As US life expectancy lags, nutritional deficiency is often an overlooked factor

Nutritional deficiency is far from a leading cause of death in the United States, but the mortality rate has grown significantly enough in recent years to impact life expectancy.

More than 21,000 people died from malnutrition in 2022, according to data from the US Centers from Disease Control and Prevention – more than doubling over the past five years. And a 20% spike in mortality between 2021 and 2022 put nutritional deficiency among the top five factors with a negative effect on life expectancy estimates for 2022.

Poor nutrition is most deadly for the oldest Americans; More than half of the deaths attributed to nutritional deficiency in 2022 were among those 85 and older, CDC data shows. But deaths have increased across nearly all age groups.

Typically, the causes of death that contribute most to changes in life expectancy estimates are those that affect younger people – congenital malformations were also a key factor in 2022, for example – or those that affect a large number of people. Decreasing mortality from Covid-19 was the key factor driving life expectancy up by more than a year in 2022.

Although the effect that nutritional deficiency had on life expectancy estimates was relatively small, experts say the finding shouldn’t be discounted – and that the negative impact of malnutrition is probably underestimated.

Good nutrition involves a healthy balance of macronutrients, such as carbohydrates and proteins, that are needed in large quantities to keep bodily systems running, as well as vital micronutrients, or vitamins and minerals.

“Lack of protein can cause a lot of your bodily systems to start to potentially shut down. On the other side, a lot of the systems that our micronutrients fuel are things that lead to resilience. So when we get low in various micronutrients, all those systems start to get compromised. That can eventually lead to death or malfunction,” said Emily Ho, director of the Linus Pauling Institute, a research center at Oregon State University focused on the role of vitamins and essential minerals in health.

“When we look at the major causes of death, especially in the United States – infection, cancer, cardiovascular disease – nutrient deficiencies can all accelerate those disease processes as well. So I strongly believe that malnutrition is probably an even greater contributor than we think,” she said.

For example, it’s harder for a person who is malnourished to fight off a Covid-19 infection. When bodily systems don’t have the fuel they need to function properly, the risk of succumbing rises. Nutritional deficiencies are most common among older adults, which could have factored into the higher mortality rates from Covid-19.

“As we get older, our immunity is something that starts to decline, not only because of age but also because of nutrient deficiencies that can truly contribute to the process,” Ho said.

Older adults are more susceptible to nutritional deficiencies for a variety of reasons, experts say.

“There are many older adults that have chronic illnesses that impact their appetite – things like congestive heart failure, cancer, Alzheimer’s disease. Digestive diseases too that are common among older adults may also impact how their body absorbs nutrients,” said Kathleen Cameron, senior director of the National Council on Aging’s Center for Healthy Aging.

Many are also socially isolated, she said. “They don’t want to cook for themselves and may not have access to transportation to go to the grocery store to buy nutritious foods.”

These concerns about the health of aging adults in the US are longstanding, and mortality from nutritional deficiency had been rising long before the pandemic – but the pandemic probably exacerbated many factors.

“There are 10,000 senior centers out there where a million older adults everyday were going through the doors,” said Ramsey Alwin, president and CEO of the National Council on Aging. “When we visited some of our senior centers, we’ve heard that their congregate meals are only 50% back in terms of attendance because people are still wary, especially this respiratory season, about going out and being in those group settings. So I think we’re still unwinding some of that.”

Also, more than half of older adults who are eligible for SNAP, the federal government’s nutritional assistance program, are not actually enrolled, according to the National Council on Aging.

The US Department of Health and Human Services and the US Department of Agriculture work together to update and release the dietary guidelines every five years. The latest conversations include discussions around specific needs and healthiest balance for seniors.

A person with malnutrition isn’t always stereotypically frail and skinny.

“In the US, we often have overnutrition and malnutrition in the same person, which is something that’s a little bit unique to us. There can be an over nutrition of empty calories that leads to obesity, but the quality of diet that they have is low, so they’re malnourished when you look at the micronutrient content,” Ho said. “So the bodily systems are compromised, even though you’re not presenting with a wasting syndrome.”

A simple nutrition screening assessment that primary care physicians can use during annual wellness visits can help, experts say.

Taking a daily multivitamin is also “good insurance,” Ho said. “Even people that are trying to eat healthy sometimes still have some of those shortfalls.”