Wednesday, July 15, 2015

Micronutrients: minerals


The second class of micronutrients to be introduced is the minerals. Minerals can improperly be referred to as atoms: they are chemical elements as found in the periodic table, the main picture of this post which some people may be familiar with from chemistry classes.

Don't worry, I won't be doing a chemistry lesson today...

Although they come in molecules (sometimes organic molecules) minerals themelves cannot be synthetized by our bodies and must therefore be introduced regularly through the diet.

Macrominerals and microminerals

Minerals can be further classified into macrominerals and microminerals, based on the daily requirement and their role in the body.

Macrominerals often take part to the building structure of our body itself, notable examples are Calcium and Phosphorus (our bones are mainly made of these two minerals).

Micromineals are required in extremely small amounts, they are required only to trigger some metabolic reactions. Microminerals are also called trace minerals.

MacromineralsMicrominerals
CalciumIron
PhosphorusBoron
PotassiumChromium
MagnesiumIodine
SulfurManganese
SodiumMolybdenum
ChlorideSelenium

Silicon

Vanadium

Zinc

Lithium

Germanium

Rubidium

Minerals deficiencies

It would be utterly unrealistic to think of fitting everything about minerals deficiencies in one paragraph of a blog. Our health depends on a good balance of minerals in the diet, some deficiencies are more widespread that usually believed.

People are mostly familiar with iron deficiency (which causes anemia), iodine deficiency (hypothyroidism) and calcium deficiency (rickets, bone health).
Just to mention some others:
  • Zinc plays a role in several metabolic processes especially the production of hormones, it is required to produce HCl in the stomach. Most people are zinc-deficient to some degree
  • Magnesium is required to produce serotonin, optimizes digestion, needed in order to produce ATP (the energy molecule of muscles)
  • Selenium, potent antioxidant, it helps with thyroid health and supports the kidneys, protects against the toxicity of other minerals (for example mercury)
  • Chromium, originally considered toxic, is needed for the metabolism of glucose
  • Sulfur enters into several metabolic pathways. It is also required for liver detoxification
  • Chloride: ever wondered what the Hydrochloridric Acid is made of?
List again is far from being complete. With time I'll dedicate special posts for each mineral, their roles and the preferred food sources.

Roles of minerals in the body

As with other nutrients, minerals have multiple roles in the body.
  • Act as cofactors for enzyme reactions
  • Maintain pH balance of the body
  • Facilitate the transfer of nutrients across cell membranes
  • Maintain proper nerve conduction
  • Contract and relax muscles
  • Regulate tissue growth
  • Regulate osmotic pressure of fluids in the body
  • Provide structural and functional support

So far so good

We completed the list of macronutrients (carbohydrates, fats, fats again, proteins) and the micronutrients (vitamins and minerals). These are the bases on which we can seriously start discussing about nutrition.
In the next post I will speak about nutrient density, it is the very starting point to healthy eating. It will also help create a "nutrients awareness" that will help in evaluating everyday's choices and (why not?) build some critical thinking towards diets that forbid some foods, usually for dogmatic reasons, or restrict calories for weight loss or for the alleged health benefits of eating less (partially true, but...).

How food is prepared is very important to get the most out of every ingredient. Needless to say: stay tuned!


Tuesday, July 7, 2015

Micronutrients: vitamins


So far I have been speaking about macronutrients. In order to be healthy we need to introduce them in quantities that are in the order of hundreds of grams (carbohydrates, fats and proteins) on a daily basis.

