An evidence-based analysis of 10 popular dietary patterns shows that some promote heart health better than others.
A new American Heart Association scientific statement concludes that the Mediterranean, Dietary Approach to Stop Hypertension (DASH), pescatarian, and vegetarian eating patterns most strongly align with heart-healthy eating guidelines issued by the AHA in 2021, whereas the popular paleolithic (paleo) and ketogenic (keto) diets fall short.
“The good news for the public and their clinicians is that there are several dietary patterns that allow for substantial flexibility for following a heart healthy diet – DASH, Mediterranean, vegetarian,” writing-group chair Christopher Gardner, PhD, with Stanford (Calif.) University, told this news organization.
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“However, some of the popular diets – particularly paleo and keto – are so strictly restrictive of specific food groups that when these diets are followed as intended by their proponents, they are not aligned with the scientific evidence for a heart-healthy diet,” Dr. Gardner said.
The statement was published online in Circulation.
A tool for clinicians
“The number of different, popular dietary patterns has proliferated in recent years, and the amount of misinformation about them on social media has reached critical levels,” Dr. Gardner said in a news release.
“The public – and even many health care professionals – may rightfully be confused about heart-healthy eating, and they may feel that they don’t have the time or the training to evaluate the different diets. We hope this statement serves as a tool for clinicians and the public to understand which diets promote good cardiometabolic health,” he noted.
The writing group rated on a scale of 1-100 how well 10 popular diets or eating patterns align with AHA dietary advice for heart-healthy eating.
That advice includes consuming a wide variety of fruits and vegetables; choosing mostly whole grains instead of refined grains; using liquid plant oils rather than tropical oils; eating healthy sources of protein, such as from plants, seafood, or lean meats; minimizing added sugars and salt; limiting alcohol; choosing minimally processed foods instead of ultraprocessed foods; and following this guidance wherever food is prepared or consumed.
The 10 diets/dietary patterns were DASH, Mediterranean-style, pescatarian, ovo-lacto vegetarian, vegan, low-fat, very low–fat, low-carbohydrate, paleo, and very low–carbohydrate/keto patterns.
The diets were divided into four tiers on the basis of their scores, which ranged from a low of 31 to a high of 100.
Only the DASH eating plan got a perfect score of 100. This eating pattern is low in salt, added sugar, tropical oil, alcohol, and processed foods and high in nonstarchy vegetables, fruits, whole grains, and legumes. Proteins are mostly plant-based, such as legumes, beans, or nuts, along with fish or seafood, lean poultry and meats, and low-fat or fat-free dairy products.
The Mediterranean eating pattern achieved a slightly lower score of 89 because unlike DASH, it allows for moderate alcohol consumption and does not address added salt.
The other two top tier eating patterns were pescatarian, with a score of 92, and vegetarian, with a score of 86.
“If implemented as intended, the top-tier dietary patterns align best with the American Heart Association’s guidance and may be adapted to respect cultural practices, food preferences and budgets to enable people to always eat this way, for the long term,” Dr. Gardner said in the release.
Vegan and low-fat diets (each with a score of 78) fell into the second tier.
Though these diets emphasize fruits, vegetables, whole grains, legumes, and nuts while limiting alcohol and added sugars, the vegan diet is so restrictive that it could be challenging to follow long-term or when eating out and may increase the risk for vitamin B12 deficiency, which can lead to anemia, the writing group notes.
There also are concerns that low-fat diets treat all fats equally, whereas the AHA guidance calls for replacing saturated fats with healthier fats, they point out.
The third tier includes the very low–fat diet (score 72) and low-carb diet (score 64), whereas the paleo and very low–carb/keto diets fall into the fourth tier, with the lowest scores of 53 and 31, respectively.
Dr. Gardner said that it’s important to note that all 10 diet patterns “share four positive characteristics: more veggies, more whole foods, less added sugars, less refined grains.”
“These are all areas for which Americans have substantial room for improvement, and these are all things that we could work on together. Progress across these aspects would make a large difference in the heart-healthiness of the U.S. diet,” he told this news organization.
This scientific statement was prepared by the volunteer writing group on behalf of the AHA Council on Lifestyle and Cardiometabolic Health, the Council on Cardiovascular and Stroke Nursing, the Council on Hypertension, and the Council on Peripheral Vascular Disease.
A version of this article first appeared on Medscape.com.