Since this week seems to have developed a bit of an environmental justice theme, this story seemed appropriate. Oligosaccharides are complex sugars in breast milk that help the development of an infant’s immune system, and help protect from infections. Because they’re polymers, made up of monosaccharides, there are plenty of ways they can be put together, meaning that as a group, oligosaccharides are pretty diverse, with over 200 having been identified by scientists so far. Apparently, the more oligosaccharide diversity the breast milk has, the better for the baby, and new research has shown that living around greenery increases that diversity:

The oligosaccharides in breastmilk can protect the infant from harmful microbes and reduce the risk of developing allergies and diseases. The oligosaccharides are also closely connected to the immune system and gut microbiota which also have an impact the infant’s health.

“Earlier studies have shown that genetic and biological factors, such as mother’s obesity, can change the oligosaccharide composition in breastmilk. Our aim was to study how green living environments affect the composition of oligosaccharides in breastmilk, as greener environments have been found to have a beneficial impact on immunity and reduce the risk of disease in children,” says Adjunct Professor Mirkka Lahdenperä from the Department of Biology at the University of Turku.

Closer connection to nature may affect child’s health via breastmilk

Approximately 800 mothers participated in the longitudinal follow-up study, the STEPS Study, that started at the University of Turku in 2007. The breastmilk samples were collected when the infants were three months old, after which the oligosaccharide composition was analysed at the Bode Lab at the University of California San Diego.

The residential green environments were measured at the time the child was born around the homes of the families with measures of greenness, diversity of vegetation, and naturalness index, i.e. how much human impact and intervention there has been in the residential area. The results were independent of the education level, occupation, marital status and health of the children’s parents as well as the socio-economic disadvantage in the residential area.

The study showed that the diversity of oligosaccharides increases and the composition of several individual oligosaccharides changes when the mother’s residential area includes more green environments.

“This could indicate that increased everyday contacts with nature could be beneficial for breastfeeding mothers and their children as the oligosaccharide composition of breastmilk would become more diverse. The results imply that breastfeeding could have a mediating role between residential green environments and health in infancy,” says Lahdenperä and continues:

“The results highlight the importance of understanding the biological pathways that can impact health and lead to the development of different diseases starting from infancy.”

I think a lot of the time, when I talk about environmental injustice and environmental racism, I’m focused on pollution sources like traffic, factories, and waste disposal. Another facet to that issue is the racial disparity in access to nature. The reality is that in the U.S. and other wealthy nations, the history of white supremacy has forced non-white people into neighborhoods that are worse not because of the people there (as some like to claim), but because they’re poorer, more crowded, have worse services, and have less in the way of access to “green spaces”.

Racial differences in urban greenspace availability and access are evidence-backed and analyzed in a number of studies and policy reports. A study on factors affecting access to green space conducted by Nesbitt et. al. (2019) provides some relevant findings. Areas with higher Latinx and African-American populations are less likely to have access to green space. Meanwhile, the share of white residents is positively associated with access to green space. Dai (2011) has similar results. In New York City, the average park size is 7.9 acres in predominantly Black neighborhoods compared to 29.8 acres in predominantly white neighborhoods, and the former are five times more crowded than the latter.

There is substantial evidence that suggests the disparity in outdoor space stems from systemic racism. For instance, by studying cities with a history of majority Black populations, it was found that in Memphis, Tennessee, just five percent of land area consists of parks, while in Baton Rouge, Louisiana, only three percent of the city is dedicated to parkland, as compared to the national median of 15 percent (Trust for Public Lands, 2019). Currently, due to the inequitable nature of park availability, there is an observance of disproportionate heat exposure as well. Hoffman, Shandas & Pendleton (2020) found that red-lined communities were the hottest neighborhoods in 94 percent of cities, indicating a trickle-down effect of historically racist urban planning policies. Also, analysis by Jesdale et.al. (2013) showed that Black individuals were 52% more likely to live in areas with higher heat risk and the risk increased with increasing degrees of segregation.

There are also racial disparities in the way Black people access the outdoors, best illustrated by the incident when a white woman called the police on Christian Cooper, a Black birdwatcher, when he simply asked her to leash her dog. This incident is singular neither in context nor in outrage. In a survey of racial minorities using a city park, Black, Latinx, and Asian users reported feeling discriminated against by other users, police, and park staff at higher rates than white users (Gobster, 2002). According to Carolyn Finney, scholar-in-residence at Middlebury College, including non-white communities as stakeholders in the process of creating and programming parks can work towards addressing universally accessible park design.

Think of this as being similar to the way redlining – race-based residential districting that’s supposedly a thing of the past – can determine a child’s lead exposure, it also affects other aspects of life, including access to nature. I was fortunate, as a kid. When we lived in the Boston area, I still spent a lot of time in forests and wetlands because my dad was a botanist, and my school was near a section of conservation land. In New Hampshire, of course, I lived in the woods. When I was working as a ridgerunner in college, I ran into kids who were part of various summer programs, and for some it was pretty clear that they’d never been in a forest before. Later, living in the city as an adult without a car, I realized how hard it can be to actually get out into the country. It feels like something nobody should need to say, but access to nature shouldn’t be gate-kept; not by race, not by class – not at all.

This also, of course, fits very well with my position that our cities should be green. We should be growing plants wherever we can in cities, and designing new construction to be easier to grow plants on. Obviously the details are going to vary from place to place – the plants need to be able to survive without too much help, but I think it’s worth having an army of gardeners in every city, for the sake of making them healthier places to live.

This is also why efforts to defend urban green spaces are also important – it’s literally a matter of guarding the health of the people who live there. Destroying parks and cutting off access to forest is, as I’ve said, the opposite of what we should be doing. It’s the kind of thing that’s often treated (by the rich and powerful) as if it doesn’t relate to a population’s quality of life, but as we’ve seen, it can measurably affect people’s health during the time when we are the most vulnerable, and during which conditions can most affect our development in ways that might last for our entire lives. Aesthetics are important to us as humans, for all the denigration of art education seems to have been in vogue, in the United States, for my entire life. I would think it correct to fight for green spaces even if their only benefits were for our mental health (the notion that that’s separate from “health” is a rant for another day), but it has been shown over, and over, and over again that it goes far beyond that. As I keep saying, we are part of the ecosystems that surround us, and the sooner we start acting like it, the better off the whole world will be.