Women who properly replace their estrogen and progesterone usually feel better, sleep better, look better, think better, have stronger bones, firmer muscles, improved endothelial function, and longer life spans.1,2
The downside to all these benefits is concern of increased cancer risk in certain women (colon cancer risk is an exception, which goes down).3,4
Compelling evidence indicates that natural progesterone slashes estrogen-induced cellular proliferation, particularly in the breast and endo-metrium, without the adverse risks associated with synthetic progestins.5,6
Consuming cruciferous vegetables, avoiding well-done meat, ensuring higher vitamin D blood levels, and following other healthy lifestyle choices also reduce breast cancer risk.7-10
Unlike biased propaganda based on economic motives, Life Extension® wants maturing women to understand the facts and decide for themselves if they want to consider using a natural progesterone cream along with a precise individualized dose of natural estrogen to restore their sex hormones to youthful ranges.
Concern about cancer is a reason why more aging women do not restore their hormones to youthful levels.3 Hormones like estrogen and testosterone affect cell growth and proliferation.5,11 Does that mean aging women should simply accept the sex hormone deficiencies they face as a part of “normal” aging?
Based on the data suggesting beneficial effects upon cell growth and maturation, as well as favorable ways to affect estrogen metabolism that point to cancer prevention, restoring hormones to more youthful levels appears to be an important strategy that should not be ignored.1,2,7,9
As we describe in this article, large human population studies show major reductions in cancer risk and often specific protective mechanisms against hormone-responsive cancers like breast cancer when vitamin D,12-14 cruciferous vegetables7,15-17 (a source of indole-3-carbinol, or I3C), soy,18-20 D-glucarate,21,22 and lignans23,24 are consumed. Dramatic cancer rate reductions also occur when meat, particularly red and processed meat, sweets, and other deleterious foods are reduced or eliminated from the diet.25,26
Although prudence dictates caution in not assuming causation with correlation-based study data, misconceptions, misinterpretations, and associated media hype have created an environment in which aging people suffer the agonies caused by sex hormone imbalances, yet do nothing to correct this because of fear of cancer. When one looks at what the real cancer risk factors are, it would appear that altering one’s lifestyle at any age—including properly restoring natural hormone balance to reflect a more youthful range—would result in significant reductions in malignant disease.
The Underlying Cause of Cancer
As females age, their cell growth-regulatory genes accumulate mutations.27 Aging reduces the ability to rapidly repair this damage.28 When genes that regulate cell division undergo mutation, the result can be uncontrolled cell propagation that can result in tumor formation. Aging women experience a dramatic rise in cancer incidence, even as their estrogen levels plummet.29
In the presence of changes to genes involved in the growth and proliferation of breast tissue cells, estrogen can promote cancer cell propagation.30,31 The good news is that the ingestion of vitamin D, cruciferous vegetables, and other compounds can prevent and help repair gene mutations and thus reduce cancer risk.27,32-35 All women (including those who maintain youthful estrogen levels) should make sure they are ingesting optimal amounts of vitamin D and other compounds that favorably alter gene expression.
Vitamin D confers significant protective effects against breast cancer. Laboratory studies have shown that vitamin D suppresses growth of breast cancer by:
- Blocking signals that stimulate cancer cell growth;
- Enhancing signals that inhibit cancer cell growth, and
- Favorably altering gene regulators of the cell cycle.36-39
Studies have found a strong correlation between blood levels of vitamin D and the risk of breast cancer. A case-control study comparing 1,394 postmenopausal breast cancer patients with 1,365 controls showed that low blood levels of vitamin D were significantly related to breast cancer risk. In fact, women with the highest levels of vitamin D had a nearly 70% reduction in their risk of breast cancer, compared to women with the lowest vitamin D levels.9
Similar research examining the relationship between blood levels of vitamin D and breast cancer risk revealed that women with blood vitamin D levels of approximately 52 ng/mL had a 50% lower risk of breast cancer compared with women who had vitamin D levels below 13 ng/mL.12
In one report, the effects of administering 1,100 IU a day of vitamin D (with calcium) was evaluated in postmenopausal women.40 After only four years, the risk of developing any cancer was 60% lower in the vitamin D (and calcium) group, compared with those who received placebo. The scientists then performed a more detailed analysis of the data. When excluding cancers diagnosed in the first year of the study, which would have included pre-existing cancers present at the time participants began taking vitamin D (with calcium), they found an astounding 77% reduction in cancer incidence in the group receiving vitamin D, compared with placebo.40
Ensuring vitamin D blood levels over 50 ng/mL is a critical step in reducing cancer risk. Life Extension is finding that for many people, around 5,000 IU a day of supplemental vitamin D3 can provide reasonable assurance that these optimal blood levels will be achieved. This dose has been shown to be both effective and safe in human trials.41,42 The heavier a person is, the more supplemental vitamin D they often require. (Note that vitamin D status in the body is measured as serum 25-hydroxyvitamin D.)