• Too much salt, sugar and fat can damage your ability to remember things.
  • It takes as little as one week for the effects to be seen.
  • Western-style diets high in fats and sugars are becoming increasingly popular all over the world.

Eating food that is high in salt, fats and added sugars could harm your cognitive abilities.

That’s one of the headline findings from a research experiment that monitored the harm done by a diet high in saturated fats, salt, and sucrose – referred to as the Western-style diet.

The research team, based at Macquarie University in Sydney, Australia, recruited 110 students aged 17-35 and split them into two groups – a control group and one that would go through the experiment. They were all fit and healthy, with a body mass index (BMI) between 17 and 26.

You are what you eat

The group eating the Western-style diet were told to eat toasted sandwiches and milkshakes, Belgian waffles, and fast-food meals, all of which were high in saturated fat and added sugar. The control group was given two low-fat, low-sugar breakfasts of toasted sandwiches and milkshakes and then asked to stick to their normal eating habits for the rest of the test.

Each group was given memory tests to complete. By Day 8 of the experiment, there was “a significant main effect” on the results of the Western-style diet group. The findings support the results of a similar piece of work undertaken at Macquarie in 2017.

People in the Western-style diet group were more likely to suffer from “impairments in hippocampal function” the researchers found.

The hippocampus is an important part of the brain which helps control short-term and long-term memories. It is the part of the brain that is damaged by Alzheimer’s disease and other forms of dementia.

At the World Economic Forum's Annual Meeting 2020, it announced it is joining forces with the Global CEO Initiative to form a coalition of public and private stakeholders in the fight against Alzheimer’s disease.

A harmful spread of eating habits

The harmful effects of a high-fat, high-sugar diet on people’s physical wellbeing are well documented. Heart disease, high blood pressure and diabetes are three of the most well-known adverse effects of a typical Western diet. Their impact is now being felt in parts of the world that have not traditionally eaten these kinds of food.

This has been particularly evident in China where a significant change in eating habits has accompanied the country’s rapid economic transformation and increased urbanization. This has led to the spread of Western-style food – but it has also led to the spread of Chinese waistlines.

Obesity rates in China have increased from 1% to 20% and the Chinese Center for Disease Control and Prevention estimates there may be 120 million overweight and obese people in the country. In the US, there are about 93.3 million obese adults – around 39.8% of the population. More than 70% of US adults are classed as either overweight or obese.

Between 1990 and 2016 the number of people in China with cardiovascular disease went up by almost 15%. In 2016, there were around 93.8 million cases of cardiovascular disease in China – more than double the number in 1990 – and 3.97 million deaths, making it the leading cause of death.

food unhealth health diet fat sugar cheese chips western meat burger fast food mcdonalds affect weight weight-lossdiet
Prevalence of stunting, thinness and overweight among children (7-18 years old) in China 1885-2014.
Image: UNICEF

It’s a far cry from how things used to be: In 1985, 16% of children in China were so malnourished their growth had been stunted. Now there may be as many as 15 million clinically obese children there.

A healthier outlook

The healthiest diets are those that include a lot of fresh food, plenty of fruit and vegetables, and little in the way of saturated fats. The Japanese diet is one of the healthiest. Food tends to be steamed or simmered, rather than fried, and many things are eaten raw. Another healthy alternative is the Mediterannean diet, which contains plenty of seeds, legumes, whole grains, fish, seafood and extra virgin olive oil.

Promoting healthy lifestyles is a major concern for global policymakers. As highlighted in the World Economic Forum’s Global Risks Report 2020, illnesses like heart disease, cancer, diabetes, and respiratory diseases, along with mental illness, could cost the global economy an estimated $47 trillion in treatment and lost productivity by the end of this decade.