Ask Gerda: Can My Diet and Supplements Affect Blood Clotting?

Ask Gerda: Can My Diet and Supplements Affect Blood Clotting?

Ask Gerda: Can My Diet and
Supplements Affect Blood Clotting?

gerda endemann

Gerda Endemann, our senior director of science and research, has a BS in nutrition from UC Berkeley, a PhD in nutritional biochemistry from MIT, and a passion for cherry-picking from our wellness shop. She spends a lot of her time interpreting research—established and emerging. And our wellness routines thank her for this. (Yours will, too. Send us your own questions for Gerda: [email protected].)

Dear goop, I never really thought about how blood clotting works, but I’m wondering if it’s really a good idea to take vitamin K—it’s in my multi—given that it promotes blood clotting. And should I be taking fish oil, which I’ve heard is a blood thinner? —Beth H.

Hi, Beth. Don’t worry—it’s not that easy to circumvent the body’s natural homeostatic mechanisms. The body is very good at resisting our nutritional attempts to manipulate processes such as blood clotting. Eat a variety of whole foods and your body will find the nutrients it needs to achieve a healthy balance. This is true for healthy blood clotting.

The problem is that we don’t always offer optimal support. And we may not be taking good enough care of our blood vessels, which are crucial in determining whether we have overzealous blood clotting. Here’s some information about how blood clots form and how commonly consumed foods and supplements can affect this process. This information is provided to help you support good health and is not intended to treat any illness. Always consult your doctor about any medical condition.

To form a blood clot, a protein in the blood called fibrinogen is turned into long fibers of fibrin that form the scaffold of the clot. When the tiny white blood cells called platelets are activated, they aggregate together with the fibrin to fill in the plug. Clots form in blood vessels and can stay put or travel to another part of the body. When they block a blood vessel, it’s called thrombosis, and blood can’t get through to nourish tissues with oxygen and fuel. Tissues may be injured or die.

Leech saliva is one source of an enzyme that breaks down fibrin. In their search for additional enzymes that could break down fibrin, scientists from several universities in Japan tested more than 173 foods. They found a powerful enzyme in natto, a fermented cheeselike food made from soybeans that’s popular in Japan.

Appropriately enough, natto has been used as a folk medicine for cardiovascular health. And research has shown a correlation between eating lots of natto and cardiovascular health. The enzyme in natto that breaks down fibrin is called nattokinase, and it is made by Bacillus subtilis bacteria during the fermentation process.

Most enzymes in food are destroyed by stomach acid and digestive enzymes. However, eating natto or nattokinase has been shown to support healthy fibrinogen levels in people’s blood, demonstrating that nattokinase may survive digestion. Nattokinase is sold as a supplement—if you want to try it, find a reputable manufacturer with a facility that’s GMP certified (good manufacturing practices). Nattokinase is being studied clinically at USC to see if it can support cardiovascular and brain health.

A food more commonly associated with reduced blood clotting is fish. Fish oil has been popular ever since two Danish doctors discovered that Greenland Inuit people were much less likely to die from heart disease than Danes or Americans. The doctors attributed the Inuits’ superior cardiovascular health to the whale blubber and seal fat—rich sources of omega-3 fats—that they ate.

The Inuits’ blood was found to be slower to clot than typical human blood, and this was attributed to the high levels of omega-3 fats in their platelets. The amount of omega-3 fats in platelets affects how likely these cells are to become activated and form a clot, and doctors have feared that fish oil supplements could cause bleeding. All evidence points to that not being a problem. The bottom line is that platelets need omega-3s to function in a healthy way. In addition to seafood, good sources of omega-3s include walnuts, flax, and soy.

And all five of the goop vitamin regimens contain an omega-3 softgel or two, with over a gram of these valuable fatty acids. The protocols also contain the nutrient most associated with healthy blood clotting, vitamin K.

  1. goop Wellness Daily Vitamin and Supplement Regimen
    goop Wellness Daily Vitamin and Supplement Regimen goop, $90/$75 with subscription

Vitamin K helps make some of the factors needed for blood clotting. Blocking vitamin K—which is what the drug warfarin, a blood thinner, does—reduces blood clotting. Warfarin is used long-term in low doses by people with a high risk of blood clots. It’s also used in high doses in some rat poisons, but please don’t resort to these. Anticoagulants are fatal for the owls and hawks who eat rats poisoned by these drugs.

But vitamin K shouldn’t be thought of as only promoting blood coagulation. It’s needed to make anticoagulant factors as well as procoagulant factors, so good vitamin K nutrition will support healthy, normal blood coagulation. Vitamin K does other good things, too, such as directing calcium out of arteries to where it’s wanted in bones.

The vegan form of this vitamin—K1 or phylloquinone—is found in green vegetables. Vitamin K2—menoquinone—is made by bacteria and found in fermented foods, including aged cheeses. I love telling people about the nutritional value of aged cheeses, which are good sources of calcium and protein in addition to vitamin K2.

Other foods and herbs that may affect blood clotting include garlic, ginger, and turmeric. They contain compounds that can inhibit platelet activation in test tubes. This sort of finding does not always translate to meaningful effects in people, but there is a little evidence that large amounts of garlic might slow down blood clotting. The effects of these plant foods are likely to be small—they are not so strong as to cause unwanted bleeding.

My go-to these days for turmeric is Original Golde superfood latte blend with organic turmeric, ginger, and cinnamon powders. I’ve always refused to eat or drink anything that doesn’t taste great, no matter how good it’s supposed to be for you. That sort of sacrifice doesn’t seem necessary or worthwhile. The Golde blend contains organic coconut milk powder, so you really need only water to mix up a latte, but I love Original Golde mixed into hot almond milk for a super creamy, rich, and flavorful version.


On the other hand, there is a potential for large amounts of certain herbs to cause bleeding, especially when used together with blood thinners. Consult your medical practitioner about safe and appropriate use of supplements. Preliminary evidence suggests that chamomile, green tea, ginkgo, and ginseng contain compounds that can slow down blood coagulation. Dong quai is an herb from traditional Chinese medicine that’s used for gynecological health, and there is some evidence that it could have anticoagulant effects that increase bleeding. Evening primrose oil may also have the potential to slow down blood clotting.

This article is for informational purposes only. It is not, nor is it intended to be, a substitute for professional medical advice, diagnosis, or treatment and should never be relied upon for specific medical advice. To the extent that this article features the advice of physicians or medical practitioners, the views expressed are the views of the cited expert and do not necessarily represent the views of goop.

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