Tag: 3/7/25

Who in the World Can Afford Healthy Food?

The cost of each recommended diet, defined as the cost of the least expensive food items to meet FBDG at a constant energy total of 2,330 kcal d−1 in 2021 PPP dollars per person per day. Diet cost estimates were derived for 172 countries where available to calculate the cost of meeting FBDG of Argentina (ARG), Benin (BEN), Malta (MLT), Pakistan (PAK), the United States (USA) and Viet Nam (VNM); from 171 countries of the HDB, Bangladesh (BGD), China (CHN), Ghana (GHA), India (IND), Indonesia (IDN), Jamaica (JAM), the Netherlands (NLD) and Zambia (ZMB); from 169 countries of Ethiopia (ETH), Oman (OMN); and 162 countries of the EAT-Lancet reference diet (EAT). Source: Herforth et al., Nature Food 2025.

A decade-long project measuring access to healthy foods worldwide is wrapping up in August, after shedding new light on the scope and specifics of nutrition insecurity, kickstarting solutions, and shifting the conversation around the affordability of healthy diets.

Since 2020, the United Nations’ Food and Agriculture Organization has used data and methods from the Food Prices for Nutrition project at the Gerald J. and Dorothy R. Friedman School of Nutrition Science and Policy at Tufts University to monitor and report the cost and affordability of a healthy diet in every country of the world. Dozens of researchers and five national governments have also used the new metric to track variation in food access within a country. 

“I’m just stunned by the speed of adoption,” said Will Masters, director of the project and professor of food policy and economics at the Friedman School. “For the first time, governments are measuring whether people have access to the biological requisites of an active and healthy life.” 

Based on national dietary guidelines from many countries around the world, the team’s Healthy Diet Basket dietary standard was validated as a way to measure diet costs in the most recent of the team’s 27 scientific journal articles. The new study appeared this month in Nature Food

“The indicator captures an implicit consensus on what countries around the world agree that people need for healthy diets,” said Anna Herforth, N05, co-director of Food Prices for Nutrition and lead author of the paper. “The importance of meeting dietary needs has been recognized for a long time, but measuring whether people can actually do that has been elusive until now.”

Measuring Affordability

The team has found that the minimum cost of a healthy diet, using the cheapest locally available food options in each country, was generally between $3 and $4 per person in 2021, with a global average of $3.68 per person. That same year, the international extreme poverty line was $2.15.

Photo by Towfiqu barbhuiya on Unsplash

In other words, “many people in the world who are counted as ‘non-poor’ still can’t afford to meet the basic requirements for a healthy diet,” Herforth said.

A healthy diet is more than just having enough calories. Our bodies need a balance of different foods from different food groups—vegetables, fruits, starchy staples, legumes, animal-source foods such as meat, eggs, or dairy—to acquire all the nutrients for an active, healthy life. 

Buying a healthy diet of the cheapest, most basic foods is “completely out of reach” for more than 80 percent of people in African countries, and a total of 2.8 billion people worldwide, Masters said. “For many people, even if they put all their resources into buying food, they wouldn’t have enough to meet dietary standards for lifelong health,” he said.

The project’s purpose is to provide a diagnostic metric that distinguishes between prices, incomes, and other factors as potential causes behind malnutrition, and helps identify what the best solutions might be. Their research shows how some people still face unavailability or high prices for even the least expensive option in each food group needed for a healthy diet. In that situation, governments can make a healthy diet more accessible and affordable by investing in innovation to lower the cost of production and distribution of those products. 

What the new cost and affordability data has revealed, says Masters, is the extent to which malnutrition is caused by low incomes available for food, after accounting for nonfood expenses. People whose available income is below the total cost of even the least expensive locally available options for a healthy diet need wage increases or social safety nets to help them afford a healthy life. And if low-cost options for a healthy diet could be purchased but people are choosing less nutritious foods, it is likely the result of other factors such as time use and the cost of meal preparation, or aspirations shaped by culture and marketing. These factors need to be identified and addressed directly to improve diet quality. 

