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This article is copyright 2008 International Schizophrenia Foundation and may not be reprinted or otherwise used without ISF's written permission. If you are interested in using or reprinting this article, please contact ISF at or write to International Schizophrenia Foundation, 16 Florence Avenue, Toronto, Ontario, Canada M2N 1E9. Fax (416) 733-2352.

Orthomolecular Medicine News Service, November 18, 2008

Which Kills Smokers: "Camels" or Carrots?
Are Smokers Getting Lung Cancer From Beta-Carotene?

by Andrew W. Saul

(OMNS, November 18, 2008) If one is to believe the way Reuters reports it (1), carotene is a killer. Carotene? As in carrots? Nope: just the carotene in vitamin tablets. A recent study is critical, very critical, of beta-carotene in dietary supplements. The study authors wrote, "High-dose beta-carotene supplementation appears to increase the risk of lung cancer among current smokers." (2) The "high doses" they say are harmful are only 20-30 milligrams (mg) per day. To come up with this sensational conclusion, they chose only four studies for their analysis. All four were selected from the Medline database; none were from non-Medline-indexed nutritional medicine journals such as the Journal of Orthomolecular Medicine. (3)

Why did the authors choose to target only those "high doses" obtained from supplements? As the headlines do not differentiate between natural and "synthetic" beta-carotene, they are in effect saying that it does not matter whether it is in a tablet or in carrot cake: carotene looks bad for smokers.

Actually, smoking is bad for carotene. It destroys carotene's beneficial antioxidant properties. So it is much more likely that smokers need higher doses of antioxidants than nonsmokers. Smoking burns tobacco. Burning is fast oxidation. Smoking also oxidizes essential substances in the body, including carotenes. These long molecules have many carbon-carbon double bonds that are vulnerable to free radical attack. A smoker's antioxidants are consumed in trying to protect him or her from the toxins in tobacco. As smokers persist in smoking, they need more antioxidants, not less. R. F. Cathcart, M.D., found this to be true with the antioxidant vitamin C. When the vitamin is oxidized into dehydroascorbate, he said, patients need more of it, not less. Vitamin C, Dr. Cathcart said, is a non-rate-limited free radical scavenger. (4) Similarly, Drs. Wilfrid and Evan Shute treated patients with very high doses of antioxidant vitamin E. (5) Giving smokers a greatly increased amount of supplemental antioxidants (carotene, vitamins E and C, plus the mineral selenium) would likely change things for the better. Studies purporting to try this with smokers, without success, usually employed low doses of these nutrients. (6,7) A small dose is an ineffective dose.

Researchers using higher doses get better results. Carotene in high doses has been specifically shown to strengthen the immune system by helping the body to build more helper T cells. (8) The amount used in one well-controlled study was 180 milligrams of beta-carotene per day. This is the equivalent of nearly three dozen carrots per day. And nobody died. How about that.

Perhaps it is because beta-carotene is such a vital antioxidant. Says one review paper, "Numerous animal and laboratory studies have substantiated beta-carotene's ability to inhibit tumor cell growth and the progression of carcinogenesis." (9) Another large study showed that men consuming the beta-carotene equivalent of just one carrot each day, over 25 years, had a 28 percent lower risk of death from all causes compared with men eating less. (10) USA Today comments that you should "keep eating beta carotene-rich foods. Nobody disputes that the beta carotene in food is healthful and safe." (11)

Safe in food, but perhaps not safe in supplements? You cannot have it both ways: either beta carotene in doses of only 20-30 mg/day is harmful to smokers, as the study claims, or it is not. Whether it is derived from pills or your plate should not matter, unless synthetic beta-carotene is not as good for you as natural food-source beta-carotene. Research still has that to determine. (9) In the meantime, people uncritically accepting what the study purports to say may, unfortunately, stop consuming supplemental beta-carotene. For smokers, ceasing would be a genuine risk. About one-quarter of North America's adult population consists of smokers. Their diet, like everybody else's, is generally devoid of carrots. We are not eating vegetables in general, smoker or not. According to the American Heart Association, nine out of ten Americans do not meet the (rather low) US RDA of five servings a day of fruit or vegetables. And one-quarter of Americans do not eat even one single serving of a fruit or vegetable in a given day, according to the National Cancer Institute.

Everywhere you look you see cancer-fighting recommendations for all of us to eat more green and yellow vegetables. For smokers, the stakes are higher. For them, six carrots, or their supplemental equivalent of 20-30 mg of carotene a day is too little, too late. Indeed, cigarette smoking is "significantly related to lower beta-carotene concentrations (even) after supplementation." (12) Smokers should not send the proverbial boy to do a man's job. They need more carotene, not less. And they need it any way they can get it.

Smokers can start by eating their vegetables. Beta carotene is abundant in orange fruits and vegetables, such as pumpkin, squash and apricots, as well as dark green leafy vegetables like spinach. One medium carrot has only about 30 calories. It has zero cholesterol. It has zero fat. It is an excellent source of potassium and fiber. A single medium sweet potato contains about 10 milligrams of beta carotene. Do you really think that two or three sweet potatoes a day is harmful? Do you really think that six carrots a day are bad for you? Does spinach kill smokers? Then why are supplements with exactly that amount of beta-carotene a problem? The answer is, they aren't. Smoking is what is harmful to smokers. Carrots are good for you. Cigarettes aren't.

