Long-Term Study Shows a Healthy Diet Reduces Risk of Cardiovascular Disease

Changing your diet is one of the biggest ways to reduce the risk of cardiovascular disease (CVD), the primary cause of death in the United States and worldwide. A study published on June 15 in the Journal of the American Medical Association (JAMA) highlights just how much dietary patterns can make a difference over time—32 years, to be exact.

Researchers from the Harvard T.H. Chan School of Public Health found that a diet rich in foods like vegetables, fruits, nuts, and legumes but low in saturated fats and refined sugars is associated with a lower risk of developing CVD.

Typically, research regarding diet and CVD risk is focused on individual nutrients or foods, like how eating walnuts once a week reduces the risk of CVD by 19%. However, nutrients and foods are not consumed in isolation. By identifying dietary patterns—the amount, variety, or combination of different foods and beverages consumed—researchers were able to look more holistically at the link between what people eat and their risk of CVD.

This research, which drew from three separate studies, analyzed data from 169,310 women and 41,526 men over 32 years.

“This study is remarkable for the large number of individual studies, the inclusion of multiple ethnic groups, and a long follow-up with 5,257,190 patient years," Barry Silverman, MD, a cardiologist at Northside Hospital in Atlanta, Georgia, tells Verywell Health.

Researchers found the more people adhered to certain types of diets, the lower their risk was of CVD. This remained true regardless of race and ethnicity.

Which Dietary Patterns Were Studied?

In this study, researchers looked at how adherence to four very similar dietary patterns influenced risk of CVD. They created scoring systems to measure compliance; a higher score meant a higher-quality diet.

Healthy Eating Index – 2015 (HEI-2015)

To earn a high compliance score for this dietary pattern, participants needed to eat diets rich in foods like:

• Fruits
• Vegetables
• Beans
• Whole grains
• Dairy
• Seafood/plant protein
• Healthy fats (e.g., avocado, olive oil, walnuts)

Diets heavy in saturated fats, added sugars, sodium, and refined grains received a lower score.

Alternate Mediterranean Diet Score (AMED)

Those who were more compliant with the Mediterranean diet guidelines received a higher score. This type of diet encourages high consumption of:

• Whole grains
• Vegetables
• Fruits
• Legumes
• Nuts
• Fish
• Monounsaturated fats (e.g., avocado)

This diet also calls for limited consumption of red meat and moderate alcohol consumption.

Healthful Plant-Based Diet Index (HPDI) 

In this dietary pattern, people received higher compliance scores if their diets contained large amounts of foods like:

• Whole grains
• Fruits
• Vegetables
• Nuts
• Legumes
• Plant-based oils
• Tea
• Coffee

People who consumed animal foods or less healthy plant foods—like juices, refined grains, potatoes, fries, and sweets—received lower scores.

Alternate Healthy Eating Index (AHEI)

To receive a higher compliance score, participants had to eat more:

• Polyunsaturated fats (especially omega 3s, like salmon)
• Nuts
• Legumes
• Whole grains
• Fruits
• Vegetables

Consuming less alcohol, red meat, sodium, sugar-sweetened beverages and fruit juice also contributed to a higher score. 

What Should You Eat to Reduce CVD Risk?

There is no single food that will reduce the risk of CVD in everyone. However, following dietary patterns that emphasize certain foods and limit others can reduce the risk.

Researchers concluded that long-term adherence to any of the four dietary patterns evaluated led to a reduced risk of developing CVD.

 “In general, the heart-healthiest diets tend to be the ones that include the most plants, and this new study corroborates that," Laura Yautz, RDN, a registered dietitian who specializes in heart health, tells Verywell Health. "Some adherence is good, and more is better.”

Moses Osoro, MD, a cardiologist based in Knoxville, Tennessee, offers the following diet and lifestyle modifications for people who are aiming to reduce their risk of CVD:

•  Avoid sodium. It's the biggest trigger for hypertension and heart failure exacerbation. Some high-sodium foods include processed meats, frozen entrees, and canned soups.
• Incorporate fruits or vegetables in every meal.
• Exercise on a moderate-to-intense level for at least 30 minutes a day for five to seven days a week. Fast walking is a good example.
• Try a whole-food diet (preferably plant-based) or Mediterranean diet.

When it comes to diet, the key to reducing your risk of CVD is thinking about the big picture. Your overall diet should align with the recommendations above, but the occasional indulgence of your favorite fried chicken or fast-food is okay. No one food will make or break your heart health.