In reaction to medical cannabis access referendums on the ballots in Arizona and California, former presidents Gerald Ford, Jimmy Carter, and George Bush signed a letter stating that they categorically oppose access to cannabis for its many proven therapeutic uses such as the prevention of blindness and epileptic seizures .Their chief concern was that legal medical access would send the message that cannabis is safe. The presidents can, however, lay their safety concerns to rest because the scientific literature overwhelmingly confirms that cannabis is both an effective and safe medicine.
When we know the facts we can understand why in 1988, after extensive review of the scientific literature, the DEA's own administrative judge Frances Young concluded that Marijuana is one of the safest therapeutically active substances know to man. 
Opponents of legal cannabis access would have us believe that there is not enough research available to determine its safety. Nothing could be further from the truth. Cannabis is one of the most thoroughly researched drugs in history, and the evidence gathered over the centuries clearly proves that it is safe:
The Indian Hemp Drugs Commission Report (1894): an exhaustive seven-volume, 3,281-page report that concludes: Moderate [cannabis] use produces practically no ill effects. 
The Panama Canal Military Study (1916-1929), amassing extensive data on the health impact of cannabis smoking upon American soldiers stationed in Panama, recommended that no steps be taken by the Canal Zone authorities to prevent the sale or use of Marihuana.The research also concluded that, here is no evidence that Marihuana...is..habit-forming.  The LaGuardia Report (1939-1944), commissioned by New York City Mayor Fiorello LaGuardia, which included evidence gathered over thousands of years, concluded that Smoking marihuana does not lead to addiction... does not lead to morphine, heroin, or cocaine addiction and that the publicity concerning the catastrophic effects of marihuana smoking in New York City is unfounded.
The Baroness Wootton Report (1968), commissioned by the Advisory Committee on Drug Dependence of the United Kingdom Home Office, concluded, There is no evidence that...serious physical dangers are directly associated with the smoking of cannabis.
The report also noted that Cannabis use does not lead to heroin addiction and that there is no evidence that [cannabis]...is producing in otherwise normal people conditions of dependence or psychosis, requiring medical treatment. 
The HARVARD MEDICAL SCHOOL MENTAL HEALTH LETTER 
reports the findings of other major cannabis studies:
In three major studies conducted in Jamaica, Costa Rica, and Greece, researchers have compared heavy long-term cannabis users with non-users and found no evidence of intellectual or neurological damage, no changes in personality, and no loss of the will to work or participate in society.
The Jamaican study states that, even as cannabis use in Jamaica is pervasive and is used in heavier quantities with greater THC potency than in the U.S., its use is without deleterious social or psychological consequences. 
What's more, the three studies cited, the largest human cannabis studies to date, also revealed that heavy long-term cannabis users scored slightly higher on IQ tests, had slightly lower rates of illness and cancer, and lived longer on average than non-users. Users also proved to be more relaxed and sociable than non-users  . The best evidence indicates, contrary to GovtMedia disinformation, that cannabis is safe and good for you.
In line with the findings of the Panama Canal study and the LaGuardia Report, current research confirms that the addictive potential of cannabis is very low. The journal TRENDS IN PHARMACOLOGICAL SCIENCES states that research shows cannabis has limited potential for development of...psychological dependence due to the weak reinforcing properties of Delta-9-THC.  BRAIN RESEARCH journal observes that "cannabinoid dependence and withdrawal phenomena are minimal." 
Research proves that cannabis is nontoxic. For example, in the journal FUNDAMENTAL AND APPLIED TOXICOLOGY , Dr. William Slikker, director of the Neurotoxicology Division of the National Center for Toxicological Research (NCTR), described the health of monkeys exposed to very high levels of cannabis for an extended period:
The general health of the monkeys was not compromised by a year of marijuana exposure as indicated by weight gain, carboxyhemoglobin and clinical chemistry/hematology values.
When THE ARKANSAS TIMES  asked Dr. Merle Paule of NCTR about evidence of cannabis toxicity and the health
of the monkeys in the study, Dr. Paule said, There's just nothing there. They were all fine.
The journal TOXICOLOGY LETTERS  published a study that found no link between cannabis smoking and lung
cancer. The seven researchers in the study concluded:
It has been suggested that marijuana smoking is a proximal cause of respiratory cancer. However, these intimations have not been borne out by epidemiological investigation.
