Polyunsaturated Fatty Acids: Genetics and Impact on Weight

Understanding Polyunsaturated Fatty Acids

Polyunsaturated fatty acids (PUFAs) are a type of dietary fat, mainly found in plant-based foods and oils, and fish.

Unlike saturated fats, PUFAs contain two or more double bonds in their chemical structure, which is where their ‘polyunsaturated’ name comes from.

There are two main types of PUFAs that are essential to human health – omega-3 and omega-6 fatty acids, as the human body can’t produce them.

PUFAs and Weight: Is There a Link?

Emerging research indicates that PUFAs may play a role in body weight regulation. Polyunsaturated Fatty Acids have been suggested to enhance satiety, improve metabolism, and increase fat oxidation.

Studies have found that diets higher in PUFAs may be associated with lower body weight and less fat accumulation.

However, more research is needed to fully understand this relationship.

Unveiling the Health Benefits of PUFAs

Polyunsaturated fatty acids are critical for the body’s normal functioning and overall health.

As essential fats that the body cannot produce, they must be obtained from the diet.

Let’s explore why these fats are so significant.

Cardiovascular Health

Polyunsaturated Fatty Acids, especially omega-3 and omega-6 fatty acids, are crucial for heart health.

They play a key role in lowering low-density lipoprotein (LDL), or “bad” cholesterol, levels and raising high-density lipoprotein (HDL), or “good” cholesterol, levels.

This function is important as it can decrease the risk of developing atherosclerosis and heart disease.

Omega-3 fatty acids, in particular, can also reduce inflammation and blood pressure, further promoting heart health.

Brain Function

Omega-3 fatty acids, including docosahexaenoic acid (DHA), are major structural components of the brain and retina.

DHA is crucial during pregnancy and infancy for brain development.

Additionally, it plays a significant role in maintaining normal brain function throughout life.

A sufficient intake of omega-3 PUFAs has been associated with a lower risk of age-related cognitive decline and dementia.

Anti-inflammatory Effects

Omega-3 fatty acids have anti-inflammatory properties.

They are precursors to molecules called resolvins and protectins, which have been shown to help resolve inflammation.

A diet rich in omega-3 fatty acids may help manage or reduce the symptoms of inflammatory diseases such as arthritis and asthma.

Metabolic Health

Some evidence suggests that PUFAs can have beneficial effects on metabolic health.

They may improve body composition and help manage body weight by promoting feelings of fullness, enhancing metabolic rate, and increasing fat oxidation.

Moreover, they can enhance insulin sensitivity, which is important for blood sugar control.

Skin and Eye Health

PUFAs play a role in maintaining healthy skin and eyes.

They form vital components of skin cells, contributing to healthy cell membranes that result in moist, supple, and wrinkle-resistant skin.

In addition, the omega-3 fatty acid DHA is a major structural component of the retina of the eye, and inadequate intake can lead to vision problems.

Immune System Function

PUFAs are involved in producing and regulating immune system components.

They aid in the formation of eicosanoids, signaling molecules that mediate immune and inflammatory responses.

A balanced intake of omega-3 and omega-6 fatty acids is required for a well-functioning immune system.

Section Summary

Polyunsaturated Fatty Acids are vital for various bodily functions and overall health.

They contribute significantly to heart and brain health, have anti-inflammatory effects, enhance metabolic health, and support skin, eye, and immune system health.

As they can’t be produced by the body, it’s essential to ensure sufficient intake through a balanced diet.

Optimal Intake Levels for Polyunsaturated Fatty Acids

The World Health Organization (WHO) recommends that PUFAs should comprise 6-11% of daily energy intake.

It’s also recommended to aim for an omega-6 to omega-3 ratio of about 4:1 to 10:1.

However, given that many modern diets are heavy in omega-6-rich foods (like vegetable oils) and low in omega-3-rich foods (like fatty fish), many people consume far more omega-6 than omega-3.

Genetic Influence on PUFA Metabolism and Weight

Understanding the role of genetics in weight gain and the metabolism of polyunsaturated fatty acids (PUFAs) is an active area of research.

Several genes and genetic variations are believed to influence how we metabolize and respond to PUFAs, and consequently, how Polyunsaturated Fatty Acids might impact our body weight.

FADS1 and FADS2

The genes FADS1 and FADS2 encode enzymes that are crucial in the metabolism of both omega-3 and omega-6 PUFAs.

These enzymes convert dietary PUFAs into active forms that can be utilized by the body.

