Studies have shown that flaxseeds inhibit the growth of human estrogen-dependent cancers. In the same way, they help to reduce man boobs by inhibiting the effects of excess estrogen.
In a 2005 study published in the journal Clinical Cancer Research, breast cancer patients who received a muffin a day containing 25 grams of flaxseed for 32 days, were found to have a significant reduction in tumor markers and significant increase in programmed cell death of the cancer cells. The researchers concluded that “Dietary flaxseed has the potential to reduce tumor growth in patients with breast cancer.”
“How does it work?”
Flaxseeds have a particularly powerful effect when it comes to lowering estrogen because they do so via multiple different mechanisms.
1. High in Omega-3 Fatty Acids
Omega-3 is the good form of polyunsaturated fat, and we folks in the west these days are severely depleted of this ultra-healthy fat. We have a high omega-6 intake and low omega-3, giving us a high omega-6:3 ratio, resulting in a cascade of different illnesses, including inflammation (which itself leads to countless diseases like asthma, eczema, psoriasis, cancer, heart disease, etc), high blood pressure, depressed immune function, blood clots, sub-optimal brain function and development, and obesity.
Increasing your intake of omega-3s will help you to lose weight, help reverse inflammatory diseases, reduce your blood pressure, improve your immune system… the list goes on.
As though improving insulin sensitivity and helping us to lose weight wasn't enough, omega-3s in flaxseeds also help to lower estrogen. They do this by helping to modulate estrogen metabolism. Estrogen in the liver can either be metabolized via the C-2, C-4 or C-16 pathway. When metabolized via the C-2 pathway, it forms 2-hydroxylated estrone. 2-hydroxylated estrone is a “good” form of estrogen that has very low estrogenic activity. Studies show that when 2-hydroxylation increases, the body resists cancer, and when it decreases, the risk of cancer increases.
C-4 and C-16 hydroxylated estrone on the other hand, have more estrogenic activity than even the original mother compounds, estradiol and estrone. Where some foods are known to increase the C-16 pathway, omega-3s are a potent stimulator of the much preferred C-2 pathway.
2. Contain Lignans
Another property of flaxseeds that helps them to reduce your body's estrogen levels, is they contain ‘lignans'. Flaxseeds contain higher concentrations of lignan precursors than any other plant.
Like isoflavones in soy, lignans are another major form of phytoestrogen. They bind to your body's estrogen receptors and have a very weak estrogenic effect. While they're bound to the receptor, other, more powerful human and animal estrogens, and xenoestrogens will be unable to bind to it. So lignans act as competitive inhibitors to stronger estrogens.
3. Good Source of Fermentable, ‘Prebiotic' Fiber
Yet another property that helps flaxseeds reduce the estrogenic effect on your body, is they are a good source of fermentable, ‘prebiotic' form of soluble fiber. Soluble fiber increases butyrate production in your colon, which helps increase estrogen excretion and reduce estrogen re-uptake.
4. Down-Regulate IGF-1
Aside from estrogen, studies have found that flaxseeds also down-regulate IGF-1. As I mentioned in this article on dairy, IGF-1 may be just as important in the development of man boobs as estrogen.
So what are you waiting for? Start getting some flaxseeds in your diet right away! I like to freshly grind mine in a coffee grinder, and add it to my freshly made fruit and vegetable juices. You can also sprinkle ground flaxseeds onto your food, but do this after you've cooked your food. Cooking flaxseeds above 120°F will destroy most of the omega-3s.
Whatever you do, you must grind flaxseeds first to benefit from the omega-3 goodness inside. Your body can't break down the rigid outer husk of flax seeds. After grinding, keep it refrigerated in an airtight container, else it'll go rancid.
I don't recommend flaxseed oil because of it's instability and tendency to go rancid very easily. That stuff can really make you feel sick, so best avoid the oil form.