In the most diverse study of nutrition and health outcomes in the world – and the only study with sufficient representation from high, middle, and low-income countries – PHRI researchers and collaborators have analyzed combined data from several international studies to determine the optimum type and amount of foods to prevent cardiovascular disease and mortality.
Analysis of the data of 245,000 people in 80 countries indicated that eating more fruit, vegetables, nuts, legumes, fish, and whole-fat dairy was associated with lower cardiovascular disease and mortality in all world regions, especially in lower-income countries where consumption of these foods is low,” says first author Andrew Mente.
Co-authors include PHRI’s Mahshid Dehghan, Hertzel Gerstein and Salim Yusuf. The study was published today in the European Heart Journal.
PHRI researchers and their global collaborators asked the research question: “Is a healthy diet score developed in the large international PURE cohort study – and examined for consistency in five independent studies – associated with health outcomes in different world regions and in people with and without prior cardiovascular disease? ” Those five studies were: ORIGIN, ONTARGET, TRANSCEND, INTERSTROKE, and INTERHEART.
As well as the six essential foods to be consumed daily/weekly, the researchers found that a healthy diet is not necessarily a ‘one size fits all’ approach. “We determined that a healthy diet can be achieved in a number of ways which does not necessarily require either including or excluding any specific food category – such as a moderate amount of whole grains or unprocessed meats can be part of a healthy diet,” says Mente.
“Previous diet scores – including the EAT-Lancet Planetary Diet and the Mediterranean Diet tested the relationship of diet to CVD and death mainly in Western countries, where excess intake of some foods may be the predominant problem. The PURE Healthy Diet Score included a good representation of high, middle, and low-income countries,” says Salim Yusuf, senior author and principal investigator of PURE.
Higher consumption of protective foods
As well as being truly global, the PURE Healthy Diet Score focused exclusively on protective (aka natural) foods and nutrients.
“We were unique in that focus. The other diet scores combined foods considered to be harmful – such as processed and ultra-processed foods – with foods and nutrients believed to be protective of one’s health,” said Mente, a PHRI Scientist and an Associate Professor at McMaster’s Department of Health Research Methods, Evidence, and Impact.
“There is a recent increased focus on higher consumption of protective foods for disease prevention, which might be especially important in low-income regions where inadequate intake of some key foods is a major concern,” says Mente.
The connection between the PURE diet and health outcomes was found in generally healthy people, patients with CVD, patients with diabetes, and across economies.
Need to re-evaluate ‘unrelenting guidelines’
In an accompanying EHJ editorial, Dariush Mozaffarian, of the Friedman School of Nutrition Science and Policy, Tufts University, writes:
“The new results in PURE, in combination with prior reports, call for a re-evaluation of unrelenting guidelines to avoid whole-fat dairy products. Investigations like the one by Mente and colleagues remind us of the continuing and devastating rise in diet-related chronic diseases globally, and of the power of protective foods to help address these burdens.
It’s time for national nutrition guidelines, private sector innovations, government tax policy and agricultural incentives, food procurement policies, labelling and other regulatory priorities, and food-based healthcare interventions to catch up to the science. Millions of lives depend on it.”
Recommendations of the PURE Healthy Diet Score
- 4-5 daily servings of fruit/vegetables combined (e.g. of a serving: 1 medium apple or banana; 1 cup leafy greens, 1/2 cup other veg)
- 3-4 weekly servings of legumes (e.g. of a serving: 1/2 beans or lentils)
- 7 weekly servings of nuts (e.g. of a serving: 1 oz. of tree nuts or peanuts)
- 2-3 weekly servings of fish (e.g. of a serving: 3 oz. cooked fish)
- 14 weekly servings of dairy products (e.g. of a serving: 1 cup milk or yogurt; 1.5 oz. cheese)
- 1 daily serving of whole grains – optional (e.g. of a serving: 1 slice bread; 1/2 cup cooked rice, barley, or quinoa)
- 1 daily serving of unprocessed meats – optional (e.g. of a serving: 3 oz. of cooked red meat or poultry)