsters, shrimp, crayfish, and others). The report was based on eight criteria for sentience, including nervous system structure and behaviors and responses to painful situations.
Based on their review of the research literature, the authors of the report concluded that "all cephalopod mollusks and decapod crustaceans should be regarded as sentient animals for the purposes of UK animal welfare law." They also concluded that there is no slaughter method for octopuses and squid that is "humane and commercially viable on a large scale." While this report focuses on "best practices" for humane treatment of these animals, it unfortunately does not address their use as food for humans. The United States animal welfare laws do not cover these animals. Those who don't eat cows or chickens but do eat crabs, shrimp, lobsters, and similar animals may want to consider the findings of this report.
Birch J, Burn C, Schnell A, et al. Review of the evidence of sentience in cephalopod molluscs and decapod crustaceans. lse.ac.uk/News/News-Assets/PDFs/2021/Sentience-in-Cephalopod-Molluscs-and-Decapod-Crustaceans-Final-Report-November-2021.pdf
Vegan Children
The German VeChi Diet Study is a comprehensive examination of the diets of 139 vegan, 127 vegetarian (use dairy products and/or eggs), and 164 nonvegetarian children age one to three years. Parents provided information about their children's diets and this information was used to classify the children's diets and to compare nutrient intakes. Most vegan children (97%) took a supplement providing vitamin B12, while only 35% of vegetarian children took a supplement supplying vitamin B12. This supplement use was reflected in nutrient intake—vegan children's median intake met or exceeded recommendations. Vegetarian children may need vitamin B12 supplements since, in this study, their median intake was below recommendations. Vegan children had the highest intake of vitamin C, folate, potassium, unsaturated fats, and iron and the lowest intakes of saturated fat. Intakes, including diet and supplements, of vitamin D were below recommendations for the vegetarian and nonvegetarian children; supplemental vitamin D was more commonly used by vegan children. Median calcium intakes of vegan children were below recommendations. This study suggests that vegan diets can be nutritionally adequate for young children, especially with the use of supplemental vitamin B12 and vitamin D and attention to good sources of calcium.
Weder S, Keller M, Fischer M, et al. Intake of micronutrients and fatty acids of vegetarian, vegan, and omnivorous children (1-3 years) in Germany (VeChi Diet Study) Eur J Nutr. 2021
Bean Counting
Legumes is an umbrella category that includes beans, peas, and lentils. These foods have many health benefits, and most dietary recommendations call for eating more of them. The food industry is increasingly developing new products that include legumes. Researchers in Australia visited four major supermarkets in Sydney in 2019 and 2021 to determine how many products containing legumes were available. They decided not to include products containing peanuts, which are technically legumes but are usually classified as nuts. They also excluded veggie burgers made from legumes. Between 2019 and 2021, the number of legume products doubled, going from 312 to 610. The greatest growth was in legume snacks, specifically legume chips. There were also large increases in the number of canned and dried legume products being sold. Product label information indicating that products were vegan or vegetarian increased from appearing on 81 products in 2019 to 232 products in 2021. Plant-based was not used on labels in 2019 but appeared on 27 products in 2021.
Bielefeld D, Hughes J, Grafenauer S. The changing landscape of legume products available in Australian supermarkets. Nutrients. 2021;13:3226.
Gestational Diabetes
Gestational diabetes is a condition in which blood sugar levels become excessively high and diabetes is diagnosed during pregnancy. It occurs in 4% to 9% of pregnancies in the United States and can have negative effects on the pregnancy and the baby's health. A group of researchers wondered if eating a healthy diet based on plant foods could affect the chances of developing gestational diabetes.
In this study, a "plant-based diet" is not a vegetarian diet but is a diet that is higher in plant foods. They studied close to 15,000 women, keeping track of what they ate before becoming pregnant and whether they developed gestational diabetes. The researchers developed a "plant-based diet index," a "healthful plant-based diet index," and an "unhealthful plant-based diet index." Healthy plant foods included whole grains, beans, fruits, vegetables, nuts, and vegetable oils. Less healthy plant foods were identified as fruit juices, sugary desserts, sugar-sweetened beverages, refined grains, and potatoes. Women eating more foods from a group (like healthy plant foods) received a higher score in that group. Compared to those eating a more animal-based diet or a diet containing fewer healthy plant-based foods, those eating more healthy plant foods had about a 25% lower risk of developing gestational diabetes. Additional research is needed to see if eating a vegan or vegetarian diet before and during pregnancy affects the risk of developing gestational diabetes.
Chen Z, Qian F, Liu G, et al. Prepregnancy plant-based diets and the risk of gestational diabetes mellitus: a prospective cohort study of 14,926 women. Am J Clin Nutr. 2021;114:1997-2005.
