Broccoli has been shown to protect against a number of cancers (I reported its benefits on bladder cancer in March), partly because its content of isothiocyanate, which induces the production of antioxidant enzymes. A new study on prostate cancer shows that sulforaphane (the broccoli isothiocyanate) also has other benefits. (Traka M, et al., Broccoli consumption interacts with GSTM1 to perturb oncogenic signalling pathways in the prostate. PLoS ONE. 2008 Jul 2;3(7):e2568.)
In this six-month study of volunteers on either a broccoli-rich diet or a control diet rich in peas, sulforaphane influenced peptides in growth-factor signaling pathways to reduce cell growth and inhibit inflammation. It provides some mechanisms for the lower incidence and less aggressive prostate cancers in men who consume at least one serving of broccoli and other cruciferous vegetables per week.
It appears that sulforaphane switches on genes that protect against cancer developing and switches off genes that promote the spread of cancer. These benefits are in addition to the antioxidant effects of many of the nutrients found in these vegetables. Eating them a few times a week can make a significant difference.
It is also noteworthy that isothio-cyanates can inhibit inflammation, and thus cruciferous vegetables might be of benefit not only in prevention of prostate cancer, but also in the management of chronic prostatitis. Other cruciferous vegetables include cabbage, kale, collards, cauliflower, mustard greens, arugula, bok choy, watercress, radish, broccoli rabe, and Brussels sprouts. This wide selection provides variety in meal planning for taste and health.
Several recent articles on vitamin C have confirmed its value both from food and supplemental sources, including intravenous administration of high doses for cancer treatment.
In one article, it appears that having a high level of vitamin C in the blood is associated with a lower incidence of new-onset, type 2 diabetes, as is a high intake of fruits and vegetables. Researchers evaluated 21,831 subjects aged 40 to 75 years with both plasma levels of vitamin C and questionnaires about food intake. They followed them for 12 years. In subjects with the highest plasma vitamin C, the risk of diabetes was lowered by 62 percent compared to those with the lowest plasma levels. (Harding AH, et al., Plasma vitamin C level, fruit and vegetable consumption, and the risk of new-onset type 2 diabetes mellitus: the European prospective investigation of cancer--Norfolk prospective study. Arch Intern Med. 2008 Jul 28;168(14):1493-9.)
Subjects with the highest consumption of fruits and vegetables had a 22 percent lower incidence of diabetes compared to those with the lowest intake. The researchers emphatically pointed out that a high level of vitamin C in the blood is closely correlated with fruit and vegetable consumption. Nowhere in the abstract of the article did they mention whether any subjects were taking supplements.
This is significant because any subjects taking supplements would almost certainly have relatively high plasma levels. The finding of a much better benefit from high plasma vitamin C compared to just a high fruit and vegetable intake suggests that the plasma levels must be coming from something other than just fruits and vegetables, such as supplements.
In spite of this risk discrepancy, it is curious that neither the abstract nor the news articles reporting this information mentioned vitamin C supplements, one of the most popular of all vitamins with consumers. It is important to eat a diet that is high in fruits and vegetables, not only for their vitamin C content, but also for all of the other vitamins, protective phytochemicals (as noted above with cruciferous vegetables), fiber, minerals, and flavor variety. Based on this information, I would also recommend supplements of vitamin C to make sure you are in the group with the highest plasma level (while it is important not to try to replace healthy foods with supplements alone).
Another article showed that high-dose vitamin C could be valuable as a treatment for cancer. Although vitamin C is a well-known antioxidant, at very high blood levels it can act as a pro-oxidant, but it is only effective in cancer cells where it helps to kill them.