Micronutrients are nutrients that are needed in smaller amounts (less than one gram) with some being needed in traces. Despite the small requirements, they are fundamental for optimal health. Some of them are essential, meaning we have no choice and need to introduce them regularly through a balanced diet. Deficiencies in some micronutrients are the root cause of diseases such as:
  • Beri-Beri (Vitamin B1)
  • Ariboflavinosis (Vitamin B2)
  • Pellagra (Vitamin B3)
  • Paraestesia (Vitamin B5),
  • Hypocobalaminemia (Vitamin B12)
  • Scurvy (Vitamin C)
  • Rickets (Vitamin A, D, K2 and Calcium)
  • Night Blindness (Vitamin A)
  • Hypothyroidism (Iodine)
  • Anemia (Iron)
  • Kesha disease (Selenium)
Some conditions don't have a specific name but are still caused by micronutrient deficiencies:
  • Vitamin K deficiency (difficulty in coagulation)
  • Biotin deficiency (Vitamin B7)
  • Zinc deficiency (several non-life threatening signs and symptoms, zinc deficiency is far more widespread than usually thought)
The two lists are obviously incomplete, I just wanted the readers to realize how important these small molecules are and maybe scare them a little: you wouldn't believe how many people in the civilized world are borderline with the intake of some vitamins: bleeding gums is the first stage of scurvy.

Micronutrients are either molecules (vitamins, bioflavonoids, phytonutrients, enzymes, co-factors, ...) or elements (minerals). Today I'd like to introduce vitamins, the most important amongst the molecule micronutrients for one simple reason: they are essential, meaning we can't produce them.

Water soluble and fat soluble

There are two classes of vitamin, the water soluble (or hydrosoluble) vitamins and the fat soluble (or liposoluble) vitamins. The first are dissolved in water or other watery liquids. The second in fats, this detail is important because without healthy fats in the diet their absorption is impaired.

Fat solubleWater soluble
Vitamin AVitamin B1, 2, ..., 15
Vitamin DVitamin C
Vitamin ECholine
Vitamin KInositol
Para-Aminobenzoic Acid

Where to find them

You may have noticed that the main picture of the post shows one egg religiously fried in butter from grass-fed cows, some grass-fed beef liver, organic blueberries and pickled olives. Normally, a blogger would have introduced the subject with a rainbow of exotic fruits. But this is not simply a blog about on nutrition, this is YET another blog on nutrition, my role is to inform with state of the art of science, go against dogmata and - where needed - against Conventional Wisdom and ethics (don't hate me).

Fruits, vegetables, spices, herbs and whole grains are excellent sources of vitamins, bioflavonoids, anti-oxidants, anti-inflammatory compounds... This is where vegans are totally right. Anybody trying to do the Inuit Diet (a 100% meat/fish based diet) is doomed to fail on the long run, despite the initial benefits. Paleo dieters attempting to live on coconut, almonds and bacon simply didn't get what the original idea of paleo itself is... moreover they are experiencing miserable meals from an organoleptic point of view, but this is not me to judge: de gustibus non est disputandum.

The other side of the medal is that several vitamins and other micronutrients which are not perforce vitamins (and therefore less popularized) are only found in animal sources. This is where traditional diets got it right, as Weston A. Price observed during his researches: there is no native culture thriving on a plant-based diet. I would add a corollary: if any culture in the history of mankind ever tried to become vegan they are not here anymore to tell us.

The table below is a not-exaustive list of sources for the most common vitamins.


VitaminSources
A
Egg yolks, liver, oily fish, dairy
B1
Pork, yeast, avocado, wheat germ, spinaches, cauliflower, most nuts, sunflower seeds, legumes
B2
Dairy, leavy vegetables, liver, kidney, legumes, yeast, mushrooms, nuts
B3
Liver, heart, kidney, chicken, beef, oily fish, eggs, avocados, dates, tomatoes, leafy vegetables, broccoli, carrots, sweet potatoes, asparagus, nuts, whole grains, legumes, mushrooms
B5
Almost any food
B6
Meat (pork, turkey, beef), bananas, legumes, potatoes, pistachios, dairy, wheat germ
B7
Swiss chard, raw egg yolks, liver. Can be produced by bacteria in a healthy gut
B9
Almost any food, especially leafy greens, yeast, avocado, asparagus, dairy, meats, eggs
B12
Seashells, egg yolks, liver
C
Bell peppers, kiwi, lemon, lime, oranges, grapefruits, pine needles, bovine adrenal glands
D
Egg yolks, liver, oily fish, dairy
E
Most nuts and seeds, olives, some fruits (kiwi, mangoes, papayas, avocados)
K
Egg yolks, liver, oily fish, dairy, lacto-fermented food
Choline
Almost any food, especially: egg yolks, yeast, wheat germ, fish, meat

Usual question: confused? Some may be. Let's look in detail some of these vitamins to clear some doubts.

