Fats, Part 3--Unsaturated Fats

For many years, I didn't eat nuts.  Not because I didn't like them, but because they contained fat.  And everyone knew fat was "bad".  Thank goodness, we have now come out of nutritional darkness and into the light!  Nuts are a great source of unsaturated fats.  And now a moderate amount of nuts are part of my daily diet.

In the first Fats post, I covered Fat basics and trans fats.  And in Fats, Part 2, I covered saturated fats.  Now it is time for unsaturated fats to shine!

A little more about unsaturated fats

Unsaturated fats are important to good health.  Replacing saturated fats with unsaturated fats reduces heart disease risk and LDL (bad) cholesterol levels. 

In unsaturated fats, some carbons are joined by double bonds, making the fats "bendy" and usually liquid at room temperature.  This also means unsaturated fats are more likely to spoil.  A single double bond means that the fat is monounsaturated.  Two or more double bonds is described as polyunsaturated.  To save my typing fingers, I will use MUFA for monounsaturated fatty acids and PUFA for polyunsaturated fatty acids.

Unless you live under a rock, you probably have not missed packages touting food products as great sources of omega-3 (not a great thing if you have a fish allergy as many products have fish oil added).  Omega-3 and omega-6 are both PUFA.  The number just indicates the location of the first double bond.  Most MUFA are in the omega-9 group.

One key point to remember is that oils and solid fats are a mixture of saturated, MUFA, and PUFA.  For a quick comparison of three common cooking fats: 

Amt per Tablespoon in grams	Saturated Fat	MUFA	Linoleic Acid (a kind of omega-6 PUFA)	Alpha-linolenic Acid (a kind of omega-3 PUFA)
Canola Oil	1.0	8.2	2.8	1.3
Olive Oil	1.8	10.0	1.1	0.1
Butter	7.2	3.3	0.3	0.2

(data taken from this 2007 PDF)

As the table above notes, linoleic acid is part of the omega-6 family (and is its primary member).  Alpha-linolenic acid (or ALA) is the primary member of the omega-3 family.  Both of these fatty acids are essential, meaning the body cannot create them.  They must be consumed via diet. 

Using ALA, the body can make small amounts of DHA (docosahexaaenoic acid) and EPA (eicosapentaenoic acid), two important omega-3 fatty acids.  However, the conversion is not very efficient.  While ALA is found in plant sources, DHA and EPA are found in animal (fish) sources.  This difference has led to the recommendation that we consume fatty fish as a means to increase our omega-3 intake.

Omega-3 fatty acids get a lot of attention as they have been implicated in lowering blood pressure, reducing inflammation and other health benefits.  However, before you start taking big doses of fish oil, remember that these supplements are not regulated by the FDA (buy only a trusted brand).  Additionally, there are possible side effects of too much omega-3:  interference with wound healing, suppressed immune function, and increased prostate cancer risk.  Omega-6 fatty acids are essential, but have also been implicated in some negative impacts like promoting clot formation and blood vessel constriction.  But, as we see from omega-3's pluses and minuses, balance is key.

Balance--the omega-6 to omega-3 ratio

Both omega-3 and omega-6 fatty acids used the same enzymes in the body.  As a result, they compete for those enzymes and sometimes oppose each other's actions.  Given this competition, there has been much interest in the "ideal" ratio between omega-6 and omega-3.  Suggestions for good ratios to maximize health range from 4:1 (omega-6 to omega-3) to 10:1.  Typical Western diets are 15:1, but like more because of our high intake of animal fats and corn oil.  Generally, it is thought we should try to increase our omega-3 intake to get our ratio in balance. 

How Much?

There is no recommended daily amount (RDA) for omega-3.  The current suggested Adequate Intake for ALA is 1.6 grams for adults males and 1.1 grams for adult women.  Canola oil has 1.3 grams per tablespoon and walnuts are at 0.7 grams per tablespoon.  Pretty easy to meet this suggested amount.  More study will be needed to come up with an RDA for ALA, DHA, and EPA.

A Few Food Sources (this is by no means a comprehensive list)


Monounsaturated Fats 

Great post-run snack of toast and
fresh ground peanut butter

• Peanuts and peanut butter (consider natural peanut butter without added sugar or fat)
• Avocados
• Nuts: raw or dry roasted (great table of fat amounts on the Mayo Clinic's website)
• Olive Oil
• Canola Oil

Polyunsaturated Fats

Omega-3

• ALA--flaxseed and canola oils, flaxseeds, eggs (from hens raised in pastures or fed flaxseed meal), walnuts, green leafy vegetables (check out this link for an extensive list)
• EPA and DHA--Fatty fish like sardines and salmon (consider opting for wild salmon which has less saturated fat than farmed)

Omega-6
Corn and soybean oils, whole grain bread, animal fats

Additional thought--As I noted in my previous post on saturated fats, pastured animals have a better omega-6 to omega-3 ratio and contain more unsaturated fatty acids.

