Obviously, when we’re talking about how long we are ever going to live, the “diet hypothesis” holds. Poor food choices make us ill, and these illnesses make us die sooner. They also generally degrade our physical functions, and as our telomeres and organs deteriorate increasingly into shreds, we become weaker and weaker. Just about everybody who has ever written about longevity and food has the general idea right: food matters.
On the other hand, I am now coming to believe that so long as no drastic health issues are at stake, the perfect diet is not necessarily the path to a long life (or at least definitely not the sole path). If you look at studies done on centarians the world over, what we find over and over again is not necessarily that they eat a certain diet. Some eat lots of pork, others a fair bit of rice, others tons of home-made yogurt, for example. I know one woman who eats frozen dinners. Doctors and health theorists argue over what the perfect longevity diet might be all of the time. But there really never has been shown to be a bulletproof, universal, centenarian-begetting diet, so far as I can tell. Usually they stick to whole foods. That seems to work quite well.
From my perspective, the real common variable is that centenarians (and especially the springy ones, not the bedridden) tend to live simple and happy lifestyles. Relatively healthful food, very little stress, some sleep, some walking. There’s actually a fair bit of data that demonstrates the benefits of walking. And personally, what I have found in my observation is that those people I know and read about whom are both elderly but still enormously youthful… they exist in existential satisfaction. Whether at peace because of their communities and family, or because they have faith, or are committed to charity, or because they are immersed in passionate pursuits, their degree of satisfaction with existence stands out as their primary characteristic. In my opinion.
Plenty data show that stress weakens the immune system and decreases lifespan. Here, here, and here, for example. And many show how crucial both metabolic and psychological stress are for cellular decay, for example, here.
But what about the converse? Why not think about it in terms of the opposite of stress? Of peace, of contentment, of authentic happiness?
Which brings me to my favorite study this week: Smile Intensity Predicts Longevity.
The study, found here, was conducted on 196 Major League Baseball players from the 20th century. MLB players were chosen because fairly good data about their lives already exist. The researchers did their best to control for factors that have already been found to influence longevity:
“The Baseball Register (1952) and Lahman (2006) allowed us to control for numerous factors related to longevity, such as year of birth, body mass index (BMI), career length (a reflection of continued physical fitness and performance), career precocity (Abel & Kruger, 2005, 2006, 2007), marital status (Lillard & Panis, 1996), and college attendance (Kalist & Peng, 2007).”
They didn’t look at diet at all.
What they did was study the intensity of the smiles on each of the MLB player’s official baseball cards. What they found was striking:
Controlling for the above variables, the degree of smile authenticity in each photograph taken decades ago remained significantly correlated with longevity. The more authentic the smile, the longer the player lived.
How do you know what an authentic smile is, you ask? It’s called the Duchenne smile (wikipedia it, here), and it’s a pretty well-known and well-regarded marker of happiness in psychological studies. It is the smile that pulls at muslces around the mouth and particularly the eyes… the smile that you feel when you’re laughing, or hugging someone you love. Try comparing it to the smile you muster up for strangers you pass in the hallway on a bad day. There is a world of difference.
We can see that difference in photographs, and calculate it precisely. And from that, we have found that authentic happiness predicts longevity.
Players who had Duchenne smiles were half as likely in any given year to die than non-smilers.
Players who had Duchenne smiles had greater longevity predictions than those who wore partial smiles, but not in a statistically significant way, who in turn did not differ significantly from non-smilers. ( “Adding smile ratings led to a significant improvement in predicting mortality, χ2(2, N = 162) = 8.2, p < .017.”) This seems to indicate that partial smiles sat somewhere in the middle, whereas non-smilers experienced reduced longevity and Duchenne smilers experienced increased longevity relative to them.
The study concludes with two interesting notes: 1) that physical attractiveness was not a significant correlate with longevity, and 2) that teaching ourselves to smile can actually influence our emotions (more in which in subsequent posts).
In other studies, individuals instructed on how to make Duchenne smiles generated patterns of regional brain activity associated with subjective enjoyment (Ekman, Davidson, & Friesen, 1990). If the phenomenology and expressions of emotion are hardwired (Ekman, 2007), individuals whose underlying emotional disposition is reflected in voluntary or involuntary Duchenne smiles may be basically happier than those with less intense smiles, and hence more predisposed to benefit from the effects of positive emotionality. Attractiveness did not influence longevity.
