Meat, Dairy, and Mortality: TMAO

Recently two articles in the New York Times shocked many of its readers. In review, the Times reported on the findings of two different studies conducted at the Cleveland Clinic and found a new and startling connection between diet and heart disease. 

Specifically, and unsurprisingly, the link was established between the consumption of animal products and the increased risk in mortality from heart disease. While the results of the work by researchers such as Dr. Caldwell Esselstyn has shown for years that those following a plant-based diet have a significantly reduced risk of heart disease (America’s number one killer), until these studies, it was not known exactly why that was. 

Basically it goes like this: within 24 hours after the consumption of carnitine, a chemical found naturally in meats, certain gut bacteria metabolize it into a more toxic chemical known as trimethylamine. Trimethylamine gets oxidized in our livers and converted into Trimethylamine-Oxide (TMAO) which circulates throughout our blood stream. 

The problem with TMAO is that it increases the buildup of cholesterol and plaque in our arteries. This, of course, greatly increases the risk of having a heart attack, stroke, aneurism, and a few other un-pleasantries.

Now, our bodies naturally produce carnitine, however that doesn’t get turned into TMAO. It is only when we ingest outside sources that the carnitine ends up in our guts and gets oxidized. Carnitine is found in very limited amounts in plants, but animal products are human's major source of the chemical. So obviously we should stay away from the greatest sources of canitine which is red meat- so think about avoiding all forms of cow.

But avoiding red meat is not enough. The problem is that a second chemical known as choline can also be oxidized into TMAO when ingested due to the similarity in structure between carnitine and choline. According to the research, “eggs, milk, liver, red meat, poultry, shell fish, and fish are all major dietary sources for choline, and hence TMAO production.” 

Now for the really interesting part: the researchers discovered the oxidation process doesn’t occur until these chemicals reached the microbial-gut bacteria. They discovered this by introducing a potent antibacterial to the gut, wiping out all of the microbial-gut bacteria and then measuring the production of TMAO after consuming animal products. The result was that no TMAO was produced when animal products were consumed. However, those same people were fed a steak a second time a few weeks later (after the gut was able to restore some of its habitat) and the production of TMAO skyrocketed after the meal was consumed. 

However, when the researchers got a “vegan” (or perhaps more accurately someone who avoids all animal products but apparently has no moral objection to consuming them in the name of science) to eat an 8oz sirloin steak, there was no increase in TMAO production- even without the antibiotics. This was explained by the differences in microbial communities between vegans and omnivores. Basically, when you eat certain foods, certain bacteria will grow in your gut. When you change your diet and start eating completely different foods, the make up of your floral gut will also change. Since the vegan hadn't been regularly consuming animal products, they did not have the bacteria that oxidizes into TMAO. This suggest, among other things, that those eating a plant-based diet will have a healthier floral gut.

Even if you were to eat a completely plant-based diet, you’re not 100% safe. Most energy drinks contain large amounts of carnitine in them. The weight-loss supplement lecithin contains choline and the regular consumption of these products could result in the development of certain bacteria in the gut that will oxidize TMAO, and thus, consuming these products regularly can increase the risk of heart disease.

As is so often the case with linking diet to disease and mortality, the consumption of these foods impacts more than just our hearts. The regular consumption of eggs was also found to increase the risk of prostate cancer in men. In a study looking at the diet of men who were already diagnosed with cancer, those who consumed more eggs had a rate of progression of prostate cancer by more than 2 to 1. According to researchers from Harvard University, the “plausible mechanism that may explain our observed association between eggs and prostate cancer progression is high dietary choline.” 

So not only did consuming eggs increase their risk, and potentially helped cause them to get prostate cancer in the first place, continuing to eat the eggs actually helped to spread the cancer from its isolated area in the prostate to the rest of the body. Once this happens, survival rates plummet down to 1 in 3. According to one study, those who ate 1 egg every few days had “an 81% increased risk of lethal prostate cancer compared to men who consumed less than .5 eggs per week.”

While the New York Times articles attempted to put their readers at ease by stating that a new drug is being worked on to target and wipe out the bacteria that oxides these chemicals, it seems to be far more simple, and reasonable to limit- or better yet- completely eliminate the consumption of animal foods.  

Further reading:

Kolata, Gina, “Culprit in Heart Disease Goes Beyond Meat’s Fat.” NYT April 7, 2013.

