Cancer
Research
Diet &
Lifestyle
Milk (USA)
& Cancer
Earlier this year, experts from Harvard
Medical School reported that they found conclusive, indisputable evidence
linking a hormone found in milk in the USA with cancer.
A synthetic form of IGF-1, otherwise known
as insulin like growth factor 1, injected into milk cows to stimulate milk
production increases the risk of prostate cancer, breast cancer and
gastro-intestinal cancers.
All mammals produce IGF-1 molecules similar
in structure. However the human body's production of IGF-1 is regulated by
human growth hormones and peaks at puberty and declines with age. It is a
very powerful hormone with profound effects on the body's chemistry even
though it makes up less than 0.2 millionth of a gram per millilitre.
It is well established that IGF-1
stimulates the growth of cancer cells, and researchers at Stanford
University reported as far back as 1990 that it is linked to prostate
cancer. In 1993 a study revealed that this hormone accelerates the growth
of breast cancer cells, and in 1996 researchers at the National Institute
of Health reported that IGF-1 plays a key role in the progression of many
childhood cancers , breast cancer, small cell lung cancer, skin cancer,
and cancers of the prostate and pancreas.
In January of this year a report from
Harvard Medical School confirmed that high IGF-1 concentrations is linked
to an increase risk of prostate cancer. men who had high serum IGF-1
levels (i.e. between 300 and 500mg/ml) were found to have more than four
times the risk of developing prostate cancer than men who had serum levels
between 100 and 185 mg/ml.
Concerns over the safety of bovine growth
hormones (rBGH) were raised as far back as 1988, however the evidence of a
strong link between cancer risk and high serum IGF-1 levels is now
indisputable. One of the major concerns is that IGF-1 levels are 10 times
higher in cows treated with rBGH. Despite the overwhelming scientific
data, the Food & Drug Administration in the USA still approves the use
rBGH in milk production and consumers in America have no means of knowing
whether the milk they drink is produced from rBGH-treated cows or not.
Thankfully, Europe has a moratorium on the use of rBGH and milk products
from treated cows are not allowed to be sold within the European Union.
Canada has also, so far, resisted pressure from the USA to approve rBGH in
milk production. Watch this space!
Vide Journal of Alternative &
Complementary Medicine May 1998 pp.9 - 10.
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Vitamins &
Vegetables
& Cancer
Researchers at the East Caroline University School of Medicine have found
that there is a clear link between vitamin E and breast cancer and
prostate cancer.
Assessing the effects of vitamin E on
cancer cells, the researchers found that there was a dose-related
inhibition of cell growth in all cell lines studied including prostate and
breast cancer cell lines (prostate cells showing a particularly strong
suppression of growth).
The researchers concluded that vitamin E
inhibits cell proliferation with breast and prostate cancer cells and
should, therefore, be considered as a supplement of choice in the
prevention and treatment of these cancers.
Sigounas G et al. dl-alpha-tocopherl
induces apoptosis in erythroeulemai, prostate, and breast cancer cells.
Nutri Cancer 1997, 28:1;30-35
Researchers in Melbourne, Australia
conducted a case-control study of 88 consecutive males admitted for the
surgical removal of a non-melanocytic skin cancer who were matched with
another 88 male control patients admitted for small elective surgical
procedures unrelated to skin cancer. The researchers analysed the
patients’ previous diet, alcohol consumption, and smoking habit measured
their serum beta-carotene and vitamin A levels. The results revealed that
there was a statistically significant inverse relation-ship between the
risk of skin cancer and a high intake of vegetables in general, beans,
lentils, or peas, carrots, silverbeet (Swiss chard), or pumpkin;
cruciferous vegetables (cabbage, brussels sprouts, or broccoli); and
beta-carotene- and vitamin C-containing foods. Patients with skin cancer
had a lower mean serum level of beta-carotene and the researchers
concluded that a high intake of vegetables including cruciferous
vegetables, beta-carotene- and vitamin C-containing foods, appears to be
protective for non-melanocytic skin cancer, and de-serves further study,
as does the possible etiologic relevance of the low serum levels of
beta-carotene and vitamin A.
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Diet
& Cancer
A case-control study was
carried out at the Department of Epidemiology, Harbin Medical College,
Heilogjiang, China to assess the role of diet in the aetiology of cancer
of the colon and rectum. A total of 336 incident cases of histologically
confirmed colorectal cancer (111 colon cancer and 225 rectal cancer) and
an equal number of controls with other non-cancerous diseases were
interviewed in hospital wards. Data concerning the average frequency of
consumption and amount consumed of single food items were obtained by a
dietary history questionnaire and the information analysed by computer.