And, again, they didn’t even look at diet. We might argue that each of these players was born into a more traditional diet, and perhaps a fairly homogenous one– and therefore the variable would not have been as significant for this group, but these men still probably ate things such as carbohydrates, nuts, nightshades, rice, and lots of other ~paleo/non-paleo foods we are worrying about these days. I’d bet they ate dairy and wheat products, too. Which isn’t to say, of course, that a better diet would not have helped them live even longer. I certainly think that it would. But this goes to show that the amount of authentic joy in your life really is a major player in your lifespan.
More on happiness, longevity, and how to make it all happen forthcoming.Read More
While the title of this post may sound hyperbolic, it nonetheless is grounded in truth. There are a wide variety of dietary and lifestyle factors that affect reproduction. Stress may be one of the greatest of all.
Dozens of studies performed on cynomolgus monkeys, bonobos, chimps, and baboons have demonstrated that having low social status–even while maintaining the exact same diet at high social status individuals–induces impaired fertility in primates. Human models, while approximations, do not differ. In some, a simple progesterone-dampening effect occurs, in others the levels decrease precipitously, in most cortisol levels skyrocket, but in general a wide spectrum of reproductive disorders- from hormone deficiency to full-blown long-term amenorrheic infertility- follow from psychological stress. This is something about which I have written before, and it’s a serious problem, causing not just outright and obvious infertility but also sneakily impaired and sub-optimal fertility all across the country.
Pysychological stress wreaks all sorts of havoc on the body. Most importantly, cortisol levels rise, and the body’s inflammatory and immune responses become impaired. Blood sugar levels rise, and insulin levels rise, too. When these things happen, healing cannot occur, and tissues become progressively damaged with time. This applies to reproductive tissues as much as it does to the rest of them. Hypercortisolemia is good for nobody.
Several hormone responses also occur. Three of the primary ones are as follows:
1) As I mentioned, due to elevated cortisol levels, insulin levels may rise, and testosterone levels rise right alongside it. This is because insulin directly stimulates testosterone production in the ovaries. This is bad for reproduction because a proper balance between testosterone and female balance needs to be maintained in order for proper reproductive signalling and tissue development to occur. One particularly potent way in which this imbalance often hurts women is in the hormone condition Poly Cystic Ovarian Syndrome. It is not the only thing that contributes to PCOS– definitely not– but it can play a big time role in it.
2) Moreover, another effect that may occur as a result of stress is an increase in production of DHEA-S, a hormone produced in the stress glands. DHEA-S is, like all other hormones, an important and very healthful hormone in proper balance. But if the stress glands are in overdrive, they might over-produce everything, including DHEA-S. This is detrimental, because DHEA-S is also a classically male sex hormone, and it plays a role similar to testosterone in PCOS. DHEA-S in excess blocks estrogen signaling, interferes with LH and FSH signaling, and also increases hormonal acne. DHEA-S can play a role in both type I and type II PCOS.
3) Finally, the brain, via the hypothalamus, sometimes turns off pituitary activity in response to stress. This often leads to a cessation of LH and FSH signaling–the two primary pituitary signalling molecules–which in turn decreases levels of estrogen and progesterone in the blood. Recall that reduced progesterone levels are one of the primary markers of reproductive distress in primate studies. Prolactin levels may also decrease. These facts make it impossible both to ovulate and to menstruate.
*Graphic extracted from PCOS Unlocked: The Manual.
These three categories– testosterone elevation, DHEA-S elevation, and pituitary decreases may occur differently in all women. And there are a wide variety of other, more subtle, hormonal responses that also occur, especially when considered in conjunction with all of the other bodily stress that follows from psychological woes.
All that being said, STRESS IS BAD. We know some of the reasons why, as I’ve explained above. Others likely exist. Even if you don’t have infertility problems, you may have hormone imbalances or deficiencies, and those can be just as insidious. Eat right, sleep right, live well, breath deeply. Repeat.
Stress is a significant problem for women’s health, and particularly women’s hormonal health. This is manifested in a wide array of problems, but also most predominantly these days in the condition PCOS, or Poly Cystic Ovarian Syndrome.
You can read more about stress and it’s interplay with cysts, as well as how to overcome it all, in my forthcoming guide, PCOS Unlocked: The Manual. Coming to this website on 10.17.12, ONE WEEK FROM TODAY.
Protein, composed of amino acids, is the building block molecule. For this reason, we usually think of it as constructing our bones, our skin, and our muscles. A lesser-known fact of amino acids, however, is that they are also the building blocks of neurotransmitters. This means that when certain amino acids break down from proteins during digestion, we can experience mood changes and anxiety. Other amino acids can help relieve anxiety, depending on what foods are consumed. Tyrosine uniquely increases dopamine concentrations in the brain, for example. This can have positive effects for people with dopamine deficiencies, but it can hurt people who are already excitable. Another example is Leucine. Leucine increases m-Tor signalling, which is somewhat inflammatory and has been shown in many cases to be associated with aging and poor immune response.
