We have it good here in Texas. This time of year- winter- the Texas Ruby Red grapefruit are in season, and they are cheap, plentiful, and sweeter than any other grapefruit you are ever going to eat. Texas grows oranges too, although I don't say they surpass the best California navels. But, I like oranges and grapefruits, and I like other acid fruits, such as kiwis, berries of all kinds, and pineapples. And even apples are quite acidic, being high in malic acid rather than citric acid. And there are plenty of other fruits with rather high acid content, such as plums, mangoes, grapes, and more. Oops, I left out tomatoes.
So, if you are eating a wide variety of these fruits in significant quantity, that's a heck of a lot of acid. Are there any negative consequences to that?
First note that there is no danger of the acid building up in your body and making you acid, that is, your blood acid. These organic acids are broken down very quickly to carbonic acid, and that very quickly gets converted to carbon dioxide, which you automatically exhale. So, you breathe out the acid from these fruits, and the process by which this happens is very efficient. So, that isn't a worry.
The biggest problem from eating acid fruit is the effect it has on your teeth, which is to erode your dental enamel. And, that enamel doesn't grow back. Once it's gone, it's gone. And when it's gone, your teeth look yellow and dingy; they may chip and break more easily; they may become painfully sensitive to heat and cold and sugar, and they may become more prone to tooth decay. So, you want to hold on to your teeth enamel for as long as you possibly can.
Then, the other problem that has been linked to eating a lot of acid fruit is the development of canker sores. These mouth sores, which can form on the inside of the lips or the undersurface of the tongue or the inside of the cheek are the painful ulcers can last for 1 to 2 weeks and making eating, talking, and even sleeping painful and difficult. Acid fruits are known to be a major trigger of canker sores. And that has been true in my experience and the experience of others I know. Someone may have a citrus tree or a plum tree at home, and when they're plentiful, they indulge liberally, and in a little while, they have one or more canker sores. The acid irritates the cells- actually burns them a little- and the body responds with inflammation, and in susceptible people, the inflammation advances to a destructive form. It really is like an auto-immune disease- one that millions upon millions of people have.
The good news is that canker sores, except in rare cases, eventually heal without a trace, leaving no scar and no remnant that they were ever there. No remnant, that is, except the memory of how painful they were.
So, what can you do to prevent them?
First, control the amount of acid fruit you eat. Limit it to reasonable, moderate amounts. Second, if a fruit is unusually acidic, meaning that the orange or the grapefruit or the pineapple or whatever is super-sour, then don't eat it. For instance, you really shouldn't buy navel oranges until January. They rush them to market in the fall, as early as October, but they really aren't ripe yet. You know how tart a fruit should be, and if it's more sour than that, don't eat it. Pass on it. Make that a rule. Third, rinse out your mouth with warm water after eating acid fruits to remove any film of acid that may still be clinging to your teeth. Fourth, for the most part, avoid acidic drinks. If you take your oranges or grapefruit in juice form, it may actually concentrate the acid since the fiber and other solid matter is being discarded. The acid easily passes into the juice. And note also that when you start juicing, you usually wind up consuming more. Once you start juicing oranges, you might go through 3 or 4 to come up with a whole glass, or even more than 3 or 4, depending on how juicy they are. And that's more than you would eat if you were just eating them.
A life without oranges, grapefruits, plums, mangoes, etc.- I'm not sure it would be worth living. So, I am not suggesting that you avoid these foods completely. In one of the largest and longest longitudinal studies ever done, the lifestyle factor that was most associated with living longer was eating fresh fruit. So, let's not throw the baby out with the bath water. But, there is a happy medium in which you can enjoy these fruits but not suffer ill-effects from eating them. Be conscious and aware of how much acid fruits you eat, and don't go overboard.
I should also point out that mechanical trauma to the mouth from biting your lip or cheek can trigger the start of a canker sore. So, what can I say except eat slowly and chew your food well, taking small, manageable bites without carelessly traumatizing yourself. Become a conscious eater.