What to cook with?

For a great overview of cooking oils, Eating Well covered the options in their September/October 2014 issue.  In short, canola makes a great choice for cooking because of its high smoke point.  The smoke point is the temperature at which the oil breaks down and harmful chemicals are created.  If you are using low heat, consider olive oil for sautéing (extra virgin olive oil has a low smoke point).  And extra-virgin is always a good choice for salad dressings and for finishing a dish.  Butter also has a low smoke point, so it is best for low heat sautéing or baking.

What to eat?

If I have taken away any lesson from these posts on fats, it is the need to eat real food and all foods in moderation.  Marion Nestle writes in What to Eat that she doesn't worry about the omega-6 to omega-3 ratio because she gets these PUFA from foods, not oils.  She notes, "...you are better paying attention to your overall dietary pattern than worrying about whether any one single food is better for you than another."  As Dr. Frank Hu notes in a New York Times article, "The single macronutrient approach is outdated.  I think future dietary guidelines will put more and more emphasis on real food rather than giving an absolute upper limit or cutoff point for certain macronutrients."

Perhaps we would do well to take a page from Brazil's new dietary guidelines.  The second point is:
Use oils, fats, salt, and sugar in small amounts when seasoning and cooking natural or minimally processed foods and to create culinary preparations
 
But Brazil's overall focus is on cooking, eating real food, and community.  As it should be.

References

All quotes and sources are linked in the above text.  General nutrition information came from Whitney and Rolfes' Understanding Nutrition, 13th ed., from Nutrition for Sport and Exercise, 2nd ed. by Dunford and Doyle, and from Marion Nestlé's What to Eat.

   

Fats, Part 2--Saturated Fats

My girls love steak.  And I truly enjoy a great medium-rare filet mignon at Morton's.  So I have to admit that I went into my research on saturated fats with desire to find reasons to continue my meat-eating lifestyle!

In the first post on fats, I covered Fat Basics, a quick overview of the types of fats.  In this post, I will focus on saturated fats, with unsaturated fats the focus on Fats, Part 3.  However, it is important to remember that fat containing foods are often a mixture of saturated and unsaturated fats (and, sometimes, trans fats).

Recommendations on Saturated Fats

In my last post, I covered the current recommendation that no more than 10% of daily calories should come from saturated fats.  However, there has been a lot of attention on saturated fats lately.  Basically, the newest focus comes from a meta-analysis published earlier this year.  In this paper, researchers went back and looked at many different studies and determined that there is no evidence that consuming saturated fat increased heart attacks and heart disease. 

As noted in an overview of the paper, saturated fat does increase LDL ("bad") cholesterol, but it also increases good HDL cholesterol.  And the LDL increased by saturated fat is LDL pattern A, generally thought to be benign.  LDL pattern B is the artery-clogging kind and is actually associated with a high carbohydrate/high sugar diet.  Additionally, researchers found that the saturated fat in milk and milk products were associated with decreased heart disease risk.  Not surprisingly, the meta-analysis found a link between trans fats and heart disease. 

Given this study, how much saturated fat should you be eating?  Is butter back?

In All Things, Balance

The meta-analysis is the latest study to look at the question of saturated fats.  But my guess is this story is far from over.  Remember, nutrition is a young science and what might seem like the "right" path today could change over time.  Keep in mind, everyone thought partially hydrogenated oil seemed like a great idea until evidence against trans fats started piling up.  My take?  This study is not a license to consume a giant mound of bacon (my dear husband, I am thinking of you as I write this sentence), but to consider adding a few saturated fats back into your life.  A little shredded Parmesan cheese is just what my girls needed to enjoy broccoli.  Indeed, Ellyn Satter in her Secrets to Feeding a Healthy Family advocates the use of butter (and salt) to help make vegetables more palatable for children.  Just remember, at 9 calories per gram, fats can add up quickly (proteins and carbs are 4 calories per gram). 

By the way, if you do decide to cook bacon, try the oven.  Perfect bacon with less mess!

Saturated fats vs Unsaturated fats vs Refined carbohydrates

In several commentaries on the meta-analysis, experts pointed out that while replacing saturated fats with unsaturated fats is generally a step in the right direction, replacing fats with refined carbohydrates and sugars is not.  As I mentioned previously, many experts believe that in our rush to expel fat from our diets, we ran headfirst into a pile of sugar and Snackwells, leading in part to our current obesity issues. 

