Tag Archives: Science

The Paleo Diet.

What is paleo?

The Paleolithic diet is not a “diet” in the count-every-calorie-I-hate-my-life sense. It is a lifestyle that encourages us to eat and live the way that our ancestors did for hundreds of thousands of years. The first homo sapiens appeared on earth 200,000 years ago. They hunted and gathered, slept, made shelter, and occasionally ran for their lives. They were strong and healthy and didn’t suffer from the diseases that we do now. The agricultural revolution changed the way we modern homo sapiens eat 10,000 years ago. Meaning, we have only been eating wheat and other grains and domesticated animal products for 10,000 years out of our 200,000 year existence. The paleo diet is the avoidance of all grains (even whole grains), refined sugar, legumes, and dairy products. It is eating vegetables, meat, poultry, fish, nuts, and fruit. The paleo lifestyle is to exercise the way we used to: lots of movement, like walking, some heavy lifting, and some sprinting. Our ancestors did not read magazines for two hours on the elliptical or run marathons.

What to eat

Fruit and veg: Go crazy for veggies. Make them the base of your diet and you can’t go wrong. For people trying to lose weight, reduce fruit and starchy vegetables like potatoes, beets, winter squash, and root veggies. For maintaining weight, gaining weight, and sustaining heavy exercise, use starchy vegetables and fruit as your carbohydrate source.

Nuts and oils: Any nut is fair game except for peanuts, which are technically legumes. Monounsaturated fat is good for us, while polyunsaturated fat is more complicated. Polyunsaturated fat is divided between omega 3s and omega 6s. While we do need omega 6s, the ratio of omega 3 to 6 should be 1:1. Modern diets are 1:10, which increases our risk of heart disease. We should emphasize omega 3s and reduce omega 6s. 

  • Monounsaturated oils include: nuts, avocados, olives and olive oil, fish, cod liver oil, grass fed meats, and plants (which obviously don’t have that much fat)
  • Polyunsaturated omega 6 sources include: corn, soy, cottonseed, grapeseed, sunflower, safflower and other vegetable oils, and grains
  • Polyunsaturated omega 3 sources include: salmon, sardines, fish, walnuts, flax, hemp, nuts, grass fed meat, pasture raised chicken & eggs

Meat: meat should ideally be grass fed and organic. Grass fed meat is naturally leaner and contains increased levels of omega 3 fats and decreased levels of omega 6 fats compared to grain fed animals. This is good because omega 3s are anti-inflammatory where as omega 6 fats are pro-inflammatory (bad!). Post-agricultural revolution, cattle began being grain-fed because it is cheaper and they get fatter. If you can’t afford grass fed meat, go for the leanest cuts of conventional meat and supplement with other forms of healthy fat, like avocados, nuts, olive oil and coconut oil. Avoid vegetable oils, as they are high in omega 6.

Poultry and fish: Poultry and eggs should ideally be free-range and not fed a “vegetarian” diet, which really just means corn and soy. Again, this is so that the fat content of the meat and eggs is higher in the fats that reduce CVD. Fish should ideally be wild caught because farm-raised fish are fed (surprise!) corn and grain feed. Remember, the reason that corn and grain fed animals and fish are less healthy than their naturally grazing counterparts is their fat content. Naturally grazing species will have a more anti-inflammatory omega 3 fats and less inflammatory (and thus CVD inducing) omega 6 fats.

About red meat and saturated fat

Paleo or no paleo, the consumption of red meat believed by many to be unhealthy. This is based on studies that link high consumption of red meat to cardiovascular disease (CVD) and cancer, and it is usually explained as the increased level of saturated fat in the diet. This is not the whole story. The studies that claim this are flawed in their methods and/or reporting. They are usually population studies that take large groups of people and have them fill out food frequency questionaires (which are sketchy in their own right since they are based on memory and estimation). The results look at the frequency of cancer and CVD in the population tested. Those who ate more red meat had higher rates of cancer and CVD. What the study doesn’t mention, is that these people were also more likely to smoke, be overweight, obese, diabetic, inactive, or combinations of all of these characteristics.

In this cross over study (which is the most trustworthy type of study), two groups were divided among heavy red meat consumption versus fish and chicken consumption. The red meat group ate far more cholesterol and saturated fat, however, their HDL and cholesterol levels were the same as the fish and chicken group. Interestingly, in women only, red meat actually lowered blood triacylglycerol (=fat, TAG)  levels and the fish and chicken increased the blood TAG levels. This is important because blood TAG levels are now thought to be more indicative of heart disease risk. Another interesting thing about this study was the carb intake, which usually regulates serum TAGs, was similar in both groups. This suggests that red meat has a TAG-lowering effect independent from simply replacing carbs from the diet with protein.  Also worth noting is that the red meat group ate ~200 calories more than the chicken and fish group per day, but did not gain any weight. This is a great blog post that summarizes more studies on this topic.