The project’s core finding, according to Masters, is that “farmers and food traders can deliver the products needed for a healthy diet at roughly similar cost in most of the world. Malnutrition happens because the poorest third of the world can’t afford to buy enough of the vegetables, fruits, dairy, and fish or other animal source foods needed for health, and the rest of us all too often consume other foods instead.”  

What’s Next 

Impacts of the new data are already being felt in Nigeria, which became the world’s first country to publish official monthly bulletins on healthy diet costs in January 2024. Labour unions used their findings to negotiate a raise in the national minimum wage that July, and others are using the data to push for changes in farm and trade policy. National bulletins have also been published in Ethiopia, Malawi, Pakistan, and in other countries where the new data can help guide change. 

In a larger sense, Yan Bai, AG09, F16, N20, co-corresponding author on Food Prices for Nutrition’s most recent paper, said the work is “contributing to a global shift from focusing on calories alone to embracing a much more rigorous understanding of food and nutrition security—one that prioritises economic access, human health, and sustainability.”

Bai, who started working with the Food Prices for Nutrition project while earning his doctorate at Tufts, is now helping to implement the work at a global scale as an economist with the Development Data Group of the World Bank. 

“By providing internationally consistent metrics, we aim to inform evidence-based policymaking and hope to help catalyse broader multisectoral actions to make healthy diets more affordable and accessible to all,” Bai said.

Next, the researchers will collaborate with food providers in Africa to provide data and create new metrics to help build the supply chains for healthy, low-cost foods. They are also planning to continue supporting national governments and international organizations in calculating and using the cost and affordability metrics for healthy diets.

“People have talked about affordability for decades. Now we have a practical way to measure it,” Masters said. “The next step is using those data to guide actions, and bring healthy diets within reach for everyone.” 

Source: Tufts University

Slower Arm Movements Linked to Greater Fall Risk for Older Adults

Photo by Mikhail Nilov

When a person starts to lose their balance on a slippery surface, the natural reaction is to raise the arms to restore balance. Adults age 65 and older may move their arms more slowly when slipping, which could increase their risk of falling, according to a University of Arizona Health Sciences-led study.

The paper, published in Scientific Reports, marked the first analysis of balance-correcting arm movements that may assist in reducing the incidence of hip fractures, said senior author Jonathan Lee-Confer, PhD, an assistant professor of physical therapy at the U of A Mel and Enid Zuckerman College of Public Health. He and his collaborators studied older adults walking in everyday conditions. 

“We know older adults lose mass in the shoulder muscles used for these types of arm movements,” Lee-Confer said. “This research fills a gap by looking at how older adults move and revealing those detriments to functional performance during a slip.” 

The research team gathered data from two groups of people, the first with an average age of 26 and the second with an average age of 72. They found that all participants achieved comparable peak arm abduction during slips of similar severity; however, the older group were on average 58% slower than the younger group.

Additionally, they found that faster, more explosive arm corrections helped limit whole-body movement during a slip, quantifying the difference just 1/25 of a second made in how much participants’ bodies shifted sideways.

“It’s actually quite a bit – about an inch [2.5cm] to the side. So if someone is delayed with their arm movement, they are going to fall more toward the side than if they were able to react quickly,” said Lee-Confer, adding that until about seven years ago, the physical therapy community’s prevailing belief was that slips caused people to fall backward. 

Lee-Confer’s prior research found that many people instead fall to the side. The distinction is important in preventing injury, as slip-induced falls are strongly associated with hip fractures. 

“When an older adult fractures their hip, it can only be from a sideways fall, not purely backward,” he said.

Lee-Confer’s new study establishes a foundation for further research into interventions that could strengthen arms to improve balance reactions to slips. He plans to investigate whether strengthening targeted muscles by employing quick dumbbell raises to the side makes subjects’ arms move more rapidly when a slip occurs.

The balance-correcting arm movements happen almost as quickly as an automatic reflex and having existing strength to draw on may speed the process, he said.

