The latest on the fat debate
The art of science
The hotly debated topic of how much fat we should be consuming in our diet is forcing more and more studies to be conducted. This is great news, as we can work towards improving dietary guidelines and prevent heart disease in (hopefully) many. Unfortunately, when it comes to good quality research, it's simply not as easy as having some people eat a high fat diet, and others eating low fat diets. Before I get into the latest study on fat intake, I wanted to share a bit about what a good quality study actually is.
Researchers must cover all possible variables that might affect the studies results. If they don't, the findings can essentially be invalid, providing us with false or misleading information. These include lifestyle factors such as smoking status, activity level, stress levels, and economic status. Once these are taken into consideration, i.e. the appropriate scientific calculations and formulas are applied to the research findings, the study results have a much higher chance of being accurate. Other things to consider are genetics and health status. Keeping on topic with heart disease, possible factors that affect the likelihood of an individual having heart disease include - a family history of heart disease, obesity, diabetes, high blood pressure, and depression.
Once we know all this information about the participants of a study, we can assess the data accurately and figure out of there is any truth to what we are hypothesising.
Before the researcher has even got to this point though, they must decide what level of evidence their study will provide. Costs, ethics, time and other factors dictate what is the most appropriate study to conduct. However, in the scientific world, the highest level of evidence comes from meta analyses of randomised controlled trials (RCT's). Basically a study that looks at all the evidence from the top level studies, RCTs, and analyses and combines the findings to give overall evidence on a topic.
Simplified, RCT's mean the participants were divided up randomly into a test group, and a control group. This is done to reduce bias or confounding factors in the study. For example: a study examining the effects of a weight loss pill combined with diet and exercise: you can't have all obese in one group, and all slim in the control group. The results are likely to show the obese test individuals lose much more weight than the already slim individuals who took a placebo 'fake' tablet. It's well known that the more weight you have to lose, the quicker it usually comes off, compared to the pesky last 5kg. Thus swaying the results in favour of the product.
Back to the fat debate though. A new study has come out in the Journal of the Academy of Nutrition and Dietetics showing some varied results. It was a meta analysis of 32 RCT studies.
What it showed:
A low fat diet decreases total and LDL 'bad' cholesterol
A high fat diet increases HDL 'good' cholesterol, and reduces triglyceride levels 'bad' fats in the blood.
When they compared both low fat and high fat diets, factoring in the total calories of the participant's intakes, the studies that made the participants eat a reduced amount of calories saw the changes in cholesterol become insignificant, regardless of the type of diet they were following.
The researchers then took it a step further, doing some scientific calculations to help assess relationships, and found the higher the carbohydrate in the participant's diet, the higher level of triglycerides they had in their blood.
Lower LDL cholesterol however, was marginally associated with a lower saturated fat intake.
So which is it? What diet should we be following to prevent heart disease?
There is no clear cut answer as of yet, however sticking to a diet that has a moderate intake of a variety of quality fats including avocado, olive oil, nuts, seeds, and coconut, appears to be a step in the right direction. Plus quitting smoking, losing weight, keeping active, minimising stress, and cutting out fried and refined processed carbohydrates is only going to help reduce your risk.
Image 1: academics.com
Image 2: From earth to plate blog