Walnuts have been seen as something of a superfood for many years now. Packed full of antioxidants, healthy fats and vitamins, the versatile nut is a staple health food the world over, with a new study by Penn State research university now linking the heart health benefits of walnuts to their positive impact on the gut.
Gut health has emerged as a key ‘supertrend' of late, with the shift in consumer concern towards health and wellbeing leading to a plethora of innovative retail releases across categories such as cereal, snacking and dairy focused on promoting good-for-your-gut bacteria.
Over 70% of our immune system is found in the digestive tract, with new walnut research suggesting the “good” bacteria could be contributing to the heart-health benefits of walnuts.
And there are now more niche areas of healthy eating than ever before, such as immune system support and brain health, with wellbeing slowly becoming a more personal proposition for consumers.
So, could walnuts earn a new lease of life as a go-to gut health ingredient?
In the recent walnut study, which was funded by the Californian Walnut Commission, researchers randomly assigned three separate diets to 42 overweight/obese participants.
The first included whole walnuts, the second included the same amount of polyunsaturated fats (considered to be healthy, heart-benefitting fats found in walnuts) as the first but without actual walnuts, and the third included partially substituted fatty acids, also without any walnuts.
The participants stuck to the diet (which also saw walnut/vegetable oil replacing all saturated fats) for six weeks, with researchers analysing the bacteria in the gastrointestinal tract following the trial period.
They found that the walnut diet enriched a number of gut bacteria that have been associated with health benefits.
“Replacing your usual snack — especially if it’s an unhealthy snack — with walnuts is a small change you can make to improve your diet,” said Kristina Petersen, an assistant research professor at Penn State.
“Substantial evidence shows that small improvements in diet greatly benefit health. Eating two to three ounces of walnuts a day as part of a healthy diet could be a good way to improve gut health and reduce the risk of heart disease.”
Learning more and more
While gut health is right up there in terms of the future food development agenda, there is still a lot to be understood about the digestive health category, with the experimental work being done in fermentation a prime example.
Dr Laura Wyness, the award-winning nutritionist, agrees that further studies concerning walnuts and gut health would be the next step as our knowledge of how these ‘good’ bacteria are affected by individual food stuffs.
“The research about walnuts and gut health is certainly encouraging, but more studies are needed to increase our understanding on whether any benefits are due to the omega-3 fatty acids, the fibre or the bioactive plant compounds,” Wyness tells Food Spark.
“What we do know is that eating a healthy diet with lots of variety is likely to lead to an equally diverse and healthy microbiome.
“So, whilst research is ongoing, walnuts are a great food to include as a snack or to add to salads, breakfast cereals, soups or baked goods to improve the nutritional and fibre content as well as some variety to the diet.”