Two other interesting studies were analyses of other studies. Looking at all the studies that met their standards and criteria, they determined factors that increase and decrease risk of heart disease.

  • Increased risk factors: trans fats and high glycemic loads (AKA sugar, simple carbohydrates, and excessive carbs REGARDLESS of carb type).
  • Decreased risk factors: fiber, fish, beta carotene, omega 3s, fruit, veg, nuts, monounsaturated fats, vitamins C and E, Meditteranean style eating, and whole grains. [I will get to grains a bit later.]

They noted the lack of evidence supporting the notion that reducing saturated fat intake will lower the risk of CVD. Furthermore, according to this study, there is no study yet that reduces saturated fat intake with no other changes to the diet. Meaning, if reductions in CVD were seen with reduced saturated fat intake, it could be due to the other changes made in the study, like reduced carb intake, increased omega 3 intake, etc. Also, note that polyunsaturated fats were not part of the decreased risk factor list, which is what we have increased in out diets by feeding our animals and ourselves lots of corn and vegetable oils.

Main point: Current research seems to indicate that it is not saturated fat that is responsible for our current state of heart disease, but rather the increased ratio of omega 6 to omega 3 fats in our diet. This doesn’t mean you can drown yourself in french fries and steaks. It means that grass-fed meats or extra lean conventional meats do have a healthy place in our diet, along with fish, healthy oils, nuts, and plants.

About grains and legumes

Grains and legumes (beans + peanuts) are out because they contain lectins and anti-nutrients. Wheat germ agglutinin (WGA) is one type of lectin, which is a molecule that can bind to other molecules in our body. Lectins are not broken down during digestion and can bind to receptors on the gut lining. This binding can lead to decreased digestion and absorption of other dietary proteins as well as transportation of the lectins through the gut and into the blood circulation. While they are transported, lectins can damage (in rough terms: “poke holes”) in our intestinal lining. These circulating lectins are then recognized by our immune systems as foreign invaders, and we will launch an immune response against them. Unfortunately, lectins can often resemble normal cells in our body, so these immune responses can essentially become immune attacks on our own tissues. Read: inflammation and auto-immune diseases. Because there is now perforations in the gut lining, other microscopic proteins from our diet can cross the lining, and immune responses can be raised against those proteins as well. Read: food allergies.

The strongest evidence against grains is definitely for those whom have autoimmune disease such as rheumatoid arthritis, celiac, lupus,  Sjogrens, MS, T1 diabetes, and ulcerative colitis. This, this, this, and many more studies indicate that dietary gluten and grains do negatively impact those with decreased immune systems. However, not everyone has an overt immune disease. Like most things in this world, we are on a sliding scale. This study showed that those with celiac disease and people with increased genetic susceptibility to autoimmune disease had increased gut permeability when consuming a diet high in gluten. And as for completely healthy individuals with great immune systems? There is hardly any research. This study, ironically done by a student under the original Paleo-pusher, Dr. Cordaine, showed that healthy individuals did not see an increase in plasma levels of lectins after consuming 50 grams of gluten (although several explanations were offered for these results). However, this study did show that peanut lectins made their way through the intestinal lining and into circulation. This study showed the same with wheat germ agglutinin, but it was done on rats. This study showed that anti-bodies to WGA can be found in human circulation.  Also, this research article is all about using lectins as a way to get pharmaceutical drugs absorbed more efficiently through the intestines, and cites studies that were done on human tissue. Therefore, it does appear likely that lectins are able to enter circulation and possibly cause damage. 

Main point: Anyone with imperfect immune function (which you wouldn’t necessarily know if you were included in that group), and possibly everyone, can benefit from removing grains and legumes from their diet due to their lectin content. Even completely healthy individuals may benefit from lectin avoidance because lectins may at the very least be causing a constant low-grade inflammation in the body. Just try it for a few weeks and see how you feel. 

