Plant Protein Intake Linked to Disease Prevention, Healthy Aging Among Women

A new study revealed a strong association between plant protein intake in midlife and healthy aging among women. Findings were published in the American Journal of Clinical Nutrition.¹

Compared with animal protein, dairy protein, and total protein, plant protein intake in midlife was associated with the most favorable outcomes across multiple markers of health. These included maintenance of cognitive and physical functioning, absence of chronic diseases, and good mental health status.

Although past research has examined the general health effects of protein intake, the benefits of specific protein sources remain unclear. In conducting their longitudinal study, investigators sought to collect data regarding the long-term role of dietary protein intake in midlife and its unique contribution to healthy aging in women.

Out of nearly 85,000 registered female nurses who filled out a Nurses’ Health Study questionnaire about their lifestyle practices and medical history in 1984, investigators selected 48,762 women to participate in the present analysis. All participants were younger than 60 years old and the mean age of participants was 48.6 years old. Data was collected between 1984 and 2016.

Respondents were given survey items to answer regarding 4 individual domains of health used by investigators to define healthy aging: being free from major chronic diseases, having good mental health, having no memory complaints, and maintaining physical function. Eleven major chronic diseases were selected for evaluation, including cancer, type 2 diabetes, and chronic obstructive pulmonary disorder.

Respondents were also asked to record food frequency trends. The primary contributors considered were beef, chicken, milk, fish/seafood, and cheese for animal protein; milk, cheese, pizza, yogurt, and ice cream for dairy protein; and bread, vegetables, fruits, pizza, cereal, baked items, mashed potatoes, nuts, beans, peanut butter, and pasta for plant protein. To calculate total protein intake, investigators multiplied the reported consumption frequency of each food item by its estimated protein content and then summed the results across all food items.

When it comes to healthy aging, study results revealed that plant protein intake outperformed animal protein intake across all domains. In general, consumption of animal protein was unfavorably associated with 6% (95% CI: 2%, 9%) lower odds of healthy aging, and plant protein was favorably associated with 46% (30%, 65%) higher odds of healthy aging for every 3%-energy increment. Whereas total and animal protein intake were associated with increased risk of chronic disease in all models, dairy protein and plant protein were associated with increased absence of chronic diseases.

Although none of the protein sources demonstrated an association with the absence of memory complaints, plant protein intake (41% [27%, 57%]) beat animal protein intake (5% [2%, 9%]) when it came to increasing the likelihood of maintaining physical functioning.

Plant protein was the only protein source to be significantly associated with having good mental health status.

Unfavorable diet-related health outcomes pose immense burdens on individuals, accounting for 1 of every 5 deaths worldwide.² The issue has attracted legislative attention in the US for more than half a century, dating back to the 1972 passing of WIC as a supplemental nutrition program to aid low-income and malnourished mothers and children. In 2022, the White House hosted the first White House Conference on Hunger, Nutrition, and Health in over 50 years. During it, President Biden promised to increase healthy eating and physical activity by 2030 so that less Americans experience diet-related chronic diseases.³

Interventions addressing the issue of diet-related health outcomes have begun to reframe healthy foods as medical treatments, reflecting a shift that has come to characterize the "food is medicine" movement. This movement, which has gained significant momentum in the past decade, promotes policies and programs that integrate food into health care settings.

One such program includes produce prescription interventions, whereby health care providers provide benefits (eg, vouchers) to eligible patients to encourage the purchase and consumption of fruits and vegetables.⁴

In addition to the adoption of legislation and implementation of intervention strategies, findings like those regarding the impact of plant protein intake on healthy aging lend scientific credence to the idea that making informed dietary choices can help promote favorable health outcomes.

References

1. Korat VA A, Shea, M K, Jacques, F P, et al. Dietary protein intake in midlife in relation to healthy aging – results from the prospective Nurses’ Health Study cohort. Am. J. Clin. Published online January 17, 2024. https://doi.org/10.1016/j.ajcnut.2023.11.010

2. GBD 2017 Diet Collaborators. Health effects of dietary risks in 195 countries, 1990-2017: a systematic analysis for the Global Burden of Disease Study 2017 [published correction appears in Lancet. 2021 Jun 26;397(10293):2466]. Lancet. 2019;393(10184):1958-1972. doi:10.1016/S0140-6736(19)30041-8

3. Ending hunger and reducing diet-related diseases and disparities. News release. US Department of Health and Human Services. Accessed January 19. 2024. https://health.gov/our-work/nutrition-physical-activity/white-house-conference-hunger-nutrition-and-health

4. Bhat S, Coyle DH, Trieu K, et al. Healthy food prescription programs and their impact on dietary behavior and cardiometabolic risk factors: A systematic review and meta-Analysis. Adv Nutr. 2021;12(5):1944-1956. doi:10.1093/advances/nmab039