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From the Director

Balz Frei, Ph.D.
Director & Endowed Chair
Linus Pauling Institute

Photo of Dr. Frei at his desk

Every year since 1940, Oregon State University has produced the "Biology Colloquium", which is dedicated to the public discussion of research topics relevant to the Universityís academic mission. This year, the Linus Pauling Institute organized the Colloquium and dedicated it to the 98th anniversary of Linus Paulingís birth. The topic was "Micronutrients, Phytochemicals and Optimal Health", which is the same as LPIís mission, namely, "to determine the function and role of micronutrients, phytochemicals and microconstituents of food in promoting health and preventing and treating disease."

Audio tapes of the talks presented at the Biology Colloquium are available to LPI supporters at a cost of $5 per tape ($25 for the set of 7). Send checks payable to "OSU Fdn for Linus Pauling Institute" to Oregon State University, 571 Weniger Hall, Corvallis, OR 97331-6512. Please note which tapes you want and the quantity. 50% of the check amount is tax deductible.

John Erdman, Ph.D.
University of Illinois/Urbana-Champaign
"Carotenoids and Health"

Mark Levine, M.D.
National Institute of Diabetes and Digestive and Kidney Diseases
"Vitamin C and Optimal Health"

Balz Frei, Ph.D.
Director of the Linus Pauling Institute, Oregon State University
"Antioxidant Vitamins and Heart Disease"

Eric B. Rimm, Sc.D.
Harvard School of Public Health
"Micronutrients, Coronary Heart Disease and Cancer: Should We All Be on Supplements?"

Roderick Dashwood, Ph.D.
Linus Pauling Institute, Oregon State University
"Phytochemicals and Cancer"

Mark P. Mattson, Ph.D.
University of Kentucky
"Dietary and Genetic Factors in Age-Related Neurodegenerative Disorders"

Darrell G. Medcalf, Ph.D.
HealthComm International, Inc.
"Functional Foods: Past, Present and Future"

Five invited speakers and two from LPI, Dr. Rod Dashwood and myself, presented an overview of the latest findings in their respective research areas to an audience of about 700, unprecedented for an OSU Biology Colloquium. The first speaker was Dr. John Erdman from the University of Illinois, Urbana-Champaign, who discussed the role of carotenoids in human health. Carotenoids are the orange, yellow and red pigments in fruits and vegetables. The evidence that these compounds are healthful is derived mainly from epidemiological studies of fruit and vegetable intake, the majority of which have shown protection against cancer. Interestingly, when one carotenoid, beta-carotene, was tested as a supplement in three large studies involving tens of thousands of volunteers, no benefits were seen in preventing cancer or heart disease. In fact, heavy smokers taking beta-carotene supplements had a slightly increased risk of lung cancer, a finding that has stirred a lot of debate and instigated additional mechanistic studies.

Dr. Mark Levine from the National Institutes of Health then addressed the topic of vitamin C and optimal health. Dr. Levine has studied the relationship between vitamin C intake and resultant levels in serum and white blood cells. Based on careful pharmacokinetic studies in young, healthy men, he has concluded that 200 mg of vitamin C per day, easily obtained from fruits and vegetables, is sufficient in healthy people to achieve maximal benefits. At higher doses of vitamin C, "bioavailability" decreases--less is absorbed and more is excreted. For example, only 50% of a 1,250 mg dose is absorbed and almost all is then excreted. While this is true for healthy people, we still know very little about vitamin C requirements in people suffering from cancer, viral infections and other illnesses, or in older people. It is very likely that they need much more vitamin C than healthy, younger people to maintain the same blood and body vitamin C levels. As you may know, over twenty years ago, Linus Pauling proposed that the RDA for vitamin C should be 200 mg/day.

In the introduction to my presentation, I gave an overview of the mortality data from cardiovascular diseases (CVD), which include heart disease and stroke. CVD cause 42% of all deaths in the U.S., compared to 24% for cancer, the number one and two killers. Every year since 1984, CVD have claimed the lives of more women than men, and almost one in two womenís deaths is from CVD, but only one in 27 is from breast cancer, which is the number two cancer killer in women after lung cancer. Remarkably, more than a dozen recent studies have shown that vitamin C supplements produce substantial improvement of blood vessel relaxation in patients with heart disease, diabetes or high cholesterol levels. Some of these studies, performed at Harvard and top hospitals, have used large, gram quantities of vitamin C, sometimes directly infused into arteries supplying the heart muscle with blood. It is exciting to see these clinical benefits of vitamin C in disease treatment, in addition to the role of vitamin C in disease prevention.