High Protein Diets, Stress and Anxiety in the Short Term
Regardless of the differences in amino acids, higher protein diets correlate with anxiety in both animal and human studies. Here, in one study, researchers set out to show that a high carbohydrate diet would induce more stress than a high protein diet, yet their finding ended up being the opposite: a high protein meal created a greater cortisol response than a high carbohydrate meal in women. Here, high protein diets are shown to decrease testosterone and increase cortisol in men. These studies demonstrate that high protein meals increase stress responses. Moreover, MDs anecdotally report acute anxiety in patients once they start high protein diets. Finally, protein can raise norepinephrine and dopamine levels, both of which are usually high in anxious individuals, and both of which stimulate arousal.
Protein and the neurobiology of GABA
So on the surface the literature on protein intake and mental health is present, but its actually pretty sparse. Certainly, it seems as though cortisol is associated with high protein consumption, especially in the short term. But the amount of data out there is not all that much compared to how much research has been done on fat and carbohydrates. For example: nearly everyone agrees that fluctuating blood sugar is bad for mental health; they also know that tryptophan, a result of carbohydrate metabolism, helps induce feelings of calm and well-being. So these are ways in which carbohydrates have been thoroughly studied. Furthermore, nearly everyone also agrees that fat is excellent for mental health. High fat diets, but not higher protein, nor high carbohydrate, decrease anxiety in rats. So we know a lot about fat, too. What about protein? What we might be able to assert about protein comes not, then, from any epidemiological data, but from neurobiology. What does looking at amino acid chemistry and neurobiology tell us might be going on with protein metabolism?
It all has to do with GABA. For more on GABA neurons in general, refer to this post. In sum: GABA neurons are inhibitory neurons. They tell the brain to be quiet. For people who are depressed and fatigued, therefore, GABA might seem like a problematic molecule, but that’s inaccurate. GABA malfunctioning has been shown to play a role in almost all mood disorders, and in insomnia, and really any kind of imbalance in the brain that might lead to disordered behavior. GABA is strongly associated with well-being, calmness, proper memory function, proper circadian rhythms, and good sleep. GABA, because it inhibits the amygdala, also has been shown to inhibit pain and fear.
Low protein diets enhance GABA production.
One particularly powerful animal study showed the complex relationship between protein restriction and GABA. The researchers were interested in longevity, which is a topic for a whole other slew of posts, but the high GABA activity that manifests as a result of protein restriction applies equally well to mental health. Aging rats, when eating a lower protein diet, saw a long-term elevation of GABA activity. This increased the functioning of the rats’ immune systems as well as prolonged their lives. A high protein diet had the exact opposite effect. Another study found the same effect, except that both young and old rats saw the highest GABA activity on a low protein diet. These studies are conducted over weeks and months and years. What this means is that over time, a lower protein diet is optimal for GABA activity in the brain. This helps with aging, with immune function, and presumably with mood disorders.
The fact of increased GABA activity, along with having the lowest cortisol response to a meal, means that a lower protein diet may be optimal for some people’s mental health. The cortisol response is immediate; the GABA activity, also immediate, but it’s also more important on long time scales. The best way to move forward with this information is to just be cognizant of mood throughout the day. Is heart-rate spiking, or the mind racing, after a high protein meal? On a day with a particularly high protein intake? Try mitigating this by spreading protein intake out throughout the day, instead of eating it all at once. Or try keeping the absolute total to a minimum. Most people recommend .5 g of protein per lean pound of body weight, and I stand by that as well. It’s important both in the hour-by-hour day-to-day, as well as for long term mental health.
Of course, protein is also essential for mental health. I mentioned above that amino acids make up and heavily influence neurotransmitters. This is true. It is only an imbalance that can do real harm. For this reason, the best bet is to eat a sufficient amount of protein, and feel the way forward cautiously, respecting the individuality of each person’s needs.
Neurotransmitters: Exciting and Inhibiting
Gamma-Amino-Butyric-Acid, or GABA, is the chief inhibitory neurotransmitter in the human brain. Along with serotonin, dopamine, glutamate, glycine, histamine, and norepinephrine, among dozens of other neurotransmitters, GABA regulates brain function. Different neurotransmitters are in relationship with different types of receptors, and these receptors signal excitation or inhibition. For this reason, neurotransmitters are commonly classified by their excitatory or inhibitory activity. Some neurotransmitters signal to both kinds of receptors and play both excitatory and inhibitory roles. Others are just one or the other. GABA is one of these. It is powerfully inhibitory.
