There are a number of toxins you
can eat and drink that can have a harmful effect on your brain, driving down
its performance and having to make those essential nutrients work far harder than
they should to keep your brain in great condition. This is the same as filling
up your car with high octane fuel and then throwing in a handful of sugar –
disastrous!
• Refined sugar (sucrose) -sugar is as disastrous for your brain as
it is for petrol tanks. Sugar is broken down into smaller units called glucose
and fructose when you digest your food. Glucose (also known as blood sugar) is
the preferred source of energy for your brain.
Excess glucose in your blood can harm your brain in two ways:
It damages blood vessels in
the brain so they can’t deliver oxygen as efficiently, or clear away the
protein linked to causing Alzheimer’s Disease. Diabetics are particularly at
risk from this type of damage.
High glucose levels also
affect the function of specialized proteins in your brain called neurotrophins.
These protect brain cells from damage and help new brain cells develop. One
neurotrophin, called BDNF, is needed for memory formation, so you can see how
excess glucose can directly harm learning and memory.
Foods containing high levels
of refined sugar to watch out for are: sweets, syrups, prepared meals and
desserts (including tinned products), biscuits, muffins, cakes, sauces, tinned
fruit, yoghurt, breakfast cereals , ready to drink beverages including soft
drinks, energy drinks, teas and fruit juices.
The World Health Organisation
recently recommended that we reduce our intake of sugar from all sources to 5%
of our energy intake, which is around 6 teaspoons a day (25g) for the average
adult eating 2000Cal/8,400kj per day.
· Saturated fats - excess saturated fats have the same effect as excess glucose on the action of neurotrophins, and directly harm learning and memory.
Saturated fats can be found in animal products such as
meat, dairy and eggs, and most possessed packaged foods including cakes, biscuits
and ready meals.
Lowering your intake of sugar and saturated fat has the
added benefit of helping you manage your weight, which then has the additional
bonus of reducing your risk of dementia: if you are overweight in middle age
your risk of dementia is increased by 35%, if you are obese it’s a whopping
74%.
· Trans-fats – these unnatural fats can become lodged in your brain cells and disrupt
their function. These unnatural fats are
commonly found in commercial, pre-packaged foods, margarine, biscuits, crackers
and fried foods (including potato chips). They are listed as ‘vegetable oil’ on ingredient lists and are usually
oils that have been heated to high temperatures. Watch out for this toxin by checking labels
and choosing options that are free of trans-fats and hydrogenated fats, as these can contain trans-fats. Fats that are
naturally solids at room temperature are safest. Try small servings of
spreadable butter (size of your thumb) instead of margarine.
Note that heat, oxygen and light can damage
fats and oils and make them rancid (oxidised). Oxidised fats then draw on your
body’s reserves of anti-oxidants to prevent them from harming your cells. We
need those antioxidants at work protecting your brain not putting out fires
elsewhere!
Good quality oils such as cold pressed, extra virgin olive oil are best left unheated, as they have a low smoke point and are particularly susceptible to damage from overheating. Rice bran oil or a small amount of butter are great for stir frying and sautéing. Try adding olive oil after cooking to add flavour, or use it in salad dressings. Store oil in air-tight containers away from heat and light.
· Alcohol - having more than 14 standard*
alcoholic drinks a week can shrink your brain by 1.6%! This is important as
brain volume is a measure of brain age i.e. the more brain you have the more
youthful it is. If that’s not enough, chronic excessive alcoholic intake can
lead to vitamin B1 deficiency, which causes mental confusion as well as other
unwanted effects such as loss of coordination and eye paralysis. If alcohol
intake remains high the damage to short-term memory is particularly harsh and can
become permanent.
Limit alcoholic drinks to one or two per evening and if possible choose those that are low in sugar and also contain antioxidants such as red wine.
*One standard drink contains 10g of alcohol e.g. 100ml glass of wine,
330ml can of beer or a 30ml measure of spirits.
In summary,
any excess refined sugar and saturated fat, damaged fats and alcohol you
consume will take a hefty toll on the health of your brain, so keep that in
mind (pun intended) when making your choices.
In my
upcoming articles I’ll be looking into food sensitivities and how they
affect your brain, followed by medications that can reduce your brainpower.
