It’s time for the NutritionFacts Grab Bag, where we look at the latest science on a whole variety of topics.
First up is a new story on the role of epigenetics in the obesity debate. Identical twins don’t just share DNA; they also shared a uterus. Might that also help account for some of their metabolic similarities? Fetal overnutrition, evidenced by an abnormally large birth weight, seems to be a strong predictor of obesity in childhood and later in life. Could it be you are what your mom ate?
A dramatic illustration from the animal world is the cross breeding of Shetland ponies with massive draft horses. Either way, the offspring are half pony/half horse, but in the pony uterus they come out much smaller (thank heavens for the poor pony). This is presumably the same reason why the mule (donkey dad and mare) is larger than the hinny (stallion and donkey mom). The way you test this in people is to study the size of babies from surrogate mothers after in vitro fertilization.
Who do you think most determines the birth weight of a test-tube baby—the donor mom who provided all the DNA, or the surrogate mom who provided the intrauterine environment? When it was put to the test, the womb won. Incredibly, a baby born to an obese surrogate mother with a skinny biological mom may harbor a greater risk of becoming obese than a baby from a big biological mom born to a slim surrogate. The researchers conclude “the environment provided by the human mother is more important than her genetic contribution to birth weight.”
The most compelling data comes from comparing obesity rates in siblings born to the exact same mother before and after her bariatric surgery. Compared to their brothers and sisters born before the surgery, those born when mom weighed about 100 pounds less had lower rates of inflammation, metabolic derangements, and, most critically, three times less risk of developing severe obesity (affecting 35 percent of those born before the weight loss compared to 11 percent born after). The researchers conclude “these data emphasize how critical it is to prevent obesity and treat it effectively to prevent further transmission to future generations.”
But wait. Mom had the same DNA before and after surgery. She passed the same genes down. How could her weight during pregnancy affect the weight destiny of her children any differently? Darwin himself admitted that the greatest error he committed “had been not allowing sufﬁcient weight to the direct action of the environment, like food…independently of natural selection.” We finally figured out the mechanism by which this can happen: epigenetics.
Epigenetics (literally meaning “above genetics”) layers an extra level of information on top of the DNA sequence that can be both affected by our surrounds and potentially passed on to our children. This is thought to explain the “developmental programming” that can occur in the womb depending on the weight of the mother, or even your grandmother. Since all the eggs in your infant daughters’ ovaries are already preformed before birth, a mother’s weight status during pregnancy could potentially affect the obesity risk of her grandchildren, too. Either way, you can imagine how this could result in an intergenerational vicious cycle where obesity begets obesity.
Is there anything we can do about it? Well, breastfed infants may be at lower risk for later obesity, though the benefits may be confined to exclusive breastfeeding, as the effect may be due to growth factors triggered by exposure to the excess protein in baby formula. The breastfeeding data is controversial though, with charges leveled of a “white hat bias.” That’s the concern that public health researchers might disproportionally shelve research results that doesn’t fit some goal for the greater good (in this case, preferably publishing breastfeeding studies showing more positive results)––but, of course that’s coming from someone who works for an infant formula company. Breast is best regardless; its role in the childhood obesity epidemic just remains arguably uncertain.
Prevention may be the key. Given the epigenetic influence of maternal weight during pregnancy, a symposium of experts on pediatric nutrition concluded that “planning of pregnancy, including prior optimization of maternal weight and metabolic condition, offers a safe means to initiate the prevention rather than treatment of pediatric obesity.” Easier said than done, but overweight moms-to-be may take comfort in the fact that after the weight loss in the surgery study, even the moms who gave birth to kids with three times lower risk were still, on average, obese themselves, suggesting weight loss before pregnancy is not an all-or-nothing proposition.
Next up, we look at how the nutrition and health effects of quinoa compare to whole grains.
Approximately 90 percent of the world’s calories are provided by less than one percent of the quarter million known edible plants. The big three are wheat, corn, and rice, the reliance upon which may be unsustainable, given the ongoing climate crisis. This has spurred new interest in underutilized crops like quinoa, which might do better with drought and heat.
Quinoa has only been introduced into the Northern hemisphere recently, but humans have been eating quinoa for more than 7,000 years. Is there any truth to this “superfood” designation, or is it all just marketing hooey?
Quinoa is a “pseudograin,” since the plant it comes from isn’t a type of grass. Technically, it’s a seed-like fruit. It does have a lot of protein, and also lots of vitamins and minerals, but so do all whole grains. Yeah, it has more protein than other grains, but since when do we need more protein? Fiber is what we’re sorely lacking, and its fiber content is relatively modest, compared to barley or rye. Pretty strong on folate and vitamin E, and leads the pack on magnesium, iron, and zinc. So, nutritious? Sure, but when I think superfood, I think some sort of special clinical benefit. So, broccoli is a superfood; strawberries are a superfood; garlic is a superfood. But what about quinoa? Consumer demand is up, thanks in part to perceived health benefits. In lab animals, it has all sorts of purported benefits, but there have been very few human studies.
