CANCER

VITAMIN B12 DEFICIENCY: A NEW RISK FACTOR FOR BREAST CANCER?

A recent study suggests that postmenopausal women with low levels of vitamin B12 have an increased incidence of breast cancer. This mechanism may relate to an increase in DNA strand breaks or an alteration of DNA methylation by the methyl folate trap.

Choi S, Mayer J.
NUTRITION REVIEWS 1999, 57 (8) 250-3
Courtesy AUST. J. MED. HERBALISM

A PROSPECTIVE STUDY OF RECREATIONAL PHYSICAL ACTIVITY AND BREAST CANCER RISK

Increased physical activity has been hypothesised to prevent breast cancer, largely by reducing cumulative lifetime exposure to circulating ovarian hormones. However, epidemiologic findings are inconsistent, and there is no consensus on the best way to quantify physical activity. Therefore, a study was carried out to examine this issue in women in the Nurses’ Health study. In 1980 and on subsequent surveys, women were asked about the average number of hours per week spent in various moderate and vigorous recreational physical activity.

During 16 years of follow-up 3,137 cases of invasive breast cancer were identified. It was found that women who were more physically active in adulthood had a lower risk of breast cancer than those who were less physically active. Comparing those who reported engaging in moderate or vigorous physical activity for 7 or more hours per week with those who engaged in such activity for less than 1 hour per week, the relative risk was 0.82. These results, therefore, support the evidence suggesting that higher levels of adult physical activity afford modest protection against breast cancer.

Rockhill, B et al
ARCH. INT. MED. 1999, 159 (19) 2290-96

CONTRIBUTION OF FAMILY HISTORY AND HELICOBACTER PYLORI INFECTION TO THE RISK OF GASTRIC CARCINOMA

It is now well established that Helicobacter pylori infection is a risk factor for gastric carcinoma as is a positive family history of the disease. Researchers therefore, carried out a population-based, case-control study to assess the individual and joint contributions of family history and H. pylori infection to the risk of gastric carcinoma. It was found that H. pylori infection and family history were positively related, and both risk factors were more common among cases than among controls. Compared with uninfected subjects who had no family history, subjects with both a positive family history and infection with a CagA positive H. pylori strain had a more than 8-fold total risk of gastric carcinoma and a 16-fold risk of non-cardia gastric carcinoma.

Brenner, H et al
CANCER 2000,88 (2) 274-9

FRESH EVIDENCE FOUND OF CANCER RISK NEAR PYLONS

New research conducted by Professor Denis Henshaw, of Bristol University’s human radiation effects group, firmly links the power lines with childhood leukaemia and other forms of cancer. The levels recorded in some areas were two times higher than the legal maximum allowed for adult nuclear power workers. The most serious implication is that more than 23,000 homes built under or near power lines are unsafe, especially for children. The effect of the fields can extend over 100 yards either side of the lines.

Three years ago Prof. Henshaw showed that there was a theoretical mechanism whereby power lines could increase human uptake of the radioactive gases produced naturally in the soil and also of traffic pollution, and the latest study of over 2,000 field measurements confirms this effect.

The International Journal of Radiation Biology
SUNDAY TIMES, 28th November 1999

GASTRIC CANCER STUDY

Researchers in Mexico City have found that consumption of vegetables and fruits decreases the risk of gastric cancer. In a case control study of 220 patients with gastric cancer, it was found that yellow and orange vegetables significantly reduce the risk of gastric cancer, whereas high consumption of meat approximately trebled the risk of gastric cancer.

Ward, M.H. and Lopez-Carillo L.
AM. J. EPIDEMIOL. 1999, 149 (10) 925-32
Courtesy WORLD CANC. RES. FUND

CANCER PREVENTION WITH GINSENG

Studies have shown a significant reduction in cancer risk among people who regularly consume ginseng. A prospective cohort study was conducted over 5 years on 4,634 people over 40 years of age who were free of cancer at the outset. Questions included the frequency and duration of ginseng use and the species of ginseng taken, which were classified as fresh (less than 4 years’ growth), white (4-6 years growth) and red (6 years old or over). Whole ginseng was also compared to extracts. Frequency of intake was classed as no intake, 1-3 times a year, 4-11 times a year, and 12 or more times a year.

