Cholesterol, saturated fat, coconut oil and stress. They’ve all be indicated in causing (and then preventing) heart disease, but the research can tell a much different story. Over the past few weeks, the American heart Association has villainized coconut oil, claiming that it increased the risk of heart disease because it is a saturated fat. Instead, it promoted the use of canola and corn oils as healthier alternatives. My news feed lit up faster than I could keep up with it, and the conversations had in my medical office over the next few weeks focused primarily on teaching people about fats – and how nutrition interventions are researched.
At the same time I was also questioning the eight years of post-secondary education where I had focused primarily on nutrition and health policy. Had I missed a large potion of research somehow? Was there something missing in the biochemical analysis of fat metabolism? What links had yet to be discovered? How did this add up? And finally, what did this mean for my patients and their nutrition?
My father had his first heart attack when I was in grade 4. Five years later he had his second. I was in the middle of my third year of my undergraduate degree when my mum called to let me know his latest surgery had been successful and there were two more stents placed in the arteries responsible for delivering oxygen to his heart. I know what my heart rhythm looks like on an EKG because by the time I turned 20 I’d had every possible cardiac test run, including being genetically tested for a heart condition that runs in my family. I later found out that I’m negative for the gene, but that hasn’t stopped me from caring about my heart.
Due to my early heart health introduction, I’ve spent most of my life noticing the on and off trends surrounding heart disease prevention. From funding changes to the increasing epidemic that is obesity to the shift from a low-fat obsessed society to one adapting to a ketogenic or paleo lifestyle. We flip-flop so quickly that it can be impossible to try and keep with the latest research.
Which brings me back to my Facebook newsfeed, infiltrated with articles condemning coconut oil and saturated fat for raising LDL cholesterol and contributing to cardiovascular disease. Before we toss our Costco tubs of coconut oil and reach for canola oil let’s look at what cholesterol actually is, and how nutritional research is conducted.
CHOLESTEROL HAS A PR PROBLEM
Before we start, you should know a few things about terminology. LDL cholesterol is a term that stands for Low Density Lipoprotein, and it actually describes multiple different forms of LDL particles. HDL cholesterol stands for, you guess it, high density lipoprotein (molecules). In general, LDL cholesterol is talked about as our “bad cholesterol” and HDL cholesterol is the “good cholesterol”. Even though it’s touted as bad cholesterol, LDL has very important functions in the body. It delivers nutrients to our cells, it’s an anti-inflammatory molecule, it’s an antioxidant and it’s used to make your immune system run.
Here’s the kicker – not all LDL particle types are associated with cardiovascular disease. This means that an increase in LDL levels doesn’t necessarily mean that there is a greater risk of developing cardiovascular disease. In fact, the increase in LDL that comes from eating saturated fats are specifically from the particle type not associated with cardiovascular disease risk (1). In addition, 15 different meta-analyses and systemic reviews have been unable to establish a clear link between saturated fat intake and cardiovascular disease (2-16).
Providing we believe the above research articles, even if the saturated fat found in coconut oil won’t raise LDL levels to the point of being bad for our hearts, there’s still the question about how saturated fat impacts HDL levels. Contrary to popular belief it actually increases HDL levels, which has been shown to lower your risk of cardiovascular disease (17).
When I say cholesterol has a PR problem I mean we spend most of our days talking about solely HDL and LDL cholesterol, which are generalized terms for a far more complicated scenario. I’m not saying that we have to talk about all the nuances all the time, but we do need to be cognizant that when we introduce sweeping public health measures based on generalizations we aren’t necessarily focusing on health optimization.
THE PROBLEM WITH NUTRITIONAL RESEARCH
There is also a problem with how we study nutrition, and one of the main challenges lies within the way scientific studies are designed. From a research validity scenario, the highest level of evidence involves pitting one variable against another in order to study them. These randomized controlled trials (RCTs) have one group that receives an intervention (like a dietary plan, pill, or a new addition) and another group receives a placebo or are just told to continue eating like they normally do.
Next down the validity totem pole you have animal studies, which tend to be dramatized because the animal in question is usually fed just the one food (like a high amount of sugar) or one part of a food. This particular type of research only highlights what over consuming a nutrient or single food source results in and does not show a realistic diet. Eating according to one particular plan all the time, or eating only one food just isn’t feasible in the day-to-day world, because nutrition consists of an infinite number of different factors.
The other issue with most human studies on nutrition is that many are epidemiological (yet another step down the validity totem pole). This means that research tracks a population of a certain number of people for years, and then attempts to synthesize data to create a story. It’s like making a documentary by shooting all the video, and then trying to figure out what you can say after the fact. This type of study can take into account individual variability, but it’s still difficult to draw hard conclusions. None of these studies really take into account genetic variability, gene SNiPs and methylation pathways that define how well we’re able to synthesize molecules and compounds from each other.
