Saturated fat role in heart disease again questioned: What diet works?

Kathleen Blanchard's picture
Low saturated fat diet may not curb heart disease.

In an observational review of studies, researchers again question the role of saturated fat as a contributor to heart disease.

The analysis, published in the Annals of Internal Medicine, isn't the first to suggest saturated fat, like the kind found in butter, leads to heart heart attack.

Advice for replacing saturated fat with PUFA (polyunsaturated fatty acids) like that found in sunflower seeds, olive oil, almonds, walnuts and more may be unfounded, according to the review that included 72 studies of 600,000 participants.

The review failed to find any evidence that total saturated fat in the blood or consumed from food was associated with heart disease. Nor did polyunsaturated fat appear to have cardioprotective benefits.

That's not to say we should eat saturated fat freely the authors emphasize, but it does mean switching to a high polyunsaturated, low saturated fat diet may not be the best advice for heart health. It's also important to understand eating too much saturated fat will raise your cholesterol that could mean higher risk of heart disease.

But even high cholesterol has been questioned as a heart disease contributor. In October, 2013, Aseem Malhotra, interventional cardiology specialist at Croydon University Hospital wrote in the British Medical Journal that it's time to stop blaming saturated fat for raising heart attack risks. Instead, Malhotra suggested researchers should look at the type of saturated fat consumed.


What type of diet might be best for heart health?

Avoiding sugar, limiting salt, eating fish and following a Mediterranean type diet, unprocessed meats and dairy and avoiding trans-fats could be the dietary approach to curbing heart disease that should be included in nutritional guidelines, Malhotra said.

But even high cholesterol's role in heart disease has been the subject of debate. Rather than total cholesterol, there are other important factors known to boost heart risks, including LDL cholesterol level (the bad kind), oxidation of LDL molecules, inflammation, smoking, lack of exercise and skimping on fruits and vegetables.

There have also been questions about the way food is prepared that can contribute to heart disease and even cancer. For instance, fried and grilled foods, cooked with high heat, produce by-products that could lead to poor arterial health and inflammation.

Dr Rajiv Chowdhury, the lead author of the newest research , said: "These are interesting results that potentially stimulate new lines of scientific inquiry and encourage careful reappraisal of our current nutritional guidelines."

"Current evidence does not clearly support cardiovascular guidelines that encourage high consumption of polyunsaturated fatty acids and low consumption of total saturated fats," the British Heart Foundation funded study concluded."

Before you go out an order a burger, it's important to understand the study was observational. Most people eat too much saturated fat with their meal. If you do eat meat, limit your portion to the size of your palm and make sure you have three vegetables on your plate. It will take more research to unravel the mystery of how specific fats in the diet, food additives and even the way we cook contribute to heart disease before physicians would change current heart healthy diet recommendations.

Ann Intern Med. 2014;160(6):398-406-406. doi:10.7326/M13-1788