Over the study period, 137 subjects developed cancer, the most common being stomach, lung and liver. Of these, 54.7% had a history of ginseng intake compared to 71.2% of non-ginseng users. From the data available, fresh ginseng was significantly superior to white ginseng in its cancer-protective qualities. There were no deaths among the 24 red ginseng consumers.

Results showed that ginseng had the best protective effect against stomach and lung cancers no matter what the primary cause was. This effect was dose related according to frequency of ginseng intake. The authors conclude that ginseng (Panax ginseng CA Meyer) has a non-organ specific preventive effect against cancer, providing further support for previous case-control studies.

The subjects of this study are being followed up to assess the long term protective effect of ginseng.

Taik-Koo Yng and Soo-Yong Choi,
INT. J. EPIDEMIOLOGY 1998, 27, 359-364
Courtesy Lamberts Nutrition Bites

IN COLORECTAL CARCINOMA PATIENTS, SERUM VITAMIN D LEVELS VARY ACCORDING TO STAGE OF THE CARCINOMA

Raised serum levels of the biologically active form of vitamin D, 1,25-dihydroxyvitamin D3 (1,25(OH)2D3), have been associated with considerable reduction in the incidence of colorectal carcinoma. However, previous to this study, there had been no research into serum levels of vitamin D in patients with this neoplasm. Therefore, comparisons were made between serum levels of 1, 25-dihydroxyvitamin D3, 25-hydroxyvitamin D3, and parathyroid hormone (PTH), in patients with colorectal carcinoma and healthy individuals.

Results showed that serum levels of 25-hydroxyvitamin D3 were higher in patients with cancer than controls. Serum 1,25-dihydroxyvitamin D3 levels decreased with advancing stage of the colorectal cancer, and PTH levels were correspondingly elevated. No correlation was found between vitamin D metabolite levels and gender, age, tumour localisation, or histological grade. The research showed an inverse relationship between serum levels of 1,25(OH)2D3 and advancing stage of colorectal carcinoma.

As previous investigations indicate that this vitamin D metabolite inhibits proliferation of colonic epithelial cells, lowered serum levels may facilitate the growth of colorectal carcinoma.

Niv, Y. et al
CANCER 1999, 86 (3), 391-7

EAT WATERCRESS FOR A BALANCING ACT

The body’s own digestive enzymes can work for or against us in cancer prevention. The secret is in the combinations of food that we eat. Caroline White reports on research funded by the World Cancer Research Fund into the delicate enzyme balance that is critical to bowel cancer prevention.

The enzyme sulphotransferase comes in 2 forms. The M form neutralises amines found in cooked meat, certain food preservatives and colourants. The P form can also neutralise high levels of amines. However, a high level of sulphation can also cause a chain reaction that can lead to cancer. Compounds in vegetables and fruits (probably flavonoids) can block this process, which is important for people who produce high amounts of sulphotransferase.

Watercress was the best food for inhibiting the P form enzyme and neutralising the M form, followed by lettuce, grapefruit, and red, yellow and green peppers.

WORLD CANCER RESEARCH FUND NEWSLETTER, Issue 36, Autumn 1999.

FOOD GROUPS AND COLORECTAL CANCER RISK

According to researchers in Italy, eating diets high in both meat and refined grains may increase the risk of colorectal cancer, corroborating previous research. Using a case-control study design, with 223 colorectal cancer cases and 491 hospital controls, the researchers found significant positive associations between refined grains, red meat, pork and processed meat, alcohol and colorectal cancer risk. High consumption of whole grains, raw and cooked vegetables, citrus and other fruits were found to significantly reduce the risk of colorectal cancer. It was concluded that these findings support the hypothesis that a diet rich in refined grains and red meat increases the risk of colorectal cancer.

