Surprise! Many organic foods are GMOs, and they are transgenic

A new study finds that many common foods, including beer and tea, turn out to be "natural" GMOs. What's a health-food purist to do?

Even though no one has found any evidence that genetically modified organisms (GMOs) are harmful, anti-GMO activists have campaigned against them for years, with considerable success. As of this writing, 19 out of 28 countries in the European Union have voted to ban or severely restrict genetically modified plants, and many other countries impose similar bans.

But all of these restrictions may be in vain, because nature got there first. It turns out that many common foods have already been genetically modified, by a bacterium called Agrobacterium. (Read on to see the list.) And, in news that should be even more frightening to the anti-GMO crowd, these foods are transgenic: they contain genetic material from completely different species. Frankenfoods!

First, as I've argued before, genetic modification technology is just a tool, and a very precise one at that. Scientifically, claiming that GMOs are bad for you is nonsensical–it depends entirely on what the genetic modification is. Whether a food scientist modifies a tomato to taste better by traditional breeding or by using GM technology, you still end up with a tomato that has different genetic content. The only difference is that with traditional breeding, you have no idea what exactly you changed in the plant's DNA. And humans have already consumed billions of servings of GM foods with no ill effects. The GM foods we eat today are perfectly safe.

So back to my first point. What are all these natural Frankenfoods, and how did they get that way?

I'll start with the common sweet potato, or yam. Humans eat hundreds of varieties of sweet potatoes, and you can buy them in markets on every continent. Back in 2015, a group of scientists from Belgium, Peru, China, and the US (Tina Kyndt and colleagues) discovered that every cultivated variety of sweet potato has "foreign" DNA integrated into its genome, from a bacterium called (appropriately) Agrobacterium. They tested 291 different varieties, and found the bacterium 100% of the time. They also tested wild relatives of sweet potato, and found that the wild varieties (which humans don't eat) are missing the bacterial DNA.

Agrobacterium is a bacterium with special properties: it has evolved to be able to insert its DNA directly into the genomes of a wide variety of plants. (Don't worry, it doesn't infect humans.) In sweet potatoes, this happened naturally, centuries or millenia ago, long before humans were cultivating it. But then we came along, and (apparently) we liked the taste of these naturally transgenic sweet potatoes, so those are the ones that we chose to cultivate. As a result, all the sweet potatoes we eat are GMOs, although it happened naturally.

That was five years ago. But in a newly published study, scientists Tatiana Matveeva from Russia and Léon Otten from France discovered that Agrobacterium has made its way into dozens of other plants, including some of our favorite foods and drinks. Matveeva and Otten searched through the genomes (the DNA) of hundreds of plants, and found 39 natural GMOs, as they called them.

So without further ado, here are the natural GMO foods, all of them transgenic, with the common name followed by the formal species name in italics:

  • bananas (Musa acuminata)
  • beer (hops) (Humulus lupulus)
  • cranberries (Vaccinium macrocarpon)
  • date-plum (Diospyros lotus)
  • guava (Psidium guajava)
  • peanuts (Arachis hypogaea)
  • pomelo fruit (Citrus maxima)
  • Suriname cherry (Eugenia uniflora)
  • sweet potatoes (Ipomoea species)
  • tea (Camellia sinensis, which is used for most teas)
  • walnuts (Juglans species)
  • yams (Dioscorea alata)

That's right, beer and tea are GMOs–even if they are labelled as "organic." Keep in mind that this list is undoubtedly incomplete: the new study relied on current genome databases, which are still missing many common foods. 

If you're reading this, you've probably already consumed countless servings of transgenic, GMO foods. As I wrote above, there's no reason to believe that GMO foods are harmful in any way. Plenty of plants are naturally poisonous, of course (think hemlock), but widely-consumed foods got that way for a reason: people like to eat them, and they help sustain us.

If you believe the alarmist claims of the anti-GMO movement, then you're going to have to start avoiding many more foods, including everything on the list above. And yes, that includes beer. 

