Putrescine, spermine, and spermidine may not have the most appetizing names, but these amino-acid derived molecules (called polyamines) are ingredients of all mammal milks. The presence of polyamines in milk is not surprising—putrescine, spermine, and spermidine are manufactured by all mammalian body cells, including mammary tissue. But polyamines are not accidental milk ingredients, passed on simply because they are ubiquitous in mammalian cells. Research from human and non-human animal models demonstrates that optimal nutrient absorption, the composition of the intestinal microbiome, and even food allergy may all depend on a sufficient supply of polyamines during the neonatal period. Milk polyamines, although odd in name, are essential for the proper maturation of the gastrointestinal tract in humans and other mammals.
Eating dairy products positively influences brain function, with higher dairy intake associated with improved cognitive ability and short-term memory, and reduced cognitive decline and dementia. However, previous studies that looked at these associations could not rule out the effects of confounding factors such as genetics and family environment, which are also known to affect cognitive ability and food intake.
A team of scientists from four continents has gathered evidence to demonstrate that it should be possible to cut methane emissions from dairy cattle without reducing how much milk they produce nor having to change the conditions in which they are kept. The answer is simply to add an ingredient to their feed. In tests lasting several months, this ingredient, 3-nitrooxypropanol known as 3NOP, cut methane emissions from Holstein dairy cows by about 30%. Achieving such a reduction in enteric methane output across the dairy industry would be a significant contribution to wider efforts to reduce greenhouse gas emissions.
People obsess about fat. Many have much more fat than they need deposited in various locations in the body and it threatens both health and fashion. Fat has now developed a bad reputation. In times gone by, a bit of extra fat meant a lifesaving energy reserve in times of food scarcity. Indeed, the metabolism we have inherited from our ancestors was originally fine-tuned to suit the feast or famine lifestyle of the past; however, it is not suitable for most people in today’s world where food abundance is the norm. Fat is a simple thing, or so we thought. There have been several surprises of late.
Superman earned his “super” for his ability to outrun a speeding bullet and leap tall buildings in a single bound. Superfoods like açaí berries, kale, and tomatoes earned their “super” for their high concentration of nutrients, particularly those that act as antioxidants. The superlative name is appropriate. Antioxidants possess superhero-like powers that prevent damage to cells and DNA from oxidative stress, thereby reducing the risk of developing certain cancers, type 2 diabetes, heart disease, and neurodegenerative diseases.
Controversy in science is good. It invites additional investigation generating new data, and ultimately there is either adequate proof or a lack of substantiation of an idea. The scientific idea then either swims into the future or sinks into oblivion. It is a proven but brutal, survival- of-the-fittest evolutionary process. This is how science works. In the intriguing case of the functions of milk microRNAs, this laborious scientific process is still underway.
Even though human milk is one of the most important substances to the healthy development of people everywhere, its basic composition is still the subject of entirely new discoveries. In a paper published in February this year, researchers from two institutions in Japan—the Institute of Health Sciences at Ezaki Glico Company and the University of Shiga Prefecture—report the presence of glycogen in human milk. Over the years, there have been circumstantial suggestions that human milk may contain this carbohydrate. But this new finding is the first example of strong, confirmatory evidence of glycogen’s presence.
“Paper or plastic?” This simple question, asked daily at grocery stores and markets around the world, has become increasingly complex over the past couple of decades. The choice between all-natural, biodegradable fibers and synthetic, single-use films has political and environmental consequences ranging from deforestation to endangered sea turtles. But a recent innovation in the development of food packaging may signal a new option altogether. Instead of recycling or wasting your bag, what if you could eat it?
Lactation biologists have long known that human milk synthesis varies across and within mothers. In the search for sources of this variation, the spotlight has been primarily directed at maternal factors. But it takes two to nurse, and human infants are not simply passive consumers of milk. Infant characteristics, from low birth weight to illness, are known to affect milk synthesis, primarily through an increase in the very ingredients needed to improve infant health, growth, or cognitive development. Human milk appears to be tailored to specific infant needs—one milk does not fit all.
Mothers transmit more than genes to their offspring. Some intergenerational maternal influences can impact newborns through their ingestion of milk, which can enhance their chances of optimal growth and survival. Currently, the accepted opinion is that most of these maternal influences do not persist beyond weaning. However, there are scattered and tantalizing pieces of evidence suggesting there may be some exceptions to acceptance of that opinion.