Medically reviewed by Shahzadi Devje, Registered Dietitian (RD) & Certified Diabetes Educator (CDE)
From headlines telling you to keep your dietary fat intake as low as possible, to popular diets that recommend you to load your diet with fat... Understandably, many of us are left confused. Get the lowdown on heart healthy fats!
Many of us know someone who's had a heart attack. As a Desi (South Asian), it's all too familiar. In fact, experts argue that while South Asians represent about a quarter of the world’s population, they account for roughly 60% of heart disease patients.
Without a doubt, food is directly involved in many of the risk factors for heart disease. As such, paying attention to what you eat is one of the most important preventative steps you can take.
The Big Fat Debate
The debate surrounding the recommended intake of dietary fat has been a longstanding one.
A few days ago, the American Heart Association issued a “new” advisory, urging that we reduce dietary cholesterol to reduce the risk of cardiovascular disease. It's not a case of "the experts can agree!" According to Dr. David Katz, "No one ever said dietary cholesterol does NOT matter. Rather, the shift was that it did not warrant a specific focus- because if you focus on getting the foods right in general, cholesterol intake winds up being addressed.”
In the past, we’ve also seen recommendations to limit total fat intake turn into an outburst of fad low-fat diets and, consequently, increased consumption of over-processed, refined carbohydrates – not an ideal outcome (see article here).
These days, we hear more and more talk about high fat, low carbohydrate diets (I’m sure you’ve seen lots of posts about the keto diet).
More recent discussion surrounding dietary fat has brought into question whether or not the recommendation to limit the intake of saturated fat, specifically, is still warranted.
With all the information (and misinformation) out there, it can be difficult (not to mention frustrating!) to make sense of it.
In this guide, we break down the different types of fat and share what we think is the most crucial takeaway when it comes to heart healthy fats and your diet.
Is Eating Dietary Fat Necessary?
First of all, it is important to acknowledge the many roles dietary fat plays in keeping our bodies healthy. It provides us with energy, plays a vital role in growth and development, helps us absorb vitamins A, D, E and K (the fat-soluble vitamins), and much, much more. In fact, we require some degree of fat in our diets to meet our recommended intake of essential fatty acids (more on this later!).
Indeed, eliminating fat from your diet is not the answer. So which dietary fats should be the focus?
All Fats Are NOT Created Equal!
What Are Good And Bad Fats?
Saturated fat, unsaturated fat, trans fat, omega-3s, omega-6s, etc. What do all of these categories mean? Where can you get them in food? Which ones should you be focusing on? Perhaps you’re asking yourself: “What’s the best change I can make to my diet to reduce my risk of heart disease?”
Without going into way too much science-y detail, the names of the different categories of fats are based on the chemical structure of the fat molecule.
Let’s break down the three main categories of fat you’ll find on the food label:
Unsaturated fat (= total fat - saturated fat and trans fat)
Unsaturated fats have gained a name as the ‘healthy fats’ due to their positive effects on cholesterol levels and heart disease risk - when they are used to replace saturated fat and trans fat in the diet (see here). In other words, you want to include these as part of a heart healthy diet.
Unsaturated fatty acids are further categorized into MUFAs (monounsaturated fatty acids) and PUFAs (polyunsaturated fatty acids).
PUFAs can be even further broken down into omega-3 fats and omega-6 fats. These are essential fatty acids that our bodies are unable to produce on their own and thus must be consumed via our diet.
For as long as I can remember, numerous authoritative bodies have recommended that people eat heart healthy fatty fish rich at least twice a week. The omega-3 fatty acids in fish (along with other nutrients) may benefit heart health and reduce the risk of death from heart disease.
In stark contrast to unsaturated fats, trans fats have earned lousy press when it comes to healthy eating and heart disease risk (and rightfully so!).
Science tells us that these fats raise LDL (bad) cholesterol and decrease HDL (good) cholesterol. In turn, this increases our risk of heart disease. (To learn more about cholesterol check out my article here).
