Grapefruit vs Lemon – Which is Healthier?

Our Verdict

When comparing grapefruit to lemon, we picked the lemon.

Why?

Grapefruit has its merits, but in the battle of the citrus fruits, lemons come out on top nutritionally:

In terms of macros, grapefruit has more carbs while lemons have more fiber. So, while both have a low glycemic index, lemon is still the winner by the numbers.

Looking at the vitamins, here we say grapefruit’s strengths: grapefruit has more of vitamins A, B2, B3, and choline, while lemon has more of vitamins B6 and C. So, a 4:2 win for grapefruit here.

In the category of minerals, lemons retake the lead: grapefruit has more zinc, while lemon has more calcium, copper, iron, manganese, and selenium.

One final consideration that’s not shown in the nutritional values, is that grapefruit contains high levels of furanocoumarin, which can inhibit cytochrome P-450 3A4 isoenzyme and P-glycoptrotein transporters in the intestine and liver—slowing down their drug metabolism capabilities, thus effectively increasing the bioavailability of many drugs manifold.

This may sound superficially like a good thing (improving bioavailability of things we want), but in practice it means that in the case of many drugs, if you take them with (or near in time to) grapefruit or grapefruit juice, then congratulations, you just took an overdose. This happens with a lot of meds for blood pressure, cholesterol (including statins), calcium channel-blockers, anti-depressants, benzo-family drugs, beta-blockers, and more. Oh, and Viagra, too. Which latter might sound funny, but remember, Viagra’s mechanism of action is blood pressure modulation, and that is not something you want to mess around with unduly. So, do check with your pharmacist to know if you’re on any meds that would be affected by grapefruit or grapefruit juice!

PS: the same substance is quite available in pummelos and sour oranges (but not meaningfully in sweet oranges); you can see a chart here showing the relative furanocoumarin contents of many citrus fruits, or lack thereof as the case may be, as it is for lemons and most limes)

Adding up the sections gives us a clear win for lemons, but by all means enjoy either or both; just watch out for that furanocoumarin content of grapefruit if you’re on any meds affected by such (again, do check with your pharmacist, as our list was far from exhaustive—and yes, this question is one that a pharmacist will answer more easily and accurately than a doctor will).

Want to learn more?

You might like to read:

Top 8 Fruits That Prevent & Kill Cancer ← citrus fruits in general make the list; they inhibit tumor growth and kill cancer cells; regular consumption is also associated with a lower cancer risk 🙂

Enjoy!