Cognitive health: Exercise and the brain

Whether we get enough of it or not, we all know exercise is good for us. It keeps us fit, helps keep our weight down and reduces our risk of major illnesses such as heart disease, stroke, type 2 diabetes and cancer by up to 50 per cent (i). But one thing that may not immediately spring to mind when you think of exercise is the amazing effect it has on your brain.

Is exercise good for your brain?

A growing number of studies confirm the positive effect physical activity has on human cognitive function. Here are just a few examples:

• A review of 39 studies on exercise and cognitive health in the over 50s suggests physical activity improves cognitive function, regardless of the individual’s brain health status. Published in the British Journal of Sports Medicine (ii), the review concludes you should do moderate intensity aerobic and resistance-based exercise on as many days of the week as possible to improve cognitive function.

• Researchers following adults with at least one parent with Alzheimer’s disease or with at least one gene linked to Alzheimer’s (or both) found those who were active for at least 68 minutes a day had healthier brains than those who were less active (iii).

• Younger people’s brains benefit from exercise too. One study of primary schoolchildren in the Netherlands found breaking up lessons with 20-minute exercise sessions improved the children’s attention spans (iv). Another study found after-school sports classes improved cognitive performance and brain function in children when they performed tasks that needed greater executive control (executive functions include things like working memory, self-control, planning, flexible thinking, time management and organisation) (v).

• Studies suggest exercise prevents the loss of total brain volume in older people, which can lead to a drop in cognitive functioning. One report – which scanned older adults’ brains – found their brain volume increased after just six months of exercise training (vi). Another study discovered regular walking may reverse age-related shrinkage of the hippocampus (part of the brain that’s associated with learning and memory) (vii).

This study also showed exercise increases the amount of a protein called brain-derived neurotropic factor (BDNF) in the bloodstream. BDNF is linked with the adult brain’s ability to develop new neurons (brain cells), a process called neurogenesis. Some experts believe BDNF-induced neurogenesis may help protect memory in the long term (viii).

What does exercise do to the brain?

Preventing shrinkage or loss of volume in the brain is just one of the findings scientists have discovered that may explain why exercise is so good for cognitive health. There are other possible explanations too, including:

• Exercise boosts growth factors in the brain, say researchers from the University of California Los Angeles (ix). This, they suggest, makes it easier for the brain to make new connections between neurons.

• Another study, which was presented at a meeting of the American Physiological Society in Chicago, has suggested walking is particularly good for the brain. Why? Because the impact your feet make when they make contact with the ground boosts cerebral blood flow (x). And if blood flow to the brain is improved, it means the brain gets more essential nutrients and oxygen, all of which helps keep it healthy.

Indeed, the brain needs a good deal of blood supply – it receives around 20 per cent of the body’s blood supply despite the fact it accounts for just two per cent of the body’s mass (xi).

• More recent research suggests exercise makes immune cells in the brain called microglia more efficient as we age, which may make them better at repairing damage caused by inflammation that can affect brain function, including memory (xii).

• As well as increasing levels of BDNF, exercise is thought to boost levels of other brain chemicals (neurotransmitters), including serotonin, dopamine, norepinephrine, while reducing levels of the stress hormones cortisol and adrenaline (though the effect on cognition – such as better focus and reaction times – may only be temporary).

How much exercise a week?

You don’t have to start marathon training to reap the cognitive benefits of exercise, just try to achieve the recommendations in the government’s physical activity guidelines.

Adults aged 19 to 64 should do at least 150 minutes of moderate activity each week (for example, you could be moderately active for 30 minutes, five times a week – though you should aim to be physically active every day). Moderate activity is classed as anything that raises your heart rate, makes you breathe faster and feel warmer. You should still be able to carry on a conversation, but singing should be difficult.

The sorts of activities that are of moderate intensity include:

• Brisk walking

• Cycling

• Hiking

• Rollerblading

• Dancing

• Doubles tennis

• Water aerobics

Instead of 150 weekly minutes of moderate activity you could do 75 minutes of more vigorous activity. This should make you breathe hard and fast, and you shouldn’t be able to say more than a few words without getting out of breath. Examples of vigorous activities include:

• Running

• Jogging

• Cycling uphill

• Skipping

• Aerobics

• Gymnastics

• Stair climbing

Just 15 minutes of working out vigorously, five times a week is all you need to meet your target. During those 15 minutes you could also do some very vigorous activities, which include things like spinning, running up stairs, lifting heavy weight and circuit training, where you do short bursts of exercise broken up with short periods of rest.