To examine this in the real world, I decided to look deeper into a standard morning breakfast.  I often make my girls English muffins spread with butter.  But would jam be a better choice?  This morning, I measured a typical spread on the muffins.  I usually buy local berry jam at my farmer's market, but for this analysis used Bonne Maman Raspberry jam.  Additionally, we use butter from pastured cows, delivered by South Mountain Creamery.  For this analysis, I used Whole Foods butter.  In both cases, I used these products as nutrition information is readily available. 

	Jam	Butter	Whole wheat English muffin	Whole wheat English muffin  and Jam	Whole wheat English muffin and Butter
calories	67	50	120	187	170
total fat (g)	0	5.5	1.5	1.5	7
sat fat  (g)	0	3.5	0	0	3.5
carbs  (g)	17.3	0	24	41.3	24
sugar  (g)	17.3	0	1	18.3	1
fiber  (g)	0	0	3	3	3
protein  (g)	0	0	7	7	7

Four grams of sugar is the equivalent of 1 teaspoon of sugar.  The English muffin with jam, in red, is sporting over 4 teaspoons of sugar.  But the muffin with butter has just one gram of sugar.  Additionally, the buttered muffin has just under 16% of the daily saturated fat intake for a 2,000 calorie per day diet (3.5g x 9 cal/g = 31.5 calories.  31.5 is 15.8% of 200 calories).  Additionally, while the sugars in the jam are processed by our bodies quickly, the fat in the butter provides satiety, resulting a feeling of fullness longer.  This satiety may result in fewer calories consumed later.  Best choice?  A little butter on your English muffin.


Real food vs Donuts

To me, it is important to look at your saturated fat intake in context and make choices based on what the rest of the food's nutrition profile.  Taking a look at a few foods: 

	Total Fat	Saturated Fat	Protein	Carbohydrates
Egg	5 g	1.5 g	6 g	0 g
Whole milk (1 cup)	8 g	5 g	8 g	12 g
Krispy Kreme donut	11 g	5 g	2 g	21 g
Butter (1 Tbsp)	11 g	7 g	0 g	0 g
Starbucks grande frappucino (skim, with whip)	11 g	7 g	4 g	72 g
Starbucks grande gingerbread latte (2% milk, with whip)	13 g	8 g	12 g	42 g

For years, I steered away from eggs.  But with just 1.5 grams of saturated fat and a good serving of protein, they are a great food choice.  Moving to two items with 5 grams of saturated fats, the better choice is whole milk with its protein, vitamins, and minerals (and fewer sugars).  The saturated fats of the Starbucks drinks mostly come from the whipped cream, but the 7 grams in butter doesn't come with a huge helping of sugar.  As Mark Bittman writes in his Butter is Back article, we need to eat real foods, not processed junk.

Cows and Chickens--They are what they eat

Meats and animal products are a major source of saturated fat in our diets.  But animals, whether fish, fowl, or cow, are products of what they eat and that, in turn, alters their fat profile.  Conventionally raised dairy cows, cattle, and chickens don't eat the grasses and, in the case of chickens, bugs, that they are designed to eat.  Instead they eat corn, soy, and other commercial feed. 

Several studies have shown a better fat profile of eggs, milk, and beef raised on grass or pastured.  In the case of eggs, pastured chickens produce eggs with more omega-3 unsaturated fat and vitamin E and less saturated fat.  In our house, we often eat eggs from the farmers market or  Vital Farms Backyard Eggs.  Vital Farms chickens forage and are given additional feed.  Unfortunately, their packaging uses the standard nutrition information for eggs (1.5 grams of saturated fat).  I emailed Vital Farms, but they have not done independent testing on their eggs.  In this case, I am relying on the overall science regarding the fat profile.  Plus the eggs just taste better!

For more comparisons, the Union of Concerned Scientists summarized many studies of pasture vs conventional feeding on the fat profiles of milk (page 41) and steak (page 44).

The differences may be small.  For example, Organic Valley produces a conventional butter and a pastured butter.  Both butters have 7 grams of saturated fat per tablespoon, but the pastured butter has better balance between the omega-3 and omega-6 unsaturated fatty acids (an issue that I will cover more fully in the next post). 

These are small differences, as noted in an article on grass-fed beef, and may or may not play a significant role in our overall health.  Our family typically eats beef once or twice a week.  I usually buy grass-fed because I know that if we eat out, our beef is likely conventionally raised.  I am hoping to balance our diet.  However, grass-fed beef is expensive.  If I had to choose, I would spend my money on pastured items we eat more frequently, like eggs and butter, thinking that the cumulative effect of these pastured foods may have more impact.

References
All quotes and sources are linked in the above text.  General nutrition information came from Whitney and Rolfes' Understanding Nutrition, 13th ed., from Nutrition for Sport and Exercise, 2nd ed. by Dunford and Doyle, and from Marion Nestlé's What to Eat.