To synthesize the data used for these research studies we use something known as a Food Frequency Questionnaire. In it, participants get asked how often they eat certain foods per week and they track them on a weekly or daily rate. If you’re sitting in my office you get asked something very similar. The immediate reaction of 99% of my patients is “yesterday wasn’t a good day”. See, we have these preconceived notions about what we should and should not be eating, and then we automatically feel guilty about what we’ve consumed as soon as someone asks us about our food. As a clinician I’m interested in trends, about what my patients typically eat, not individual amounts and moments. I’m looking for areas to optimize and usually I end up adding more food to someone’s routine (because most of us don’t eat enough!). The main issue with diet recall is the accuracy from which someone can tell me about what they’ve eaten. The mundane memories of our meals tend to evade us, and we tend to deceive ourselves based on how we feel we should be eating, rather than how we actually area. By utilizing FFQs in nutritional research we also fall into that trap, and we’re more likely to fill out something based on what we assume researchers want to hear than what we may have actually consumed.
What we don’t necessarily take into account with nutritional research is the rest of the confounding factors. This includes the state of the gut flora (the good and bad bugs that digest food for us), our antioxidant or mineral status, the health of the animals whose meat we consume, whether we lived in cities or in the country, what our relationships were like, what our stress levels were like, how well we were sleeping, etc. This is exactly what makes nutritional research so difficult. These studies are incredibly important to allow us to understand the relationship between nutrition and health, but the limitations can only take us so far. A multitude of the above factors have an impact on both our nutrient intake and absorption.
Therefore, if research is only part of the equation, and the PR problem associated with cholesterol is another – where should we get our nutrition knowhow from?
Canada’s Food Guide was designed in the 1940’s to help Canadian families ration their food during the war, and its recommendations haven’t changed too much since then, and it hasn’t been updated since 1993 (though Canada is currently overhauling it as we speak!). Currently, there is an overemphasization on grains and dairy, and an underemphasization on the importance of fat. It’s a generalized product that could help you start off if you’re looking for some basic understanding of food, but it isn’t designed to promote health optimization.
When it comes to food consumption, the Standard American Diet isn’t the most nutrient dense of the diets in the world. We tend to over-consume macronutrient rich foods that are higher in fats, carbohydrates, proteins and calories; and as a result we tend to under-consume micronutrient-rich foods like fruits and vegetables. Because of this, as a population we tend to fail to meet the levels of vitamins, minerals and antioxidants essential for optimal bodily function. When you start breaking down the merits of many “healthy” diets we start to notice something else. That they tend to restrict a certain group of foods while over-emphasizing others. Whole 30, FODMAP, Paleo, Ketogenic, Vegetarian, Vegan, etc all focus on eliminating one type of food group, while incorporating more of another. What they all tend to emphasize, however, is fruit and vegetable consumption (the micronutrient-rich foods – notice a trend?). When we’re studying the merits of any of these diets, it may actually be those non-starchy, micronutrient-rich vegetables that confirm most of the health benefits, and it’s our individual biochemical make up and genes that dictates which of these type of diets we feel best on. Good nutrition might not have anything to do with carbohydrate, fat or protein content. It might, in fact, be all about the micros.
So, what should we be doing? Eat a variety of foods and focus on incorporating more fruits and vegetables into your diet. As a result, you’ll start balancing out your fat, protein and carbohydrate intake to what fits your unique biochemical needs. I truly believe that there are no “good” or “bad” foods, generally speaking. There is a place for saturated fat, animal protein, dietary cholesterol and carbohydrates in a balanced diet. That being said, listen to you body. If you wake up bloated and not feeling great try to figure out if there’s a pattern. Whole Foods are not inherently good or bad, but some can be better or worse for certain people, and that can change throughout your life.
What we do need to be doing as a society is focusing on feeding our bodies, and our minds. We can calm inflammation, heal the lining of your digestive tract, help identify food sensitivities, clear your skin and manage autoimmune diseases. We can work to optimize your brain function, help you rebound after a concussion and get you sleeping. Sometimes foods need to be removed, but usually only temporarily. If you experience insulin resistance due to PCOS, obesity, diabetes or metabolic syndrome you may do better on a low-carbohydrate diet because it will help restore your insulin sensitivity. Dealing with painful or difficult periods might also be addressed through a low-carbohydrate, higher fat diet to help restore your hormone balance. Older adults may require less protein intake to lower their levels of growth factors, whereas athletes and stressed-out-adults may require high amounts of protein to promote muscle building and/or to create mood-regulating neuro-chemicals. Someone who is iron-deficient may need to consume more red meat, whereas someone with a family history of colon cancer may need to consume less.
There are so many factors we need to take into consideration. We also need to (probably) stop judging each other and ourselves for eating a certain way. Our health goals, health status, nutrient status, brain health, stress levels, toxic load and inflammation are just some of the things we need to take into consideration. Then, we take into account lifestyle preferences, tradition, culture, religious backgrounds, cooking abilities, time constraints and the number of people you’re eating with. We always consider emotional attachments and the culture around food. Morals and values matter. If cooking each meal from scratch stresses you out more than picking up an already-done chicken and a salad from Superstore or Sobey’s then focus on that, it’s a much better option than MacDonalds or take-out.
Research tells us a lot. Like the fact that investigations into the eating patterns of traditional societies tell us that human beings thrive on a variety of different diets. Optimizing your individual diet goes beyond following just the latest research or health recommendations from the government and industry. It involves eating a variety of natural, whole foods, learning to listen to your unique needs and working with someone who is going to use your diet to promote optimal health.