Paleo, vegan, Mediterranean: which diet is better for the heart?

Stanford University scientists compared popular eating habits with the recommendations of the American Heart Association for a cardioprotective diet.

What is included in the AHA recommendations?

Over the past 30 years, the AHA's dietary guidelines have expanded beyond just nutrients, to include foods and dietary patterns.
The most recent statement from 2021 contains 10 important principles for a diet to support a healthy heart.
It is based on nutritional choices rich in fruit, vegetables, pulses and wholemeal products; while meat, sugar and salt is to be consumed in moderation.

What types of diet were analysed?

The researchers identified various common eating habits and analysed them against these criteria. They wanted to know which diet is most beneficial for heart health. To do this, they developed a scoring system reflecting compliance with the AHA criteria: 1 point if the diet was fully compliant with a principle; 0.75 and 0.5 points for predominant and partial compliance respectively; 0 points if the diet did not comply with a recommendation. The scientists also looked at how practicable the individual eating habits were and how well they could be implemented in the long term.

The following diets were included in the ranking:

The Mediterranean diet, which is based on the cuisine of the Mediterranean region and contains a relatively high proportion of unsaturated fatty acids in addition to plenty of vegetables, fruit, wholegrain cereals, pulses, nuts, and seeds.
Vegetarian diets such as the pescetarian diet (focusing on fish), the lacto-ovo-vegetarian diet (animal protein only from milk or eggs) and the vegan diet (exclusion of all foods of animal origin).
Low-fat and very low-fat diets, in which only a certain proportion of total energy may come from fat.
Low-carbohydrate and very low-carbohydrate diets, in which the intake of carbohydrates is restricted.
The paleo diet, which is based on the supposed diet of Stone Age people with a focus on meat, poultry and fish as well as vegetables, fruit and nuts.

Which diet is best for the heart?

The individual diets were categorised into a total of 4 levels. With a score > 85, the DASH diet (Dietary Approaches to Stop Hypertension), Mediterranean, pescetarian, and ovo-lacto-vegetarian diets came out on top. If they are implemented correctly, they fulfil the AHA guidelines best. According to the researchers, they are also easy to implement in the long term. And finally, they are not only beneficial to health, but also protect the environment due to the reduced meat consumption.

Vegan and low-fat diets came in second place with a score of 75-85. They largely fulfil the AHA criteria and are therefore also cardioprotective. However, the study authors emphasise that attention should be paid to healthy sources of vegetable proteins and unsaturated fats.

At 55 to 74 points, low-carbohydrate and very low-fat diets do not optimally fulfil the AHA criteria. The avoidance of nuts and liquid vegetable oils in very low-fat dietary patterns is not in line with the recommendation to consume healthy fats. Low carbohydrate dietary patterns, on the other hand, are problematic because they limit the consumption of healthy grains and legumes, which are among the AHA's priorities.

Finally, the Paleo and very low carbohydrate diets came bottom with a score of < 55. They restrict food groups that are considered essential components of a heart-healthy diet (pulses, wholemeal products) and, conversely, allow highly saturated fat sources (meat and dairy products), which the AHA strongly advises against.

The best nutritional advice is evidence-based

There is no shortage of diet guides and tips for losing weight. But not every diet advertised is healthy and good for the heart. Physicians should be aware of common dietary patterns in order to provide their patients with optimal, evidence-based advice. This ultimately benefits not only human health, but also the health of the planet.

Source

Gardner CD et al. Popular Dietary Patterns: Alignment With American Heart Association 2021 Dietary Guidance: A Scientific Statement From the American Heart Association. Circulation 2023;147:1715–1730. https://doi.org/10.1161/CIR.0000000000001146