In tissue cultures it has been shown that high concentrations of vitamin C can kill cancer cells while not harming normal cells. It does so by generating hydrogen peroxide, a potent oxidant, directly within the cancer tissues, without damaging the surrounding normal tissues. Using high levels, researchers were able to shrink ovarian, pancreatic, and brain tumors in mice. (Chen Q, et al., Pharmaco-logic doses of ascorbate act as a pro-oxidant and decrease growth of aggressive tumor xenografts in mice. Proc Natl Acad Sci U S A. 2008 Aug 4. [Epub ahead of print])
These high levels of vitamin C can be achieved in humans only by giving intravenous treatments. Absorption is limited when taking vitamin C by mouth. I and numerous colleagues are recommending doses of 35, 50, 75, or even 100 gms of vitamin C (that’s 35,000 to 100,000 mg) once or twice a week, and cancer patients are having remarkable success with these doses.
A new study confirms data from previous research showing that a healthy diet is helpful in preventing colorectal cancer. This is a huge study of 293,576 men and 198,270 women aged 50-71 years and followed for five years. (Wirfält E, et al., Associations between food patterns defined by cluster analysis and colorectal cancer incidence in the NIH-AARP diet and health study. Eur J Clin Nutr. 2008 Aug 6. [Epub ahead of print].
In men, following a diet pattern largely based on fruits, vegetables, whole grains, and other high-fiber, low-fat foods reduced colorectal cancer risk by 25-30 percent. In women, the reduction was 18 percent (even though the data for women did not reach statistical significance). The risk was higher in men and women who consumed less healthful foods, such as animal fats, sugar, and red meat.
A large study from Japan on 78,771 men and women aged 45-74 and followed for 6-10 years showed a link between regular exercise and a reduced risk of colon, liver, and pancreatic cancer in men, and stomach cancer in women. (Inoue M, et al., Daily total physical activity level and total cancer risk in men and women: results from a large-scale population-based cohort study in Japan. Am J Epidemiol. 2008 Aug 15;168(4):391-403. Epub 2008 Jul 2)
In this study the risk reduction for those with the highest level of physical activity was 15-20 percent compared to those subjects who were least active. The benefit was most clearly seen in women, especially among those who were older. I have previously reported on the 20-40 percent reduction of breast cancer among women with the highest level of physical activity (April, 2008). Other studies have shown that sedentary activity, such as watching television, is associated with an increased risk of cancer –up to 60 percent higher. (Howard RA, Physical activity, sedentary behavior, and the risk of colon and rectal cancer in the NIH-AARP Diet and Health Study. Cancer Causes Control. 2008 Apr 25. [Epub ahead of print])
In spite of a significant body of evidence on the cancer-exercise relationship, a new report shows that only 15 percent of people are aware that exercise might lower their cancer risk. Awareness was particularly low in those over 50 years old, those with less education, and those who find exercise recommendations confusing. (Coups EJ, et al., Awareness of the role of physical activity in colon cancer prevention. Patient Educ Couns. 2008 Aug;72(2):246-51. Epub 2008 May 1).
In addition, awareness was low in people who had less exposure to information about both cancer and exercise. While this is partly due to lack of education, it is also partly a result of doctors not informing patients of the potential benefits of exercise. Unfortunately, doctors often have inadequate time with patients to fully educate them about exercise (or diet and stress management).
Garlic has long been used medicinally (in addition to its culinary wonders) for controlling blood pressure. An Australian meta-analysis (study of studies) now shows that in randomized controlled trials, garlic supplements can lower blood pressure effectively in patients whose pressure is elevated, while having much less effect on those with normal pressures. (Ried K, et al., Effect of garlic on blood pressure: a systematic review and meta-analysis. BMC Cardiovasc Disord. 2008 Jun 16;8:13.).
These authors included 11 studies that were deemed well-designed and executed out of 25 studies that they evaluated. They found that on average systolic blood pressures declined by 4.7 points in the garlic takers compared with controls. When they looked only at those subjects with hypertension, they found that systolic blood pressure dropped by an average of 8.4 points. In this group, diastolic pressure (the lower number) declined by 7.3 points, on average. These are significant benefits that help people avoid blood pressure medications.
Garlic is one among many nutritional, herbal, and lifestyle treatments that can help control hypertension. Exercise, stress management, vegetarian diets, vitamins C and E, coenzyme Q10, magnesium, fish oil, taurine, hawthorn, and arginine are all beneficial in blood pressure control.
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