Vitamin A

Carrots, apricots, melons and pumpkins, with their wonderful orange colors, are usually considered good vegetable sources of Vitamin A. Unfortunately this is untrue: they are sources of carotenoids, which are not the true Vitamin A, whose real name is retinol.
Some people are good at converting carotenoids into retinol, these are the exceptions, not the rule. Most humans are inefficient in this conversion and some cannot convert it at all, just like the conversion of the ω-3 ALA into DHA and EPA.

In other words: you can binge on carrots and still be Vitamin A deficient.

Vitamin D

This is my favourite vitamin, and it is also the most misunderstood. I started my health journey from here several years ago.
A typical mistake is considering nuts, seeds and their oils as sources of Vitamin D. There are two natural forms: Vitamin D2 (ergocalciferol) and Vitamin D3 (cholecalciferol). The one that is active in the human body is the D3 and is only found in animal sources.
It is also produced in our skin from cholesterol when we expose ourselves to sun rays, unfortunately the sun-phobia, our indoor jobs and the use of sunscreens greatly limit this conversion. Finally, not all of us work as lifesavers in the tropics, the average civilized humans are able to expose themselves to the sun only a couple of weeks per year. Definitely not enough.

In other words: if you expose yourself to the sun only for a short period during the year (and use sunscreen in that occasion), and if you rely on vegetable sources for vitamin D, you can still be Vitamin D deficient, with a number of consequences of health, both short and long termed.

Vitamin E

Let's speak in favour of vegetables now: there are no reliable sources of Vitamin E from animal sources. The group of Vitamins E is definitely from plants, with olives and their oil being by far the most excellent, tasty and versatile source.

In other words: the Mediterranean Diet with its big salads generously flooded with Extra Virgin Oil of Olive wins again.

Vitamin K

Again, there are several forms, with Vitamin K1 and Vitamin K2 being the ones naturally occurring and both being essential for optimal health.
There are no vegetable sources of Vitamin K2 , however this vitamin is the byproduct of the process of lacto-fermentation of some bacteria. Good vegetarian and vegan sources of vitamin K2 are: natto, tempeh, and dairy (especially yoghurt and aged cheese, for lacto-vegetarians).

Vitamin C

This is another Vitamin that comes preferably from plants. It is also highly delicate to oxidation and easily destroyed with temperatures: exposure to 60°C is enough to get rid of it. Now, some food for thought: the bottled orange juice sold in supermarkets is pasteurised, therefore...?

There are sources of Vitamin C from animals, namely the lungs and the adrenal glands. Considering that Vitamin C is quickly destroyed with temperatures, unless you are eating raw lungs and adrenals from freshly butched animals, this is not working for you (it works for the Inuits).

In other words: Vitamin C deficiency is quite widespread and although nowadays nobody is developing scurvy in the western world, for most people the intake is just slightly above the lower limit to prevent diseases. That enough to survive, but with sub-optimal health.

Vitamin B12

This is a hot topic. There are two forms of Vitamin B12. One is from vegetable sources, the other from animal sources. Once again, which one do we, humans, need? The one from animal sources.

However: some studies claim that Vitamin B12 can be produced inside the organism by probiotic bacteria, this is naturally done in the rumen of ruminants.

Can this be replicated in the human gut? There is a certain controversy on this: healthy bacteria usually populate the large intestine, where the Vitamin B12 cannot be absorbed (it is absorbed in the small intestine).

There are cases of vegans with serious Vitamin B12 deficiency after just 5 years, on the other side there are long term vegans (35+ years) which are perfectly healthy. Biochemical individuality? Probably. The question stays open.

Conclusions?

Impossile to conclude here, there is still too much to say. I hope as usual to have answered some questions, but also to have stimulated your curiosity. Let me know in the comments your ideas.

The next topic will be the minerals, after that I will go back to practical examples and soon recipes. Therefore... stay tuned.

