Ultra-Processed Foods Linked With Higher Rates of Depression and Anxiety: Research

Processed food containing high amounts of sugar, fat, and other additives are a leading cause of obesity and type 2 diabetes. Photo by Luis Ascui/Getty Images

Consuming ultra-processed food such as soft drinks, fast foods and frozen meals has been linked to an increased risk of depression, according to a newly published paper by Australian researchers.

Experts from Deakin University in Victoria found that the rapid rise in cheap, convenient and heavily marketed ultra-processed foods on supermarket shelves has an adverse effect on our brains, our bodies and our planet.

In the paper, “Good Food is Vital for Brain Health, So We Must Change the Food Industry,” the researchers argued that ultra-processed foods are associated with a heightened risk for many serious diseases like heart disease, diabetes, and mental health issues like anxiety and depression.

The researchers also found that ultra-processed foods increase the risk of inflammation, oxidative stress, reduction in brain adaptiveness and disruption of the microbiota-gut-brain axis.

“That is why the gut microbiome is increasingly recognized as a key factor unifying environmental and human health,” the paper noted.

“Loss of diversity in the human gut microbiome owing to dietary intake is associated with worse health outcomes in cancer, immune, and metabolic diseases, as well as emotional health in children and depression and cognitive ability in aging.”

Leading author Melissa Lane from Deakin’s Food and Mood Centre on Tuesday said the study showed that even if we eat up a higher amount of ultra-processed food, we can’t necessarily offset our risk of depression by eating fruits and vegetables.

“It shows that the risk of getting depression jumps up markedly among people whose daily diet is about 30 percent of ultra-processed food,” Lane told 3AW Breakfast.

“That was just a really interesting finding that there appears to be this kind of threshold where the increased risk for depression jumps up.”

The paper was published by Rice University’s Baker Institute for Public Policy on May 8.

What Are Ultra-Processed Foods?

According to the globally-recognised NOVA food classification system, ultra-processed foods are made mostly from industrial formulations that often can’t be found in the kitchen, such as artificial sweeteners, emulsifiers, hydrogenated oils, and fats.

They contain little, if any, natural ingredients, while substances are added to replicate the characteristics of real food.

Examples of ultra-processed foods are mass-produced packaged breads and buns, packaged snacks, packaged instant soups, pre-pared pies and pizzas, burgers, hotdogs, cookies, energy drinks, breakfast ‘cereals’, and infant formulas.

Accounting for 17 percent to 56 percent of total daily energy intake in 28 countries, ultra-processed food often has attractive packaging and is promoted intensively to consumers.

Meanwhile, processed foods usually contain two or three ingredients, with examples including preserved fruit and vegetables, fresh bread, canned fish, and cheese.

The Deakin experts argued the corporate-industrial food industry that dominates today’s global food systems is behind the rise of ultra-processed food, causing food insecurity and undermining “brain capital.”

Brain capital is understood as the collective intelligence, talents, and expertise of people that can be used for problem-solving, innovation, and learning. It highlights the significance of education, skill-building, mental health and intellectual capacity in achieving progress and success.

Calls For Public Policy Reform

Deakin Professor Michael Berk, co-author of the paper, called for a change in public policy to improve mental, brain and gut health.

“There needs to be a transformation of global food systems through public policy, reforming clinical care, and defending against misinformation driven by the food industry, “ Berk said, according to Deakin University’s news.

The paper made a range of recommendations, including targeting ultra-processed foods in dietary guidelines and policies, restricting the advertising of junk food, especially to kids, and developing food assistance programs to promote diets rich in unprocessed or minimally processed whole foods.

It also suggested authorities should require front-of-package labelling that warns against the health implications of ultra-processed foods available in public institutions and implement strong conflict-of-interest policies to limit the impact of the food industry on policy development.

“The global corporate-industrial food industry has enabled the supply and affordability of diverse and nutritious foods, allowing food production to keep pace with rapid population growth and reducing famines,” the paper said.

“However, it is also responsible for up to one-third of global greenhouse gas emissions, 70 percent of all freshwater withdrawals, major single-use plastic production and pollution, agricultural chemical toxins, and is the main driver of global deforestation and biodiversity loss.

“Recent modelling estimates the costs of the current global food system at US$20 trillion per year, with 11 trillion arising from the downstream impacts on human health, and 7 trillion from the environmental impacts.”

Associate Professor Harris Eyre, Fellow in Brain Health at the Baker Institute and Adjunct Associate Professor, said public health messaging needs to emphasise the impact of food systems and food intake on brain health.

“This type of messaging has been shown to lead to changes in dietary habits, even in challenging populations like young men,” Associate Professor Eyre said.

“Shifting the focus of historic (and ineffective) diet-related policies and recommendations from weight reduction to improving mental, brain, and gut health by increasing diet quality may result in better food choices, especially when cost savings are highlighted,” he said.