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FATS & HEART HEALTH: AN UPDATE

I don’t think that a nutrition topic has been as controversial or as hotly debated as the one on fat and whether we should be consuming more or less of this nutrient. For many years we have been told to consume less fat, but now we are being told to consume a high fat diet. This is confusing you right? I take a look at what the research says and what guidelines are now being implemented in order to guide you to making your own decision.

WHAT IS THE SITUATION IN AMERICA?

It is always interesting to see what is being done in other parts of the world, so I have decided to include an update on what is happening in America. The US Department of Agriculture as well as the Department of Health and Human Services release the Dietary Guidelines for Americans every 5 years1. This is done so that the guidelines are always based on the latest research. The Dietary Guidelines Advisory Committee (DGAC) is essential to this process, as they systematically review what the literature states and provide a report with evidence-based recommendations to the above-mentioned organisations. They then review these recommendations, as well as comments from other parties, such as academics, and finalise the Dietary Guidelines.

In the latest report provided by DGAC, there were a number of interesting changes:

  • Cholesterol has been eliminated as a “nutrient of concern”1.
    • Recent scientific research found no substantial relationship between dietary cholesterol and that which is found in the blood, or cardiovascular events in general populations1.
  • An upper limit on total fat consumption was absent, even for obesity prevention1.
    • It is recommended that dietary advice should place emphasis on the types of fat consumed, as opposed to reducing total fat intake. This is due to the fact that when we limit fat intake, this also limits the intake of good fats, i.e. monounsaturated (MUFAs) and polyunsaturated (PUFAs) fatty acids, which have health benefits.
    • In order to prevent obesity, focus is placed on more healthy food-based diet patterns, such as including more fruit and vegetables, as well as whole-grain products, and excluding sugar-sweetened foods, drinks and refined grains1.
  • Substituting saturated fat with carbohydrates has no beneficial effect on health outcomes1.
    • Saturated fat increases LDL-cholesterol (bad cholesterol), but it also increases HDL-cholesterol (good cholesterol).
    • Apolipoprotein-B in high levels is linked with heart disease. Saturated fat has minimal effect on this molecule when compared with carbohydrates.
    • This explains why substituting saturated fat with carbohydrate does not decrease your risk for heart disease, especially when considering the harms of highly processed carbohydrates (e.g. refined grains, potato products and sugar)1.

So what do the new Dietary Guidelines for Americans state about fat, having taken the above into consideration?

  • It is important to include oils as part of a healthy eating pattern, as they are a major source of essential fatty acids (e.g. omega-3) and Vitamin E2.
  • It is recommended to consume 27g (about 5 tsp) per day as part of a 2000 kcal diet.
  • Although oils are part of healthy eating patterns, they are still a concentrated source of energy and thus the amount consumed should still be within 20 – 35% of total energy (AMDR for fat for adults).
  • Instead of being added to the diet, oils should replace solid fats.
  • Saturated fat should contribute < 10% to the total energy consumed for the day, and should rather be replaced with unsaturated fats while keeping within the AMDR for age.
  • Strong evidence indicates that replacing saturated fats with unsaturated fats reduces total blood cholesterol and LDL-cholesterol, and is also associated with a decreased risk of heart disease and death related to heart disease2.
  • Limit trans-fat intake to as low as possible by limiting foods, such as partially hydrogenated oils in margarines, which contain synthetic sources of trans-fat. This is due to the fact that a number of studies have observed an association between increased risk of CVD with increased intake of trans-fat2.
  • Aim to eat as little dietary cholesterol as possible, while consuming a healthy eating pattern. In general, foods such as fatty meats and high-fat dairy products that are higher in cholesterol are also higher in saturated fat. Shellfish and eggs can be consumed together with a variety of different choices within the protein food group recommendations2.

WHAT IS THE SITUATION IN SOUTH AFRICA?

There has been a mass-movement towards the “Banting diet” which is high in fat (including saturated fat), and low in carbohydrates, in order to lose weight, as well as manage some disease conditions (e.g. insulin resistance). ADSA and the Nutrition Society of South Africa (NSSA) have subsequently released a joint statement on low carbohydrate diets for health and weight loss. They indicate that consuming an extreme low carbohydrate diet for reducing risk of disease is not supported by current available evidence3. Though a low carb diet may help some people to lose weight by reducing their total energy intake and achieving an energy deficit, this dietary pattern makes it difficult to ensure that it is nutritionally adequate. This is due to the fact that emphasis is placed on high fat intake from predominantly animal foods and restricts and eliminates many nutrient- and fibre-rich foods. In this statement, they also say that fat should be included in a healthy diet, but one should focus on the quality of the fat, i.e. the type of fat3.

Just as America has the Dietary Guidelines for Americans, South Africa has the Food Based Dietary Guidelines (FBDG), which aid in advising people on what to eat. The FBDG state: “Use fats sparingly. Choose vegetable oils, rather than hard fats”4. Furthermore, a group of South African fatty acid and health scientists have adapted guidelines for fat intake, which are in line with international health bodies and current evidence for the country.

The following represents the guidelines set for South Africans above the age of 2 years4:

  • Total fat should provide 20 – 30% of total energy intake.
  • Total energy intake must balance energy expenditure.
  • Saturated fat should provide < 10% of total energy intake, and < 7% of total energy in those at risk of CVD.
  • PUFAs should contribute 6 – 10% of total energy, with omega-6 providing 5 – 8% of energy and omega-3 providing 1 – 2% of energy.
  • The remainder of energy from total fat should be provided by MUFAs.
  • The intake of trans-fat should be less than 1% of total energy.

WHERE DOES FUTURELIFE® FIT IN?

Most of the FUTURELIFE® products have a moderate total fat content, lying on the lower side of the “moderate” range, the same can be said for the saturated fat content. Further to this, most FUTURELIFE® products boast a high Omega-3 fatty acid content. For more product information, visit www.futurelife.co.za.

REFERENCES

  1. [Online] http://www.commed.vcu.edu/Chronic_Disease/Obesity/2016/2015dietguide.pdf.
  2. [Online] https://health.gov/dietaryguidelines/2015/guidelines/.
  3. [Online] http://www.nutritionsociety.co.za/attachments/article/84/Statement_Low%20Carbohydrate%20Diets_NSSA%20ADSA_23March2016.pdf.
  4. [Online] http://www.adsa.org.za/Portals/14/Documents/FoodBasedDietaryGuidelinesforSouthAfrica.pdf.

 

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