Z. Wang, E. Klipfell, B. J. Bennett, R. Koeth, B. S. Levison, B. Dugar, A. E. Feldstein, E. B. Britt, X. Fu, Y.-M. Chung, Y. Wu, P. Schauer, J. D. Smith, H. Allayee, W. H. W. Tang, J. A. DiDonato, A. J. Lusis, S. L. Hazen. “Gut flora metabolism of phosphatidylcholine promotes cardiovascular disease”. Nature 2011 472(7341):57 – 63.

J. E. Lee, E. Giovannucci, C. S. Fuchs, W. C. Willett, S. H. Zeisel, E. Cho. “Choline and betaine intake and the risk of colorectal cancer in men. Cancer Epidemiol.” Biomarkers Prev. 2010 19(3):884 – 887.

Koeth RA, Wang Z, Levison BS, Buffa JA, Org E, Sheehy BT, et al.. “Intestinal microbiota metabolism of l-carnitine, a nutrient in red meat, promotes atherosclerosis.” Nat Med. 2013 Apr 7. 

E. L. Richman, S. A. Kenfield, M. J. Stampfer, E. L. Giovannucci, J. M. Chan. “Egg, red meat, and poultry intake and risk of lethal prostate cancer in the prostate-specific antigen-era: Incidence and survival.” Cancer Prev Res (Phila) 2011 4(12):2110 - 2121

Dr. Greger also has an excellent video summarizing much of this research and many other studies on this top.

Pseudograins: Staples for Fitness and Optimual Health

For those of you who are looking for a less-starchy staple food, I’d like to introduce you to Pseudograins. These foods have become mainstays in my pantry and I consume them on a daily bases.

So what are they? Well, for starters pseudograins are commonly mistaken for starches or grains, but in fact, they are actually seeds. Because of this, they are all naturally gluten-free and far less starchy than their counterparts, which for some people can greatly help improve digestibility. Also, unlike some other grains, all of these foods are alkaline-forming, which helps reduce inflammation, making them particularly great foods before and after hard workouts.

As a general rule, pseudograins are excellent sources of protein (20 to 25 percent by volume) among other nutrients. Because they are seeds and not grains, it is always a good idea to soak them in water for a few hours before cooking. A rice cooker is a perfect and easy way to cook all of these superfoods!

Amaranth: A broadleaf plant which could easily be mistaken for soybeans early in the growing season, only a few weeks later there is no mistaking this striking, tall crop which develops brilliantly colored grain heads producing thousands of tiny seeds per plant.

Although amaranth was cultivated on a large scale in ancient Mexico, Guatemala, and Peru, nowadays it is mostly grown in India, China, Nepal, and other tropical countries- a perfect example of the globalization of crops that began in the late 1400s. Due to its weed like nature, amaranth grows easily in most regions

Compared to other grains and even pseudograins, amaranth is particularly high in protein. It is also a good source of iron, magnesium and phosphorus, and a very good source of manganese.

Like all of the other foods on this list, Amaranth is a seed that is gluten free and greatly benefits from being soaked for a few hours prior to cooking. Several studies have shown that like oats, amaranth may be beneficial for those with hypertension and cardiovascular disease. Regular consumption has been shown to reduce blood pressure and cholesterol levels, while improving antioxidant status and some immune parameters.

To cook amaranth, boil it in 2.5-3 cups of water or veggie broth for every 1 dry cup of this seed. Cooking time takes between 25 and 30 minutes but can be cooked faster if soaked ahead of time.

 Buckwheat: Despite its name, Buckwheat is not actually wheat. Rather the name 'buckwheat' or 'beech wheat' comes from its triangular seeds, which resemble the much larger seeds of the beech nut from the beech tree and in fact is a seed in the rhubarb family. An incredibly old food, buckwheat was first cultivated in the high elevations of the Yunnan region in China. From there it spread to the Middle East and Europe. It was one of the first crops brought to North America by the European explorers during the Age of Discovery.

This grain contains a surprisingly large amount of the amino acid, tryptophan, which is a precursor to the neurotransmitter, serotonin, a known mood-enhancing chemical. For a single cup, it packs 22 grams of protein and all of your daily needs for magnesium, copper, and manganese.  Like all plant foods, it is also a good source of dietary fiber as well as vitamins E and B.