Friday, July 3, 2015

Hitchhiker's guide to fats



My original plans were to post more articles on general reccomentations but I have seen, both in the comments on the blog and from people I directly met, that fats is a confusing topic. The reader is King! I will change my plans and today I will write about fats, how to choose them and how to use them.

Good fats and bad fats

This time it is a matter of black and white: there are indeed good fats and bad fats. Where do bad fats come from? And where do we find them?

Good fats Bad fats
Saturated fats Hydrogenated fats
Monounsaturated fats Trans fats
Polyunsaturated fats Margarines
Good fats gone rancid

Hydrogenated fats, trans-fats and margarines are the result of a deliberate industrial process whose objective is to create a fat that is solid at room temperature (butter-like texture) starting from a liquid vegetable oil.

We can also read it in this way: people want something creamy to spread on their crackers but butter has a short shelf life, let's invent something so toxic that even moulds or bacteria won't eat.

Still not convinced? I don't know whether the following picture is real or fake, I haven't performed the experiment myself (but one day I will). If it turns out to be true, it is quite enlightening:


Attention: the unhealthy trans fatty acids are those obtained through industrial processes and do not exist in nature: our body doesn't recognise them as food. There are natural forms of TFA that are beneficial such as the Conjugated Linoleic Acid (CLA), also found in butter from grass-fed cows. I'll speak about them when I'll debunk the myth that butter is bad for you.

Rancid fats are the product of the involontary deterioration of good fats, either by the action of bacteria and moulds, oxidation, exposure to light or to heat.

Bacteria and moulds are a matter of hygene and proper food conservation. Same for oxidation: exposure to oxigen is likely to promote the degeneration of a lot of food.

Exposure to light is an interesting one: ever wondered why good quality oils are sold in dark bottles? That's correct: so that maintain their status of good quality oils. Light can alter the chemical structure of some delicate oils, this is especially true for those composed in prevalence by monounsaturated fatty acids (ex. olive) and polyunsaturated (ex. flaxseed, canola, soy, corn, safflower, ...).

Exposure to heat: cooking with fats

Cooking deserves a special section.

Polyunsaturated fats are by far the most delicate fatty acids that can be found in an oil. They get rancid with light alone, why should they maintain their properties if you use them for baking of frying? The following oils should never be used for cooking, however they do a perfect dressing on salads or poured over steamed vegetables, or an already cooked steak or fish:
  • flaxseed oil
  • sesame seed oil (my favourite, on smoked salmon...)
  • blackcurrant oil
  • walnut oil
  • hazelnut oil
  • argan oil

Monounsaturated fats are "ok" for baking and sauté. Although they can be altered with heat, they tend to maintain their healthy properties longer than PUFAs.
The following oils can be used both as salad dressing and occasionally for cooking:
  • oil of olive
  • avocado oil
  • macadamia oil
Walnut oil, although it contains monounsaturated fats and is usually considered as a source of MUFAs, contains plenty of polyunsaturates as well (63%). It makes a good salad dressing anyway.

Saturated fats are the preferred choice for cooking. Their tolerance to high temperatures make them the perfect fats for baking, sauté and even deep frying. My favourites are:
  • coconut oil
  • red palm oil
  • butter / ghee (clarified butter)
  • cocoa butter (also called theobroma oil)
  • rendered fat from pork, beef, goose or duck

A short note on fish

Fish is a well know source of ω-3 polyunsaturated fatty acids. One of the biggest insult you can do to fish is overcooking of deep frying it. Ideally, it should be eaten raw (sashimi), smoked or marinated (for example 24 hours in lemon juice).

The technique of cooking fish has a great impact on the health benefits that come from eating it, you can turn a healthy food into an unhealthy one in a matter in minutes. Food for thought: what do Japanese centenaries eat? Fried fish... or sushi?

