Food preferences play a significant role in shaping our dietary habits. Highly palatable foods rich in sugars, fats and salts often appeal to people’s tastebuds and provide immediate satisfaction. However, these foods are typically high in calories and low in essential nutrients, leading to weight gain, and a higher risk of physical and mental health conditions.
Now, we know that the food you choose to eat isn’t just linked to your physical and mental health, but also to your cognitive function, brain structure, and genetics.
A widespread preference for fast food is likely contributing to an increase in obesity worldwide. According to the World Health Organization, in 2022 one in eight people worldwide were obese. This rate has doubled since 1990.
Obesity isn’t just linked with an increased risk of diseases including type 2 diabetes and cardiovascular disease, but also with a 30-70 percent higher risk of mental health disorders. Science shows that your brain shrinks as your waist expands.
Benefits of a healthy, balanced diet
Our new collaborative study from Fudan University in China and the University of Cambridge in the UK, published in Nature Mental Health, used a large sample of 181,990 participants from the UK Biobank to examine how food choices are associated with cognitive function, mental health, metabolism, brain imaging and genetics.
We examined the consumption of vegetables, fruit, fish, meat, cheese, cereal, red wine, spirits and bread. We found that 57 percent of participants had food preferences for a healthy balanced diet. This included a balanced mix of all the foods examined, with no excessive amounts in any category.
The study showed that people with a healthy balanced diet had better brain health, cognitive function and mental health than others. We compared the balanced diet to three other diet groups — low-carb (18%), vegetarian (6%) and high protein/low fibre (19%). We found that people who ate a more balanced diet had better:
- fluid intelligence (the ability to solve new problems),
- processing speed, memory and
- executive functions (a set of mental skills that include flexible thinking and self-control)
than the other diets. This also corresponded to better brain health — with higher grey matter volumes (the outermost layer of the brain) and better structured neurons (brain cells), which are key markers of brain health.
Protein is brain food
Surprisingly, the vegetarian diet did not fare as well as a balanced diet. One reason for this may be that many vegetarians usually don’t get enough protein. Two healthy, balanced diets for the brain are the Mediterranean and Mind (Mediterranean intervention for neurodegenerative delay) diets. Both diets promote oily fish, dark leafy vegetables, fresh fruits, grains, nuts, seeds, as well as some meat, such as chicken. These diets limit red meat, fats, and sugars.
In fact, research has shown that the Mediterranean diet can alter our brains and cognition. One study showed that people showed improved cognition after only ten weeks on the diet.
Another study showed that following the Mediterranean diet was associated with lower levels of a harmful peptide known as beta-amyloid in the brain. Beta-amyloid, together with tau protein, are measures of the brain damage that occurs in Alzheimer’s disease.
Previous studies have also shown that Japanese diets, including rice, fish and shellfish, miso, pickles and fruits, protect against brain shrinkage.
Genes may play a part in food preferences
We also discovered that there were some genes that may be contributing to the association between dietary patterns and brain health, cognitive function, and mental health. This may mean that our genes partly determine what we like to eat, which in turn determines our brain function.
However, our food choice priorities are also affected by a number of factors, including price, allergies, convenience, and what our friends and family eat.
Some people opt for going on diets, which may lead to weight loss, but involve cutting out entire food groups that are important for the brain. While there’s some evidence that ketogenic diets (low carb), for example, have beneficial affects on the immune system and mental health, it does seem that balanced diets, such as the Mediterranean diet, are best for overall brain health and cognition.
Food preference aren’t destiny
It is clear that adopting a healthy, balanced diet and exercising is good for your brain. However, for many people, this is easier said than done. Eating healthy food can be especially difficult if current food preferences are for very sweet or high fat foods.
However, food preferences aren’t destiny.
For example, if you reduce your sugar and fat intake slowly and maintain it at a very low level over a number of months, you will actually begin to prefer that type of food. Establishing healthy food preferences and an active lifestyle early in childhood is vital. Other practices that can help are:
Eat mindfully
Pay attention to what you eat and enjoy it. As opposed to finishing a sandwich on the go or scarfing down a pizza while staring at a screen.
Eat slowly
It takes time for your brain to register that you are full. For example, it has been shown that consumers eat more when watching television, listening to music, or in the presence of others. The distractions decrease our reliance on internal satiety signals.
Encourage yourself
Social support from friends has also been shown to encourage adherence to healthy eating habits, as has cognitive behavioural therapy. Distraction is another excellent technique — literally doing anything you like to do (other than eating) could help you change your eating habits.
Make being healthy your goal
One interesting survey study found that how you set your priorities affects your food choices. If you are keen to remain healthy and to have a physically fit appearance, you will choose healthy foods. We live in tough economic times. Socioeconomic status shouldn’t limit dietary choices, though this seems to currently be the case. Clearly, governments have an important duty to prioritise affordable healthy eating options. This will help many of us choose a healthy diet for either health reasons, reduced food prices, or both.
Now that we know that the food we eat can actually affect our brains and how well we perform cognitively, having a healthy balanced diet is more important than ever.
This article is republished from The Conversation under a Creative Commons license. Read the original article written by researchers Barbara Jacquelyn Sahakian and Christelle Langley of Cambridge University and Jianfeng Feng and Wei Cheng of Fudan University.
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