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Saturated Fats Unpuzzled

Important Points:

  • Saturated fats
  • Unsaturated fats
  • Cholesterol levels
  • Cardiovascular risk
  • Fatty acids

Saturated Fats Unpuzzled

In the last decade, there has been a lot of controversy surrounding saturated fats. In case the news hasn’t caught up with you, scientists are rethinking the bad label attached to saturated fats. While this does not dispel the negative vibe attached to fatty meat and cheese, it seeks to clarify some broad generalizations that have been misleading.

For starters, saturated fats are not a single nutrient but a varied group of fatty acids that have different effects on the body. This means that while some saturated fats may be downright unhealthy for you, others are not and may even offer some health benefits.

This article examines some of the most common saturated fats, their health effects and what foods contain them.

What are Saturated Fats?

Fats can be divided into two broad categories: Saturated and unsaturated fats. Saturated fats are solid at room temperature while unsaturated fats are liquid at room temperature. This is the most general way to differentiate the two groups. For a long time, it has been believed that saturated fats are unhealthy while unsaturated fats are healthy. This is why the advice has always been to opt for liquid oils such as canola, safflower or sunflower oil which are unsaturated oils and not coconut or palm oils which are saturated.

Examples of saturated fats include fatty meat, lard, tallow, cheese, cream, coconut oil, palm oil, and cocoa butter. All fats are made up of fatty acids. There are a number of saturated fats which can be distinguished by the length of their carbon chains. Here is an example of how this looks like:

Saturated fatty acid Number of carbon atoms
Stearic acid 18
Palmitic acid 16
Myristic acid 14
Lauric acid: 12
Capric acid: 10
Caproic acid 10

Saturated fats can either be a short-chain, medium-chain or long-chain fatty acids. Those with less than six carbon atoms are referred to as short-chain while those with more are referred to as long-chain fatty acids. Short-chain fatty acids are produced in the gut through the fermentation process. They may also be found in some fermented foods. Long-chain fatty acids are like the ones in the chart above which are found in dietary sources.

Do Saturated Fats Make Us Sick?

As mentioned above, saturated fats were slowly becoming taboo in health circles. As cardiovascular diseases took over a large chunk of the modern burden of disease, saturated fats were pushed to the sidelines as a strong risk factor. People switched to the heart-friendly mono- and polyunsaturated fats as they abandoned saturated fatty acids.

However, recent research has disputed the earlier beliefs that saturated fats are the main cause of cardiovascular diseases. This has not ruled out the fact that there is a link between the two, however, the exact role they play is still being debated. Also, it has emerged that not all saturated fats are created equal and hence some may be beneficial for your health.

Stearic acid

Stearic acid is a common saturated fatty acid with 18 carbon atoms. It is a major component of various animal and plant fats as well as cocoa butter. Research has shown that it may lower bad cholesterol levels or have no effect. The body converts some of the stearic acids into oleic acid which is a healthy unsaturated fat. This means that as compared to some saturated fats that are bad for the heart, stearic acid may be a safer option. It appears that stearic acid has neutral effects on the lipid profile. The main dietary sources of stearic acid are animal fat, coconut oil, cocoa butter, and palm kernel oil.

Palmitic acid

Palmitic acid is the most common saturated fat in plants and animals, and it makes up over 50% of the total amount of saturated fat consumed in the US. Palmitic acid is mostly found in palm oil and red meat. It raises bad cholesterol levels and has no effect on good cholesterol levels. This means that it may predispose one to the risk of cardiovascular disease. Palmitic acid has also been associated with low moods lack of motivation to engage in physical activities, and weight gain.  Consuming linoleic acid, an unsaturated fat, together with palmitic acid can help to offset some of the negative effects of palmitic acid.

Myristic acid

Myristic acid raises total cholesterol levels as well as bad cholesterols levels, and most likely means that it increases the risk of cardiovascular disease. Myristic acid is a rare fatty acid found in coconut oil and palm kernel oil.

Lauric acid

Lauric acid has 1 carbon atoms It increases good cholesterol levels as well as total cholesterol levels. This means that it reduces the amount of total cholesterol relative to HDL cholesterol. A study published in NCBI in 1996 concluded that “Lauric acid raises total cholesterol concentrations more than palmitic acid, which is partly due to a stronger rise in HDL cholesterol.” It may be beneficial for heart health.

