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The Effects of Grapefruit on the Brain

Grapefruits are not my favourite fruit. How many of you, when I mention grapefruit, are pulling a face as you think about how they taste? I’m going to go out on a limb here and guess that the vast majority of you are in the “it tastes terrible” corner rather than the “I eat one for breakfast every day” one (it’s a little ironic that its botanical name means "fruit of paradise.”) Yet here I am to tell you that this bitter tasting fruit is a great source of the nutrient known as folic acid, which, research suggests, may enhance brain health!

Nutrients are chemical substances in food that body cells use for growth, maintenance and repair. The six main types of nutrients are: water, carbohydrates, lipids, proteins, minerals and vitamins.

You may have heard of folic acid (folate, folacin), especially if you or someone you know has been pregnant. It’s a type of B vitamin also named vitamin B9. Many vitamins help catalyze metabolic reactions—the chemical reactions that take place within each cell of a living organism. Some vitamins, like folic acid, are essential nutrients, meaning that the body cannot make them in sufficient quantity to meet its needs. You can’t make folic acid on your own, so you have to get it from eating food.

Folic acid benefits everyone because it:

  • helps to synthesize DNA and RNA, your body's “building blocks”
  • aids in rapid cell division and growth
  • helps produce healthy red blood cells (deficiency of folic acid can lead to the production of abnormally large red blood cells, a condition known as megaloblastic anaemia)

Health Organizations usually stress how important it is for pregnant women to have enough folic acid in their diet. Research has shown it helps prevent major birth defects (neural tube defects, including spina bifida and anencephaly).

Like it or not, we are all aging and our bodies naturally respond to the changes that accompany growing older. Research on brain dysfunction as a result of aging has shown that folic acid deficiency can lead to a further decrease in cognition, the mental abilities and processes related to knowledge.

However, before you race out to buy yourself a grapefruit, let me mention that they might also have negative effects. Organic chemical compounds called furanocoumarins are produced by many plants, grapefruits included, as a defense mechanism against predators. Furanocoumarins can increase or decrease the bioavailability of certain prescription drugs, meaning you might end up with more or less of the drug that you need in your bloodstream.

Grapefruit furanocoumarins change drug effects by supressing the action of some enzymes, the biological catalysts, which would usually change the drug into a form your body can use. This could have a severe, sometimes fatal, interaction. Two enzymes called CYP3A4 and CYP3A5 are known to be significantly affected by even small amounts of grapefruit juice in many people. If you’re currently taking medication, you should check with your doctor if you’re worried about furanocoumarins affecting your health.

Further reading on the benefits and risks of folic acid can be found here. If you'd like to find out more about how the brain works and take a look at a real human brain, visit our BodyWorks Gallery.