Levi, F. et al,
BR. J. CANCER 1999, 79 (7-8) 1283-7
Courtesy WORLD CANCER RES. FUND

DIET AND OVARIAN CANCER

Eating green leafy vegetables may help prevent ovarian cancer. Evidence on dietary risk factors for ovarian cancer – mainly from case-control studies – is inconsistent, but some studies have suggested positive associations with dietary factors. The Iowa Women’s Health Study, an ongoing prospective study of approximately 29,000 post-menopausal women, has shown that eating lots of green leafy vegetables may lower the risk of ovarian cancer. Consumption of eggs and cholesterol was associated with an increased risk of ovarian cancer: those eating eggs 4 times a week were found to have an 80% higher risk of developing ovarian cancer compared with those women rarely eating eggs.

Kushi L.H. et al,
AM. J. EPIDEMIOL. 1999, 149 (1) 21-31
Courtesy WORLD CANCER RES. FUND

REFINED BREAD AND COLORECTAL CANCER

Researchers in Italy conducted a multi-centre case-control study including 1,953 cases and 4,154 hospitalised controls. Subjects from 6 Italian regions were interviewed, using a food frequency questionnaire, over a period of 4 years. Results showed that individuals with the highest consumption of refined bread had a 28% higher risk of colorectal cancer than those with the lowest. For refined sugar, an increase of one serving (4 teaspoons) per day showed an 11% increase in colorectal cancer risk. Both results remained statistically significant after adjustment for confounders. Eating either raw or cooked vegetables showed a protective effect. An increase of one serving of vegetables per day resulted in a 13% reduction in risk.

Franceschi, S .et al,
EUR. J. OF CANCER PREVENTION 7 (Suppl 2) S19-S23
Courtesy WORLD CANCER RES. FUND

HIGH FLUID INTAKE REDUCES BLADDER CANCER RISK

A recent study on nearly 48,000 male participants – the Health Professional Follow-up Study – concluded that “a high fluid intake is associated with a decreased risk of bladder cancer in men”. Earlier research ha suggested that urination frequency is inversely associated with the level of potential carcinogens in the bladder; and it has been proposed that an increase in total fluid intake may reduce contact time between carcinogens and the bladder lining.

Michaud D.S. et al,
NEW ENG. J. MED. 1999, 340 (18) 1390-97
Courtesy WORLD CANCER RES. FUND

NITRATES AND NASOPHARYNGEAL CANCER

Researchers in Washington conducted a case-control study to investigate the relationship between nitrate consumption and risk of nasopharyngeal cancer, and found that subjects with the highest consumption of preserved meats had over four times the risk of nasopharyngeal cancer. Vitamin C consumption was found to significantly reduce the risk.

Farrow D.C. et al
INT. J. CANCER 1998, 78 (6) 675-9

A PROSPECTIVE STUDY OF FOLATE INTAKE AND THE RISK OF BREAST CANCER

Low folate intake has been associated with higher risk of colon cancer in epidemiologic studies, particularly in the presence of alcohol consumption. Alcohol is a known folate antagonist and thus could plausibly increase the requirement for folate intake. Therefore, a study was carried out to assess the association between folate intake and risk of breast cancer, and whether higher folate intake may reduce excess risk among women who consume alcohol.

A total of 3483 cases of breast cancer were documented. Total folate intake was not associated with overall risk of breast cancer. However, among women who consumed at least 15 G/D of alcohol, the risk of breast cancer was highest among those with low folate intake. This risk was strongest among women with total folate intake of less than 300?g/d. Current use of multivitamin supplements, the major source of folate, was associated with lower breast cancer risk among women who consumed at least 15 g/d of alcohol. Thus, the findings suggest that the excess risk of breast cancer associated with alcohol consumption may be reduced by adequate folate intake.

