With no shortage of conflicting information on the internet and in general, it can be difficult to choose which diet is best for you. However, researchers from Harvard University have ranked four leading diets based on how effective they are in lowering the risk of early death – a great reason to choose a certain diet.
The Harvard researchers found that people who ate according to the "highest quality diets" had a 20% lower risk of premature death from any cause during the study – and a lower risk of diseases such as heart disease and cancer.
The results of the study, which was published in the peer-reviewed medical journal JAMA were based on survey data from more than 100,000 men and women across 36 years. Participants of the study were asked to fill out a nutritional questionnaire every two to four years that examined whether they were following healthy eating patterns.
All four diets tested emphasized eating more whole grains, fruits, vegetables, nuts and beans.
Results from all four Harvard diets
The first diet analyzed was implemented using the US Government’s “Healthy Eating Index,” which tests whether people follow basic dietary guidelines in the US. The US government's dietary index produces a score of zero to 100 based on the quantity of fruit, vegetables, whole grains, dairy products, seafood and fish a person ingests per 1,000 calories.
The guidelines include eating healthy, plant-based foods, reducing red and processed meat, and avoiding added sugar, unhealthy fats, and alcohol. People who scored high on this measure had a 19% lower risk of dying from a specific illness.
People who scored high on the second diet, which was measured used the "Alternative Healthy Eating Index" – a more refined version of the Healthy Eating Index developed by Harvard (developed by Harvard) – reduced their risk of early death and disease by 20%. Harvard's Alternative Healthy Eating Index calls for five servings of vegetables a day, four servings of fruit, five to six servings of whole grains, at least one serving of protein from nuts or tofu, and eating fish regularly.
The third diet is the Mediterranean diet, which emphasizes fruits, vegetables, whole grains, nuts, beans, fish and a high amount of olive oil. The dietary pattern emphasizes healthy fats, especially monounsaturated fat, in addition to plant foods and moderate alcohol, the study said.
The fourth diet was vegetarianism (including veganism and semi-vegetarianism) which focuses on eating more plant products and scores all animal products – as well as alcohol – as having a negative impact on your health.
In this diet, relatively healthy options, such as fish or some dairy products are not on the menu, explain the study. The vegetarian diets may actually promote less healthy plant foods, such as potatoes. The study found that switching to veganism reduces the risk of mortality by 14%.