The evolving relationship between diet and health

By Dr. Andrew Mente
Principal InvestigatorPopulation Health Program, Population Health Research Institute
Associate Professor, Health Research Methods, Evidence and Impact, McMaster University

Understanding how food affects our health is not a new journey, but as our societies change and evolve, so must our explorations.

In the early 1900s, researchers were focused on the role of vitamins and minerals in human health, since common conditions like scurvy were a result of nutritional deficiency. By the 1950s, Western countries saw a major increase in heart disease, so attention shifted to the “heart-healthy diet”. While this concept is still in focus today, it’s being examined through many new and different lenses.

Early Western-led studies on the effects of nutrition on health focused only on Western countries, and it was these studies that provided the evidence that informed global dietary guidelines. Since then, we’ve learned much more about nutrition around the world and we know now that we can’t take a ‘one-size-fits-all’ approach to educating people about nutrition. Increasingly, as researchers, we need to look from a global perspective as we continue to explore the relationship between diet and health. Because health concerns like heart disease are now a global issue, broadening our scope can have a greater impact and help people around the world live healthy lives.

Broadening our scope can help people around the world live healthy lives.

In 2002, myself and a team of researchers at Population Health Research Institute began the challenge of capturing dietary patterns on a global scale. This is ongoing, but we’re analyzing data from over 50 countries on six continents to explore how food intake affects the health of people all over the world from all walks of life.

So far we’ve learned that, contrary to popular belief, a higher intake of fat is actually linked to lower health risks. By contrast, a diet higher in carbohydrates is associated with a higher health risks. This means that a moderate amount of fat and lower intake of carbohydrates is best for our overall health.

As expected, a high intake of salt increases a person’s risk of health problems such as heart disease. However, we also found that a very low intake can be detrimental, too. This means that a moderate intake is salt is the healthiest option – an amount that the majority of people already consume.

Our work is already challenging common nutritional wisdom.

We also believe a strong case can be made for increasing the consumption of potassium-rich foods since we’ve found that it contributes to decreased rates of stroke in people from all countries. Since fruit, vegetables and certain dairy foods are high in potassium and consumption is low worldwide, this may be a good place to start.

These are only a few observations so far. However, our work is already challenging common nutritional wisdom and will hopefully begin to influence public health recommendations.

Since one of the largest research biobank’s in the country is onsite, we’re lucky to continually have access to the samples collected. This means the opportunities are endless on our nutritional explorations. We hope to venture into finding out why we’ve found these results – what the foods or nutrients are doing within our bodies to cause heath issues like heart disease and stroke.

For now, regardless of our dietary guidelines, “everything in moderation” is the key.