The results revealed that vegetables,
particularly green vegetables, chives and celery, have a strong protective
effect against colorectal cancer. Meat products and eggs were associated
with increasing risk for cancer of the rectum. Alcohol consumption was
also found to be an important risk factor for developing colon cancer and
male rectal cancer.
Hu JF; Liu YY; Yu YK; Zhao
TZ; Liu SD; Wang QQ. Diet and cancer of the colon and rectum: a case-control study in
China. International Journal of Epidemiology (ENGLAND) Jun 1991, 20 (2)
p362-7
Diet and cancer of the colon and rectum: a
case-control study in China. Hu JF; Liu YY; Yu YK; Zhao TZ; Liu SD; Wang
QQ Department of Epidemiology, Harbin Medical College, Heilogjiang, China.
Int J Epidemiol (ENGLAND) Jun 1991, 20 (2) p362-7
A case-control study was carried out in
Harbin city to assess the role of diet in the aetiology of colorectal
cancer. A total of 336 incident cases of histologically confirmed
colorectal cancer (111 colon cancer and 225 rectal cancer) and an equal
number of controls with other non-neoplastic diseases were interviewed in
hospital wards. Data concerning the average frequency of consumption and
amount consumed of single food items were obtained by a dietary history
questionnaire. Odds ratios and their confidence limits were computed.
Multiple regression for risk status was also used. Vegetables,
particularly green vegetables, chives and celery, have a strong protective
effect against colorectal cancer. Reduced consumption of meat, eggs, bean
products and grain was associated with increasing risk for cancer of the
rectum. Alcohol intake was found to be an important risk factor for
developing colon cancer and male rectal cancer.
Saturated Fat
& Cancer
A diet high in saturated fats can also significantly increase the risk of
skin cancer according to two major research studies. In one con-trolled
study, 76 patients with non-melanoma skin cancer were randomly assigned to
one of two groups; in one group the patients were allowed to continue
their usual high fat diet (more than 36 per cent) whereas the other group
had to change their diet so that a maxi-mum of 20 per cent of total
caloric intake was made up of fat. All of the patients were monitored in
relation to their diets and for new premalignant lesions over a period of
one year and the results then evaluated. The data revealed that those
patients in the restricted fat group showed an average of 3 lesions
whereas those in the unrestricted group showed an average of 10. The study
concluded that, in patients with a history of non-melanoma skin cancer, a
low-fat diet significantly reduces the incidence of premalignant cancerous
lesions.
These findings were confirmed by a further
investigation into the effect of a low-fat diet on occurrence of
non-melanoma skin cancer conducted over a two year period at the
Department of Dermatology. Baylor College of Medicine, USA. In this study,
a total of 101 skin-cancer patients were assigned either to a control
group that consumed, on average, 38% of caloric intake as fat, and in
which no changes in dietary habits were introduced, or to a low-fat
dietary-intervention group, in which patients were instructed to limit
their calories from fat to 20% of total caloric intake.
Patients were examined at 4-month intervals
by dermatologists who were not aware of the patients’ dietary
assignments. Nutrient analyses, conducted at each of the 4-month follow-up
visits, indicated that the percentage of calories of fat consumed in the
intervention group had been reduced to 21% at 4 months and remained below
this level for the rest of the trial period.
The results revealed that cancer occurrence
in the low-fat intervention group declined after the first 8-month period
and reached statistical significance by the last 8-month period. Patients
in this group had significantly fewer cancers in the last 8-month period
than did patients in the control group. Furthermore, there was a
significant reduction in the number of patients developing skin cancer in
the last 8-month period, as compared with the first 8-month period, within
the low-fat intervention group. There were no significant changes recorded
in the control group and the researchers were left in no doubt that their
study confirmed that a low-fat diet can significantly reduce occurrence of
a highly prevalent skin cancer.
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Sunscreen
lotions
& Cancer
Contrary to popular belief, certain high factor sun screens may also pose
a risk to the public. A report from the US Food and Drug Administration as
far back as 1989 concluded that 14 out of 17 sunscreen lotions containing
PABA (Para Amino Benzoic Acid) may actually cause skin cancer (7). PABA
has been shown to cause genetic damage to the DNA in the skin and Dr Zane
Kime (author of the book "Sun-light") believes that most high
factor sun screens can stimulate the formation of cancer cells. Dr Jacob
Liberman (author of the book "Light: Medicine of the Future")
recommends that people should "gradually build up exposure to the sun
and use no sunscreens if they have moderate to dark skin." He goes on
to recommend that "if you must be out in the bright midday sun for
more than thirty minutes, or if you have fair skin, then consider using a
sunscreen that does not contain PABA.