Dr. Eric Rimm from Harvard then discussed two large human studies conducted at Harvard Universityís Department of Nutrition:  the Nursesí Health Study and the Health Professionalsí Study. Both of these studies strongly suggest that daily vitamin E supplements of at least 100 International Units (IU) substantially reduce heart disease risk. There is also good evidence that vitamin E supplements, as well as selenium supplements, lower the risk of prostate cancer, which is why I recommend a daily supplement of 200 IU of natural vitamin E (d-alpha-tocopherol) and up to 200 micrograms of selenium. While Dr. Rimm concurs with me on vitamin E, he believes the current evidence is not convincing enough to justify selenium supplementation. He also presented intriguing data on folate intake and alcohol consumption. It is known that moderate alcohol consumption, about one drink per day, substantially reduces heart disease risk, but it also raises the risk of certain types of cancer, such as breast and colon cancer. Interestingly, the adverse effects of alcohol consumption on colon and breast cancer seem to be reversed by a folate intake of about 600 micrograms/day.

Dr. Rod Dashwood of LPI gave an overview of the role of diet in cancer, including a discussion of phytochemicals. He explained that nearly one third of all cancer deaths in the U.S. are linked to diet and obesity and another third to smoking. He also pointed out that synthetic pesticides, present as residues on fruits and vegetables, contribute very little, if at all, to cancer in the general population. When viruses, alcohol, pollution, occupational factors, physical inactivity, hormones and other risk factors are combined, they still contribute less to cancer mortality than tobacco use or poor diet. There is overwhelming evidence that eating lots of fruits and vegetables is beneficial in reducing cancer risk and promoting health. Oneís risk of dying of lung or colon/rectal cancer, the leading causes of cancer mortality in the U.S., can be reduced by as much as 95% and 75%, respectively, by a diet rich in fruits and vegetables and a healthy lifestyle, including regular exercise, weight control and, of course, not smoking. Dr. Dashwood also discussed his research on cooked meat mutagens and chemoprotective agents in the diet, such as chlorophyll and tea polyphenols (see the Fall/Winter 1998 LPI Newsletter).

Dr. Mark Mattson of the University of Kentucky discussed dietary and genetic factors in age-related neurodegenerative disorders, such as Alzheimerís disease and Parkinsonís disease. He explained that a process called lipid peroxidation (oxidation of fat leading to rancidity) in brain cells is an important factor in many acute and chronic neurodegenerative conditions. Lipid peroxidation also plays an important role in atherosclerosis and heart disease, which helps explain why antioxidants like vitamins E and C reduce the risk of heart disease. There is some evidence that vitamin C may protect against cognitive impairment in elderly people, and one study found that supplementation with vitamin E (2,000 IU/day) can delay the onset of Alzheimerís disease. Dr. Mattson noted, however, that the case for therapeutic antioxidant supplementation in neurodegenerative disorders is not convincing. His recommendation is to lower the intake of calories, which seems to reduce the risk of age-related brain dysfunction and also extend life expectancy.

Finally, Dr. Darrell Medcalf of HealthComm International, Inc. discussed the past, present and future of functional foods, which are defined as specific foods and food components that have the potential to positively affect health status.  He reviewed some claims the U.S. Food and Drug Administration has approved for food labeling under the Nutrition Labeling and Education Act. The approved health claims include: dietary saturated fat and cholesterol and risk of heart disease; fruits, vegetables and fiber-containing grain products and risk of heart disease and cancer; calcium and osteoporosis; sodium and hypertension; and dietary fat and cancer. Interestingly, there is no agreement among the scientific experts that salt is an important risk factor for high blood pressure or that fat intake influences cancer risk. In addition, recent evidence has cast doubt on the role of dietary fiber in reducing colon cancer risk (see the article by Gilberto Santana-Rios on page 9).

These health messages emerged from the conference:

  • donít smoke
  • eat at least five servings of fruits and vegetables every day
  • drink plenty of healthful fluids like water, fruit juices and tea
  • reduce the intake of saturated and hydrogenated fat (butter, margarine, cheese, animal fat, vegetable shortening)
  • use monounsaturated oils (olive, canola, peanut) instead of polyunsaturated oils (corn, soybean, safflower, sunflower)
  • limit the intake of overcooked or charred meat and eat meat or fish with ample portions of vegetables
  • exercise regularly
  • consume only moderate amounts of alcohol (not more that one drink a day for women, and two for men)
  • avoid alcohol if you have a family history of breast or colon cancer or alcohol addiction
  • take a daily folate supplement (400 micrograms or slightly more)
  • take a daily vitamin E supplement (200 IU, natural source)
  • take a daily selenium supplement (100-200 micrograms)
  • teach children to eat a healthy diet and lead a healthy lifestyle, so that they may reap the benefits as they age.

Last updated May, 1999

Honoring a Scientific Giant with Research Toward Longer, Better Lives

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