A new kind of fasting provides significant immune system benefits

I've written about fasting and its effects on health before. Six years ago, a study showed that a 3-day fast can essentially reset the immune system, providing many potential benefits. These benefits include better cardiovascular health, better endurance, lower blood pressure, and reduced inflammation.

Newer data, which I'll get to in a minute, shows that you might not have to fast nearly that long to get these benefits.

In the 2014 study, Valter Longo and colleagues at USC found that fasting lowered white blood cell counts, which in turn triggered the immune system to start producing new white blood cells. White blood cells (or lymphocytes) are a key component of your body’s immune system. Once you start eating again, according to Longo, your stem cells kick back into high gear to replenish the cells that were recycled.

The idea behind this strategy is that you have to fast for several days to get the benefits: basically, you have to fully deplete your energy reserves (in the form of glycogen), and it takes your body at least 24 hours, and probably 48 hours or more, to do this. That's the not-so-good news. The good news is that you probably only need to fast once or twice a year to gain the benefits that Longo described.

Last week, in a paper just published in the New England Journal of Medicine, Rafael de Cabo and Mark Mattson reviewed multiple strategies for fasting that have been tested in the years since Longo's study. The news continues to be very encouraging: intermittent fasting is good for you. I don't have time or space here to discuss all the results, but I want to focus on one fasting strategy that has surprisingly good benefits.

It turns out that you can get many of the benefits of fasting without doing a 3-day fast, which for most people is really, really difficult to accomplish. Instead, you can try a much easier type of fasting, called "time-restricted" fasting. With this strategy, you fast every day, by eating all of your food in a 6-hour or 8-hour window. Or you can go with the more difficult strategy (but still easier than a 3-day fast) where you fast for 2 entire days per week. Here, then, are two intermittent fasting strategies that have similar health benefits:

  • Time-restricted: eat lunch starting at 12 noon, and finish dinner by 8:00pm. Fast until the next day at noon (16 hour fast). Do this every day.
  • 5:2 fasting: fast for 2 different days each week, which means eating just 500-700 calories worth of food and drink on those days. Eat normally on the other 5 days.

The first strategy–a daily 16-hour fast–is the easiest, but its benefits might be equal to those of 5:2 fasting and the 3-day fast. (No study has directly compared these 3 fasting regimens.)

The benefits of intermittent fasting are numerous. As de Cabo and Mattson explain, they include
"[improvements in] blood pressure; resting heart rate; levels of HDL and LDL cholesterol, triglycerides, glucose, and insulin resistance.... In addition, intermittent fasting reduces markers of systemic inflammation and oxidative stress that are associated with atherosclerosis."
Fasting also helps with weight loss, for obvious reasons. Cutting out all snacks in the evening, which is the biggest change imposed by time-restricted fasting, means not only a reduction in calories consumed, but also a reduction in the amount of highly processed ("junk") foods in one's diet as well.

Furthermore, because intermittent fasting reduces inflammation, it may also improve symptoms of arthritis and even rheumatoid arthritis.

Why does fasting work? It's all about getting your body to switch over from glucose metabolism to ketone metabolism. Our usual 3-meal-a-day diet provides our body with a constant source of fuel in the form of glucose. Once that glucose is used up, though, our body switches to using fatty acids and ketone bodies. Ketone bodies provide more than fuel: as de Cabo and Mattson explain,
"Ketone bodies regulate the expression and activity of many proteins and molecules that are known to influence health and aging."
Ketone metabolism seems to bring a host of health benefits. The trick is getting our bodies to switch over to it, now and then. If we eat constantly, then our bodies happily subsist on glucose and never make the switch.

Does fasting truly reset your immune system? Six years ago, I concluded that a 3-day fast does the trick, at least partially. The science suggests that, if you can do it, a prolonged fast for 2-3 days will induce your body to clean out some old immune cells and switch on production of new ones. Now we're learning that intermittent fasting, which is easier to do, may work in much the same way, with multiple health benefits.

[Note: one of the authors of the NEJM study, Mark Mattson, is a Professor at Johns Hopkins School of Medicine, making him a colleague of mine. However, we are in different departments and we have never met.]