Nutrition ABCs...F is for Fat (Part Two)

My first post on fat described what fat actually is and why we need it. Today, let's talk practicalities - which fats you want more of and what food choices you can make to get you there. As promised, here are the good, the bad and the ugly - where fats are concerned.

Good Fats

Mono-unsaturated fats

Mono-unsaturated fats are found in most plant-based oils such as extra virgin olive oil, nuts, seeds and avocados. They do not increase your risk of disease although eating too much of them, like any fat, might add a little padding to your bottom line. Replacing saturated fats or processed carbohydrates with mono-unsaturated fats can help lower cholesterol and risk of heart disease. This type of fat is the mainstay of your healthy fat menu.

What does this mean for you? Use extra-virgin olive oil as your main culinary fat. Don't pour with abandon - you really only need about 1/2 - 1 tsp of oil per person when you cook. Enjoy avocado, raw nuts, seeds and nut butters more often as these whole food sources of fat come complexed with many other nutrients like fibre.

Poly-unsaturated fats

Poly-unsaturated fats are also found in plant-based oils, usually the nuts and seeds. Soy beans, dark green leafy veggies, algae and cold water, oily fish are also rich in poly-unsaturated fats. There are many different poly-unsaturated fatty acids but the ones with all the hoopla are the omega 3s and omega 6s. Essentially, they are twins - one is kind of evil, one is nicer. Both are necessary to your health. It is when these two are out of balance that our health suffers. Here's why:

Omega 3 fatty acids are precursors for molecules that are generally anti-inflammatory. Omega 6 fatty acids, with few exceptions, are precursors for molecules that are pro-inflammatory. The jury is still out on the "perfect" ratio of omega 3s to omega 6s. However, it should look a lot closer to 1:2 or 1:4 rather than the 1:10+ typically seen in the standard American diet. How did this come to be? Well, you see the list above of omega 3 food sources? Not exactly on the menu at Taco Bell. These are very healthy foods that just aren't that common for many people. What is common is fast food, "convenience" foods and tons of processed flour and sugar-rich baked goods that also feature tons of cheap, omega 6-laden fat like soy and corn oil.

What does this mean for you? Eat fewer processed and fast foods; rid your cabinet of margarine and cooking oils (except olive oil) to reduce your intake of omega 6s. If you are allergic to dairy or vegan, consider using an organic coconut oil-based spread but use it sparingly. Increase your intake of oily fish (if you eat fish) like herring, sablefish and salmon; eat more flax, hemp, pumpkin and chia seeds and dark green leafy veg to increase your omega 3 intake. 


If you choose to supplement, don't pay for a 3-6-9 supplement; you get plenty of 6 (most foods) and 9 (olive oil!) already. Don't buy into the marketing. Look for EPA and DHA in your supplement, as these are the omega 3 forms that are most rigorously tested in a clinical setting. I like the new algae-based supplements from a sustainability standpoint. They don't contain EPA but the body can inter-convert DHA to EPA and they usually contain oils that can theoretically increase EPA in the body.

Less Good...and sometimes bad

Saturated Fats

Saturated fats come mostly from meat and dairy and can also be found in tropical oils - such as palm and coconut. We used to think that saturated fat was terrible for you and then the team at Harvard School of Public Health published a review article that challenged this thinking. We come back to these kinds of contradictions time and time again in nutrition science. Why? In my opinion, it is because we don't eat tubs of saturated fat. We eat food. And each food is a complex substance filled with different nutrients and co-factors that we still don't fully understand. And we eat these foods in the context of diets and lifestyles that change their impact. 


So what is the current thinking on saturated fat? Generally speaking, it falls into the "a little is fine, too much is bad" category. We need some saturated fat in our diets. However, the foods and eating patterns associated with a higher intake of saturated fat (meat, dairy, fast food...) are the same ones that will point us in the direction of less healthy choices and risk for obesity and chronic disease. So look to minimize your intake of saturated fats. And what about coconut oil? Don't believe the hype - it will not cure your cancer or help you to lose 10 lbs without dieting. However, the "new" coconut oil is far less processed than the stuff that used to fill processed food in the eighties. It appears that plant-based saturated fats won't raise blood cholesterol as much as animal-based ones. But they still can't touch the health benefits of mono-unsaturated or omega 3 fats. 

