Study Says Diet Changes When Young May Increase Longevity

If young adults in the United States changed from a Western-style diet toward one including more legumes, whole grains, and nuts, they could add up to a decade on their life expectancy, according to a study in PLOS Medicine. Those who are older could also lengthen their lives, but to a more modest degree, researchers noted.

Using a food modeling calculator that estimates life expectancy with a range of dietary choices, researchers found that adding those foods specifically, and avoiding red and processed meat, had the greatest effects for both men and women.

Study Results

The largest gain was in eating more legumes, which include foods like beans, peas, and lentils. These choices have nutritional advantages, such as soluble fiber, quality protein, and micronutrients like zinc, calcium, and iron. They also are resistant starches, which help regulate blood sugar.

According to previous research, a Western diet typically includes low amounts of fruits and vegetables, high calories, large portions, excess sugar, and high amounts of saturated and trans fats.

“The takeaway message with this research is that diet changes can have a considerable impact, not just on your health throughout your life, but can significantly increase how long you live as well,” says lead researcher Lars Fadnes, PhD, professor in the department of global public health and primary care at the University of Bergen in Norway. “Even for older people, the gains would be smaller but substantial.”

Important Pivot

Finding ways to address life expectancy has taken on new urgency, considering that the U.S. seems to be moving in the wrong direction currently. The Centers for Disease Control and Prevention reported in 2020 that life expectancy at birth in the U.S. declined by 1.5 years from 2019 to 2020.

Factors for this decline included increases in accidents and unintentional injuries, drug overdoses, homicide, diabetes, chronic liver disease, and cirrhosis. The drop in life expectancy noted in the report is the largest one-year decline since World War II, when life expectancy dropped by nearly three years between 1942 and 1943.

Making a Shift

Although diet changes obviously would not directly impact issues like drug overdoses or accidents, nutritional shifts could have a significant effect on chronic diseases, such as diabetes and liver disease.

Diabetes and liver disease are considered lifestyle-related conditions because although they may have genetic components, they can be managed. In some cases, they can even be reversed through modifications like nutritious eating.

“The good news is that lifestyle changes can make a big difference for those with liver issues,” says Jeff McIntyre, NASH program director for the Global Liver Institute. “Regular exercise and good nutrition, and especially avoiding too much sugar, can be major for liver health.”

The recent study didn’t include sugar recommendations, but McIntyre says overconsumption of added sugars is related to the rise of fatty liver disease over the past couple of decades and is also tied to other metabolic problems.

Another issue is a rise in sedentary habits, which is a risk factor for metabolic disease and liver problems, he says. A report in JAMA in 2019 noted that in the U.S. population, sedentary behavior has remained high for 15 years, and has been associated with increased risk of multiple diseases and early mortality. COVID has worsened the situation, particularly for young adults, according to a study in the International Journal of Environmental Research and Public Health.

“Physical activity is huge in protecting your liver as well as maintaining your health in general,” McIntyre says. “There is also a major mental health boost that comes with exercise, which is important for staying on track with these lifestyle changes, no matter what age you are.”