In the news: New Study Emphasizes CVD Benefits of a Plant-Based Diet

Changing to a High-Quality Plant-Based Diet Reduces Risk of Total & CVD Mortality

The reported findings of a new study add compelling evidence for the heart benefits of a plant-based diet. The investigation, from the Harvard School of Public Health, was recently presented at the American Heart Association Epidemiology, Prevention, Lifestyle and Cardiometabolic Health Scientific Session in Houston. (1,2)

The results suggest that it’s never too late to increase longevity and reduce the risk of death from cardio-vascular disease (CVD) by adding high-quality plant-based foods, even for those who start out with poor-quality diets.

While previous studies have shown that eating a high-quality plant-based diet can reduce heart disease risk, this is the first to examine how dietary changes – both positive and negative – may impact the risk of total and CVD mortality.

The study included 47,983 participants in the Nurses’ Health Study and 25,737 participants in the Health Professionals Follow-Up Study – none of whom had a history of heart disease or cancer at the start of those studies.

The researchers used three diet scales for plant-based diets to examine dietary changes: an index for overall consumption of plant-based foods, an index for healthful plant-based foods (e.g. whole grains, fruits, veggies, beans and nuts), and an index for lower quality plant-based foods (e.g. fruit juices, refined grains, potatoes and sweets). Changes in the participants’ diets were assessed over a 12-year follow-up (1998-2014).

Compared with participants whose diets were stable during the follow-up period, those with the largest increase in an overall plant-based diet showed an 8% lower risk in all-cause mortality. Those with the greatest increase in a healthy plant-based diet had a 10% all-cause mortality risk.

In contrast, an 11% increase in mortality risk was seen in those with the biggest increase in an ‘unhealthy’ plant-based diet.

For death from CVD, a 10-point increase on the healthy plant-based diet scale was linked to a 10% lower risk, while a 10-point increase on the unhealthy plant-based diet scale was associated with a 6% higher risk.

Comments

Adopting a healthy plant-based diet doesn’t mean eating plant foods exclusively, but rather consuming less animal derived foods (e.g. red meat, processed meats) and swapping healthier plant derived foods for less healthy ones such as fried potatoes, sugary beverages, deserts and refined grains. This study emphasizes the link between a healthful plant-based diet and total and CVD mortality.

There are a number of ways that plants may be cardioprotective: They are sources of phytonutrients like carotenoids and polyphenols, generally lower in saturated fats and cholesterol, and tend to be less inflammatory. A study published last year, for instance, found that adherence to the plant-based Mediterranean diet was associated with fewer CVD events, and reduced markers of inflammation, glucose metabolism and insulin resistance (3).

For patients who want to transition to a heart healthier way of eating, the Harvard website ‘The Right Plant-Based Diet for You’ offers practical suggestions. (https://www.health.harvard.edu/staying-healthy/the-right-plant-based-diet-for-you).

References

1. Baden MY et al. Abstract MP38. Presented at American Heart Association Epidemiology, Prevention, Lifestyle and Cardiometabolic Health Scientific Sessions; March 5-8, 2019; Houston.
2. American Heart Association. https://medicalxpress.com/news/2019-03-adding-high-quality-plant-based-foods-diet.html
3. Ahmand S et al. Assessment of risk factors and biomarkers associated with risk of cardiovascular disease among women consuming a Mediterranean diet. JAMA. 1(8):e185708, 2018.