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Antioxidants
& Cancer
Antioxidant vitamins
A, E and beta-carontene as well as zinc and selenium play a key role in
the development and treatment of childhood cancer according to researchers
in France
170 children between the ages of 1 and 16 years, all of whom were newly
diagnosed with cancer had their serum levels of vitamins A, E,
beta-carotene, zinc, selenium and cholesterol assessed, and the results
were then compared to blood samples obtained from 632 healthy children.
The data revealed that, after adjustments for age and sex, the serum
levels of vitamins A, E, beta-carotene and zinc were all inversely related
to cancer.
Malvy DJ et al. Antioxidant micronutrients and childhood malignancy
during oncological treatment. Med Pediatr Onco. Sept 1997 29:3, 213-7.
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Asbestos
& Cancer
Asbestos is starting to be discovered in drinking water systems. The research on
asbestos inhalation reveals the lengthy process needed to prove that harmful
agents in the environment affect our health. Dr Irving J. Selikoff,
painstakingly documented the relationship between occupational asbestos exposure
and increased respirator and digestive cancers.
Selikoff's work began in 1924 and it took him several years before he was
able to show convincing evidence that asbestos exposure was causing higher rates
of cancer In fact he says "For thirty year laboratories tried to produce
cancer in animals with asbestos and were not able to. We learned in 1963-64 and
now every pathologist can produce them with ease. But for thirty years we couldn’t."
(1)
The inability to detect the cancerous effects of asbestos in animals for
thirty years is disturbing. Most tests and subsequent standards on whether or
not a substance is harmful to humans and what dose is first based on animal
studies Clearly. animal studies may not be as reliable as we would like to
believe. Also, when animals are tested for potentially harmful substances, only
one substance at a time is used. Yet when we drink water, we can be consuming
many chemicals at the same time. With over 2100 organic and inorganic
contaminants identified in our drinking water since 1974, does anyone know the
synergistic effect these substances are having?
Selikoff discovered that most workers with less than twenty years of exposure
had normal X-rays despite the fact that they worked with asbestos fibers nearly
every day. However, after twenty years, the X-rays commonly revealed extensive
cancer development. Selikoff calls this the twenty to thirty years rule for
environmental disease. It takes that long before we really start to see the
harmful effects of many chemicals, but once observed the damage can be too far
advanced.
With this background let’s look at the research on asbestos fibres in
drinking water. Probably the most publicised case took place in Duluth,
Minnesota with the Reserve Mining Company and its dumping of taconite waste and
asbestos fibers into Lake Superior. (2)
Although the cancer rates in the cities of Duluth to Minneapolis are similar,
Duluth residents have higher cancer mortality rates of the stomach, small
intestines, pancreas, gastro-intestinal area and lungs. Remember, it took twenty
to thirty years to have cancer from asbestos inhalation, yet we are starting to
see cancer from asbestos in drinking water with only ten to fifteen years of
exposure.
Studies in Iowa City, Iowa and in San Francisco, California also show the
same significant pattern. Again, the locations of cancer are similar to asbestos
inhalation. (3)(4)
Let’s hope we don’t wait thirty years to realise asbestos fibers don ‘t
belong In our drinking water. Proper filtration systems can remove asbestos
fibers that may be present in our drinking water,
-
Selikoff IJ. Asbestos in Water. In: Manners DX ed. Int’l Water Quality
Symposium: Water, its Effects on Life Quality. Wash. D.C: Water Quality
Research Council, 1974.
-
Sigurdson EE. Levy BS, McHugh R, Michienzi U, Jagger H, Pearson J. Cancer
Morbidity Investigations: Lessons from the Duluth Study of possible Effects of
Asbestos in Drinking Water Environmental Research 1981; 25: 50-61.
-
Donsbach KW, Walker M. Drinking Water. Huntingdon Beach, CA: Int’l
Institute of Natural Health Sciences, 1981.
-
Conforti PM, Kanarek MS, Jackson La, Cooper RC, Murchio JC. Asbestos in
Drinking Water and Cancer in the San Francisco Bay Area. 1969-1974 Incidence.
J. Chronic Diseases, 1981; 34: 211-224.
Source: - Healthy Water, Martin Fox, PH.d.
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Vitamin
A & Prostate cancer
A
study at the Northwestern University Medical School, Chicago has found that
vitamin A (beta-carotene) and vitamin C can help in the prevention of
prostate cancer.
In a 30 year follow up survey, researchers
discovered that 132 out of 1,899 middle-aged men developed prostate cancer.
