Several years ago I became aware of some convincing research showing a surprising lack of correlation between fat intake and risk of heart disease or stroke. This defies the commonly held notion that “fat is evil” mantra drilled into our heads by various health experts. While it can be easy to dismiss research on accounts of flawed design, low statistical power, or limited relation to a specific population, that could not be said about the studies I wrote about a few years ago. These were meta-analysis, deemed to be the most robust of studies, as they increase the power by combining the results of multiple smaller studies into one large study.
Now, there is yet another meta-analysis that finds a similar conclusion. Before I reveal a synopsis of the recent study, I’ll share an interesting anecdote about the origins of this fat phobia and it’s direct relation to me personally.
Family Fat Feud?
A few years ago, while I was waiting to perform a seminar on nutrition and a local corporate, an audience member approached me with an interesting question. Having seen my credentials displayed on the title slide, she asked me if I was related to a Dr. Joseph Stare. The lady had been Dr Joseph Stare’s secretary at Harvard, where he founded and chaired the department of nutrition at Harvard. He became a well-known authority, consulting with major food industry leaders, like the craft corporation, authoring studies, and even a text. He was most known for his “Lipid Hypothesis”, which theorized that fat in our diets was responsible for clogging our arteries and the rise in cardiovascular complication. this sparked intensive scrutiny of the role of diet in health, and a concerted effort to reduce or even eliminate fat in our diets. Even today, the notion of fat being bad is imprinted on well educated folks, although and preponderance of evidence causes us to question whether this is really true.
Dr. Joseph Stare was likely a cousin or second cousin of my grandfathers, as he too has origins in Chicago. It was ironic the a key focus of my presentation that day was to present evidence against the lipid hypothesis, not knowing a key figure in popularizing that theory was possibly a relative of mine!
So when I read that a recent study again questioned the role of fat in our diet upon our heart health, you could imagine my ears perked up. Here are the conclusions and implications from the recent study by Dr Rajiv Chowdhury from the University of Cambridge. who conducted a meta-analysis using over 80 studies on about 500,000 subjects:
1. Diets high in saturated fat did not increase the risk of heart disease
2. Those who ate diets higher in unsaturated fats did not reduce heart disease risk
3. Trans fats did increase heart disease risk
4. Certain types of fatty acids did have a correlation with heart disease risk: margaric acid (from milk/dairy) and the omega 3s in fish correlated with a lower risk while diets higher in omega 6 fatty acids (vegetable oils) correlated with a higher risk.
5. Supplementing with fish oil did not reduce cardiovascular risks.
So what does this mean?
Fat Is Not The Enemy
Of course there will be a lot of debates about this. Some will say that reducing saturated fat and increasing polyunsaturated fats won’t reduce heart disease risk if sugary and refined carbohydrates are increased. However, if these carbs are also kept low, then lowering saturated fats and replacing them with unsaturated fats will actually reduce heart disease. But this is purely speculative.
Regardless, this points out that simply saturated fat is not a logical strategy anymore based on the evidence. And I think the implications on this are huge. Perhaps now it will be easier for people to see what are the key variables that they can focus on, rather than being given a false sense of security that they are lowering their heart disease risk by shunning eggs for Cheerios.
Another bonus is that by not condemning saturated fat as a surefire path to heart disease, we can help people expand and enjoy their diets more. Relaxing the ban on eggs and full fat cottage cheese might eliminate a sense of deprivation and boredom that comes with modifying diet, thus making it a little easier to control calories and embrace the behaviors we know make a big difference, like exercise, controlling calories, managing stress, etc.
It doesn’t not mean, however that we should eat unlimited amounts of saturated fat. This study does not support the conclusion that eating high fat diets reduces heart disease risks either.
The “Good” And “Bad” Cholesterol Issue
Dr. Chowdhury is amongst a growing body of researchers questioning the role of fat increasing cholesterol, and cholesterol influencing heart disease. Although saturated fat does increase LDL (so called “bad cholesterol”) in also increases “good Cholesterol – HDL. However, it is thought that a subtype of LDL, the large fluffy particles referred to as pattern A, which are increased with saturated fat, are completely benign. In contrast, the smaller high density subtype of LDL, referred to as pattern B, are the ones the have artery clogging consequences., and these are actually increased by excessive sugary and refined carbohydrates, not fat.
Expect to see much more research on this in the future
What About Fish Oil?
Although this study did not show that fish oil reduced heart disease risk, it does not mean it is not good for your heart. Researchers speculated that perhaps because the population analyzed had a high cardiovascular disease risk, fish oil is not effective for those who already have cardiovascular disease. Instead, it may be better for preventing disease for those who do not have cardiovascular disease yet. Based on the evidence, I would not stop taking omega threes. However, I do recommend taking Krill oil instead of fish oil, as the stability and bio-availability appears to be much better. Here’s what I take and recommend.
Don’t throw up your hands when you hear sacred cows of nutrition being burned. Instead, realize that research has a hard time coming up with clear conclusions when the real cause is likely to be multifactorial. In essence, there rarely is a smoking gun with issues like cardiovascular disease, obesity, or low back pain. An over reliance on a magic pill or villain is not effective, and will eventually be exposed. Instead, realize that many factors contribute, and focus on the ones you can best control. So for most, that means lower your calories, eat healthier foods, exercise, and manage stress if you want the best chance of lowering heart disease.