Zhang, S. et al
J.A.M.A. 1999, 281 (17) 1632-7

ORGANOCHLORINE EXPOSURE AND RISK OF BREAST CANCER

Breast cancer is the most common cancer among women in many western countries. Most of the risk factors for breast cancer suggest that oestrogen has a prominent role in the pathogenesis of the disease. Some organochloride componds, including agricultural pesticides such as DDT, chlordane, lindane, dieldrin, and industrial chemicals such as polychlorinated biphenyls may have weak oestrogenic effects and are, therefore, suspected of increasing the risk of breast cancer. A study was carried out to assess prospectively the risk of breast cancer in relation to serum concentrations of several organochlorine compounds. The study group was 7712 women participating in the Copenhagen City Heart Study. During 17 years of follow-up 268 women developed invasive breast cancer. Each woman with breast cancer was matched with two cancer-free women from the remaining cohort.

Serum samples from both sets of women were analysed and it was found that dieldrin was associated with a significantly increased dose-related risk of breast cancer (adjusted odds ratio 2.05). ?-hexachlorocyclohexane increased the risk slightly but not significantly. There was no overall association between risk of breast cancer and DDT or metabolites or for polychlorinated biphenyls. The findings support the hypothesis that exposure to xeno-oestrogens may increase the risk of breast cancer.

Hoyer,A.P. et al
LANCET 1998, 352 (9143) 1816-20

MANUAL LABOUR HELPS LOWER BREAST CANCER RISK

Researchers in the US have found that when women work hard physically it is the toil itself, not the lack of energy, that stops menstruation. The physical work causes progesterone levels to drop and ovulation to cease. Exercise is known to lower the risk of breast cancer, and this may be why the incidence of breast cancer is lower in the developing world.

NEW SCIENTIST, 17th Oct. 1998

LOWER RISK OF COLORECTAL AND PANCREATIC CANCERS IN DRINKERS OF GREEN TEA

In a Chinese study, 931 patients newly diagnosed with cancers of the colon, rectum or pancreas were questioned about their lifestyles, medical history and dietary habits, including tea consumption. When matched with healthy controls the results showed that men who drank at least one cup per week of green tea for 6 months or more had a reduced risk of these cancers compared to those who were not regular tea drinkers.

INT. J. CANCER 1997, 70, 255-258
Courtesy HERBALGRAM No. 44, p17-18

DIET AND THE PREVENTION OF CANCER

An article in the “Clinical review” section of the BMJ looks at this subject. Summary points are:
Diet is one of the most important lifestyle factors and has been estimated to account for up to 80% of cancers of the large bowel, breast, and prostate. Even lung cancer may have a dietary component, although cigarette smoking is still the overwhelming cause of this.

Generally, fruit, vegetables and fibre have a protective effect, whereas red and processed meat increase the risk of developing cancer.

Other lifestyle factors that increase risk include smoking, alcohol and overweight.

Risk is decreased by physical activity.

There is no evidence that vitamin supplements help to prevent cancer.

The following risks are given for different types of cancer:

Colorectum
Probable increased risk:
Red meat
Processed meat
Possible increased risk:
Alcohol
Fat
Probable decreased risk:
Vegetables
Fibre
Possible decreased risk:
Folate

Breast
Probable increased risk:
Alcohol
Red meat
Fried meat
Probable decreased risk:
Vegetables
Possible decreased risk:
Fruit
Phyto-oestrogens

Lung
Possible increased risk:
Alcohol
Meat
Possible decreased risk:
Fruit
Vegetables

Stomach
Probable increased risk:
Salt
Pickles & preserved foods
Probable decreased risk:
Fruit
Vegetables
Vitamin C
Possible decreased risk:
Carotenoids

Prostate
Possible increased risk:
(Red) meat
Fat
Probable decreased risk:
Vitamin E
Possible decreased risk:
Vegetables