Not only is the evidence linking cannabis smoking to cancer negative, but the largest human studies cited indicated that cannabis users had lower rates of cancer than nonusers. What's more, those who smoked both cannabis and tobacco had lower rates of lung cancer than those who smoked only tobacco-a strong indication of chemo-prevention . Even more, in 1975 researchers at the Medical College of Virginia found that cannabis showed powerful antitumor activity against both benign and malignant tumors (the government then banned all future cannabis/cancer research) . In fact, the NEW ENGLISH DISPENSATORY of 1764 recommends boiled cannabis roots for the elimination of tumors . Powerful evidence that cannabis not only does not cause cancer, but that it may prevent and even cure cancer. The few studies that the GovtMedia drums into the public mind over and over, which claim to show that cannabis is a harmful drug, are almost all the work of the government's top hired gun, Dr. Gabriel Nahas. The NEW ENGLAND JOURNAL OF MEDICINE described Nahas's work as "psychopharmacological McCarthyism that compels him to use half-truths, innuendo and unverified assertions.
The JOURNAL OF THE AMERICAN MEDICAL ASSOCIATION also condemned his work, stating, Examples of biased selection and...omissions of facts abound in every chapter. 
Not only does the best scientific research overwhelmingly confirm that cannabis is both an effective medicine and a safe drug, but that it may be both chemo-preventive and therapeutic and generally beneficial to health. What this shows us most clearly, in light of the consensus to the contrary, is the enormous power of a Big Lie.
With its vast resources, the GovtMedia elite are able to fabricate and fob off a pharmacological fraud against both cannabis and the public interest. Through sheer repetition and consistent suppression of contrary information, they are able to construct an edifice of public consensus which even the hardest scientific facts fail to topple.
The truth is no stronger than the ability of true information to surpass the public distribution of false and misleading information. The GovtMedia has a greater ability to distribute a Big Lie than any other sector of society has to distribute the truth. However, this report right here contains copious quantities of carefully referenced scientific facts that consistently and conclusively confirm that cannabis is safe-thereby exploding the GovtMedia's Big Lie.
As truth is only as powerful as it is known, do all that is in your power to make these powerful facts known, that we might put an end to the destructive and illogical prohibition of the proven safe and effective drug cannabis, for possession of which 10 million Americans have been arrested since 1965 .
 Three Former U.S. Presidents Oppose Medical Marijuana Measures, Associated Press (10/30/96).
 PHARMACOLOGICAL REVIEWS: Health Aspects of Cannabis. 1986, 38:1, 1-20. pg. 17.
 Bureau of Mortality Statistics, 1988. U.S. Public Health Service statistics. National Institute of Drug Abuse statistics. U.S. Surgeon General's Report.
 The Emperor Wears No Cloths. Jack Herer, Queen of Clubs Pub, 1991. Recommended: 213-392-1806.
 INTERNATIONAL JOURNAL OF ADDICTIONS. Spring 1968, digest of 1894 Indian Hemp Drugs Commission Report.
 The Indian Hemp Drugs Commission Report of 1894. Jefferson Press, Silv.Spring, MD, 1969, John Kaplan.
 MILITARY SURGEON. 1933, vol:73, pages 269-280.
 The La Guardia Report, reprinted in "The Marijuana Papers," Indianapolis: Bobbs-Merrill, 1966.
 The Consumer's Union Report: Licit & Illicit Drugs. Mt. Vernon, New York, 1971.
 HARVARD MEDICAL SCHOOL MENTAL HEALTH LETTER: Marijuana. L. Grinspoon, vol. 4, no. 5. Nov, 1987.
 Ganja in Jamaica: A Medical Anthropological Study of Chronic Marijuana Use. 1975. Anchor Books, NY.
 Cannabis in Costa Rica: A Study of Chronic Marijuana Use, 1980-82, Institute for the Study of Human Issues, 3401 Science Center Philadelphia, PA.
 TRENDS IN PHARMACOLOGICAL SCIENCES: Neurobiology of Marijuana Abuse. 1992, 13:201-206. pg. 203.
 BRAIN RESEARCH: Chronic cannabinoid administration alters cannabinoid receptor binding in rat brain: a quantitative autoradiographic study. 1993, 616:293-302. pg. 300.
 FUNDAMENTAL AND APPLIED TOXICOLOGY: Chronic Marijuana Smoke Exposure in the Rhesus Monkey. 1991, Aug; 17, 321-34.
 THE ARKANSAS TIMES: Refer Madness. 9/16/93.
 TOXICOLOGY LETTERS, No Increase in Carcinogen-DNA
Adducts in the Lungs of Monkeys Exposed Chronically to Marijuana Smoke, 1992, Dec;63 (3): 321-32.
 Marijuana: The First 12,000 Years. Plenum Press, 1980.
 The Great Drug War, Macmillan Publishing, 1987.
 MPP Marijuana Policy Project, 202-462-5747, P.O. Box 77492, Capitol Hill, Washington, D.C. 20013.
For information on the medical uses of cannabis visit Ian Goddard's home page.
(c) 1996 Ian Williams Goddard - (*) free to copy nonprofit w/ attribute.