You’ve probably read the stories claiming that eating blueberries reduces your risk of dementia, whether red wine is good for your heart, or coffee protects against type 2 diabetes — or, indeed, many of the other big health claims for a particular ” superfood”. †
But what is the truth in these statements?
While a group of nutrition scientists have been involved in this research, we are not responsible for the headlines.
Beneath those standout stories, however, is important and serious research that will help keep us all happier and healthier.
We study parts of foods called bioactive compounds that have an effect on health (good or bad).
Unlike vitamins and minerals, bioactive substances, such as certain fatty acids, fiber, or flavanols (a group of compounds found, for example, in tea or apples), are not essential for survival, but they still affect our health.
The big challenge in bioactives research is to separate a food’s effect from an individual compound (foods are incredibly complex and contain many compounds).
A cup of coffee contains some phenolic acids that have a positive effect on heart health, as well as other compounds that can raise cholesterol. This makes our research difficult but also exciting.
We need to find ways to differentiate between the health effects of different parts of food to understand what is happening and ultimately give us more confidence in our recommendations.
One way to learn about the effect of individual foods on health is to compare people on different diets and follow them over a long period.
That approach has helped us demonstrate that Mediterranean and Scandinavian diets keep us healthy for longer. But this approach is flawed if we want to learn more about individual foods or their components.
There is some evidence that a Nordic diet is good for you.
Food is never consumed in isolation, and it is incredibly difficult to tell apart in such studies.
To make the results of such research more understandable, these findings are often turned into food equivalents – the infamous tray of raspberries, cups of tea, or bottles of wine that you should be consuming for your health. In reality, it is much more difficult.
Research into nutrition and health is difficult because there are many things to consider.
There are the essential nutrients we need to survive. Some dietary patterns can affect overall health and form the basis for recommendations, such as the UK Government’s Eatwell Guide. And then, there are the bioactive substances mainly found in plant foods which can benefit health.
Research on bioactive compounds often results in headlines about amazing foods. Only a small part of the food can usually be found elsewhere.
A notable example is blueberries. They contain bioactive substances, but they are also expensive. Blackberries and plums offer the same bioactive compounds but are much cheaper.
Over the decades, we’ve learned a lot about the chemicals naturally found in foods – what they are and how they affect the body. Some benefit our hearts, brains, and gut, allowing us to sprint faster, cycle longer, focus harder, and relax more easily.
Focus on variety
However, many of them cause problems when consumed in excessive amounts.
For example, green tea flavanols can cause liver damage when consumed in large amounts. We are just beginning to discover whether there is an ideal amount of these compounds that will provide maximum benefits. Until then, you can safely say that a varied diet is the best approach.
The beauty of our understanding of nutrition is that it is constantly evolving and improving, and we understand much better which foods to look out for as research progresses.
Everyone should build a diet portfolio with the essential nutrients, fiber, and bioactive compounds needed to stay healthy and age well.
Our bodies are incredibly complex and require many different vitamins, minerals, macro and micronutrients to sustain us optimally. It now seems likely that we should add bioactive compounds to this list. But it doesn’t matter where they come from – variety is important.
You should be wary of nutritional advice suggesting cutting out the delicious food offerings and focusing on a few “superfoods” with seemingly magical properties.
Nutrition is much more complex than that – and eating healthy is much easier.
Gunter Kuhnle, Professor of Nutrition and Nutritional Sciences, University of Reading; Charlotte Mills, Human Nutrition Lecturer, University of Reading; and Jeremy Spencer, Professor, Nutrition and Food Science, University of Reading