We now know that your brain continues to develop throughout your lifetime, and many studies link how well your brain ages with the foods you eat. So here are some of the foods that will not only be delicious, but will also nourish your neurons.

One of the great medical misconceptions of the 20th century was that you do not grow new brain cells. The last few decades have shown that in the olfactory bulb (smell) and the hippocampus (memory and cognitive processes), new neurons can grow throughout life. We also know that health-promoting foods can stimulate neuron growth. For instance, polyphenol compounds (from foods like tea, grapes, wine, olive oil, cocoa, nuts, fruits and vegetables) and polyunsaturated fatty acids (from fish, corn, soybeans and sunflower seeds) lead to significantly higher rates of neuron growth in both the olfactory bulb and the hippocampus.

To keep your brain healthy as you age, choosing the right foods is an important, and essential, first step.

The Mediterranean diet

There is plenty of evidence suggesting that the Mediterranean style of eating keeps your brain sharper as you age. The basis of the Mediterranean diet is a lot of fruits, vegetables, legumes (beans, peas, lentils), olive oil and fish, along with a little wine. Typically, red meat does not play a major part in the Mediterranean way of eating, although it is eaten perhaps once a week and is almost always lean. From the fruit and vegetables you get nutrients including antioxidants and fibre. Legumes are a protein source and also provide a range of nutrients. Olive oil yields healthy monounsaturated fats as well as antioxidants. Fish provides protein and healthy omega-3 fats while wine offers antioxidants.

Over the years the Mediterranean diet has been credited with reducing the risk of developing a range of conditions potentially related to ageing like heart disease, cancer and diabetes. As far as your mind goes, one study of almost 4000 people aged 65 and over set out to see how a Mediterranean diet impacts the brain and mental function. The people in the study were assessed as to how closely their diet matched a Mediterranean-style diet using a test called the MedDiet scale. Then every three years the participants did tests that measured their word memory and basic maths skills to see if they were experiencing cognitive decline.

Over time it emerged that people who scored higher on the MedDiet scale had slower rates of cognitive decline. In other words, the closer people were to the Mediterranean style of eating, the younger their brain. It all happens because the antioxidants and healthy fats in the Mediterranean diet reduce the oxidation and inflammation that contribute to conditions like Alzheimer’s disease. An additional factor in all of this is that most of the Mediterranean diet is based on raw foods with minimal processing. Add the fact that these foods are often consumed around a table with family and friends and it is not hard to imagine why the Mediterranean way of eating is such a positive thing for your brain.

Cacao and cocoa

The cacao bean is the source of both cacao and cocoa powders. Cacao beans are found inside the fruit of the Theobroma cacao tree in fleshy, oval-shaped pods. The beans are harvested, fermented and dried. When you see cacao nibs, powdered cacao (or cacao powder) in the grocery stores, the bean is in its raw state — uncooked, additive-free and unprocessed. Cacao contains an abundance of antioxidants as well as fibre, magnesium, essential fatty acids, iron, copper, zinc, sulphur and calcium. It is only to switch a few vowels to get from “cacao” to “cocoa”, but there can be a world of difference.

When cacao beans are roasted and processed they are called “cocoa”. Most cocoa powders have additives like sweeteners or cocoa butter. Once roasted and processed (turning cacao to cocoa), the beans lose much of their nutritional benefits. There are two processes used to make cocoa powder. Dutch process cocoa powder is made from cacao beans that have been washed with a potassium carbonate solution to neutralise their acidity. Dutch process cocoa is dark brown in colour. Natural cocoa powder is reddish-brown and is made from cocoa beans that are simply roasted and ground into a fine powder. Natural unsweetened cocoa powder is very similar to raw cacao powder except for experiencing higher temperatures during production, which decreases antioxidant activity.

Research has shown that antioxidant flavanols from cocoa might improve memory via a process called “neurovascular coupling”. Neurovascular coupling refers to the fact that as an area of the brain is called into action it requires more energy and it needs an increase in blood flow to achieve it. So healthy neurovascular coupling results in a rapid blood flow response to brain activity, and Harvard researchers wanted to see whether cocoa flavanols might enhance that process.

To test this they used ultrasound to measure the neurovascular coupling of a group of subjects as they completed some mental tasks. Around 30 per cent of people showed as having impaired neurovascular coupling. The subjects were then asked to drink two cups of hot cocoa daily for 30 days. Half of the subjects drank a high-flavanol cocoa while the rest drank a flavanol-poor cocoa. Since the cocoa was high in flavanols it is effectively equivalent to cacao.

Those people with impaired neurovascular coupling experienced improvements in brain function regardless of which drink they consumed. The people with normal neurovascular coupling did not receive any benefit from their cocoa. This tells us that even moderate daily intake of cocoa flavanols will improve brain function where the brain is functioning less than optimally. You will get more bang for your buck with cacao, but even cocoa will offer some benefit.

Omega-3

Omega-3 fats accumulate in your central nervous system when you are in the womb. It has been assumed that these fatty acids are replaced continuously throughout life, although little is known about how this occurs, and some diseases are known to impact the fatty acids in the brain. Alzheimer’s disease, for instance, is associated with lower than normal concentrations of the omega-3 fat docosahexaenoic acid (DHA). People taking omega-3 supplements do show reduced inflammatory markers in their cerebrospinal fluid as well as improvements in their Alzheimer’s disease.