Whilst there was no significant association between vitamin A and C
consumption and the risk of developing prostate cancer, the researchers did
find that dietary intake of vitamins A and C was positively correlated to
overall survival.
Daviglus M L et Al. Dietary
beta-carotene, vitamin C and the risk of prostate cancer: results from the
Western Electric Study. Epidemiology. !996 7(5) 472-7
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Sesame
oil
Ayurvedic
medicine recommends regular topical application to the skin of sesame oil,
above all other oils, as a health-promoting procedure. Scientists at the
Department of Physiological and Biological Sciences, Maharishi International
University, Fairfield, Iowa USA examined the effect of sesame oil and several
other vegetable oils and their major component fatty acids on the
proliferation rate of human normal and malignant melanocytes growing at
similar rates in serum-free media. The scientists found that sesame and
safflower oils, both of which contain large amounts of linoleate in
triglyceride form, selectively inhibited malignant melanoma growth over normal
melanocytes whereas coconut, olive and mineral oils, did not.
These oils were tested at a range of
10-300 micrograms/ml. These results suggest that certain vegetable oils rich
in linoleic acid, such as the sesame oil, recommended for topical use by
Ayurveda, may contain selective antineoplastic properties which are similar to
those demonstrated for essential polyunsaturated fatty acids and their
metabolites. This suggests that whole vegetable oils may have potential
therapeutic clinical usefulness.
Smith DE; Salerno JW. Selective
growth inhibition of a human malignant melanoma cell line by sesame oil in
vitro. Prostaglandins Leukot Essent Fatty Acids (SCOTLAND) Jun 1992, 46 (2)
p145-50
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Green
Tea & Cancer
Cancer
chemoprevention is a new and important medical science in its own right. On the
occasion of my presentation entitled "Natural agents and cancer
chemoprevention" at the 90th AACR Meeting in 1999, I summarized our recent
results on cancer prevention with green tea. In this article, the present status
of clinical trials supported by the Chemoprevention Branch of the National
Cancer Institute in the United States is first described by way of introduction.
Although various natural products are now under investigation in phase I
clinical trials, green tea has, perhaps, the greatest potential for further
development. In order to expand our understanding of the effects of tea
polyphenols and green tea, I review their ability to inhibit growth and cause
apoptosis of cancer cells, their distribution into target organs and their other
cancer-preventing properties. In addition, the paper focuses on the significance
of reducing tumor necrosis factor alpha (TNFalpha) gene expression in cells and
TNFalpha release from cells as essential activities for cancer prevention. As
for the amounts of green tea effective in cancer prevention, I present two
results from our Research Institute: a prospective cohort study with over 8000
individuals in Saitama Prefecture revealed that the daily consumption of at
least ten Japanese-size cups of green tea resulted in delayed cancer onset, and
a follow-up study of breast cancer patients conducted at our Hospital found that
stages I and II breast cancer patients consuming over five cups per day
experienced a lower recurrence rate and longer disease-free period than those
consuming fewer than four cups per day. Thus, I propose here, for the first
time, the two-stage approach to analyzing cancer prevention with green tea:
cancer prevention before cancer onset and cancer prevention following cancer
treatment. As an additional example of cancer prevention with natural agents,
kava, a daily beverage in Fiji, is mentioned. All the evidence reminds us of the
significance of alternative medicine in practical cancer prevention.
J Cancer Res CLin Oncol 1999 Oct
4; 125 (11): 589-597
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PUVA
& Cancer
There is concern
about the long-term carcinogenic effects of psoralen and ultraviolet A radiation
(PUVA) for treatment of skin disorders. Many authors have found an increased
risk for cutaneous squamous cell carcinoma (SCC). Except in anecdotal reports,
malignant melanoma had not been observed in patients treated with PUVA until
recently. In the U.S.A., a 16-centre prospective study of 1380 patients showed
for the first time that there might also be an increased risk for malignant
melanoma in patients treated with high cumulative dosages of PUVA. We have
therefore followed up the Swedish PUVA cohort until 1994. This cohort had
previously been followed up until 1985. Information from 4799 Swedish patients
(2343 men, 2456 women) who had received PUVA between 1974 and 1985 was linked to
the compulsory Swedish Cancer Registry in order to identify individuals with
cancer. The average follow-up period was 15.9 years for men and 16.2 for women.
