Full-fat dairy – the Heart Foundation’s new position

In 2019, the Heart Foundation of Australia changed its stand against the fat in dairy. Instead of prohibiting all full-fat foods like milk, yoghurt and cheese, it would appear that the Foundation has now reversed its once-strong position.

Like all things in life, the reality is a tad more complicated.

The reversal on full-fat dairy - which will gladden the hearts (and stomachs) of those who live for great cheese and butter oozing from their slice of toast - is not so much a reversal as a summary of the confusing and complex overview of the existing research.

In the end, it’s not clear and there is evidence for and against full-fat. The more I read this Report from the Heart Foundation, the more confused I got. It seems the new message of “go back to full-fat diary”- which grabbed all the media attention - is not that certain unless you are classified as “healthy” (more on this later).

How did the Foundation come up with these findings?

 There’s a long, boring PDF Report on the Foundation’s website. It’s meant for health professionals like me and is 17 pages long including four pages of references of which there are a total of 72. The Report is called “Dairy and Cardiovascular Health: Summary of evidence”. I have read it in detail and am now not so convinced about the ‘good news’ on dairy. 

In reviewing the evidence on dairy, the Foundation’s staff looked at the findings of more than 56 studies, published between 2013 and 2018, which were then supplemented with reviews, trials and meta-analyses from 2009. These studies covered participants from:

• across five continents
• more than 21 countries.

Words from the Foundation

The Foundation’s Executive Summary from page 3 sums it all up neatly:

“On balance, the existing evidence on dairy foods and cardiovascular risk points to a ‘neutral’ effect, and a possible protective effect with consumption of dairy food and hypertension, stroke and type 2 diabetes risk, and with the consumption of yoghurt and type 2 diabetes risk.”

They go on to say:

“We have removed our restriction for healthy Australians on eating full-fat milk, cheese and yoghurt. While the evidence was mixed, this type of dairy was found to have a neutral effect, in that it doesn’t increase or decrease your risks for heart disease or stroke.” 

“Given this, we believe there is not enough evidence to support a restriction on full-fat milk, yoghurt and cheese for a healthy person, as they also provide important nutrients like calcium.”

So this is the actual message – the Foundation says over and over again. There is mixed evidence for a link between dairy and high blood pressure, type 2 diabetes, high cholesterol, stroke, heart failure and other cardiometabolic measures. It’s not that cut and dried, it seems.

So, what is a healthy person?

All of this hinges on what we can describe as a healthy person (these are the ones that can now eat what they like whether full-fat or low-fat or skim). A healthy person is apparently one who:

• is not overweight or obese nor actively trying to lose weight
• has no heart issues
• has no diabetes or any family history

It’s all very confusing. If you have existing high cholesterol or a family history, I’d still be wary of full-fat anything and be looking to stick to reduced-fat milk and low-fat yoghurts (not skim unless you want the kilojoule reduction – skim has half the kilojoules of full-fat). Cheese is hard to make in lower-fat forms, so I’d just reduce my total intake. Have a little but don’t go overboard. Be wary of those huge cheese platters that are all the rage now.

Again, from the Foundation’s media release:

“Limits apply to this new advice around dairy. For people who suffer high cholesterol or heart disease, we recommend unflavoured reduced-fat milk, yoghurt and cheese. 

"Butter, cream, ice-cream and dairy-based desserts are not recommended as heart-healthy, as they contain higher fat and sugar levels and less protein. Evidence found the dairy fat in milk, cheese and yoghurt does not raise bad LDL-cholesterol levels as much as butter or other dairy products.”

So, milk, yoghurt and cheese are OK but butter, cream, ice-cream and dairy desserts are not.

Background on dairy and saturated fats

The reasons dairy fats are a worry is because they are mostly high in saturated fatty acids. About 70 per cent are saturated with only 25 per cent monounsaturated, a tiny 2-3 per cent polyunsaturated plus a tiny 2-3 per cent being ruminant trans fats. 

Dairy fats are leading contributors to saturated and trans fat intake. There are established links between saturated fat (only those fats with carbon length of 12, 14 and 16 carbons) and trans fat and a high LDL- or bad cholesterol. And there is evidence that a high LDL-cholesterol will lead to greater levels of heart disease (although I know of many who would dispute this). 

Examples of the evidence

Take a look at the Report’s entries trying to sort out a relationship between total dairy intake and cardiovascular risks. The bottom line is that there is mixed evidence on the relationship. As you’ll see, it is hard to work out what is happening:

For hypertension (high blood pressure)

Total dairy was inversely associated with blood pressure. In other words, the more dairy consumed, the less high blood pressure which is good.

For type 2 diabetes

Again, total dairy was inversely associated with diabetes. More good news.

For stroke

Again, total dairy was inversely associated with stroke. Further good news. But one meta-analysis (super-analysis) of 12 studies found no association at all.

For coronary heart disease

For the past five years, there has been no association found between dairy and heart disease. This conflicts with earlier analyses which did report a relationship with heart disease and which formed the basis of the Australian Dietary Guidelines which say to choose reduced-fat dairy food.

For heart failure

No studies, bar one, which reported a link between dairy and heart failure.

It’s not that clear cut, is it?

Yoghurt, cheese and fermentation

I had hoped that the fermentation process would explain the findings on yoghurt and cheese. After all, there’s something different about the action of certain bacteria. Certainly, there’s great emerging interest in these and similar fermented foods like sauerkraut and kombucha.

In one meta-analysis of 9 cohorts, there was a dose-response relationship between over 200g (a classic tub) of yoghurt a day with less risk of heart disease, but then some studies found no effect at all.

For diabetes, yoghurt and fermented dairy were found to consistently have an inverse relationship with the risk of diabetes.

The bottom line

If you’re healthy without any need to lose weight or any heart problems, you can now buy what you like - full-fat or low-fat in milk, yoghurt and cheese. In fact, these are healthy snack options over junk foods such as sugary drinks, alcohol and ultra-processed foods. Think a glass of milk or a tub of yoghurt.

It is likely that milk, yoghurt and cheese won’t affect your risk of heart problems. Most of the time, they are neutral or even protective. However, if you are at risk (say you already have a high cholesterol or heart disease), the Foundation advises you should continue to buy reduced-fat dairy over full-cream. No slabs of butter or huge dollops of cream for you! 

References

The Heart Foundation’s Summary of Evidence for Dairy and Cardiovascular Health reviewed the evidence for dairy products and cardiovascular health outcomes. This evidence informs the Heart Foundation’s position on dairy, and the Heart Foundation’s broader position on heart healthy eating patterns.

Heart Foundation (2019) Summary of Evidence: Dairy and Cardiovascular Health. NHFA: Melbourne. Dairy & Cardiovascular Health (PDF)