Cervix
Probable decreased risk:
Fruit
Vegetables
Vitamin C
Possible decreased risk:
Folate
Vitamin A

Oesophagus
Probable increased risk:
Alcohol
Probable decreased risk:
Fruit
Vegetables

Pancreas
Possible increased risk:
Red meat
Possible decreased risk:
Fruit
Vegetables
Vitamin C
Fibre

Bladder
Probable decreased risk:
Fruit
Vegetables

Liver
Probable increased risk:
Alcohol

Cummings and Bingham
BMJ no.7173 pp1636-1640

FRUIT AND VEGETABLE CONSUMPTION IN LATER LIFE

Fruit and vegetable consumption may reduce the risk of several chronic diseases, including cancers, cardiovascular disease, coronary heart disease, hypertension and stroke. The World Health Organisation therefore recommends the consumption of at least 400g, or 5 portions of fruit and vegetables a day. Most adults’ consumption falls short of this recommendation, so a study was carried out to assess the levels of fruit and vegetable consumption in elderly people, and to examine the socio-economic, physical and psychological factors which influence this consumption. The subject group was 445 elderly people (aged 65+) living in the East Midlands.

The recommended target of 5 portions of fruit and vegetables a day was achieved by less than half the respondents: 37% of those living in the urban area and 51% of those living in the rural area. Low fruit and vegetable consumption was particularly associated with being male, smoking and having low levels of social engagement. Health programmes promoting fruit and vegetable consumption may not be successfully reaching elderly people and need to target those particularly at risk of low consumption.

Johnson, A.E. et al
AGE & AGEING 1998, 27 (6) 723-8

EXCESSIVE DIETARY INTAKE OF VITAMIN A IS ASSOCIATED WITH REDUCED BONE MINERAL DENSITY AND INCREASED RISK FOR HIP FRACTURE

Age-adjusted rates of hip fracture incidence vary more than sevenfold in Europe; the highest rates are found in northern Europe, particularly Sweden and Norway. When dietary patterns in Europe were compared, a large variation in vitamin A intake was found: median intake was up to six-fold higher in Scandinavian countries than in southern Europe. Therefore, a study was carried out to investigate whether excessive dietary intake of vitamin A is associated with decreased bone mineral density and increased risk for hip fracture in a group of Swedish women. Retinol intake was estimated from dietary records and a food frequency questionnaire.

In multivariate analysis, retinol intake was negatively associated with bone mineral density. For every 1mg increase in daily intake of retinol, risk for hip fracture increased by 68%. For intake greater than 1.5 mg/d compared with intake less than 0.5 mg/d, bone mineral density was reduced by 10% at the femoral neck, 14% at the lumbar spine, and 6% for the total body and risk for hip fracture was doubled. Thus, a high dietary intake of retinol seems to be associated with osteoporosis.

Melhus, H. et al
ANN. INT. MED. 1998, 129 (10) 770-8

ALLIUM VEGETABLES VS CANCER

In a review of 20 studies on Allium vegetables and their influence on cancer, with a single exception a protective effect was shown. This was particularly evident in cancer of the colon and gastro-intestinal tract as the Iowa Women’s Health Study from 1994, including 41,000 participants aged 55-69, confirmed. Another cohort study also found that eating onions has protective effects against cancer.

Ernst E. 1997
PHYTOMEDICINE 4 (I): 79-83

STUDY REPORTS THAT DIET IS CRITICAL TO CANCER PREVENTION

A predominantly plant based diet and maintenance of a healthy body weight could prevent four million cases of cancer worldwide, concludes a report by the World Cancer Research Fund. A separate British report, Nutritional Aspects of the Development of Cancer, published by the Committee on the Medical Aspects of Food and Nutrition Policy, includes similar recommendations.

Both reports emphasise the importance of increasing intake of fibre and of fruits and vegetables to five or more servings a day. They also both recommend a reduction in daily red and processed meat consumption, to less than 80-90g, equivalent to two rashers of bacon and a ham sandwich.

