Title: The Role of Food in Sustaining Human and Planetary Health with Dr. Kathryn Bradbury

GJIA: In your most recent work, “Quantifying the Greenhouse Gas Emissions of New Zealand Households’ Food Purchases: An Analysis by Demographic Variables,” you found a positive correlation between the age of the primary shopper in a household and per capita dietary emissions. You posited that this could be due to older people tending to have a “traditional Western diet” with large amounts of meat and dairy. Whether in New Zealand or the global context, compared to factors like affordability or a given area’s suitability for growing certain produce, how much do you feel culinary tradition has posed a challenge to introducing more sustainable or conservation-friendly diets? 

KB: In New Zealand, culinary tradition has a major influence on what we eat and how resistant we are to changing that–eating meat is kind of wrapped up in our national identity. In New Zealand, we produce a lot of beef, lamb, and dairy products and export about 90 percent of those. They play an important role in our economy, and I think we get wrapped up in the pride of those products. And, if you grew up eating meat with every evening meal, as many people do in New Zealand, it is difficult to think about different ways of eating when those are the foods that you grew up with and are comforted by.

In New Zealand, in terms of growing food, there are some areas of land where it wouldn’t be good for growing crops, but much of the land would be. It’s not really the land that is stopping us necessarily. But our work does show that households with younger shoppers are more likely to have lower dietary greenhouse gas emissions. The foods they are purchasing have a lower environmental impact.

GJIA: On the other hand, have there been instances where cultural cuisines that are conducive to supporting a sustainable diet or cultural cuisines are broadly adapting to supporting a more sustainable diet? How much can restaurants play a role in contributing to more sustainable dietary customs? Which other players should contribute?

KB: There are cultures with a diet that is quite environmentally friendly. The Eat Lancet Commission developed a Planetary Health Diet where they evaluated the evidence and tried to develop a dietary pattern that’s good for human and planetary health. They came up with a plate that’s half fruit and vegetables. The rest is whole grains, plant proteins, and a small amount of meat and dairy. They also saw what that would look like in different countries; it fits lots of different contexts. The Mediterranean diet is predominantly plant-based with some yogurt and other animal-source foods. Some Scandinavian traditional diets, such as the Nordic diet, have some fish but also a lot of different plant foods. A Brazilian traditional diet with a lot of rice and beans is very plant-based. There are good global examples of local culinary traditions that are actually very plant-based.

In terms of restaurants, I think they can be champions of a more sustainable way to eat. They can buy produce locally, offer foods when in season and foraged foods, and show different ways to prepare and eat plant-based foods. It is important to acknowledge not everyone can access restaurants, but they could be doing more [for their current customers].

Other players include food companies and manufacturers. Obviously, they are trying to sell products in order to make a profit. Sometimes, this goal can create tension with public health and environmental goals. I think it’s important to think about who this food system really works for and to keep that in mind when addressing these issues.

GJIA: You have also focused much of your research on the intersection of nutrition and epidemiology. While our everyday dietary habits and the terminology surrounding nutrition may be more familiar to people, general populations may not be as quick to easily understand medical terminology and the exact nature of how different diseases are spread to affect patients. Based on your expertise, how can professionals in your field effectively communicate important medical information to mass audiences? What can the public also do to be better informed on how our diet can affect health?

KB: Lots of scientists—and I include myself—are guilty of forgetting that we are not talking to our colleagues. We don’t think about the jargon; we just use it. A lot of the ways we talk probably aren’t the best ways to communicate to the public. I think media training can be really helpful for scientists because it makes you reflect on how you are communicating and how to make that more accessible [to a general audience].

As for the public staying better informed, one can find a study about nutrition and diet in the news every week, and I don’t know how helpful it is to keep up with each one that comes out. But I think there are simple messages. We know that vegetables and fruit are healthy. And yes–in New Zealand and elsewhere, we have problems with how affordable vegetables and fruits are at the moment. But there are simple messages, and we don’t need to get caught up in everything that comes along. Fruits and vegetables are healthy, whole grains are healthy, and try not to eat too much meat.

I would also say most countries have food-based dietary guidelines. Maybe they are not as exciting as new studies coming out all the time, but food-based dietary guidelines are developed with committees of experts in their field. Renowned scientists are discussing and evaluating the evidence to determine which foods we should eat more and which we should eat less often. The guidelines are also adapted to your country. I think those national dietary guidelines are quite robust and a good place to start.

GJIA: Climate change is certainly a wide-ranging issue that requires a comprehensive solution. In terms of the impact of consumption patterns on greenhouse emissions, what do you recommend countries do on a national or even international level to promote more sustainable dietary options? If individuals are interested in learning more about changing their own dietary emissions, where would you recommend they start?

KB: In New Zealand and other countries, we have made commitments to reduce our greenhouse gas emissions without a clear action plan of how are we going to achieve these goals. For instance, agriculture accounts for almost half of New Zealand’s emissions, but the government is not addressing it. People are making some efforts with ruminant animals, such as selectively breeding them so that the next generation produces less methane, but these measures have only a marginal impact. Do we need to reduce stock numbers? Do we need to shift the incentives that have led to the predominance of growing animals for human consumption to growing more plant foods? There’s much work to be done.

It also goes back to what I was saying earlier about the food industry. Some of their products are not great for our health or the environment. Anything that governments can do to ensure that individuals are not influenced by companies whose goals are often at odds with public health is good.

For individuals who want to learn more about their own dietary emissions, there are freely available calculators online where you can input the foods you eat to estimate your carbon footprint. Personally, I wouldn’t recommend doing that every day. I think food should be enjoyed and eaten, but it can be good to do so every once in a while to see what the major contributors are to your carbon footprint. If you are eating red meat, that is a big one. Anything you can do to cut down on red meat and dairy products will lower your carbon footprint.

In New Zealand as well as many Western countries, although there has been a rise in plant-based products, the actual numbers of vegetarians and vegans are quite small. We did work in New Zealand looking at the prevalence of vegetarians: only about 2 percent of adult New Zealanders are vegetarian, and less than 1 percent are vegan. I think we are going to get more gains from the population eating less meat than we will from trying to convince a few more people to become strict vegetarians. We know from health recommendations that to reduce the risk of bowel cancer, one should limit their red meat consumption to no more than three times a week. That’s a feasible goal, and it would also help the environment. If everyone cuts down [their meat intake], it will have a substantial impact.

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This transcript has been lightly edited for clarity and length.

Interview conducted by Rachel Li.

Dr. Kathryn Bradbury is a Senior Research Fellow and the Director of Research in the School of Population and Health at the University of Auckland (New Zealand). She previously worked as a nutritional epidemiologist on large cohort studies in the Cancer Epidemiology Unit at the University of Oxford, and she has worked as a consultant for the World Health Organization Department of Nutrition and Food Safety. She has published many works in various peer-reviewed academic journals and edited several book chapters.

Image Credit: Celsia