Battle of the diets: Which is best for your heart?

Misinformation is a common problem when it comes to diet advice – it spreads through diet books, blogs and social media outlets such as TikTok, Instagram and Twitter. According to Christopher D. Gardner, the director of nutrition studies at the Stanford Prevention Research Center, misinformation has reached critical levels, leading to widespread confusion about what we should eat to prevent disease and promote health.

To help us make sense of the barrage of diet messages we receive, a team of scientists, cardiologists, health experts and dietitians headed by Gardner evaluated common diet plans to determine how they comply with evidence-based guidelines for promoting heart health. Their findings appear in the journal Circulation.

So let’s start with what we know promotes heart and metabolic health: We should eat plenty of vegetables and fruit, prefer whole to refined grains, choose healthy proteins, mostly from plants, but also from fish and seafood, and if consuming meat and poultry avoid processed and fatty forms, prefer plant oils to animal and tropical oils, limit ultra processed foods, minimize sugary drinks and foods with added sugars, and moderate alcohol intake.

The best and the worst

The panel identified 10 popular diet plans. These include (1)  DASH  (Dietary  Approaches  to  Stop  Hypertension)-style, (2) Mediterranean-style, (3) pescetarian,  (4)  ovo/lacto-vegetarian,  (5)  vegan,  (6)  low-fat,  (7)  very low-fat, (8) low-carbohydrate (including Zone, South Beach, low glycemic), (9) Paleolithic (Paleo), and (10) very low-carbohydrate/ketogenic patterns (which includes Atkins and the ketogenic diet). For the several vegetarian style diets the researchers considered optimal versions of the diets – chips and soda are vegan, yet don’t represent a plant-based diet, as eating more plants is a central tenet of this food philosophy. Same applies to the other diet plans.

They then compared these popular diets to the ideal diet as defined by the American Heart Association’s dietary guidelines. Diets were ranked using a 0-100 point system.

And the results: 

The best diets are Mediterranean, DASH-Style, pescetarian, and ovo/lacto-vegetarian diets. They score high (above 85 points) because they emphasize vegetables, fruit, whole grain, healthy oils and moderate alcohol intake. They are also flexible, providing a wide range of choices. They also score high on sustainability, and have a lower environmental impact.

The lowest scoring diets: Paleo diets and very low carb/ketogenic diets with a score of under 55 points. Following these diets doesn’t align as well with dietary guidelines. These diets are promoted for weight loss and the notion that carbs are bad is widespread, but painting carbs with a broad brush eliminates healthy carbs, such as fruits, vegetables, legumes and whole grains, the cornerstone of a healthy diet. So although the Atkins and keto diet restrict some foods that should be limited, such as added sugar and refined grains, they miss the point on many other healthy, whole, fiber-rich plant based carbs, and introduce lots of animal products and fatty meats.

Taking the long view

Although the ketogenic and low carb diet may curb appetite and lead to short term weight loss, they’re not a good long-term plan. These diets often increase “bad” cholesterol levels, which can elevate the risk of heart disease, they impose a strain on the kidneys, and they’re difficult to maintain long term due to their restrictiveness. “A diet that’s effective at helping an individual maintain weight loss goals, from a practical perspective, needs to be sustainable,” says Gardner.

The Keto and paleo diets not only have a lower dietary quality, they also have a higher carbon footprint according to a recent study in the American Journal of Clinical Nutrition. The keto diet, which is a high-fat low-carb diet, is estimated to produce almost 3 kg of carbon dioxide for every 1,000 calories of food. The paleo diet, which prioritizes meats, nuts and vegetables, emits 2.6 kg of carbon dioxide for every 1,000 calories. A vegan diet, on the other hand, generates 0.7 kg of carbon dioxide per 1,000 calories – less than a fourth of a keto diet.

Common sense would suggest that it’s moderation that’s key to a sustainable, healthy diet. 

The sensible, practical, socially acceptable diet plan you can keep long term is the most promising plan for weight control and for wellness. 

Dr. Ayala