BMJ 315 p831

MODULATION OF ABNORMAL COLONIC EPITHELIAL CELL PROLIFERATION AND DIFFERENTIATION BY LOW-FAT DAIRY FOODS

Colon cancer claims 134,000 victims and causes about 55,000 deaths each year in the United States. Epidemiological evidence suggests that dietary levels of calcium and vitamin D intake are inversely related to the incidence of colon cancer. Supplementary dietary calcium inhibits colonic epithelial cell proliferation and cytotoxicity of faecal water and colonic tumour formation.

A study was carried out, therefore, to determine whether increasing calcium intake via dairy products alters colonic biomarkers toward normal. The trial subjects had a history of polypectomy for colonic adenomatous polyps. Low-fat dairy products containing up to 1200 mg/d of calcium were used and subjects were randomised to 4 strata by diet (control vs. higher calcium) and age (<60 vs. >60). It was found that during 6 and 12 months of treatment there was reduction of colonic epithelial cell proliferative activity, reduction in size of the proliferative compartment, and restoration of acidic mucin, cytokeratin AE1 distribution, and nuclear size, toward that of normal cells. In contrast, control subjects showed no differences from baseline values at 6 and 12 months.

Thus, increasing the daily intake of calcium by up to 1200 mg via low-fat dairy food in subjects at risk for colonic neoplasia reduces proliferative activity of colonic epithelial cells and restores markers of normal cellular differentiation.

Holt, P.R. et al
J.A.M.A. 1998, 280 (12) 1074-9

A QUESTION OF TIMING

The success of breast cancer surgery may partly depend on the phase of the menstrual cycle at which it is performed. A study reanalysed tissue samples from women who had tumours removed during the follicular phase of the menstrual cycle with samples from those operated on in the luteal phase. The former were found to have a poorer prognosis.

NEW SCIENTIST, 23rd May 1998, p27

MEDITERRANEAN DIETARY PATTERN IN A RANDOMISED TRIAL

A trial was conducted to see whether the Mediterranean dietary pattern can reduce the risk of cancer in addition to being cardioprotective. The study group was 605 patients with coronary heart disease randomised in the Lyon Diet Heart Study and following either a cardioprotective Mediterranean type diet or a control diet close to the step 1 American Heart Association prudent diet.

During the follow-up period of 4 years there were a total of 38 deaths (24 in controls vs 14 in the experimental group). This included 25 cardiac deaths (19 vs 6) and 7 cancer deaths (4 vs 3), and 24 cancers (17 vs 7). After adjustment for age, sex, smoking, leukocyte count, cholesterol level, and aspirin use, the reduction in risk in experimental subjects compared with controls was 56% for total deaths, 61% for cancers, and 56% for the combination of deaths and cancers. Those on the experimental diet had significantly higher intakes of fruits, vegetables, and cereals providing larger amounts of fibre and vitamin C. The intakes of cholesterol and saturated and polyunsaturated fats were lower and those of oleic acid and omega-3 fatty acids were higher in experimental subjects. Plasma levels of vitamins C and E were also higher in the experimental subjects.

Thus, it appears that patients following a cardioprotective Mediterranean diet have a prolonged survival and may also be protected against cancer.

Lorgeril, M. et al
ARCH.INT.MED. 1998, 158 (11) 1181-87

VITAMIN E INDUCES APOPTOSIS IN ERYTHROLEUKEMIA, PROSTATE, AND BREAST CANCER CELLS

Scientists at East Carolina University School of Medicine have shown the effect of vitamin E on a number of cancer cell lines, including 2 erythroleukemia, a hormone responsive breast and prostate cancer cell lines. Results showed a dose-dependent inhibition of cell growth, and apoptosis, in all cell lines studied, with breast and prostate cancer cells significantly more sensitive than erythroleukemia cells.

