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New research examines the links between different diets and the risk of sudden cardiac death. Cathy Scola/Getty Images
  • Sudden cardiac death accounts for about 1 in 7.5 deaths in the United States.
  • Researchers have shown that diet plays an important role in a person’s cardiovascular health.
  • In the present study, researchers found that people who followed the Mediterranean diet most closely and did not have coronary heart disease had a lower risk of sudden cardiac death.
  • People who primarily ate a traditional Southern diet, involving more fried food and sugary drinks, were more at risk of sudden cardiac death.

In a new study, researchers have found a positive association between the Southern diet — which involves more fried food and sugary drinks — and sudden cardiac death. They also linked the Mediterranean diet to a reduced risk of sudden cardiac death.

The research, which appears in the Journal of the American Heart Association, offers further evidence of the importance of diet to cardiovascular health.

Death certificates show that sudden cardiac death is a factor in 1 in 7.5 deaths in the United States. A key underlying cause is coronary heart disease.

According to the Office of Disease Prevention and Health Promotion (ODPHP), a person can improve their heart health by changing their diet. The ODPHP suggests that people eat a variety of fruit and vegetables, low fat dairy, whole grains, a variety of proteins, and unsaturated fats.

Research has shown that the Mediterranean diet, which focuses on legumes, vegetables, fruits, fish, and grains, can be protective against cardiovascular disease.

Researchers have also identified an inverse link between the Mediterranean diet and sudden cardiac death. However, the study had significant limitations, as it included a hugely disproportionate number of white participants and focused primarily on women.

In the present study, the researchers drew on data from the Reasons for Geographic and Racial Differences in Stroke Study cohort in the U.S. This cohort consists of 30,239 African American and white adults aged 45 years or older, who all joined the study between 2003 and 2007.

The researchers excluded participants who were missing appropriate recorded information or were unavailable at follow-up. This left them with a sample size of 21,069 for the current analysis. Of these participants, 33% were Black, and 56% were women.

A total of 56% of the participants lived in the Southeastern United States. This area is known as the Stroke Belt because it has had a higher-than-normal rate of death due to stroke since the 1940s.

The researchers took background health and demographic information from the participants at baseline and asked them to complete a food frequency questionnaire each year to show how many of 110 different food items they had eaten during the previous 12 months.

Looking at this data, the researchers were able to give each participant a Mediterranean diet score, reflecting their adherence to the Mediterranean diet.

The researchers were also able to identify five dietary patterns:

  1. The convenience pattern: This dietary pattern primarily consisted of pasta, pizza, and Mexican and Chinese food.
  2. The plant-based pattern: People following this pattern ate lots of vegetables, fruits, cereals, legumes, yogurt, chicken, and fish.
  3. The sweets pattern: This pattern included high amounts of dessert, candy, chocolate, and sugary cereal.
  4. The Southern pattern: The Southern diet is high in fried foods, sweetened drinks, processed and organ meats, and eggs.
  5. The alcohol and salad pattern: People following this pattern consumed lots of leafy greens, dressings, tomatoes, and alcoholic drinks.

According to lead author Prof. James M. Shikany, who is a professor of medicine and associate director for research in the Division of Preventive Medicine at the University of Alabama at Birmingham, “All participants had some level of adherence to each pattern but usually adhered more to some patterns and less to others.”

“For example, it would not be unusual for an individual who adheres highly to the Southern pattern to also adhere to the plant-based pattern but to a much lower degree.”

The researchers attempted to contact the participants approximately every 6 months over a 10-year period, which enabled them to record any cardiovascular events, including sudden cardiac death. During this period, there were 401 recorded instances of sudden cardiac death.

The researchers found that the participants who had the closest adherence to the Southern dietary pattern had a 46% higher risk of sudden cardiac death than those who adhered to it the least closely.

Conversely, the participants who most closely adhered to the Mediterranean diet were 26% less at risk of sudden cardiac death than those who had the lowest adherence.

According to Prof. Shikany: “While this study was observational in nature, the results suggest that diet may be a modifiable risk factor for sudden cardiac death, and, therefore, diet is a risk factor that we have some control over.”

“Improving one’s diet by eating a diet abundant in fruits, vegetables, whole grains, and fish — such as the Mediterranean diet — and low in fried foods, organ meats, and processed meats — characteristics of the Southern-style dietary pattern — may decrease one’s risk for sudden cardiac death.”

However, Prof. Shikany believes that people who wish to move from a Southern diet toward a Mediterranean diet should not attempt to do so all at once.

“I suggest small, gradual changes in one’s diet — they seem to be more sustainable,” said Prof. Shikany.

“For example: eating meat (especially processed meats) only a few days a week instead of every day and reducing the portion sizes; adding fish 1 or 2 days a week instead of always eating beef or pork; adding vegetables more frequently as a side instead of always potatoes or other starchy sides; cutting back on the number of sugar-sweetened beverages consumed each day; and cutting back on sweets, but not eliminating them (make them an occasional treat).”

“It really depends on what the person’s baseline diet is, but there is almost always room to make small changes, with the goal of incorporating these changes into one’s regular diet and building up to larger changes over time. However, large, wholesale changes in one’s diet made all at once almost never last — gradual seems best.”

Prof. Shikany believes that both clinicians and the government have a role to play in improving people’s diet.

“Regarding the medical profession, speak to patients about their diets at every possible occasion,” said Prof. Shikany. “Although nutrition science has made important advancements in what we consider to be a healthy diet as far as preventing chronic disease, the message does not always get to patients.”

“Just as patients are asked about smoking and exercise (or at least, they should be), they should also be asked about their diets during each regular checkup, and suggestions for improving their diets should be offered.”

“Regarding the government, there are disincentives on consuming foods that would not be considered healthy, such as taxes on things like sugar-sweetened beverages, that may be helpful.”

“I think we also should consider how we might provide incentives for eating more healthy foods, such as reductions in health insurance premiums for healthy eating, much as we provide for nonsmokers. Certainly, this would be harder to document for diet, and [it would] involve insurance companies rather than the government, but I think incentivizing healthy eating is an area worthy of discussion.”

Looking to the future, Prof. Shikany acknowledged that further research is necessary to confirm and expand the initial findings.

“The results of this study need to be corroborated in other populations and cohorts to see if our results hold up in study samples of different ages, in participants of varying socioeconomic status, and in underserved/under-resourced populations. In other words, we want to know how generalizable our results are,” said Prof. Shikany.

“Also, much more research is needed in the area of behavioral change related to diet — how do we get people to make changes in their diets? We know much about how people should eat, but getting them to make changes really is the most challenging part of this.”