Lower Sodium Is Leading to Longer Lives in Japan

Americans, no matter which state they live in, die younger than people in every other high-income country. But if Japan’s experience is any guide, it’s possible for the United States to begin to reverse its fortunes, maybe even in the span of a few years.

People in Japan live, on average, 8.1 years longer than people in the U.S. But in 1960, Japan actually had a lower life expectancy. In just six years, it managed to surpass the U.S., and the gap between the two countries has only grown since then — particularly with U.S. life expectancy on the decline since 2018.

Life expectancy is a complicated metric driven by many factors, including socioeconomic status and access to strong public infrastructure like health care. Although Japan’s recipe for success is wide-ranging, one key ingredient stands out: salt. Specifically, less of it.

Japan’s Recipe for Success

Japan’s rapid economic rebound following World War II facilitated greater investment in education, health, and nutrition, among other areas. While this caused modest life expectancy increases in the 1960s, life spans remained low compared to peer countries. This was in large part because of high rates of cerebrovascular disease, or conditions related to blood flow in the brain, and stomach cancer; in 1960, Japan had the highest stroke rate among developed countries.

Things started to really change when the Japanese government developed a comprehensive public health program aimed at improving outcomes. It emphasized creating a health- and hygiene-conscious culture through childhood vaccine initiatives, the expansion of health coverage to all citizens, and the promotion of blood pressure medications. One key aspect of the program was a population-based campaign to reduce salt intake that involved interventions at every level of society. Reducing salt consumption is a key way of limiting sodium, the component of salt that can cause disease if ingested in high quantities.

Japan’s salt intake reduction campaign involved sustained public education around the dangers of high sodium and the health benefits of reducing salt consumption, as well as strict regulations for processed foods. Average salt intake in the 1950s ranged from extremes of 17 to 27 grams per day, depending on the region. By the early 2010s, it had dropped to roughly 10 grams per day — though this was still twice the World Health Organization’s (WHO) recommended five grams per day.

Lower sodium intake, combined with an overall low obesity rate and the reduction of processed food in Japanese diets, led to significant decreases in cerebrovascular mortality and stomach cancer rates. Research shows that people following the Japanese government’s dietary and salt intake recommendations also had a lower risk of death from all causes.

America’s Battle Against Poor Diets

In the United States, a leading cause of mortality is the excessive consumption of processed and ultraprocessed foods, which are made up of food extracts like fats, starches, added sugars, hydrogenated fats, and often artificial color and flavors. In addition to being high in fat and sugar, these foods are also high in salt, all of which can wreak havoc on health. The average American adult consumes 60 percent of their daily calories from ultraprocessed foods.

While Japan is successfully regulating processed foods, the U.S. government has less scope to act similarly. The U.S. Food and Drug Administration (FDA) regulates additives to foods, but notable loopholes allow food manufactures to skirt the rules.

The U.S. also faces significant structural barriers to improving people’s diets: 18.8 million people — roughly 6 percent of the U.S. population — live in a food desert, meaning they have limited access to a supermarket or grocery store within one to 10 miles of their home.

In 2013, the WHO recommended that countries reduce their mean sodium intake by 30 percent by 2025. So far, no country has achieved this goal, though the Japanese government has committed to reducing the current average sodium intake by four to eight grams per day by the end of 2023 — still above the WHO’s five-gram-per-day recommendation, but a step in the right direction. While the FDA has laid out a framework for what Americans need to do to reduce sodium in their diet, we lack a clear plan to effectively implement it.

Improving life expectancy in the United States is no small task, considering the many factors that contribute to our decreasing life spans. But Japan makes it clear that lowering sodium intake can significantly reduce mortality from disease and health complications.

The authors would like to thank Tom Frieden , M.D., M.P.H., and Luc Hagenaars rs, Ph.D., M.Sc., for their contributions to this Insight.