The anti-nutrients in grains that I mentioned are protease inhibitors and phytates. Protease inhibitors are molecules that inhibit our enzymes from breaking down some of our dietary protein and lectins (which are proteins). I think that this is a bit exaggerated in The Paleo Solution because it is not as if your burger isnt going to get digested just because you ate it with a bun. That would require a LOT of protease inhibitors. Phytates are found in grains and seeds and can bind to important minerals, like magnesium, zinc, iron, calcium, and copper. Thus, when you eat phytates (which are mostly in the bran of the grains) they bind to those nutrients so that you cannot absorb them. While this is bad, I think it is also slightly exaggerated. Phytates will bind those nutrients, but not all of them! Then again, the typical American diet is grain heavy and lacking in fruits and veg, so I guess it could actually make quite a difference in a person’s nutritional status!

About dairy

The case against dairy seems to be mostly based its effect of raising insulin levels. Insulin increases fat storage, and chronically elevated insulin levels can lead to insulin resistance. Clearly, for diabetics and people whom are overweight, this is  bad. I also read that some studies correlate milk intake with auto-immune diseases. However, I am happy to report that some people actually can consume dairy given that they do not have any auto-immune issues, have a healthy gut and weight, and are not lactose intolerant. While strict paleo does say no dairy, even the some of the most hardcore paleo-pushers admit that grass fed, whole fat, organic dairy has its benefits. If it is grass fed and organic, it won’t contain any harmful pesticides or hormones, and will have a healthy fat profile. Additionally, if the dairy is raw, than the naturally occurring enzymes will help with the digestion and absorption processes. Proper dairy can be a great source of calories, protein, fat, calcium, and probiotics, however it can be difficult (or impossible) to get your hands on.

Main point: Try giving up dairy products for a couple weeks, see how you feel, and then re-introduce it. If you feel bloated and ill…. well now you know. If not, stick with grass fed, organic, whole milk dairy products. Those with auto-immune disorders or genetic susceptibility would also likely do well to avoid dairy.

About fiber

When I first heard about how paleo excludes grains, even my beloved whole grains, I was disturbed. Almost mad! Here I was, with a blog all about eating healthfully and including whole grains into our diet, and this community was telling me that that was bad. I fought it. Whole grains have so many nutrients, like B vitamins and minerals! Whole grains have so much fiber! From my studies, I knew that the human body needs two kinds of fiber: soluble and insoluble.

Soluble fiber absorbs water, and thus slows digestion and makes us feel fuller, longer. It also helps feces transit.

Insoluble fiber is not digested by the body and adds bulk to the stool. This is important for maintaining bathroom regularity, which may be helpful with preventing colon cancer. Insoluble fiber is also a key source of food for gut flora (bacteria), which give us all sorts of immune and digestion benefits.

My first instinct was that without whole grains, I would only be getting soluble fiber from fruits and veggies. I feared that without my precious whole grain insoluble fiber sources, I would become a constipated, and thus grumpy, beezy. Turns out one can get both kinds of fiber very easily from a paleo diet.

  • Soluble fiber is found in: fruits like apples, oranges, pears, and berries. Veggies like cucumbers, celery, and carrots. And nuts and seeds like flax, almonds, and psyllium.
  • Insoluble fiber is found in: corn, seeds, nuts, zucchini, celery, broc, cabbage, root veggie skins, dark leafy veggies, onions, grapes, and other fruits.

Other considerations

While I have now made the agricultural revolution sound like the most terrible thing to ever have occurred, I must remind myself and others that it was this revolution that enabled us to feed more people and expand our population. In some ways, this is beautiful. More people, more innovation, peace, love, happiness. On the other hand, we have more people, but they are also fatter and sicker than ever before. So while the agriculture revolution certainly made food cheaper, it has also increased our medical care costs.

Another thing to think about is the environmental-friendliness of the paleo diet. Obviously, a lot of meat and animal products are consumed. While ideally the animals should be sustainably raised and grass fed, this sadly makes up only a tiny portion of our current agricultural system. Furthermore, it has been said that vegetarian diets are far more environmentally friendly than traditional diets. I have hardly done any reading on this, but it is something I have heard over and over again. I think the most important thing to keep in mind at the grocery store (or better yet, farmer’s market!) is that every dollar you spend on food is a vote. Hopefully with enough votes towards healthy, sustainable food items, they will become more affordable and we will slowly transition to a better agricultural system.

I encourage everyone to join me in giving full-on Paleo a shot for a few weeks!


Skinny celebrity pregnancies: a glimmer of truth

My apologies for the sparse blogging these past few months. Its been on my mind all the time, but I just hadn’t the drive or time to write great posts – and if they aren’t going to be great, I don’t want to waste your time. I have been debating on writing this post for a while, because it’s a bit more personal and very sciencey. If neither of those things interest you, you can skip it and I actually have several recipe posts lined up!