Sigounas G. et al,
NUTR. CANCER 1997, 28 (1) 30-5
Courtesy POSITIVE HEALTH, March 1998

PROTECTIVE ROLE OF SELENIUM

Studies in China have found that selenium supplementation has a protective effect against hepatitis B virus and primary liver cancer, and that a continuous intake is essential to sustain the chemopreventive effect.

Yu S.Y. et al,
BIOL. TRACE ELEM. RES. 1997, 117-24
Courtesy POSITIVE HEALTH, March 1998

CANCER KILLER - HORMONE IN SOYA BEANS STARVES TUMOUR CELLS

Biochemists in the University of S. California in Los Angeles have discovered that genistein, an oestrogen in soya, plays a pivotal role in suppressing growth of cancer cells. When a cancer cell is growing at full blast the cells soon run out of oxygen and glucose. To compensate they send out a chemical SOS which triggers angiogenesis. Genistein blocks the action of CCAAT-binding factor. This protein normally binds to an important genetic 'motif' in DNA and triggers the stress genes. Genistein adds phosphorus to the binding factor, neutralising it before the switch is tripped, thus starving the cancer cell.

J. NAT. CANCER INST. Vol. 90, p381
NEW SCIENTIST, 14th March 1998

VITAMIN E MAY REDUCE PROSTATE CANCER INCIDENCE

The results of a large primary-prevention trial in Finnish men have shown that vitamin E supplements could reduce prostate-cancer incidence and mortality by one-third in men who smoke. More than 29,000 male smokers aged 50-69 years were randomly assigned to receive 50 mg ?-tocopherol, 20 mg ?-carotene, both, or placebo daily for up to 8 years. At the end of the study, 246 new cases of prostate cancer and 62 deaths from the disease had occurred. However, the incidence was 32% lower, and mortality 41% lower in men taking a-tocopherol, with or without ?-carotene, than in those not taking the vitamin. ?-carotene non-significantly reduced the risk of prostate cancer in non-drinkers, but increased the risk in drinkers, the risk rising with increased alcohol consumption. ?-tocopherol is thought to block tumour progression from subclinical to clinical phase. The researchers warn, however, that studies with vitamin supplements are not a good basis for dietary advice. The bioavailability of supplements may be quite different from that of natural sources. And such studies cannot replicate potential interactions with other beneficial compounds in a natural diet, as occurs between vitamins C and E in fruit and vegetables.

Bonn,D.
LANCET 1998, 351 (9107) 961

ALLIES IN THE BREAST CANCER BATTLE - HERBS FOR PREVENTION, TREATMENT, AND HEALING

Breast cancer is the most common type of cancer among women. It develops slowly, moving through many stages and can exist for 5 to 10 years before being diagnosed. Most researchers believe that breast cancer is linked to exposure to oestrogens, which encourage the growth of breast tissue. For women who have a high risk of getting breast cancer, the recommended prevention regimen includes the use of compounds similar to, but not quite the same as, oestrogen. Instead of stimulating cell growth as natural or environmental oestrogens do, these compounds bind to the cells that are built to receive oestrogen and, in so doing, prevent oestrogen itself form binding to the receptor. Many herbs and foods contain these compounds, known as phytoestrogens, and they can protect a woman from her naturally occurring oestrogens as well as exposure to environmental oestrogens. Phytoestrogens include lignans found in flaxseed, cereal bran, vegetables, legumes, and fruits, and isoflavones found in soybeans, chickpeas, and legumes. One of the best sources of phytoestrogens are soy products such as tofu, roasted soybeans, tempeh, and soy milk.