We did not find any increased risk for malignant melanoma in our total cohort of
4799 patients treated with PUVA or in a subcohort comprising 1867 patients
followed for 15-21 years. For cutaneous SCC there was an increase in the risk:
the relative risk was 5.6 (95% confidence interval, CI 4.4-7.1) for men and 3.6
(95% CI 2.1-5.8) for women. Significant (P < 0.05) increases were also found
in the incidence of respiratory cancer in men and women and of kidney cancer in
women. In conclusion, we did not find any increased risk for malignant melanoma
in our patients treated with high doses of PUVA and followed up for a long time.
We confirm previous reports of an increase in the incidence of cutaneous SCC in
patients treated with PUVA, and recommend that patients should be carefully
selected for PUVA and rigorously followed up.
Br J Dermatol 1999
Jul;141(1):108-112, Lindelof B, Sigurgeirsson B, Tegner E, Larko O, Johannesson
A, Berne B, Ljunggren B, Andersson T, Molin L, Nylander-Lundqvist E, Emtestam L,
Division of Dermatology, Karolinska Institute, Danderyd Hospital, S-182 88,
Stockholm, Sweden.
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Prostate
Cancer & Energy and Fat Intake
BACKGROUND: The
roles of energy and fat intake as risk factors for prostate carcinoma are still
questionable. Therefore, these factors were evaluated in the Netherlands Cohort
Study described in this article.
METHODS: The cohort study consisted of 58,279 men ages 55-69 years at baseline
in 1986. After 6.3 years of follow-up, 642 incident prostate carcinoma cases
were available for analysis. Intake of energy, fat, and separate fatty acids
were measured by means of a self-administered questionnaire; fat intake was
adjusted for energy by regression analysis. The case-cohort method was used to
calculate rate ratios (RRs). Analyses were conducted for all prostate carcinoma
cases together as well as for case subgroups (latent vs. nonlatent and localized
vs. advanced).
RESULTS: No associations were found in multivariate analyses between prostate
carcinoma and intake of energy, total fat, total saturated fatty acids, or total
trans unsaturated fatty acids (RR highest vs. lowest quintile: 0.99, 1.10, 1.19,
and 0.99, respectively). Oleic acid intake showed a nonsignificant positive
association (RR = 1.38, 95% CI: 0.88-2.19). Positive associations were also
observed for intake of oleic acid in subgroup analyses. Linoleic (RR = 0.78, 95%
CI: 0. 56-1.09) and linolenic (RR = 0.76, 95% CI: 0.66-1.04) acid intake were
associated with nonsignificantly decreased risks; only for linolenic acid did
these associations persist in subgroup analyses. No associations were found for
intake of arachidonic acid, eicosapentaenoic acid, or docosahexaenoic acid.
CONCLUSIONS: These data suggest that certain fatty acids might be involved in
prostate carcinoma occurrence, although the possibility that these were chance
findings cannot be ruled out. Copyright 1999 American Cancer Society.
Cancer 1999 Sep 15;86(6):1019-27, Schuurman AG, van den
Brandt PA, Dorant E, Brants HA, Goldbohm RA, Department of Epidemiology,
Maastricht University, Maastricht, The Netherlands.
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Animal
products, calcium and protein and prostate cancer
Prostate
cancer risk in relation to consumption of animal products, and intake of calcium
and protein was investigated in the Netherlands Cohort Study. At baseline in
1986, 58,279 men aged 55-69 years completed a self-administered 150-item food
frequency questionnaire and a questionnaire on other risk factors for cancer.
After 6.3 years of follow-up, 642 prostate cancer cases were available for
analysis. In multivariate case-cohort analyses adjusted for age, family history
of prostate cancer and socioeconomic status, no associations were found for
consumption of fresh meat, fish, cheese and eggs. Positive trends in risk were
found for consumption of cured meat and milk products (P-values 0.04 and 0.02
respectively). For calcium and protein intake, no associations were observed.
The hypothesis that dietary factors might be more strongly related to advanced
prostate tumours could not be confirmed in our study. We conclude that, in this
study, animal products are not strongly related to prostate cancer risk.
Br J Cancer 1999 Jun;80(7):1107-13, Schuurman AG, van
den Brandt PA, Dorant E, Goldbohm RA, Department of Epidemiology, Maastricht
University, The Netherlands.
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Refined
Bread
A large Italian
case-controlled study reports that the individuals eating the highest amounts of
refined bread ran a 28% increased risk of cancer of the colon and rectum
compared to the lowest consumers. One serving of refined sugar (4 teaspoons)
brought an 11% increase in the cancer whilst eating either cooked or raw vegetables
had a protective effect. Just one extra serving of vegetables a day reduced the
risk by 13%
Francheschi,S
et al. European journal of Cancer Prevention 1999;7 (2), S19-S23
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