I want to talk about hormones.  I have been debating about going to medical school for quite a while now, with my interest growing at my internship at the fertility center (although I am more interested in the other branch of endocrinology, which is metabolism) and my endocrinology course. I just took the final on Tuesday and realized how in love with it I am. That’s why Im bursting at the seams to talk about female reproductive hormones.

To be blunt, I want this post to convey how the menstrual cycle works, why it is so important to have a regular cycle, the damage that amennorhea can wreak on the female body, and a bit of advice for bringing the body back to a hormonally balanced state.

To understand everything, a little anatomy is needed.

The hypothalamus is a section of the brain, composed of millions of nuclei that communicate with the rest of your body. It has centers that regulate everything, from hunger, to metabolism, to reproductive hormones, to sleeping cycles. Most importantly, when given the proper stimuli, the hypothalamus sends signals to the pituitary gland.

This depicts the hypothalamus connecting to the pituitary gland which sends hormonal signals to the rest of the body. 

The pituitary gland secretes many hormones that travel to tissues in the body and activate them to perform their necessary functions. In the case of reproductive hormones, the hypothalamus sends Gonadotropin Releasing Hormone (GnRH) to the pituitary. This causes the gonadotrope cells in the pituitary gland to secrete Follicle Stimulating Hormone (FSH) and Leutinizing Hormone (LH).

This depicts the hypothalamus connecting to the pituitary gland which then sends hormonal signals to the ovaries. LHRH is referring to GnRH.

The ovaries contain a set amount of oocytes (baby eggs) from the day you are born. At puberty, the hypothalamus begins to send enough GnRH to the pituitary which will secrete more FSH and LH which will travel to the ovaries. Once stimulated by Follicle Stimulating Hormone and Leutinizing Hormone, the oocytes begin to develop and mature further. In the monthly menstrual cycle, this is the Follicular phase. The growing follicles secrete estrogen as they mature. This estrogen causes the uterus to build up a blood lining. The follicle with the most FSH receptors continues to grow, while the others die off. After about two weeks of the follicles growing and secreting estrogen, there is a surge of LH which causes ovulation. This is the egg breaking free from the follicle, which is basically a nice little shell of hormone secreting cells. The egg is now free to hitch hike down the ovaries and try to get inseminated. Meanwhile, the empty follicle shell is transformed into the corpus luteum. This is the luteal phase of the menstrual cycle. The corpus luteum is a package of cells that begins to secrete progesterone, which maintains the lining of the uterus. Over the next two weeks, the corpus luteum secretes progesterone, but if the egg isnt fertilized, the level of progesterone falls and the lining is shed. And the cycle starts over!

Main point: No GnRH = No FSH or LH = No growing follicles or corpus luteum = No estrogen or progesterone = No period, no cycle, no babies. Nada.

And why is this relevant?

There are many things that can shut down the GnRH signal from the hypothalamus and thus cause amenorrhea. A few include..

  • High energy expenditure (like endurance athletes)
  • Stress (cortisol)
  • Melatonin (the sleepy hormone – you would have to take a shit load of this though)
  • Pregnancy and breast feeding
  • Menopause and hormonal disorders like PCOS
  • Certain medications
  • Low leptin levels

What is leptin? Leptin is a hormone that is secreted after meals to tell your brain that you are satisfied and to stop eating. It is also produced as a baseline depending on body fat levels. The more body fat you have, the more leptin. Women with very low body fat do not have enough leptin to signal the brain that they are healthy and thus will not secrete enough GnRH or FSH and LH to begin a menstrual cycle. This can be due to working out too much, not eating enough, or both. Enough body fat means that the body is healthy enough and has enough energy stores to sustain a pregnancy. The body is smart. Its not going to let you grow a fetus if you can’t even afford to not eat for a couple days. Shit happens.

So if you aren’t having a period, you can’t sustain a pregnancy. But if you don’t want to become a mother right now, then it’s no big deal, right?

Wrong.

Having a menses is for more important than just getting preggers. It means you have adequate estrogen, and estrogen is ABSOLUTELY ESSENTIAL for bone growth.

This shows the pathway between the brain, pituitary, ovaries, and bone destruction. 

When estrogen binds to receptors in bones, it stimulates the production of a protein called OsteoProtyGerin (OPG). OPG binds to osteoclasts (cells that break bones down) and prevents them from growing and proliferating. Thus, it has a bone protective effect. Estrogen also stimulates the production of growth hormone, which stimulates the production of IGF1. Both growth hormone and IGF1 contribute to bone growth. They are responsible for bone matrix formation, CALCIUM DEPOSITION, and bone cell proliferation and maturation. Therefore, estrogen is essential to both growing bones and preventing their breakdown. Unfortunately, bone break down is constant – we are constantly remodeling our bones to maintain adequate blood calcium levels. So estrogen is needed throughout our lives – not just for a couple years to grow our bones. Furthermore, it is now suspected that bone density is greatest between the ages of 18-25, so suffering from amenorrhea during these sensitive years could lead to a lifetime of weak bones and related complications.