Herbs such as red clover flowers (Trifolium pratense) and burdock root (Arctium lappa) also contain phytoestrogens and have a long history of use in the prevention of cancer. Some studies have shown that retinoids may also offer protection against breast cancer. Herbs that are high in these compounds include dandelion (Taraxacum officinale), stinging nettle (Urtica dioica), and violets (Viola spp). Carotenoids, found in carrots and other vegetables, can also be converted to vitamin A in the body. Indole-3-carbinol, a compound found mostly in cabbage, broccoli and other cruciferous vegetables, has been shown to reduce the risk of breast cancer because it interferes with oestrogen metabolism. Other herbs found to have a protective effect include rosemary (Rosmarinus officinalis), turmeric (Curcuma longa), and garlic (Allium sativum). Herbal remedies can also help with the unpleasant side effects of conventional treatment for breast cancer. Ginger (Zingiber officinale) can reduce nausea caused by anaesthesia and radiation and chemotherapies. However, it can cause complications when used with chemotherapy because it can inhibit blood clotting. Other remedies to combat nausea include catnip (Nepeta cataria), chamomile (Matricaria recutita), and red raspberry (Rubus idaeus).

Taking carotene before radiation therapy can prevent tissue damage. Because chemotherapy greatly reduces the effectiveness of the body’s immune system, herbs that help bolster the immune system are essential. Echinacea purpurea and E. pallida can enhance the function of white blood cells. Milk thistle (Silybum marianum) can help maintain a strong liver, which is very important when your body is receiving chemotherapy. Extracts of mistletoe (Viscum album) can be given to enhance the immune system of breast cancer patients and which may also have a negative effect on the cancer itself. Blood tonic herbs such as agrimony (Agrimonia eupatoria) and angelica (Angelica archangelica) can activate the spleen and tone the blood.

Jones, C.
HERBS FOR HEALTH 1998, Jan/Feb 28-33

IRON DEFICIENCY ANAEMIA

Three gastroenterologists wrote to the BMJ recommending gastrointestinal endoscopy in cases of iron deficiency anaemia, allowing small mucosal lesions to be seen, blood loss to be estimated directly, and biopsy samples to be taken (particularly from the second part of the duodenum for coeliac disease). They point out that only a small proportion of their patients have symptoms or signs pointing to the cause, and that diagnoses such as coeliac disease and carcinoma of the colon rarely have other symptoms.

Goddard et al
BMJ 314, p1759

VITAMINS ASSOCIATED WITH LOWER COLON-CANCER RISK

A recent study has shown that supplements of of multivitamins and vitamin E are associated with a lower risk of colon cancer. American researchers assessed the frequency, duration, and daily dose of individual vitamin supplements and multivitamins, for a ten year interval ending two years before diagnosis of cancer. After controlling for other predictors of colon-cancer risk such as intake of dietary vitamins, alcohol, and fibre, the risk of colon cancer was lower in men and women who took supplements of vitamins A, C, E, folic acid, calcium, and multivitamins. But the association was strongest for vitamin E and multivitamins: people who used multivitamins daily for the entire 10-year interval had half the risk of those who had not taken multivitamins. Those who averaged 200 IU or more of vitamin E per day for the 10 years had a 57% risk reduction compared to non-users.

Macready, N
THE LANCET 1997, 350 (9089) 1452

A PROSPECTIVE STUDY OF ASSOCIATION OF MONO-UNSATURATED FAT AND OTHER TYPES OF FAT WITH THE RISK OF BREAST CANCER

A population-based prospective cohort study of over 61,000 women (aged 40 to 76 years) who did not have a diagnosis of breast cancer, was carried out to determine the effect of different types of dietary fat and the risk of breast cancer. During an average follow-up of 4.2 years there were 674 cases of invasive breast cancer. After mutual adjustment of different types of fat, an inverse association with monounsaturated fat and a positive association with polyunsaturated fat were found. The relative risk (RR) for each 10g increment in daily intake of monounsaturated fat was 0.45, whereas the RR for a 5g increment of polyunsaturated fat was 1.69. Saturated fat was not associated with risk of breast cancer.

Wolk, A. et al.
ARCH. INTERN. MED. 1998, 158 (1) 41-5

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