The first trial was a before-and-after study of quinoa granola bars that showed drops in triglycerides and cholesterol, but with no control group, you don’t know how much of that would have happened without the quinoa. And, about a cup a day of cooked quinoa for 12 weeks led to a 36 percent drop in triglycerides. That’s comparable to what one gets with triglyceride-lowering drugs or high-dose fish oil supplements.
Which is better, regular quinoa or red quinoa? Well, red does have about twice the antioxidant power, leading the investigators to conclude that red quinoa might significantly contribute to the management and/or prevention of degenerative diseases associated with free radical damage––though it’s never been put to the test. What about black quinoa? Both red and black quinoa appear equally antioxidant-rich, both beating out the more conventional white.
The only caveat I could find is to inform your doctor before your next colonoscopy, else they might mistake it for parasites. Colonoscopy revealed numerous egg-like tan-yellow ovoid objects of unclear cause, but it was just undigested quinoa.
Finally today, the health benefits of spending time in nature.
For perhaps 99.99 percent of our time on Earth as a species, we’ve been living outdoors in the natural environment. Might there be a health benefit to returning now and again, and surrounding ourselves with nature? That’s a question urban planners have asked. Are people living in greener areas healthier than people living in less green areas? Should we put in a park or another carpark?
In a greener environment, people report fewer symptoms of illness, and have better perceived general and mental health––and by a considerable amount. Assuming the link is cause and effect, 10 percent more greenspace leads to a decrease in the number of symptoms that is comparable with a decrease in age by five years, but that is a big assumption.
Still, you could imagine some potential mechanisms of why it could be. It could mean less air pollution. And air pollution is no joke; it is the fifth leading cause of death on planet Earth, wiping out about five million people a year. Though, of course, our diet kills twice as many, as killer risk factor #1.
So, it could be an antipollution effect. Or, maybe there’s something special about experiencing greenspaces, beyond them just offering more opportunities to exercise. But, that’s probably the simplest explanation: natural settings simply promote “health-enhancing behavior rather than having specific and direct benefits for health.” It’s harder to go jogging in the park when there is no park. Ironically, it seems that even when people have access to nature, they don’t necessarily take advantage of it. And, even if there was a link, instead of natural environments drawing out increased physical activity, maybe physically active individuals are just drawn to living where there’s nature. But, what I wanted to know is, apart from the promotion of physical activity, are there added benefits to health of mere exposure to natural environments?
Now certainly, just exposure to sunlight can treat things like seasonal aﬀective disorder and provide the sunshine vitamin—vitamin D. But are there any other inherent benefits? You don’t know, until you put it to the test. Some of the studies are just silly, though. At first, I thought this was about academic achievement and vegetarianism, but no—it’s vegetation. They found a correlation between non-forest vegetation and graduation rates for schools. Maybe the Ivy League edge is all just ‘cause the ivy.
The view through a window may influence recovery from surgery. At this suburban hospital, some patient rooms looked out at trees, and others just to a brick wall. And, the “surgical patients assigned to rooms with windows looking out on a natural scene had shorter postoperative hospital stays” and took fewer potent painkillers than similar patients in similar rooms, but with windows facing the brick wall. You can’t chalk that up to a vitamin D effect.
What could it be about just looking at trees? Maybe it’s the vitamin G, just the color of green. We know how healthy it is to eat our greens. What about just looking at them? Researchers had people exercise while watching a video simulating going through a natural-color green setting, the same video in black and white, or everything flipped to red, and…no differences were noted (with the exception of the red just making people feel angry).
The most interesting suggested mechanism I ran across was fractals. You know how all the branches of a tree kind of have the same shape of a tree themselves? Fractal patterns are found throughout nature, where you see a cascade of self-similar patterns over a range of magniﬁcations. And, hook people up to an EEG, and for some reason our brain apparently seems to like them.
Regardless of the mechanism, if you compile together all the controlled studies on using nature as a health promotion intervention, you tend to see mostly psychological benefits, whereas the findings related to physical outcomes were less consistent. The most common type of study outcome was self-reported measures of different emotions. Like, what makes you feel better, staring at a kiwifruit orchard, or staring at a building? Awkwardly described, thanks presumably to the language barrier, as a comparison of “synthetic versus organic stimulation.”
Natural settings may make people more attentive, less sad, but when it comes to some objective measures like blood pressure, no significant effect. So, you know, you ask people who exercise outdoors, and they say they feel great, suggesting that “green exercise” activities have the capacity to increase mood, focus, and energy, and within just like five minutes of being out there in the woods.
Yet these studies tended not to be randomized trials. They just asked people who already sought out nature what they thought about nature; and so, no wonder they like it—otherwise they wouldn’t be out there. But hey, nature-based interventions are low-cost––often free in fact––and non-invasive (unless you count the mosquitoes). So, if you want “a natural high,” I say go for it; whatever makes you happy. (Though evidently not all green exercisers like trees. Golfers just viewed them as obstacles.)