What does this mean for you? Eat a modest amount of lean meats such as poultry and seafood and just a bit of red meat (if you eat meat!). Remember that meat servings don't need to be bigger than a deck of cards. Skim the fat from milk and yogurt; eat smaller portions of cheese - don't just slather everything with it. Save good quality (preferably organic) butter for occasional baking. Enjoy good quality coconut oil in recipes if you like but don't start eating it with abandon. Saturated fats are not something you need to actively seek out...there is a small amount of saturated fat in almost every other fat source we consume.

Down-Right Ugly

Industrial trans fats

A trans fat is made in two ways: the first, due to the miracle of a cow's many stomachs; the second, as a marvel of modern science. The first way does not appear to cause any harm and may even have some benefit. The second needs to be eradicated from our food supply. It is highly inflammatory; it raises our bad cholesterol and even worse...lowers our good cholesterol. It exists for the sole purpose of extending the shelf life (and profit margins) of foods we shouldn't be eating in the first place. I won't bother with much of a debate. These things are terrible.


What does this mean for you? Beware the "trans fat free" food. If a food contains less than 0.5 grams of trans fat per serving, it can be labelled trans fat free. However, if you eat 6 cookies with 0.3 grams of trans fats each, you have just consumed 1.8 grams. Doesn't sound like much, but it is essentially your "safe" daily limit for trans fats. Instead, avoid fried foods in restaurants and fast food outlets as these are most at risk for being filled with trans fats. Ditto for cheap baked goods like cookies, muffins and pastries. Read ingredients lists: if you see the words shortening, margarine or hydrogenated fat - take a pass. 


Have a question about fats? Let me know!

Nutrition ABCs...F is for Fat (Part One)

Fat. We love to eat it. We hate it on our backsides. We have tried low fat...and gotten even fatter. We demonized saturated fat and then questioned whether it is really all that bad for us. We have gone gaga for omega 3s but only if they are in the "right" ratio to omega 6s - what is the right ratio, anyway? 


Need the low down on this much-discussed macronutrient? Read on, my friends...read on.

Let's start with the basics. What is fat? 


A dietary fat is composed of a glycerol backbone and 3 fatty acid tails. The type of tails determines the structure and function of the fat. If the fatty acids are saturated, they line up nice and snug and are solid at room temperature, like butter and coconut oil. If the fatty acids are missing one little hydrogen molecule, it is called a mono-unsaturated fat. At room temperature, these are liquid fatty acids such as oleic acid, the primary component of olive oil. If there is more than one hydrogen molecule missing, the liquid fat is called poly-unsaturated. These are your omegas. These fats are so "fluid" and flexible that they stay liquid even when cold. Think of flax oil - it doesn't turn solid in the fridge like olive oil does.

What does fat do in our bodies? 

A dietary fat has 9 calories per gram, compared to 4 calories per gram for protein or carbohydrate. It is a concentrated source of energy. When we eat fats, they are digested into fatty acid components so they can be absorbed into the body. Once across the gut, they get repackaged into a molecule called a chylomicron that is transported to the bloodstream so the fatty acids can be carried to cells that need them for energy. And if the cells don't need that energy...the fatty acids travel to fat cells for storage.

We need some fat to help us absorb the fat soluble vitamins A,D,E + K and some of the fat-soluble phytochemicals, such as lycopene in tomatoes. Fatty acids also carry flavour so that we enjoy food more. Fatty acids become incorporated into our cell membranes, which is essentially the bag that holds the cell contents. Eat more saturated fats and your cell membranes will be more saturated. Eat more omega 3 fats and your cells will contain more omega 3s. Fatty acids are also the starting material for cell signalling molecules that can cause muscle contractions or even influence the immune system. 

