From soy sauce to sodium labels: How Japan is rethinking salt reduction

By Dr. Chinta SidharthanReviewed by Susha Cheriyedath, M.Sc.Feb 18 2025

Japan’s high salt intake fuels rising healthcare costs, but new research reveals how national policies, industry collaboration, and food reformulation can cut cardiovascular disease rates and save billions.

Mini Review: Evaluation of public health and economic impacts of dietary salt reduction initiatives on social security expenditures for cardiovascular disease control in Japan. Image Credit: pedphoto36pm / Shutterstock

Salt intake is closely linked to hypertension and other cardiovascular problems, and reducing even one teaspoon of salt from your daily diet could protect your heart. In a recent study published in the journal Hypertension Research, a research team from Japan explored the country’s push to lower salt intake to prevent cardiovascular disease (CVD) and curb rising medical expenses.

Salt intake

Japan is grappling with increasing healthcare costs driven by its aging population, with 29% of its citizens now aged 65 or older. CVDs account for 19% of total healthcare spending and 24% among older patients, making prevention a national priority. Excessive salt intake is a major dietary factor contributing to high blood pressure and CVDs, and reducing salt consumption is considered a cost-effective strategy to prevent these conditions and lower healthcare spending.

Over the decades, Japan’s salt intake has gradually declined due to shifts in dietary habits and public health efforts, yet the levels remain high. The average daily salt intake in Japan was 13.9 grams in 1995, decreasing to 10.1 grams by 2019, but this still doubles the World Health Organization's (WHO) recommended limit of 5 grams per day. There are also notable regional differences, with individuals in northern regions consuming more salt than those in southern areas.

Understanding where this salt comes from is key to reduction efforts. Unlike Western countries, where processed foods are the primary source, over 50% of Japan’s dietary salt comes from discretionary sources, such as salt added during cooking or at the table. Soy sauce, soybean paste, and salted fish account for 44% of total salt intake, and seasonings overall contribute 66%, according to the 2019 National Health and Nutrition Survey. Younger adults, however, are increasingly obtaining salt from processed and restaurant foods, which now provide over half of their sodium intake. These differences highlight the need for tailored interventions addressing both traditional seasoning practices and the growing consumption of convenience foods.

Salt reduction initiatives

The WHO has led global efforts to reduce salt intake, recognizing excessive sodium consumption as a major risk factor for high blood pressure and CVDs. In 2002, the WHO began recommending that individuals limit daily salt intake to below 5 grams. Over the years, it developed policies and guidelines to help countries implement salt reduction programs.

Key milestones include the 2004 Global Strategy on Diet and Health, followed by sodium intake guidelines in 2012, and the 2013 Global Action Plan on Noncommunicable Diseases, which set a target for a 30% reduction in salt intake by 2025.

Moreover, the WHO also provided practical tools for countries to reduce salt consumption through food reformulation, consumer education, and front-of-pack labeling. In 2017, the WHO identified four “Best-Buy” interventions—media campaigns, public food procurement policies, setting salt reduction targets for the food industry, and front-of-pack nutrition labeling—as the most effective strategies.

A sodium scorecard introduced in 2023 monitors national progress. As of 2024, 11 countries, including Spain, Mexico, and Malaysia, achieved the highest rating (Level 4) for implementing comprehensive policies. Japan reached Level 3, due to its mandatory sodium labeling and school lunch regulations, but lacks more aggressive food industry regulations compared to top-ranking nations.

These global efforts matter because reducing salt intake is both a public health and economic priority. Lower sodium consumption reduces blood pressure, cutting the risk of heart disease and strokes. Furthermore, countries that have implemented WHO’s policies report improved population health and reduced healthcare costs.

Initiatives in Japan

The study also reported Japan’s efforts to lower salt intake to combat CVD and reduce healthcare costs. National dietary guidelines introduced in 2000 recommended limiting daily salt intake to under 10 grams. Over time, this target was made stricter, reaching 7 grams by 2032 under the third phase of the Health Japan 21 program. However, the actual consumption remains high.

The Japanese Society of Hypertension (JSH) has played a leading role in salt reduction efforts, encouraging individuals, especially hypertensive patients, to limit salt intake to below 6 grams per day. The researchers found that since 2013, JSH has collaborated with the food industry to promote low-sodium products, approving 108 products by 2024. Sales data indicate that these products collectively prevented 9,678 tons of salt from entering the diet over a decade.

Furthermore, Japan also launched various initiatives in 2022 to cultivate a sustainable and healthy food environment, recognizing the influence of food availability and industry cooperation on salt intake. This program promotes the reformulation of food products, voluntary salt reduction targets, and support for businesses. The WHO identified Japan’s initiative as one of 95 multisectoral efforts globally, recognizing its unique approach in a high-income country. Ongoing research aims to develop simulation tools to predict the health and economic impact of these strategies.

The researchers believe that these coordinated efforts reflect Japan’s shift from relying solely on individual behavior change to fostering an environment that makes low-sodium choices easier. Moreover, such policy approaches also demonstrate the potential for balancing public health goals with industry cooperation, providing a model for other countries facing similar dietary challenges.

Economic impact and modeling predictions

The study underscores that reducing salt intake is not only a public health necessity but also an economic imperative for Japan, where rising social security costs are driven by an aging population. Researchers developed simulation models to estimate how different salt reduction strategies could affect healthcare costs and cardiovascular outcomes.

One Markov model projected that meeting Japan’s salt reduction goals could reduce CVD cases by 1–3% and cut related healthcare costs by up to 2% over 10 years. Additionally, historical simulations estimated that salt reduction efforts since 1950 prevented approximately 298,000 deaths in men and 118,000 in women. These findings highlight the long-term economic and health benefits of sustained salt reduction efforts.

Conclusions

Overall, the review indicated that sustained government policies, scientific research, and industry collaboration were all necessary to reduce salt intake and prevent CVDs. While progress has been made, Japan's salt consumption remains among the highest globally, and stricter policies may be required to meet future targets. The team believes that achieving significant, lasting reductions in salt intake will require intensified food reformulation, expanded public education efforts, and continued investment in evidence-based strategies to support healthier dietary choices.