The good news?
Partially hydrogenated oils (a leading source of trans fats) have officially been banned in Canada beginning September 17th, 2018. Keep in mind that any foods produced before the ban can still be sold during a 2-year phase-in period as food manufacturers adjust to this regulatory change. So I’d always encourage you to check those food labels for trans fats.
Also, keep in mind, trans fats do occur naturally in some foods, such as milk, meat, and butter. These trans fats differ from the artificially created kind and won’t be eliminated from our food supply.
Saturated Fat And Heart Health
The recommendations to limit saturated fat intake are based on research which shows that saturated fat increases total and LDL (bad) cholesterol levels in the blood. High total and LDL cholesterol levels, in turn, have been linked to the rise in risk for atherosclerosis (plaque buildup in the body’s arteries) and heart disease.
Recently, these recommendations have been contested in popular media and even by some individuals within the research community.
The Recent Hype on Saturated Fat
The famous PURE study (here) that looked at the relationship between macronutrients (fat, protein, carbohydrates) and risk of cardiovascular disease and death was quoted everywhere in the news and on social media in 2017. The headlines over-sensationalized the study’s claim that higher saturated and total fat intakes were associated with a lower risk of death and were not associated with cardiovascular disease.
This is not what we usually hear when it comes to saturated fat.
And that’s precisely why the study made an attention-grabbing story for popular media. Some even argued that butter is back (remember that one?!). Not really the case.
Many professionals in health and research have noted that the study’s conclusions are pretty misleading. Even I dived in and explored some of the issues with this study in more detail in one of my Huffington Post articles (here).
At the end of the day, this research certainly isn’t enough to suggest that we should boost our saturated fat intake and completely abandon existing evidence-based recommendations.
But perhaps our focus doesn’t necessarily need to be on limiting saturated fat intake to x percentage of our total calories each day. By focusing on a single nutrient, it can be confusing and sometimes impractical.
Final Thoughts On Heart Healthy Fats
Science does tell us of key foods and dietary patterns linked to improved heart health and even increased lifespan.
Dietary patterns like the DASH diet and the Mediterranean diet, are two such examples. Each of these approaches to eating emphasizes FOODS, such as vegetables, fruits, legumes, fish/seafood, nuts and vegetable oils such as olive oil (see here).
What About Heart Healthy Fat And Real Living Populations?
Staggering research from The Blue Zones - home to some of the world’s healthiest and longest-living populations – tells us that the common factor between these populations, that seems to promote health and longevity is a diet rich in plant-based foods.
All of these dietary patterns are inherently lower in saturated fat, as they encourage consumption of food sources rich in unsaturated fats: nuts, seeds, avocados and vegetable oils. They also limit foods such as red and processed meats, refined carbohydrates, and added sugar - all of which have also been linked to increased risk of diet-related diseases like heart disease as well as increased weights.
What’s more important, is dietary patterns like the DASH and Mediterranean diets, or the predominantly plant-based diets.
Consumed by individuals living in the world’s Blue Zones, these types of diets promote the consumption of a variety of whole, nutrient-dense foods that offer a range of nutritional benefits - well beyond healthy fats.
It seems that focusing on the quality of our everyday diets as a whole, rather than individual nutrients - like saturated fat - is a much more practical way to promote health and longevity.
This blog was written in collaboration with Alexandra Burghardt RD
I'd love to hear your thoughts on dietary fat and heart disease risk. What are your picks for heart healthy fats for cooking? Leave me a comment below!
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Shahzadi is an award-winning registered dietitian (RD) regulated by the College of Dietitians of Ontario and a certified diabetes educator (CDE), approved by the Canadian Diabetes Educator Certification Board. A notorious foodie, she's dedicated to helping you end your cooking wars, transform your health, and be the best version of yourself! Shahzadi is an on-air nutrition expert for CTV Your Morning and a regular contributor to other national media outlets.