Caproic, caprylic, and capric acid

The above fatty acids are abundant in goat milk; Capra actually means “female goat” in Latin. If you’ve heard of the benefits of goat milk, you may know it has to do with these fatty acids. These medium chain (having less than 12 carbon atoms) fatty acids are easily absorbed by the body and rapidly metabolized and aid in weight loss, increase insulin sensitivity as well as offer anti-seizure benefits. Consequently, these fatty acids are commonly sold as supplements which consist primarily of capric acid and caprylic acid.

Butyric Acid, Propionic Acid, and Acetic Acid

These three are short-chain fatty acids containing fewer than six carbon atoms, and are created through a fermentation process of fiber in the gut. They may be found in small amounts in dairy fat and some fermented foods. These are usually beneficial fatty acids.

Are Saturated Fats Good For You?

The jury is still out on this. Recent science is refuting earlier evidence that saturated fats are responsible for atherosclerosis. What is clear is that some types of saturated fats are either neutral or have some beneficial effects on the heart.

The key is likely the quality of the fat source, so we urge our patients to avoid vegetable oil and stick to natural fats found in real food.

References

1.   NCBI (2010): Cardiovascular disease risk of dietary stearic acid compared with trans, other saturated, and unsaturated fatty acids: a systematic review. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/19939984

2.  NCBI (2010): Cardiovascular disease risk of dietary stearic acid compared with trans, other saturated, and unsaturated fatty acids: a systematic review. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/19939984

3.  NCBI (1994): Impact of myristic acid versus palmitic acid on serum lipid and lipoprotein levels in healthy women and men. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/8148355

4.  NCBI (1996): Comparison of the effects of diets enriched in lauric, palmitic, or oleic acids on serum lipids and lipoproteins in healthy women and men. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/8644684

5.  NCBI (2016): Intestinal Short Chain Fatty Acids and their Link with Diet and Human Health. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/26925050

 

 

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Does chronic overnutrition play a role in metabolic inflammation?

Important Points:

  • Inflammation
  • overnutrition
  • obesity
  • carbohydrates
  • fatty acids

Does chronic overnutrition play a role in metabolic inflammation?

We have been looking at metabolic inflammation and its role in the development of obesity, diabetes, and other chronic diseases. Does overnutrition contribute to metabolic inflammation? How?

Background on Overnutrition

It is estimated that by 2020[b1] , two-thirds of the global burden of disease will be due to chronic non-communicable diseases, most of which are associated with an unhealthy diet. While hunger is a tremendous global health concern that cannot be minimized, overnutrition should similarly be given concentrated attention. Malnutrition affects up to 1 billion people and doesn’t just affect those who are thin due to food shortages; people who are overweight could also be malnourished.

The “double burden of malnutrition” is a term coined by the World Health Organization (WHO) to describe a situation which is characterized by “the coexistence of undernutrition along with overweight and obesity, or diet-related non-communicable diseases, within individuals, households, and populations, and across the life course. Globally, the problem is not the availability of food resources but the allocation and consumption of food.

1. What  is overnutrition?

Overnutrition is defined as the overconsumption of nutrients and food to the point at which health is adversely affected. Overnutrition can develop into obesity which increases the risk of serious health conditions including cardiovascular disease, hypertension, cancer, and type-2 diabetes.

Until recently, overnutrition had been viewed as a problem that only affected developed nations. However, this has been reviewed to affect most populations. The prevalence of obesity is increasing in developing countries with the introduction of fast food and refined sugars.

While once considered the disease of the rich, low-income groups in richer countries are also being affected by this condition.

2. What is overnutrition-induced inflammation?

Inflammation is a biological response launched by the immune system against dangerous assaults which threaten the integrity and normal physiology of an organism. Chronic nutrient overload causes an increase in fat tissue (adipose) irregularities in that, if adipose tissue expandability is low, there will be an increased presence of thickened tissue. This would lead to a proinflammatory state that can trigger insulin resistance, release of macrophage chemoattractant proteins, and in chronic inflammation, even the death of the thickened adipose tissue itself. This creates cyclic action that extends the insulin resistance to all adipose tissue.

An important characteristic of overnutrition-induced diseases is chronic low-grade inflammation caused by nutritional excess. Overnutrition-induced inflammation is thought to occur in the brain and thus plays an extensive and steering role in overnutrition-induced diseases.

3. Overnutrition and the Metabolic Syndrome

The metabolic syndrome is a constellation of metabolic risk factors including high cholesterol, elevated blood pressure, insulin resistance and elevated serum glucose, a pro-inflammatory state, and a prothrombotic state.

