Based on the latest evidence based research the short answer to both these questions is no. Fat is an excellent source of energy and unlike grains is free of anti-nutrients. In fact fats have the advantage of aiding in absorption of nutrients as well as leveling out blood sugar.
Saturated fat is important to immune function, bone health as well as an important source of the fat soluble vitamins A, D, E and K. Several large meta studies have now determined that saturated fat doesn’t cause heart disease, and in fact a diet high in saturated fat is protective against stroke. (1) In only a small percent of people does dietary intake of saturated fat increase serum cholesterol levels (but not blood levels). This is likely due to genetic factors and is why in the clinic we look at an individual’s levels, not the averages found in research. We now know that saturated fat is a healthy and important part of a real food diet.
Cholesterol is an essential nutrient and only about 20% comes from diet. Most of it is produced in the liver to perform a host of important functions throughout the body. Recent research showed that 70% of people who ate 2-4 egg yolks per day had no change in serum cholesterol levels. The other 30% showed an increase in both HDL (the protective cholesterol) and LDL (the ‘bad’ cholesterol) particles. It’s the ratio of these two that’s important and since both increased it was determined clinically insignificant. (2) Canada, the EU and Australia have lifted the recommendation to restrict cholesterol and for good reason. It’s the LDL particles rather than the amount of cholesterol in these lipoproteins that cause plaque formation. People with high cholesterol who have a heart attack always also have at least one other high risk factor like smoking or high blood pressure contributing to the incident.
What about monounsaturated fats? And naturally occurring trans fats?
The benefits of monounsaturates like oleic acid is that they reduce oxidation and inflammation, increase HDL, lower LDL, lower blood pressure and decrease thrombosis. The highest sources of this come from macadamia nuts, olive oil, avocados, almonds, duck fat, egg yolks and lard. Like saturated fats these are not toxic even in high doses. Even the American Heart Association agrees that these are healthy.
Conjugated linoleic acid comes from meat and dairy products of pasture raised animals. This is a naturally occurring trans fat. Its benefits range from reducing heart disease, inflammation and tumours to reducing type two diabetes by improving glucose tolerance and insulin sensitivity.
Does meat cause inflammation?
There has been a lot of debate around this question and it boils down to the most important long chain omega 6 arachidonic acid (ARA) which does have some pro-inflammatory compounds. The crunch is that ARA also contains anti-inflammatory compounds and the research has shown that even a high intake is not associated with an increase in inflammation. I have noticed this both personally and clinically which points to using these highly nutritious foods liberally and ensuring you also eat some of these important long chain omega 3 fats that have EPA and DHA available.
What is better than fish oil?
Eating fish of course! Ten to twenty ounces per week of cold water, fatty fish from wild sources is the best way to ensure brain health and lowered inflammation in the body. I can’t emphasize how important this is and it’s why I talk to almost all my patients about EPA and DHA levels. Due to oxidative damage that can happen with supplements, eating salmon, mackeral, sardines, herring and anchovies is the best way to ensure your levels are where they need to be. If this is not part of your diet then 1 gram of fish oil per day is enough. A shorter treatment of a higher dose is indicated for systemic inflammation but should not be continued over the long-term.
What to steer clear of completely or as much as possible.
Industrial seed oils including canola, sunflower, safflower, soy, cottonseed and grapeseed to name a few. These are high calorie, low nutrient fats that have only been around for a tiny amount of our evolutionary history. We know now that they contribute to obesity and a range of other health conditions.