One might say that the recent analysis actually shows that smoking probably destroys at least 20-30 mg of beta-carotene a day. To conclude that smokers need less seems a bit odd, doesn't it? What other anti-oxidant nutrients do smokers need less of? Certainly they cannot do with less vitamin C. Nearly fifty-five years ago, William J. McCormick, M.D., wrote that smoking just one single cigarette neutralizes in the body approximately 25 mg of ascorbic acid. That is 500 mg of vitamin C deficit per pack. The doctor wrote: "The ability of the heavy smoker to maintain normal vitamin C status from dietary sources is obviously questionable." (13) This was quite a statement in 1954, at a time when physicians were literally endorsing their favorite cigarette in magazines and on television commercials.

Some nutritional supplement preparations may, notes the Reuters article, contain "high" doses of beta-carotene. Once again, the analysis defines "high" as only 20-30 mg, and only from supplements. At 6 to 7 mg of beta carotene per typical carrot, the study is saying that the amount of beta-carotene equivalent to four carrots per day is potentially dangerous to smokers. That is a bit counterintuitive. Where are all these carrot-eating corpses? Where are the bodies? If you search decades of the medical literature, and also search the American Association of Poison Control Centers' collected data (14), you will find there have been no deaths whatsoever from beta-carotene. None. Zip. Nada. Zero. Evidently it must be singularly difficult to kill yourself with carrots. Or with carotene supplements.

Excess carotene causes the skin to turn slightly orange, once succinctly described as resembling an artificial suntan. The medical name for this condition is "hypercarotenosis" or just "carotenosis." "Hypercarotenemia" refers to elevated blood levels of carotene, and is also called just "carotenemia." Both are harmless.

In performing their limited four-study review, the authors said that they looked at many "national brands" of carotene-containing vitamin supplements. The "national brands" they should have been looking at are "Marlboro," "Winston," and "Camel." The authors are finding fault with the wrong plant. It's not carrots that hurt smokers; it's tobacco.

Given all this, it is no surprise that the study found that ex-smokers were not at all negatively affected by beta-carotene. Why? Because they stopped smoking, that's why. The preeminent danger is smoking itself. Stop today, and go have plenty of carotene.


(1) Harding A. Vision vitamins may be harmful for smokers. Reuters, Thu Jul 10, 2008.

(2) Tanvetyanon T, Bepler G. Beta-carotene in multivitamins and the possible risk of lung cancer among smokers versus former smokers: a meta-analysis and evaluation of national brands. Cancer. 2008 Jul 1;113(1):150-7.

(3) The Journal of Orthomolecular Medicine archives are posted for free access at

(4) Cathcart RF. Vitamin C, the nontoxic, nonrate-limited antioxidant free radical scavenger. Medical Hypothesis, 1985. 18:61-77.

(5) Shute WE. Complete Updated Vitamin E Book. New Canaan, CT: Keats, 1975. And: Shute WE. Health Preserver. Emmaus, PA: Rodale Press, 1977. Also: Shute WE. The Vitamin E Book. New Canaan, CT: Keats, 1978.

(6) Heinonen OP et al. The effect of vitamin E and beta carotene on the incidence of lung cancer and other cancers in male smokers. New England J of Med 330:1029-1035, 1994.

(7) Vivekananthan DP, Penn MS, Sapp SK, Hsu A, Topol EJ. Use of antioxidant vitamins for the prevention of cardiovascular disease: meta-analysis of randomised trials. Lancet. 2003 Jun 14;361(9374):2017-23. Also: Goran Bjelakovic, Dimitrinka Nikolova, Rosa G Simonetti, Christian Gluud. Antioxidant supplements for prevention of gastrointestinal cancers: a systematic review and meta-analysis. Lancet 2004; 364: 1219-28).

(8) Alexander, M et al: "Oral Beta-carotene Can Increase the Number of OKT4 Cells in Human Blood," Immunology Letters, 9:221-224, 1985.

(9) Patrick L. Beta-Carotene: The Controversy Continues. Alternative Medicine Review, Dec, 2000.;col1 (This article contains a thorough discussion of natural vs. synthetic beta-carotene.)

(10) Pandey DK, Shekelle R, Selwyn BJ, Tangney C, Stamler J. Dietary vitamin C and beta-carotene and risk of death in middle-aged men. The Western Electric Study. Am J Epidemiol. 1995 Dec 15;142(12):1269-78.


(12) McLarty JW, Holiday DB, Girard WM, Yanagihara RH, Kummet TD, Greenberg SD. Beta-Carotene, vitamin A, and lung cancer chemoprevention: results of an intermediate endpoint study. Am J Clin Nutr. 1995 Dec;62(6 Suppl):1431S-1438S.

(13) Saul AW. Taking the Cure: The pioneering work of William J. McCormick, M.D. J Orthomolecular Med, 2003. Vol 18, No 2, p 93-96.


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This article is copyright 2008 International Schizophrenia Foundation and may not be reprinted or otherwise used without ISF's written permission. If you are interested in using or reprinting this article, please contact ISF at or write to International Schizophrenia Foundation, 16 Florence Avenue, Toronto, Ontario, Canada M2N 1E9. Fax (416) 733-2352.

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