While fat can contribute to weight gain when consumed in excess, it is really the quality of fats that matter most - not the quantity - when we are talking about good health.

So in my next post, we'll break it down and talk the good, the bad and the ugly.

To Eat...or Not to Eat...Seafood

Image from http://www.vanaqua.org/oceanwise/ocean-wise-heroes.html

Five weeks in, the sleepless nights are now starting to add up and my little bundle of joy is robbing my brain of valuable thinking time. Well, at least I tell myself that my thinking time is valuable...So my "baby brain" has to thank my friend Steve for all of the good blog post ideas he has been providing me of late. 


Surprisingly (or not, for any other health professionals out there), very few of my friends or family actually ask me for nutrition advice. What is even more humorous is the discussions that occur regarding health or nutrition in my presence without anyone even so much as glancing my way. I have gotten used to just shutting my trap when this occurs because I have learned that unsolicited advice is rarely accepted with a smile. Maybe that is why I started this blog in the first place...to spew out all the information held hostage in my brain.


My friend Steve, however, is one of the few exceptions to this rule and a few days ago he asked me about what kind of seafood he should be eating, other than salmon (which is all most nutrition literature talks about). At the bottom of the email, he casually mentioned that the topic would make a good blog post and since I was stumped on what to write about next...voila!


Seafood is an interesting discussion, both from a nutrition perspective and an environmental perspective; one topic which I can claim to have a decent background in...the other, not. Here in BC, we are pretty fortunate to have the king's ransom of seafood at our doorsteps but few of us venture outside of a handful of comfortable favourites: canned tuna, fish and chips, salmon and prawns. When it comes to seafood, there are really two categories to choose from - the "superfoods" and the "healthy options". Read on, Steve...read on...


The Superfoods 
You guessed it, these are the cold water, fatty fish such as herring, mackerel, sardines and salmon. If you were only to eat one serving of seafood a week, make one of these stars your choice. Why are these so good for you? It isn't just the omega 3 fats...but that's a start. 


Omega 3s Cold water oily fish such as salmon are rich in anti-inflammatory omega 3 fats and what makes them really special is the kind of omega 3 fats they contain. We get ALA from vegetable omega 3s like pumpkin seeds and hemp seeds but fish give us what are called the "long chain" or "preformed" omega 3 fats, EPA and DHA. EPA and DHA are not technically essential fats because in theory, our body can make EPA and DHA from ALA - but we suck at it. The most efficient of us turn about 20% of the ALA we eat into EPA and DHA, which are the potent omega 3s in the body; some of us can only convert 5%. So getting your EPA and DHA directly from fish makes a lot of sense, because we know that these two fats can help us soothe chronic inflammation, help us prevent chronic disease and even boost our brain function. In fact, EPA and DHA are so good for you that they are one of only two supplements I recommend everyone take, unless they eat 3 good sized servings of fatty fish a week. Wild fish is your best source; it used to be that it had far greater amounts of omega 3 fats than farmed but of course the farmers just started adding omega 3 to the feed to boost the level in the farmed fish. Nothing like "design your own" salmon...come on, people...eat wild! If your seafood does not specifically say "wild", it isn't.....so look for the label.


Vitamin D The next reason that these fish are so good for you is vitamin D, the other of the two supplements I recommend every man, woman and child consume. You can see my post on vitamin D here. There are very few natural food sources of vitamin D, which is critical for our immune function and likely helps us to prevent cancer. Salmon is the star here, with the most vitamin D: a wild Sockeye Salmon steak can have as much as 900 IU of vitamin D (which is 90% of the 1000IU that many experts are now recommending as a daily dose). Nothing else in nature comes close to this level.


