Strength athletes may build up more muscle tissue by eating Brassica vegetables like broccoli, sprouts or cabbage daily. We base this wild speculation on a study by molecular biologists at the Second University of Naples, published in Age. According to this research, members of the cabbage family stimulate the development of mesenchymal stem cells.
Muscle growth & stem cells
Muscle tissue grows in two ways as a result of strength training: 1. the existing cells in the muscle fibres grow and 2. the number of muscle cells in the muscle fibres grows. The latter is called hyperplasia: training induces stem cells in the muscle fibres to develop into fully grown muscle cells. Hormones like IGF-1, and also supplements like NO-donors, enhance this process.
Part of the stem cells in muscle tissue comes from other tissues, for example stem cells intended for making new blood vessels, but also mesenchymal stem cells. These are the stem cells found in bone marrow.
While doctors look for ways to patch up irreparably damaged organs by injecting stem cells, supplements manufacturers are concocting mixtures that are supposed to stimulate stem cells to rejuvenate tissues. One such supplement is StemEnhance. This contains an extract of the blue algae Aphanizomenon flos-aquae, which disengages stem cells from the bone marrow so they circulate through the body. Olimpiq StemXCell contains the same extract.
Some scientists are not convinced about using Aphanizomenon flos-aquae in this way. They fear that the extract stimulates metastases. The makers of Olimpiq StemXCell seem to be taking this worry seriously: they have added nutritional cancer inhibitors to their product.
But an alternative to stem cell supplements may be lying in the vegetables at your local supermarket. All fresh Brassica vegetables – white, green, red and Chinese cabbage, sprouts, cress, broccoli and cauliflower – contain glucosinolates like glucoraphanin. Myrosinase is an enzyme that is released when you cut the vegetables, cook them lightly or chew them, and this converts the glucosinolates into sulforaphane.
A diet containing a small amount of sulforaphane activates the production of the detoxifying enzyme glutathione [GSH] and therefore offers protection against some kinds of cancer, such as intestinal cancer. This is because sulforphane attaches itself to glutathione and thus stimulates cells to produce more glutathione. Too much sulforaphane, however, robs the body of its detoxifying capacity.
Sulforaphane & stem cells
The researchers discovered that low concentrations of sulforaphane [SFN], of 1 and 0.25 micromole – that’s about the amount you find in the body of someone who has eaten cabbage – stimulate the development of mesenchymal stem cells. The graph below shows how much tetrazolium salt the stem cells convert into formazan. Cells make more of this enzyme when they increase in number.
The table above shows the amount of bromodeoxyuridine [BrdU] the stem cells absorb. BrdU is a markered building block of genetic material. The more BrdU the stem cells take up, the more often they have divided.
The low concentrations of sulforaphane not only resulted in more new stem cells; they also help existing stem cells to live longer. They inhibit apoptosis, or cell death. The figure below shows why high-dose sulforaphane supplements are probably not such a good idea.
“Low intake of R-SFN, as can be obtained by eating Brassica vegetables, may be beneficial for health because it seems to have protective effects on stem cells”, the Italians conclude.
Unencumbered by an overdose of knowledge, we would go a step further and say that a diet containing Brassica vegetables may well provide bodybuilders’ muscle tissue with more stem cells. That would improve their recovery and growth. If you’re thinking of trying this out, don’t use preserved vegetables. These only contain a fraction of the amount of glucosinolates that you find in fresh cabbage.
Dose-dependent effects of R-sulforaphane isothiocyanate on the biology of human mesenchymal stem cells, at dietary amounts, it promotes cell proliferation and reduces senescence and apoptosis, while at anti-cancer drug doses, it has a cytotoxic effect.
Brassica vegetables are attracting a great deal of attention as healthy foods because of the fact that they contain substantial amounts of secondary metabolite glucosinolates that are converted into isothiocyanates, such as sulforaphane [(-)1-isothiocyanato-4R-(methylsulfinyl)-butane] (R-SFN), through the actions of chopping or chewing the vegetables. Several studies have analyzed the biological and molecular mechanisms of the anti-cancer activity of synthetic R,S-sulforaphane, which is thought to be a result of its antioxidant properties and its ability to inhibit histone deacetylase enzymes (HDAC). Few studies have addressed the possible antioxidant effects of R-SFN, which could protect cells from the free radical damage that strongly contribute to aging. Moreover, little is known about the effect of R-SFN on stem cells whose longevity is implicated in human aging. We evaluated the effects of R-SFN on the biology on human mesenchymal stem cells (MSCs), which, in addition to their ability to differentiate into mesenchymal tissues, support hematopoiesis, and contribute to the homeostatic maintenance of many organs and tissues. Our investigation found evidence that low doses of R-SFN promote MSCs proliferation and protect them from apoptosis and senescence, while higher doses have a cytotoxic effect, leading to the induction of cell cycle arrest, programmed cell death and senescence. The beneficial effects of R-SFN may be ascribed to its antioxidant properties, which were observed when MSC cultures were incubated with low doses of R-SFN. Its cytotoxic effects, which were observed after treating MSCs with high doses of R-SFN, could be attributed to its HDAC inhibitory activity. In summary, we found that R-SFN, like many other dietary supplements, exhibits a hormetic behavior; it is able to induce biologically opposite effects at different doses.
PMID: 21465338 [PubMed – indexed for MEDLINE] PMCID: PMC3312628