Most persons with metabolic syndrome are obese and usually have abdominal obesity. Generally, obesity is a reflection of overnutrition. A current view is that when adipose tissue fails to store all excess nutrients as triglycerides, lipids (fats) begin to accumulate in various tissues (e.g., muscle, liver, pancreas, and heart). The foundation of the metabolic syndrome thus appears to be overnutrition – more nutrient intake than can be safely disposed by lipid oxidation.

When obesity is present, adipose tissue becomes inflamed. This inflammation may result in a pro-inflammatory state which could contribute to both cardiovascular disease and diabetes.

4. What is Carbohydrate Overnutrition?

Most evidence supports the concept that fatty acids represent the final common pathway to tissue nutrient overload. Less attention has been given to the possible negative effects of excessive intake of carbohydrates.

Chronic overstimulation of insulin secretion induced by dietary carbohydrates could have the following adverse effects:

  • β-cell function may be impaired by chronic glucotoxicity
  • carbohydrate-induced hyperinsulinemia may suppress muscle insulin sensitivity.

Furthermore, high-carbohydrate intakes can prompt the formation of fatty acids in the liver by way of lipogenesis; fatty acids produced in this way can feed into the final common pathway of ectopic lipid accumulation. There is thus need to look further into the role of carbohydrate overnutrition in the development of the metabolic syndrome.

5. What Factors Contribute to Overnutrition?

Obesity in the United States has reached startling heights. The National Center for Health Statistics at the Centers for Disease Control and Prevention (CDC) estimated that in 2015-2016, the prevalence of obesity in the United States was 39.8% in adults and 18.5% in youth. 

While obvious factors including genetics, drugs, and other medical conditions may contribute to obesity, behavior is perhaps the most common contributor. Healthy weight on an individual level is associated with a healthy diet and regular physical activity. Restaurants serve incredibly caloric meals, with some meals containing as much as 2,000 calories. The sedentary lifestyle practiced by most adds to the epidemic.

Unfortunately, this obesity trend has spread to other nations, including many developing countries. China, for example, now has more than 5,000 Kentucky Fried Chicken (KFC) restaurants in 1,100 cities. Similarly, McDonald’s expects to have 4,500 restaurants in China by 2022, up from 2,500 in 2017. A growing number of Chinese households also own television sets, personal vehicles, and other technologies that reduce physical activity and facilitate weight gain.

It is of note that economic inequality in developing nations is a primary cause of both overnutrition and undernutrition. Studies conducted in India show that income inequality had the same effect on the risk of being overweight as it did on the risk of being underweight; specifically, for each standard deviation increase in income inequality, the odds of being underweight increased by 19% and the odds of being obese increased by 21%. 

While some people have the resources to purchase amounts of food beyond their daily caloric requirements, others cannot meet their recommended caloric intake. However, increasing numbers of poor people are becoming overweight in more nations, as these individuals consume affordable, yet highly caloric meals, such as fast food and processed foods.

6. What Should Be Done to Avoid Overnutrition?

An approach to understanding the effects of overnutrition on the metabolic profile is through overfeeding studies. These indicate that overnutrition produces a deterioration of metabolic status. Variability in individual response is however to be expected. Such investigations are potentially useful for identifying those who are particularly susceptible to the development of metabolic risk factors.

The host of genetic factors likely act at tissue levels to influence the response to nutrient excess. Different people may react differently to accumulation of fat, but overnutrition is generally considered to trigger metabolic disorders and predispose one to chronic conditions like Type 2 Diabetes. When choosing what to eat, one should be careful to ensure they choose balanced meals rich in fiber and nutrients and avoid the modern day fast food craze, as the cost of bad eating is too high.

References

  1. Unite for sight (2018): Module 4: Overnutrition. Retrieved from http://www.uniteforsight.org/hunger/module4
  2. NCBI (2009): From chronic overnutrition to insulin resistance: the role of fat-storing capacity and inflammation. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/19171470
  3. NCBI(2013): Neuroinflammation in Overnutrition-induced Diseases. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4389772/
  4. American Federation for Medical Research (2016): Overnutrition, ectopic lipid and the metabolic syndrome. Retrieved from https://jim.bmj.com/content/jim/64/6/1082.full.pdf
  5. NCBI (2009): From chronic overnutrition to insulin resistance: the role of fat-storing capacity and inflammation. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/19171470