On top of your 150 or 75 weekly minutes you should do some strengthening activities on at least two days of each week. These activities should work all your major muscle groups, and include things like yoga, Pilates, weight lifting, doing push-ups and sit-ups, using resistance bands and even things like carrying heavy shopping and digging your garden.

What are the exercise recommendations for older adults?

If you’re aged 65 or older, the recommendations are similar as those for younger adults in that you’re advised to do at least 150 minutes of moderate activity or 75 minutes of vigorous activity a week. But as well as doing exercises that strengthen your muscles, you should aim to work on your balance and flexibility twice a week too. This aims to help you avoid having falls and feel stronger and more confident on your feet.

Try stretching exercises to improve your flexibility – yoga and Pilates are ideal ways to do this, or you could just do simple standalone stretches (for suggestions, take a look at the flexibility exercises at nhs.uk).To improve your balance, you could try activities such as dancing, playing bowls or learning t’ai chi.

It’s also advised that you stay as active as possible during your day. So instead of sitting for long periods of time, try moving around the house, doing some housework or just get up to make a cup of tea – it all counts.

Children and exercise

It’s never too early to reap the rewards exercise can have for your brain. But how active should children be? According to the NHS, children and young people aged five to 18 should aim to be moderately physically active for at least an hour a day, on average, as well as take part in activities that develop their muscles and bones (xiii).

Types of exercises children and teenagers could do include:

• Playground activities

• Walking to school

• Riding a bike

• Walking the dog

• Skateboarding

• Rollerblading

Activities that can help strengthen young muscles and bones, on the other hand, include:

• Football and rugby

• Skipping

• Gymnastics

• Climbing

• Dancing

• Running

• Games such as tug of war

• Martial arts

What exercise is best for the brain?

Any exercise is good for the brain – and definitely better for the brain than no exercise at all. There’s also evidence that certain types of exercise help boost cognitive functioning, including:

Cardio/aerobic exercise

One study that compared middle-aged people who did aerobic exercise on at least four days of the week with others who were largely sedentary found the exercisers had better cognitive performance than those who weren’t very active, including having better memory (xiv).

Meanwhile, scientists writing in the journal Nature – this time working with people with an average age of around 28 – came to the conclusion that taking part in endurance training may boost the amount of white matter in your brain (xv). Another study suggests older adults who are aerobically fit have brains that can process language more effectively than other who aren’t fit (xvi).

Aerobic exercise may also improve some cognitive functions in people with Alzheimer’s disease, say researchers writing in the journal Brain Plasticity (xvii). The small-scale study found those who followed a moderate-intensity treadmill training programme three times a week for 26 weeks improved cognitive functions such as memory, attention and planning.

Strength/resistance training

Doing weight or resistance training may also reap rewards for brain health. For instance, one study suggests doing resistance training may help improve memory and attention in older women with mild cognitive impairment (xviii). Regular resistance training may also have an effect on the brain’s frontal lobe – the area that governs things like speech, language, memory, reasoning and concentration – claims a review of 18 studies (xix).

Scientists elsewhere have looked at how strength training affects the brains of people with a high risk of developing Alzheimer’s (xx). The experts discovered that when a group of such older adults took part in six months of high-intensity strength training, there were improvements in their brains, specifically in the hippocampus area.

Yoga

If you practise yoga you’ll know how much more calm and relaxed it can make you feel. But there may be other brain benefits too. For instance, one review of 11 studies suggests people who do yoga on a regular basis have more grey matter volume in their brains than those who don’t (xxi).

Dancing

Dancing may also be good for your brain, but not just because it’s a great type of exercise. In fact dancing engages the brain as well as the body, as you have to mentally focus on the movements and staying co-ordinated (not to mention follow the music and stay in time with your partner or group). The social aspect of dancing may do your brain more good than you realise too. In one study, for instance, older people who did one hour of dance a week for six months didn’t end up with better aerobic fitness, but the physical and social stimulation helped improve their cognitive performance (xxii).

Ultimately, however, the best exercise – whether you’re doing it for your brain or any other aspect of your health and wellbeing – is one that you enjoy and can stick to, time and time again. And remember, even if you can’t meet the government’s exercise guidelines, some activity is better than being completely inactive.

More ways to keep your brain healthy

There’s little doubt that staying physically active on a regular basis can help keep your brain in good working order. But other things may help too, including eating a healthy balanced diet, not smoking, drinking alcohol in moderation, keeping your weight healthy, getting plenty of sleep and reducing stress.

