Back
Science

Increased Milk Intake in Japan Linked to Projected Stroke Reduction and Healthcare Cost Savings

Generated on: Last updated: 1 sources
View source

Boosting Milk Intake in Japan: A Path to Reduced Stroke and Healthcare Savings

A large-scale simulation study suggests that increasing milk intake to recommended levels in Japan could reduce stroke incidence and national healthcare spending, potentially indicating public health benefits from dietary adjustments. The study was published in the journal Nutrients.

The simulations indicated that increased milk consumption could reduce stroke burden and related healthcare costs in Japan.

Study Methodology

Researchers modeled the impact of increasing average milk intake to 180 grams per day, equivalent to two daily dairy servings, among adults aged 30 to 79 years. This intervention was simulated over a 10-year period.

Stroke is a significant health concern in Japan and a leading cause of death, placing considerable demands on healthcare services. Research indicates diet as a modifiable factor in reducing stroke risk, with meta-analyses suggesting a correlation between higher milk intake and a lower likelihood of stroke. Milk contains minerals such as calcium, magnesium, and potassium, which have been proposed as contributors to cardiovascular protection. However, dairy intake in Japan currently falls below national dietary guidelines.

A Markov model, stratified by age and sex, was employed to simulate the health effects and cost implications of increased milk consumption. The model projected stroke incidence, associated mortality, and stroke-related national healthcare expenditure (NHE) over a decade, with each simulation cycle representing one year.

Stroke outcomes examined included intracerebral hemorrhage, subarachnoid hemorrhage, and cerebral infarction. The simulated population included individuals without a prior stroke, stroke survivors, those who died from stroke, and those who died from unrelated causes. Stroke-related spending encompassed inpatient treatment, ambulatory services, and medication costs.

Two intervention scenarios were modeled: an immediate shift to the recommended milk intake level and a steady yearly increase until the target was reached. These were compared against a baseline scenario maintaining 2023 average milk intake levels.

Key inputs included sex-specific 28-day stroke fatality rates (14.9% for men, 15.7% for women), recurrence rates (28.2% and 24.8%, respectively), and a relative stroke risk of 0.82 per 200 grams of milk intake in Asian populations. Healthcare costs were converted to US dollars, and a 2.0% annual discount rate was applied.

Sensitivity analyses were conducted to evaluate the robustness of the projections, adjusting stroke-related model inputs and varying the assumed discount rate.

Projected Outcomes

The simulations indicated that increased milk consumption could reduce stroke burden and related healthcare costs in Japan.

Compared with the baseline scenario:

  • An immediate increase in milk intake to 180 grams per day was estimated to lower stroke incidence and stroke-associated mortality by 7.0%.
  • A gradual annual increase in intake resulted in a 3.2% reduction in these outcomes.

The model also predicted reductions in stroke-associated NHE:

  • The immediate intervention scenario projected a 5.1% decline in stroke-related spending.
  • The gradual increase scenario projected a 2.2% decrease.

In both simulated scenarios, the number of prevented cases and related deaths was consistently higher among males than females. The most significant absolute declines occurred in adults aged 70–79 years. However, the greatest percentage reductions were observed in younger groups, specifically men aged 40–49 years and women aged 30–39 years, which may reflect lower initial dairy intake among these younger adults.

Sensitivity analyses indicated that the estimated effect of milk intake on stroke risk was the primary driver of uncertainty in the projections. These analyses estimated cumulative healthcare savings ranging up to approximately USD 2.3 billion in the immediate intervention scenario and approximately USD 1.0 billion in the gradual increase scenario.

Implications

The findings suggest that increasing milk consumption to recommended levels has the potential to help reduce stroke burden in Japan. By preventing stroke incidence and related mortality, higher milk intake may also lower NHE, indicating its potential as a public health strategy. The study did not estimate the costs required to implement increased milk consumption or conduct a full cost-effectiveness analysis.

Achieving this dietary shift may necessitate coordinated efforts from policymakers, public health agencies, and food manufacturers, including nutrition education initiatives, targeted subsidies, and improvements in the food environment.

Future studies could incorporate long-term caregiving costs to provide a more comprehensive economic impact assessment of stroke prevention. Further research could also examine differences between milk types, stroke subtypes, hormonal or menopausal status, and other population characteristics to refine estimates for nutrition and health policy.