If future findings support the approach, adding arm exercises to existing fall prevention programs that condition legs could make physical therapy protocols more effective, thus saving lives and prolonging healthspans. 

“This is about using physical therapy to extend someone’s quality of life,” he said. “I like the idea of being able to give somebody more years of protection from these debilitating injuries.”

According to the Centers for Disease Control and Prevention, falls are the leading cause of nonfatal and fatal injury for Americans age 65 and older. 

Source: University of Arizona

Mitochondrial Failure Contributes to Neuron Death in Multiple Sclerosis

This is a pseudo-colored image of high-resolution gradient-echo MRI scan of a fixed cerebral hemisphere from a person with multiple sclerosis. Credit: Govind Bhagavatheeshwaran, Daniel Reich, National Institute of Neurological Disorders and Stroke, National Institutes of Health

Multiple sclerosis (MS) affects some 2.3 million people worldwide, with 80% experiencing inflammation in the cerebellum, a brain region crucial for movement and balance. This inflammation can lead to tremors, poor coordination, and motor control issues, which often worsen over time due to the loss of healthy brain tissue.

Researchers at the University of California, Riverside, have made a significant discovery about the underlying mechanisms of cerebellar degeneration in MS. Their study, published in PNAS, suggests that mitochondrial dysfunction may play a key role in the progressive loss of Purkinje cells and worsening motor impairments.

Purkinje cells are essential for coordinating smooth movements and balance. In MS, these cells can be damaged, leading to problems with coordination and movement, known as ataxia. The study found that Purkinje cells in MS patients had fewer branches, lost myelin, and experienced mitochondrial problems, resulting in a failing energy supply.

“Our study, conducted by my graduate student Kelley Atkinson, proposes that inflammation and demyelination in the cerebellum disrupt mitochondrial function, contributing to nerve damage and Purkinje cell loss,” said Seema Tiwari-Woodruff, a professor of biomedical sciences in the UC Riverside School of Medicine, who led the research team. “We observed a significant loss of the mitochondrial protein COXIV in demyelinated Purkinje cells, suggesting that mitochondrial impairment contributes directly to cell death and cerebellar damage.”

The research team used a mouse model of MS to investigate mitochondrial alterations during disease progression. They found that the mice lost Purkinje cells over time, similar to people with MS. The loss of energy seemed to be a key part of MS, with cells only dying later.

“Our research looked at brain tissue from MS patients and found major issues in these neurons: they had fewer branches, were losing myelin, and had mitochondrial problems – meaning their energy supply was failing,” Tiwari-Woodruff said. “Because Purkinje cells play such a central role in movement, their loss can cause serious mobility issues. Understanding why they’re damaged in MS could help us find better treatments to protect movement and balance in people with the disease.”

The study suggests that targeting mitochondrial health may be a promising strategy to slow or prevent neurological decline and improve quality of life for people living with MS.

The researchers plan to further investigate whether mitochondrial impairment affects other brain cells, such as oligodendrocytes and astrocytes. This research has the potential to open the door to finding ways to protect the brain early on, such as boosting energy in brain cells or aiding repair of the myelin sheaths.

Source: University of California, Riverside

Helpful Hormone – Prolactin Helps Mothers Keep Cool During Pregnancy

Otago researchers have found the hormone prolactin plays an important role in regulating body temperature during pregnancy. Credit: University of Otago

Prolactin supports milk production and stimulates caregiving behaviour in mothers, now a University of Otago – Ōtākou Whakaihu Waka study has found that this key pregnancy hormone also regulates body temperature during pregnancy.

Senior author Dr Rosie Brown, of the Department of Physiology, says adjusting body temperature is a critical function of the central nervous system and is vital to keep both mum and baby healthy.

The study, published in Cell Reports, has shown that prolactin acts within the brain’s hypothalamus to help regulate core body temperature throughout gestation.

“The body needs to function differently to cope during pregnancy – early on core body temperature rapidly elevates, likely because of rising progesterone levels, then increased metabolic heat occurs thanks to foetal growth, maternal tissue growth, and greater food intake,” Dr Brown says.

