# Leveraging a natural experiment to estimate the causal impact of blood sugar on dementia and cognition in India

> **NIH NIH R01** · UNIVERSITY OF SOUTHERN CALIFORNIA · 2023 · $439,318

## Abstract

Project Summary
The global burden of dementia is growing substantially as low- and middle-income countries (LMICs) undergo
demographic transitions resulting in rapidly aging populations. Understanding the factors that affect dementia
prevalence in LMICs such as India and identifying cost-effective interventions that may curb the onset of
dementia and cognitive decline is thus an important public health and policy priority.
Evidence from several studies indicates that diabetes increases the risk of developing cognitive impairment and
dementia, but few studies have used population-representative data from LMICs experiencing rapidly increasing
diabetes rates. Furthermore, interventions that seek to change diets and reduce diabetes risk by targeting
individuals directly have had mixed success and are costly to implement at scale. In contrast, policy-level
solutions such as sugar-sweetened beverage taxes or regulation of food supply (e.g., caps on added sugars)
have the potential to influence dietary patterns at scale, especially in low-income settings where resources are
scarce. There is a vital need to identify large-scale policy solutions for reducing diabetes and dementia in LMICs.
This project will use population-representative data on dementia in India to accomplish three aims. First, we will
study the association between dementia and diabetes, a known risk factor, in a low-income setting with a high
prevalence of diabetes. We will also study heterogeneity in this relationship by dietary practice and by sex.
Second, we will evaluate a scalable public health intervention that may reduce HbA1c levels and diabetes rates:
the delivery of parboiled rice through the Indian government’s Public Distribution System, which provides roughly
one-third of the total grain consumed in the country. To accomplish this goal, we will leverage detailed data on
the quasi-random distribution of parboiled rice in Kerala, a state with high rice consumption, as well as data on
HbA1c and blood glucose from three data sources including the Harmonized Diagnostic Assessment of
Dementia for the Longitudinal Aging Study in India (LASI-DAD). Finally, we will leverage the quasi-random
delivery of parboiled rice to study the causal effect of diabetes on dementia and cognitive decline using an
instrumental variables approach.

## Key facts

- **NIH application ID:** 10703989
- **Project number:** 3R01AG051125-07S1
- **Recipient organization:** UNIVERSITY OF SOUTHERN CALIFORNIA
- **Principal Investigator:** Jinkook Lee
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2023
- **Award amount:** $439,318
- **Award type:** 3
- **Project period:** 2015-09-15 → 2026-04-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10703989

## Citation

> US National Institutes of Health, RePORTER application 10703989, Leveraging a natural experiment to estimate the causal impact of blood sugar on dementia and cognition in India (3R01AG051125-07S1). Retrieved via AI Analytics 2026-05-26 from https://api.ai-analytics.org/grant/nih/10703989. Licensed CC0.

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