Because buckwheat is a slow release carbohydrate, when accompanied with a simple carbohydrate, buckwheat becomes one of the best endurance fuels available (it is also highly anti-inflammatory). Like all the pseudograins, it is best to soak buckwheat in warm water before cooking it. Buckwheat should be soaked for at least 1 hour to help improve digestibility.

Cook buckwheat with a 2:1 water to buckwheat ratio (cooking in veggie broth will increase its flavor.) Cooking time between 15-20 minutes.

 

 Quinoa: I know I’ve posted about quinoa a bunch in the past, (you can find a recipe for quinoa cookies and quinoa hemp pesto) but quinoa is a serious food that should be part of everyone’s diet. Nutritionally similar to Amaranth, Quinoa originated in the Andes and held a sacred place among the Incas who referred to it as the ‘mother of grains’ and had special planting and harvesting rituals to ensure a bountiful crop. Despite the Incan nickname, it is actually more closely related to beets and spinach than to modern-day wheat.

Quinoa is an endurance-athletes dream come true! High in iron, B vitamins, and calcium it’s also a great source of protein. Dishing up 6 grams of protein for each dry 1/4 cup, this is one seed that should not be dismissed. Not only is it super healthy, but it has a light, fluffy texture, mild earthy taste and is easy to prepare. To top it off, there are several different "varieties" of quinoa, coming in an array of colors- apparently red quinoa has the highest amount of antioxidants, but is often very expensive. Before cooking, soak quinoa in warm water for a few hours whenever possible. At least, rinse it well, as Quinoa contains an outer-inhibitor that otherwise prevents complete digestion. Soaking and rising removes this and increases nutritional absorption. A rice cooker works great; however, you can easily prepare Quinoa without one too.

To boil quinoa, simply put it in a pot with 2 parts water for every 1 part quinoa, stirring occasionally for 20 minutes or until all of the water is evaporated. Alternatively, you can also bake it at 350 for about 40 minutes.

 

Wild Rice: Wild Rice might be the most exotic of these four pseudograins. Not rice at all, wild rice is actually a grass that grows in shallow areas of water similar to true rice. This pseudograin has a long and storied history, particularly in North America where many tribes harvested the grains of the grass in canoes by gently brushing the stalks with wooden sticks called “knockers.”

Sometimes called “good berries” wild rice grains have a chewy outer shell with a tender inner grain that has a slightly vegetal taste. Typically sold as a dried whole grain, wild rice is high in protein, the amino acid lysine and dietary fiber, and low in fat. Like true rice, it does not contain gluten. It is also a good source of certain minerals and B vitamins.

Wild rice is roughly 80% carbohydrate and a whopping 15% protein. Normal brown rice is only 8% protein, so wild rice is an excellent food to sub for rice in a meal if you are concerned about your protein intake. Wild rice has half the fat content of brown rice. But seriously, if you are eating a whole food plant based diet, none of this is really of concern. 

To cook wild rice, first rinse it in cold water. Then you can steam, boil or microwave it. To steam it, put wild rice in a medium sauce pan, bring 1 cup wild rice, 3 cups water to a boil. Cover, reduce the heat to maintain a steady simmer, and cook until the rice is tender and the kernels pop open, 45 to 60 minutes. Uncover the rice and fluff it with a fork. You may need to add more water as needed. Steamed wild rice will be very tender when finished. To boil wild rice, bring 5-6 cups water for every dry cup of wild rice. Bring the water to a boil. If desired, add 1 tsp. salt and 1 cup wild rice. Bring everything back to a boil before reducing the heat to maintain a low boil. Cook until the rice is tender, about 45 minutes. Microwaving wild rice is perfectly safe and the fastest of the cooking methods, although the rice will be slightly chewier. Add 1 cup wild rice and 3 cups water or broth to a 2-quart glass or other microwaveable container and cover. Microwave on full power for 5 minutes. Fluff with a fork then microwave again for another 15 minutes. Check half way through. Let cool slightly then taste. If not done, start using 2 minute intervals.

Now that you have been introduced to these great foods, start looking for them in the stores. These ingredients, while might take a little bit of searching, but can typically be found in any grocery store- be sure to check the international aisles as well as bulk sections. Also start checking back here as I'll be posted some BYOL original recipes featuring each of these super star foods!   

cheers

all nutrition data gathered from nutritiondata.self.com