Smoke point, it's just half of the story

So far so good! Polyunsaturated fats are more prone to deterioration in the cooking process than monounsaturated, while saturated are the perfect type of fat for cooking. And this is biochemistry, not marketing.
Unfortunately this is not what we have been told. Still today (and I fear this will be for many years to come) there is a widespread opinion that The-One parameter to choose an oil/fat for cooking is the smoke point temperature.
The table below lists some fats and oil commonly used on cooking, ordered by smoke point temperature, I took the liberty to add an extra column with the percentage of polyunsaturated fats contained in each:

Fat/Oil Smoke point SFA MUFA PUFA
Avocado oil270°C / 520°F11.6%70.6%13.5%
Safflower oil266°C / 510°F6.2%74.6%14.3%
Ghee252°C / 485°F51.4%21.0%3.0%
Canola oil246°C / 475°F7.4%63.3%28.1%
Soybean oil238°C / 460°F15.3%21.7%58.2%
Sunflower oil232°C / 450°F9.0%57.3%29.0%
Corn oil232°C / 450°F12.9%27.6%54.7%
Peanut oil230°C / 450°F16.9%46.2%32.0%
Grapeseed oil216°C / 420°F9.6%16.1%69.9%
Cottonseed oil216°C / 420°F25.9%17.8%51.9%
Tallow (beef)215°C / 420°F49.8%41.8%4.0%
Extra virgin olive oil207°C / 405°F13.8%73.0%10.5%
Cocoa Butter205°C / 400°F59.7%32.9%3.0%
Coconut oil (extra virgin)204°C / 400°F86.5%5.8%1.8%
Lard (meat drippings)192°C / 390°F44.8%41.8%7.6%
Hemp165°C / 330°F9%11%80%
Butter149°C / 300°F51%21%3%


I empowered you with a new piece of information: polyunsaturated fats become rancid and form toxic byproducts when heated. The table above should now speak by itself, maybe our grandmothers were right: lightly frying your breakfast eggs in butter was not a bad idea after all. Ghee is an even better one.

Let's get pragmatic: real life examples

So far the theory. Unless you are a convinced foodie and cook everything from scratch, you may occasionally or even regularly buy prepared food. There is nothing wrong about it and for people who have little time to cook this is sometimes the only solution. But making the right choice is fundamental.

Trans fats have been banned in some countries and on their way to be banned in others, the evidence against them was too strong. This is a good thing, however make always sure they are not mentioned in the label. When in doubt, buy something else. Trans fats are really bad for you: don't forget that fats become cells membranes and hormones, you deserve to be made of good building blocks.

Hydrogenated oils are still widely used, check for them in the label, sometimes the producer is honest enough to mention them. If the label just reads vegetable oil you can be sure they used the cheapest and most degradable oil possible, if it had been oil of olive or extra virgin coconut oil they would have been proud to add them to the list of ingredients.

Food preparations which are cooked and mention sunflower oil, canola oil or soy oil in their labels, probably contain fatty acids that, although healthy in the beginning, are unhealthy now.

Peanut oil, despite its desirable smoke point, is not suitable for frying or deep frying, as it is usually recommended.

Flaxseed oil (an excellent vegetal source of ω-3 fatty acids) is very unstable both at temperatures and to light exposure. The same for canola oil: not only shouldn't they be used for cooking (as the marketing suggest...) they should be stored in a cold place. All nuts oils (walnut, hazelnut, almond, etc) share the same issue. When choosing oils that are made mostly by mono/poly unsaturated fats, look for the cold pressed ones and preferably in dark bottles.

Sesame seeds are probably the most tasty spice I have in my cooking arsenal. A very bad and widespread practice however is to roast them. While it is true that their taste improves adding some bitter torrefacto notes, the impact on the delicate PUFAs is disastrous. Opt for the raw ones, again: you deserve good quality building blocks.

Nut flours

Before closing, I would like to introduce an idea, which I will continue in another dedicated post. And it is about nut flours, a very popular trend in the gluten-free community. The fatty acids contained in nuts (with the exception of coconut), are mostly monounsaturated and polyunsaturated. Question: does it really make sense to use them for baking? Let me know your thoughts.

Summary

This is not even the tip of the iceberg when it comes to fats, I hope I answered some of your questions.

I am also sure that some new questions raised, so in the end the balance is even: as usual, just let me know in the comments your ideas.

And of course... stay tuned!