The moral of this novel is that if you aren’t having a menses than you are inching closer and closer to osteoporosis and you aren’t at your healthiest state. It is important to go see an endocrinologist and see what’s up! It could be many things, and low body fat is one of the more reversible issues to work with. It doesn’t mean one has to gain tons of weight, stop working out, and eat junk. In fact, weight training helps build bones, so that should always be a part of any weight plan, whether gaining or losing!

In order to prevent bone loss during the weight gain or lifestyle change process, the endocrinologist may prescribe birth control as soon as possible. This is because the synthetic estrogens are still effective at bone synthesis. When I went in to see my endocrinologist, he also said that if I didn’t want to gain weight but I wanted to have kids later on, not to worry, there are drugs for that.

That pissed me off.

But a lightbulb went off. I had always wondered how extremely thin women, like Posh Spice and Nicole Richie had managed to have children despite their skeletor-esq bodies. Turns out, fertility drugs can override the lack of leptin (and body fat) and give you large doses of FSH to stimulate follicle growth. This is just my opinion, but it seems as though that is cheating nature. Furthermore, I worry that could possibly have effects on the child later in life. Again, this is just me playing around with ideas, but there are studies out there that indicate that babies born to mothers who were pregnant during a famine or economic depression were more likely to be overweight or obese later in life. The lack of energy (or folate or something else – I’m not sure) altered the epigenetic markings on the fetus’ DNA and thus made the future men or women more prone (but not doomed) to weight gain and resistance to weight loss. Perhaps having a child via fertility drugs when your weight and energy intake isn’t adequate could have similar effects?…

If you have any questions or want any more details, information, whateva, just send me and email or leave a comment!

Why does everyone eat crap?

I am studying for my Food Chemistry midterm and I thought this would be the perfect time to share a bit of what I have learned.

For the vast majority of human existence, until the last couple hundred years, humans have relied on plants and animals for food. Everything was in its native form; no extractions, genetic modifications, or purifucations. Food was food, and people developed knowledge of food through experience through trial and error. They learned what to eat from their native land to sustain themselves and to treat illnesses. This information was passed down orally from generation to generation (think about all the weird-sounding old remedies you hear about for ailments), which is responsible for what we now think of as ethnic foods or cuisines. Humans survived and accomplished all of that without the slightest concept of fat, protein, or carbs, let alone vitamins and minerals.

Bison

In the 1900′s, science and technology made great advances. We began to look at molecules and then the atoms that make up the molecules. John Dalton created atomic theory.

This is when we started to reduce food to its constituent properties. We began to tear it apart and stare at it in a microscope. We learned about the differences between lipids, amino acids, and carbohydrates. We discovered all of the essential nutrients.

Mucci fungus

What did we do with this knowledge?

Scientists began to connect certain diseases and illnesses with nutritional deficiencies. Even some mental conditions were not mental conditions at all, but simply severe malnutrition of a particular nutrient. Curing the sick and saving lives through diet was a huge success.

And then

We began to mildly overdose the entire population.

Iodine in salt, fluoride in water, enriched wheat flour, the list goes on.

“What better way to protect the people from illness and death than to add nutrients to their food and water supply? So what if not everyone has a nutritional deficiency, lets just take care of them all by overshooting a little bit! As long we stay within the safe range, giving them a bit extra isn’t going to do any harm.”

Except it has.

By invisibly adding nutrients to food products, the government and regulatory agencies have invisibly cured many diseases. No one in the US now is worried about getting a fat goiter on their neck or having their teeth fall out (from scurvy). We don’t even need to think about diseases related to nutrition because most of it has been taken care of for us. Adding nutrients to our food supply has taken nutrition out of our consciousness. It is elective, optional even. Now, we eat for taste. Companies sell their products for taste. As my professor puts it: “The food supply competes on an almost purely hedonistic (delicious) functionality axis.”

Goiter

Of course, this has also been very good for us. The average life expectancy is now over 90 years. That is 3x longer than just over a century ago! (However, since just 1985 we are also 3x more obese.)

Even though we are no longer at risk of dying due to lack of vitamin C or protein, we now have a responsibility to take our health, education, and nutrition into our own hands.