Antioxidants Again, gorgeous wild salmon is the star here (remember, colour equals antioxidant pigments) and in salmon, it is the pigment astaxanthin that is responsible for the lovely colour. Same old story with farmed salmon...that pink colour is added via feed manipulation. A unique member of the carotenoid (like beta carotene) family, astaxanthin does not convert to vitamin A in our bodies but the significance of this is not really known. Astaxanthin is being studied for its potential role in reducing inflammation, protecting our skin from sun damage and preventing cancer.


The Healthy Choices
This is the category I will lump most other seafood into. Fish and seafood stand out for being beautifully lean sources of protein, making them a great addition to the diet. White fish and shellfish are low in fat and calories and nutritious: scallops are rich in heart healthy magnesium and anti-oxidant selenium; oysters excel for blood building iron and skin loving zinc and sablefish boasts the electrolyte potassium for healthy blood pressure. I generally recommend that (non-vegetarian) folks divide their daily protein choices between vegetarian sources, poultry and fish throughout the week for better health and choose red meats only occasionally.


There is one health caveat with shellfish and that is the cholesterol in foods like shrimp and lobster. However, these foods contribute very little cholesterol to our diets in comparison with red meats and cheese. In addition, unless you have a significant cholesterol problem, it is the saturated fat in our diet that we worry about with regards to our blood cholesterol levels than our dietary cholesterol intake so feel free to enjoy shrimp every once in a while, guilt free!


Mercury and other Contaminants
The biggest health risk that seafood poses is that of the neurotoxic contaminants, mercury and PCB. When it comes to seafood and contaminants, think to yourself: "Good things come in small packages." Women who are or can become pregnant and children are most vulnerable to dietary exposure to mercury and should take care to avoid highly contaminated species of fish. 


Since contaminants like PCBs and Mercury are not excreted, they accumulate as you move up the food chain - yes, that goes for us too! All the fish we eat (if we are eating highly contaminated species) deposit these nasty toxins into our own system where they stay put and wreak havoc with our health. The superfood fish are all low in contaminants because they are small fish. Stay away from the "big game" fish like swordfish, marlin, shark and fresh tuna. When buying canned tuna, choose light tuna over white tuna, which comes from smaller tuna species. 


Which fish are best for you when it comes to contaminant levels? Rather than have me reinvent the wheel, read this Health Canada article which lays it all out on the line...pun intended.


Sustainability
Now for the larger question...is it sustainable to eat seafood at all? This is a far more complex issue. With the best Sockeye Salmon run we have seen in BC in years, this little voice might get pushed to the back of our minds as we clammer down the dock to buy this delicacy by the bushel load. As news of the health benefits of eating fish grew, our appetite (and therefore demand) for seafood, salmon in particular, grew alongside. And what the affluent Western world wants, it gets - to the detriment of less affluent nations that used to rely on seafood as the main source of protein in their diets.


As our love for seafood grew, we learned to choose wild over farmed, line caught over trawled and local over exotic. These changes went a long way towards "greening" our seafood choices. However, some experts argue that we should refrain from eating seafood at all as even stocks of typically "sustainable" sardines and mackerel in South America and Scandinavia are at risk of overfishing (some say that we are already there) to supply us with fish meal used to fatten up farmed salmon. Others, like the pioneering chef Frank Pabst at Blue Water Cafe believe in introducing us to less favoured items like sea urchin and jellyfish. 


I will stop there or risk exposing my lack of depth when it comes to exploring this topic. Where you stand on this issue is a personal choice but there are some great resources to help you make your decisions. Home grown Ocean Wise is an education program from the Vancouver Aquarium which guides you towards local businesses providing sustainable seafood options, designated by the Ocean Wise logo. The website also provides a list of more sustainable species. The Monterrey Bay Aquarium has its own program called Seafood Watch, where you can print off a handy little pocket guide that I like because it organizes itself with a stoplight system to categorize sustainable choices and also alerts you to high mercury choices so you can avoid them. If you have an iPhone, you can even download an app to keep at your side as you shop and dine. 


In good health,
Desiree