Researchers from McMaster University and Hamilton Health Sciences, at the Population Research Health Institute (PHRI), have identified six key foods which, when inadequately consumed, can lead to a higher risk of cardiovascular disease (CVD) in adults.
Published in the European Heart Journal, the study emphasises the importance of incorporating fruits, vegetables, legumes, nuts, fish and whole-fat dairy products in one’s diet, to reduce risk of CVD, including heart attacks and strokes. Researchers also reported that a healthy diet can be achieved in various ways, such as including moderate amounts of whole grains or unprocessed meats.
The World Health Organization (WHO) estimates nearly 18mn (million) people died from CVD in 2019, representing 32% of all global deaths. Of these deaths, 85% were due to heart attacks and strokes. For this study, PHRI researchers and their global collaborators analysed data from 245,000 people in 80 countries from multiple studies.
Devising a diet score from PHRI’s ongoing large-scale global prospective urban and rural epidemiological (PURE) study, the researchers replicated it in five independent studies to measure health outcomes in different world regions and in people with and without prior CVD.
The PURE healthy diet score recommends an average daily intake of: fruits at two to three servings; vegetables at two to three servings; nuts at one serving; and dairy (whole-fat) at two servings. The score also includes three to four weekly servings of legumes and two to three weekly servings of fish. As an alternative or possible substitute, the diet recommends whole grains at one serving daily and unprocessed red meat or poultry at one serving daily.
Dr Salim Yusuf, executive director of PHRI and professor of medicine at McMaster University, explains: “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. The PURE Healthy Diet Score included a good representation of high, middle and low-income countries.” As well as being truly global, the PURE healthy diet score focuses on exclusively protective or natural foods.
“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 Prof Andrew Mente, PHRI scientist and assistant 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. Outside of larger amounts of fruits, vegetables, nuts and legumes, the researchers showed that moderation is key in the consumption of natural foods. Moderate amounts of fish and whole-fat dairy are associated with a lower risk of CVD and mortality. The same health outcomes can be achieved with moderate consumption of grains and meats, as long as they are unrefined whole grains and unprocessed meats,” he further explained.
The researchers acknowledge that their observational study design leaves some room for scepticism, as it relies on self-reported diet data being accurate.“Ideally, large randomised trials are essential to definitively clarify the clinical impact on events of a policy of proposing a dietary pattern in populations. While such trials are difficult and expensive to conduct, they are justifiable given the important public health impact of clarifying the health effects of diet,” the study reads.
In their opinion, while further research is required, the findings and guideline recommendations of the PURE healthy diet score are significant enough to be given serious consideration.