There has also been evidence that fish oil and its omega-3 fatty acids can benefit brain related conditions like ADHD in children. Research has even shown that supplementing with fish oil can change the brain structure of adults.

The best fish sources of omega-3 fats are sardines, salmon, tuna, John Dory, trout, snapper and flathead.

The omega-3s from plants have to go through an extra step within your body to be used, but for healthy people this is not usually a problem.

Chia seeds

Chia seeds come from the desert plant Salvia hispanica, a member of the mint family. Chia seeds are an excellent source of omega-3 fatty acids but also fibre, protein, iron, calcium, magnesium and zinc.

Linseeds

Linseeds (Linum usitatissium) are also known as flaxseeds. The primary omega-3 fatty acid found in linseeds is alpha-linolenic acid, or ALA. As well as omega-3 fats linseeds also contain lignans, fibre-like compounds that also have antioxidant actions and also act as phytoestrogens. Linseeds also contain fibre in the form of mucilage.

Antioxidants

One of the potential brain diseases associated with ageing is Alzheimer’s disease. The theory goes that Alzheimer’s results from brain changes that occur as a result of amyloid plaques that accumulate in the brain. It is thought that these plaques and the changes that result from them might be due to oxidative stress, so antioxidants should theoretically be of some help in preventing Alzheimer’s occurring, and this theory was proven in practice in a recent study.

Research has shown that vitamin C and beta-carotene levels are much lower in people with Alzheimer’s. Perhaps vitamin C and beta-carotene selectively act against the oxidative drivers of the Alzheimer’s process. More research needs to be done, but it is certainly worthwhile to get stuck into foods rich in these nutrients like spinach, broccoli, oranges, capsicum, berries, papayas and carrots.

Berries are wonderful brain foods because they are rich in polyphenols, the antioxidant molecules in berries that give them their various lustrous colours. Berries such as blueberries, strawberries, açaí and blackberries have been shown to help your brain stay healthy in a variety of ways. The antioxidants protect brain cells from damage, and also change the signalling of brain neurons in a way that reduces inflammation. The net result is maintaining motor co-ordination as well as cognitive powers as you age.

Oranges are another antioxidant food that is particularly worth adding to your brain-friendly diet. Citrus sinensis is the common orange we eat, but there are many other varieties with different uses. Common examples are the Seville orange (or bitter orange) Citrus aurantium and bergamot orange (Citrus bergamia). Although famous for its vitamin C content, the orange fruit also contains other substances that support your brain such as antioxidant and anti-inflammatory compounds including flavonoids. Red (blood) oranges have much higher levels of these anti-inflammatory substances.

Legumes

Legumes are a big family of foods including peas, beans, chickpeas, alfalfa and lentils. In general, legumes will help your brain as you age primarily because they will balance your blood-sugar levels and, as outlined below, high blood-sugar levels can be damaging to brain function.

Legumes are also known as pulses and they provide protein, B vitamins, iron, calcium, zinc and magnesium, and are high in soluble fibre. They have a low glycaemic index (GI), meaning that they are broken down more slowly so that you feel fuller for longer, making them a particularly good food for preventing and managing diabetes. Most importantly, studies tell us that adding legumes to the diet causes drops in blood-sugar levels and that is good news for your brain.

Lentils

Lentils are a small but nutritionally large member of the legume family. They are an excellent source of fibre as well as a good source of folate and the mineral iron. You also get a good dose of B vitamins from lentils, and the whole nutritional package comes at the expense of very few kilojoules. The other great benefit of lentils is that they are quick and easy to prepare.

Peas

Like lentils, peas are low in fat and kilojoules but high in fibre and packed with other nutrients. Although peas are so common that we may take them for granted, we now know that green peas contain unique and powerful antioxidants. In fact, the lowered risk of type-2 diabetes associated with legume and pea eating is probably thought to arise from not only their high fibre content, but this unusual combination of antioxidant and anti-inflammatory compounds as well. The other bonus for your brain is that green peas are a reliable source of omega-3 fats in the form of alpha-linolenic acid. In one cup of green peas, you can expect to find about 30 milligrams of ALA.

Cut down on sugar

There is a definite link between Alzheimer’s disease and high sugar levels. It is also known that people with diabetes are at a greater risk of developing dementia. People with high blood-sugar levels are more likely to have brain shrinkage in the areas of the hippocampus and the amygdala. These are the areas of the brain involved in memory and cognitive skills. Even if you don’t have diabetes, high-end “normal” blood-sugar levels can impact brain function, and to keep your brain ageing well you just have to cut down on sugar.

Believe in your brain

This article has focused on food, but when it comes to your brain it has to be mentioned that other factors drive ageing in your brain. Adequate sleep, regular physical exercise and continuing to use your brain (on things like crosswords and problem-solving) all lead to a better ageing brain. It is also important that you believe you can help your brain to age well. Research has shown that people told that ageing has negative effects on the brain will do around 20 per cent worse on a test given immediately afterwards than people not told this. It is a case of self-fulfilling prophecy: someone believes their brain will function less well as they age and so it does.

The truth of it is, though, that if you eat well you are on the way to having a brain that will serve you well for a lifetime.