Apple a day keeps the Oncologist away:
I made a mistake. I admit it.
Last month in extolling Park Hill's bounteous apple crop, and promoting Lakewood's Apple Cider Festival, I wrote that the old adage, "An apple a day keeps the doctor away." did not appear to have any scientific support.
Well I was wrong,
I admit it: Apples compete with grapefruit as the best dietary sources of glucaric acid. This is a bit obscure but follow with me. Glucaric acid enhances a chemical process called glucuronidation. Glucuronidation is the body's major Phase II detoxification pathway in which hormones, foreign substances and toxic chemicals, especially pesticides, are made harmless and eliminated. Many of these chemicals are potential carcinogens. The faster they are eliminated the better. In the process of glucuronidation an enzyme called glucuronyl transferase binds the target chemical to be eliminated with glucuronic acid in a chemical reaction called conjugation. The majority of these conjugated toxins are excreted with the bile into the digestive tract and eliminated with the feces. However this process can and is often reversed. An enzyme, Beta-glucuronidase, produced by bacteria in the intestine can deconjugate these toxins allowing them to be reabsorbed. Glucaric acid decreases the amount of Beta-glucuronidase.
The bottom line is that the more glucaric acid taken in through the diet the better able we are to breakdown and eliminate a broad range of carcinogens. Glucaric acid, found in food or sold in supplement form as calcium d-glucarate may reduce risk of cancer.
Numerous animal studies have indicated that glucaric acid may control cancer at particular stages and reduce the reproduction of cancer cells. In animal studies when animals with induced breast cancer consumed calcium -d-glucarate during the beginning phase (Initiation) of cancer, there was an 18% decrease in the incidence of tumors and a 28% decrease in tumor replication. When supplemented during the second (Promotion) phase of cancer there was a 42 % decrease in the incidence of tumors and a 42% decrease in tumor replication. When calcium -d-glucarate was supplemented during both the beginning and second phase of development there was a 50% decrease in tumor incidence and a 63% decrease in tumor replication. Other animal studies have shown that d-glucarate can inhibit cancers of the colon, breast, lung, liver, skin and urinary bladder. Human trials are underway. One human trial has already shown a lower recurrence rate of bladder cancer.
There is more to this. In a recent conversation with Dr. Tom Slager, an authority on calcium-d-glucarate, we talked about the mechanism of how glucaric acid works. His opinion is that there are other mechanisms we are unaware of. The cancer inhibitory effect of glucaric acid appears greater than can be explained by inhibition of Beta-glucuronidase alone. This has led me to change our treatment protocol: in the past I did not advise using calcium-d-glucarate unless lab work showed Beta-glucuronidase levels to be above normal. Now following Dr. Slager's example, I think it is advisable in all cases of either high risk for or existing hormone dependent tumors especially breast and prostate.
Back to apples. Apples are one of the best food sources of glucaric acid and contain about 3.5 gms/Kg. Because apples supply glucaric acid they help protect against cancer causing chemicals, reducing the rate of occurrence and slowing the growth of existing cancer cells. Perhaps the phrase should be, "An apple a day keeps the oncologist away."