A mother must lose this extra metabolic heat both for herself and for her developing offspring.

“Despite all these thermal pressures, core body temperature actually reduces in late pregnancy, and we now know it is prolactin which helps keep a mum cool.

“This seems to be an important change to promote heat loss and to, ultimately, provide a safe environment for the foetus, as hyperthermia can impact brain development.”

Dr Brown says the finding provides better understanding of how the changing hormones of pregnancy and lactation act in the maternal brain to alter how the body functions and promote survival and wellbeing of a mother and her offspring.

“Obviously, that helps us understand what is happening at a cellular level during pregnancy, but understanding adaptable changes in body temperature in mammals may also be critical for animal reproduction in a world facing climate change.

“The prolactin pathway in the brain may be a mechanism that helps mammals adapt to future thermal challenges.”

Source: University of Otago

Toxoplasma Gondii’s Disruption of the Brain Gives Clues to New Treatments

Source: Wikimedia CC0

A team of scientists at the University of California, Riverside, explains in a paper published in PLoS Pathogens how the microscopic parasite Toxoplasma gondii can significantly disrupt brain function, even when it infects only a small number of neurons. The team found the parasite interferes with essential communication between brain cells — research that can offer new ways to detect and treat chronic brain infections.

Toxoplasma gondii can infect nearly any warm-blooded animal and prefers to live inside brain cells, forming cysts in neurons that can persist for life. The researchers report that they found infected neurons release fewer extracellular vesicles (EVs) — tiny, membrane-bound packets used by cells to exchange information. 

“We found this disruption in EV signalling can interfere with how neurons and glial cells, especially astrocytes, maintain a healthy brain environment,” said Emma H. Wilson, a professor of biomedical sciences in the UC Riverside School of Medicine who led the research team. “Even a handful of infected neurons can shift the brain’s neurochemical balance. This suggests that communication between neurons and supporting glial cells is not only critical, but also vulnerable to hijacking by parasites.”

Approximately 10–30% of people in the United States are infected with Toxoplasma gondii, often without knowing it. The parasite is typically contracted through undercooked meat or exposure to cat feces. Although the immune system typically keeps the infection in check, the parasite can lie dormant in the brain for decades. In individuals with weakened immunity, it can reactivate and cause serious illness.

Current diagnostic tools can only detect whether someone has been exposed to Toxoplasma gondii by identifying antibodies. The tools cannot confirm whether the parasite is still present in the brain or how it may be affecting brain function.

“Our research opens the door to using EVs as biomarkers, which can be isolated from blood,” Wilson said. 

The study was conducted using mouse models and human cells in a laboratory setting.

Wilson explained that in healthy mouse brains astrocytes regulate neurotransmitters like glutamate, ensuring that neurons do not become overexcited. But when neurons infected with Toxoplasma gondii stop sending the right EV signals, this regulation breaks down. The result is elevated glutamate levels, which can lead to seizures, neural damage, or altered brain connectivity.

“The parasite may play a larger role in neurological and behavioural conditions than we previously thought,” she said.

Wilson’s research team is now working to analyse samples from human blood banks to look for EVs linked to Toxoplasma gondii brain infection. The team also hopes to better understand how glial cells detect and respond to parasite proteins — insights that could one day lead to new therapies or even vaccines.

“Our brains have built-in defences that may recognise and respond to neurons infected by Toxoplasma gondii,” Wilson said. “If we can learn how to support or enhance that process, we may be able to better protect people, especially the most vulnerable.”

Despite its potential impact, Toxoplasma gondii is often misunderstood, Wilson added. 

“There’s no need to avoid someone who is infected; most people live their entire lives without symptoms,” she said. “Pregnant individuals should be cautious as the parasite can cause serious birth defects if contracted for the first time during pregnancy. The most effective prevention is proper food handling and hygiene. Cook meat thoroughly, wash vegetables, and always wash your hands after handling cat litter, especially from young cats, which are more likely to shed the parasite.”

Source: University of California, Riverside