Brain supplements

You may also want to consider taking natural supplements that help support brain health. Here are some of the supplements you may want to consider trying – read more about them and the scientific evidence that supports their use for cognition support in our guide to nutrition for the brain

High-strength fish oils

Supplements made from oily fish that contain the omega-3 fatty acids EPA and DHA are thought to be good for your brain, so they may be particularly beneficial if you don’t like eating fish. If you’re a vegetarian or vegan you can now get these important omega-3s in a veggie/vegan-friendly formulation – look for omega-3 supplements that contain algae, which supply fish with omega-3s in the first place.

Turmeric (curcumin)

Curcumin is one of the many active ingredients found in the curry spice turmeric, and may be helpful for cognitive decline. You can add turmeric to your food, or take a turmeric supplement if that’s more convenient. Consider trying a good-quality supplement that provides a high percentage of curcuminoids (curcumin is a type of curcumninoid).

Ginkgo biloba

Nutritional therapists often use the herb ginkgo biloba to treat memory problems and cognitive function in older people.

B complex

Some of the B vitamins – including vitamin B6, B12 and folate (or folic acid) – may help slow down cognitive decline. B vitamins are widely available in our diet, but many people may not get enough of them. You can take individual B vitamin supplements, but it’s often considered more convenient to take a B complex supplement or a multivitamin formula with good levels of the Bs.

Astaxanthin

Antioxidants may be helpful in supporting cognitive health, especially if your levels are already less than decent. A particularly potent antioxidant found in a type of freshwater algae, astaxanthin can be found in supplement form as well as in foods such as salmon, lobster, crawfish, rainbow trout and crab. As a supplement it is usually suitable for vegetarians and vegans (check the label – some capsules can contain non-vegetarian and non-vegan ingredients).

Iodine

If you’re deficient in this essential mineral it can lead to an underactive thyroid, which can affect your cognition. You can get iodine in fish, eggs and other dairy products, as well as in nutritional supplements such as multivitamins.

Rosemary

Both the scent and compounds found in rosemary may be beneficial for memory problems. Add some of this fragrant herb to your food, or look for a nutritional supplement that contains it. You can also release the smell of rosemary essential oil in a heat-based diffuser.

Iron

This essential nutrient helps with blood flow, including blood flow to the brain, and is thought to help with cognitive health especially in those who are deficient in it. If you don’t eat a lot of iron-rich foods – such as red meat, liver, beans and nuts – you can get it in a single supplement or as part of a multivitamin formulation.

Zinc

This essential nutrient is found in high levels in the brain. You can get it in foods such as meat, nuts and dairy products, or if you don’t get much in your diet try a zinc supplement or multivitamin that has good zinc levels.

Phosphatidyl serine

Found in foods such as egg yolks, soya beans, fish and meat, phosphatidyl serine is often sold as a brain health supplement, as some experts think it may help boost memory and cognition.

Ashwagandha

One of the most widely used herbs in Indian Ayurvedic medicine, ashwagandha contains compounds called withanolides that some think are good for the brain. It’s widely available as a supplement, though not all brands contain beneficial levels of withanolides (look for a product that contains at least 1.5 per cent withanolides).

Vitamin C

Like the B vitamins, vitamin C is widely found in foods – yet some people may not be getting enough of it in their diets. Some scientists even believe it may help with cognitive functioning. You can get vitamin C supplements in many forms, including tablets, capsules and powder.

Magnesium

Found in foods such as dark chocolate, nuts, seeds, legumes, milk, oily fish, red meat and leafy green vegetables, magnesium may be beneficial if you want to give your brain a boost. However, despite the fact that it’s in many different foods, some people may have low levels of magnesium. If you want to try a supplement, look for magnesium in a more absorbable form, such as magnesium citrate.

Green tea

If you like drinking green tea, your brain may already be getting a supply of certain helpful compounds. If you’re not a fan of the taste, however, you can try a green tea supplement – choose a product with a good level of active antioxidant ingredients called polyphenols.

Being physically active is good for you in so many ways, including keeping your brain healthy. Discover more about what you could do to improve how well your brain works by taking a look around the cognitive health section in our health library.

 

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Disclaimer: The information presented by Nature's Best is for informational purposes only. It is based on scientific studies (human, animal, or in vitro), clinical experience, or traditional usage as cited in each article. The results reported may not necessarily occur in all individuals. Self-treatment is not recommended for life-threatening conditions that require medical treatment under a doctor's care. For many of the conditions discussed, treatment with prescription or over the counter medication is also available. Consult your doctor, practitioner, and/or pharmacist for any health problem and before using any supplements or before making any changes in prescribed medications.

 

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