GABA: Calm, Resilience, and Sleep
The GABA neurotransmitter tells the brain to be quiet. The vast majority of inhibitory synapses in the brain employ GABA. For people who are depressed and fatigued, therefore, GABA might seem like a problematic molecule. But that ends up not being the case. GABA malfunctioning has been shown to play a role in almost all mood disorders, including depression. GABA is strongly associated with well-being, calmness, proper memory function, proper circadian rhythms, and good sleep. GABA inhibits amygdala activity, too, so it has also been shown to inhibit pain and fear. For this reason, people have talked about GABA as being a molecule that promotes resilience and personal strength.
GABA is well known to be a prominent factor in mental well-being and feelings of calm. Officially it results in “sedative, hypnotic (sleep-inducing), anxiolytic (anxiety reducing!), anticonvulsant, muscle relaxant and amnesic” effects. For this reason, a whole host of drugs that mimic GABA, called benzodiazepines, have been designed and proscribed prolifically. Valium is one of them. The long-term effects of these drugs are unpleasant, as they almost always result in withdrawal. The symptoms of benzodiazepine withdrawal parallel GABA deficiency. These iclude anxiety, tension, high blood pressure, insomnia, agitation, seizures, muscle spasms, and panic disorders. For example, GABA-inhibited mice tested for anxiety demonstrate “a model of anxiety characterized by harm avoidance behavior and an explicit memory bias for threat cues, resulting in heightened sensitivity to negative associations.”
GABA is also one of the prominent molecules involved in sleep. During sleep, many parts of the brain need to be quieted, and they need to do it all at once. This is, in part, GABA’s job. Without GABA, excitatory neurotransmitters continually keep different parts of the brain and the body firing, such that it can never shut down fully enough for deep sleep. Valerian root, a natural herb and supplement, “encourages” the production of GABA. It’s one of the most successful sleep aids one can use. Melatonin is also powerful and is bio-identical, but it’s effects wane more markedly over time as the body becomes more and more used to higher levels of melatonin. Over-the-counter and prescription drugs, while knocking people out, also inhibit the deep restfulness of REM sleep. Valerian does not replace, but instead stimulates GABA production. This is why it is so naturally (and without causing addiction) effective in promoting deep sleep.
GABA and The Pituitary
GABA, even while it inhibits frenetic activity in the brain, also stimulates activity in the anterior pituitary. The anterior pituitary is where most of an individual’s hormone production takes place. GABA, therefore, is crucial for people who would like to boost hormone production. ACTH, TSH, FSH, LH, prolactin, and Human Growth Hormone are all secreted from the anterior pituitary. Low TSH is profoundly implicated in hypothyroidism; having low FSH, LH, and prolactin levels is the root biological cause of hypothalamic amenorrhea; and growth hormone is one of the primary molecules responsible for healthy metabolism. It’s activities include up-regulating fat utilization, protein sparing, and glucose-insulin sensitivity. One study at the University of Milan found that 90 minutes after 5 grams of GABA supplementation, HGH levels increased 5-fold.
Increasing GABA with diet
-GABA itself is not present in foods, but one of its key constituents — glutamic acid/glutamate — is available in a wide array of readily available foods. Glutamate-containing foods are plants and vegetables. Examples include: broccoli, spinach, lentils, walnuts, citrus, tomatoes, cheese, corn, and mushrooms. There are other foods in this category, such as wheat, wheat bran, soy, and cottonseed flour, and peanuts, but I do not recommend eating them. High glutamic acid containg foods are generally animal products. they include eggs, particularly the whites, many varieties of cheese, cod, gelatin, whitefish, and chicken, beef, and scallops.
-L-theanine also increases GABA activity. This amino acid is found in high doses in green tea.
-Foods rich in B-complex vitamins, particularly inositol, also prompt GABA production. In fact, B-vitamins are necessary for the functioning of nearly all brain processes and chemicals. Foods containing B-vitamins comprise a rich and varied list. They include: fruits such as bananas, figs, cantaloupe oranges and figs, and vegetables, particularly cruciferous vegetables, such as beets, broccoli, kale, and spinach, and nuts, and seafood, and beef and beef liver, chicken liver, all organ meats, and all game/ruminant meats.
-A lower protein diet in general is associated with increased GABA activity.
-Finally, exercise and meditation can enhance GABA activity. GABA is a lot like other body systems and muscles in that it has positive feedback effects. The calmer someone is, the more likely it is that he will be able to produce proper amounts of GABA. Some physical activities allow the mind and body to enter into calmed and relaxed state. For this reason, many natural health practitioners recommend yoga as a means of increasing GABA. Meditation and light forms of exercise such as walking also fit into that recommendation.Read More