PURE Study & It’s Impact On Nutrition Guidelines
The essential definition of nutrition has remained the same despite the changing needs of the fast-paced lifestyle. There has been much speculation about the kind of food an individual must eat. Some studies include only proteins, fruits, vegetables; others include fats and limited amount of carbohydrates too. Varied evidences on the amount of food to be eaten at a particular time, the number of meals — big or small, mixing beverages with food or not, have always come about from nutrition science. A recent study- The Prospective Urban Rural Epidemiology (PURE) — has recently been in the news regarding its findings on the inclusion of carbohydrates and fats in our diets.
The PURE study was done across 5 continents, with 135,335 participants from 18 countries spread worldwide, who were followed-up after 7 years. The study reported the health effects of eating carbohydrates and fats in different amounts and also makes suggestions on how an individual can improve his/her diet.
The study revealed that participants who included higher amounts of fat in their diet (up to 35% of daily calories) reduced their mortality risk by 23% vs. people who included minimal amounts of fat in their diets (10% of daily calories).
The results were, however, opposite for carbohydrates. Including higher amounts of carbohydrates (77% of daily calories) increased the risk of participant’s mortality risk by 28% as compared to including lower amounts of carbohydrates (46% of daily calories).
A key aspect in this study was that it included a vast population from around the globe — 18 different countries with different diets and varying income.
The participants were given a questionnaire, to understand the kind of food they ate and how often they consumed a certain item. The research was validated by redoing a diet check after 24 hours. Data regarding health updates, death certificates and autopsy reports was collected over time about the participants. The amount of macro-nutrient (carbohydrates, fats, and protein) intake was compared with the risk of outcomes: death from cardiovascular diseases, death from all causes and non-cardiovascular disease death etc.
Diets with a very high inclusion of carbohydrates played a major role in an increased mortality rate. The results suggested that including 80% refined carbohydrates in a diet can be very unhealthy. Refined carbohydrates have very high amount of calories and added sugars and are result in major swings in blood sugar levels. Moreover, they increase the blood triglyceride level which is a risk factor for heart disease and type 2 diabetes.
The countries listed in the study have been divided into high, medium and low income and vary across food availability and cultural norms. In most high income countries like Canada and UAE, the ability to afford a variety of food makes the macronutrient intake easier. But that is different for countries like India, Bangladesh and Pakistan where white rice is the major contributor of fats, carbohydrates and protein.
As for fats, eating both saturated and unsaturated fats had similar reduction in total mortality rates, but no significant effects on reduction of cardiovascular diseases. The authors of this study suggested that while “limiting fat consumption is unlikely to improve health in populations, a total fat intake of about 35% of energy with concomitant lowering of carbohydrate intake might lower risk of total mortality.”
(Source for the quote: https://www.acsh.org/news/2017/09/01/fruit-and-veggies-beneficial-heart-health-carbohydrates-arent-what-11765)
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