Variants in these genes can affect the efficiency of this conversion process, which in turn may influence Polyunsaturated Fatty Acid levels in the body and their effect on body weight and metabolic health.

Check your AncestryDNA, 23andMe raw data for the FADS1 & FADS2 gene variants

APOA2

The APOA2 gene encodes a protein involved in fat metabolism and appetite regulation.

Some research has found that a particular variant of this gene (rs5082) interacts with dietary fat intake to influence body weight.

Those carrying the variant show greater weight gain on a high-fat diet.

However, more research is needed to understand whether this effect is specific to certain types of fats, including PUFAs.

Check your AncestryDNA, 23andMe raw data for the APOA2 gene variants

PPAR Genes

The peroxisome proliferator-activated receptors (PPARs) are a group of nuclear receptor proteins that play essential roles in regulating metabolism, including the metabolism of fatty acids.

Variations in genes encoding these receptors, such as PPARα and PPARγ, may affect the body’s response to dietary Polyunsaturated Fatty Acids and influence weight regulation.

Check your AncestryDNA, 23andMe raw data for the PPAR genes variants

Other Genes

Many other genes are likely involved in the relationship between PUFA intake and weight gain.

Our response to diet and propensity for weight gain is highly complex, and polygenic traits are influenced by numerous genetic and environmental factors.

Gene	SNP	Effect	Description
FADS1	rs174547	T allele associated with efficient conversion of PUFAs	This variant in the FADS1 gene can affect the metabolism of both omega-3 and omega-6 PUFAs.
FADS2	rs1535	T allele associated with the efficient conversion of PUFAs	This variant in the FADS2 gene can also affect PUFA metabolism.
APOA2	rs5082	C allele associated with higher BMI in the context of high fat intake	This variant can influence body weight regulation in response to dietary fat, but more research is needed to confirm if this applies specifically to PUFAs.
PPARα	rs1800206	V allele associated with higher BMI	This variant in the PPARα gene, which regulates fat metabolism, may influence body weight regulation when consuming a diet high in PUFAs.
PPARγ	rs1801282	G allele associated with the efficient conversion of PUFAs	This variant in the PPARγ gene, another key regulator of fat metabolism, may also influence body weight regulation when consuming a diet high in PUFAs.
FABP2	rs1799883	A54T polymorphism associated with altered fat absorption and insulin sensitivity	Pro12Ala polymorphism is associated with lower BMI and improved insulin sensitivity
LPL	rs320	HindIII polymorphism associated with altered triglyceride levels	This variant affects an enzyme involved in the breakdown of triglycerides, a type of dietary fat.

Section Summary

Research in this area is ongoing, and while these genetic variations can influence the relationship between PUFAs and weight gain, they do not predetermine it.

Other factors, including overall diet composition, physical activity, and lifestyle habits, also play crucial roles.

Moreover, it’s worth noting that genetics can help provide personalized dietary recommendations, a concept known as nutrigenomics.

As our understanding of these genetic factors improves, it may become possible to provide more personalized dietary advice to help individuals manage their weight effectively.

The Downside of Too Much PUFA in Your Diet

Polyunsaturated fatty acids (PUFAs) are essential to our health, but like anything else, too much can have negative impacts. Here’s a list of potential downsides associated with excessive PUFA intake:

Inflammation: Although omega-3 PUFAs have anti-inflammatory properties, excessive omega-6 PUFA intake without a balanced intake of omega-3 PUFAs can promote inflammation. This is due to the different types of eicosanoids produced from omega-6 and omega-3 PUFAs, with those from omega-6 often being more pro-inflammatory.
Increased Risk of Heart Disease: While PUFAs are generally heart-healthy, excessive intake, particularly of omega-6 PUFAs without a balance of omega-3s, might contribute to cardiovascular risk through promotion of inflammation.
Oxidative Stress: PUFAs are vulnerable to oxidation due to their chemical structure. Oxidized PUFAs can cause cellular damage and contribute to various health problems, including cardiovascular disease and cancer. Cooking PUFAs at high temperatures can increase this risk.
Impact on Immune Function: High intake of omega-6 PUFAs without balanced omega-3 intake can impact the immune system, potentially making the body more susceptible to diseases and infections due to the pro-inflammatory properties of certain omega-6 metabolites.
Potential for Weight Gain: Despite the potential weight management benefits of PUFAs, they still contain the same amount of calories as other fats. Therefore, consuming them in excess without considering overall calorie intake can contribute to weight gain.
Interactions with Medications: PUFAs, specifically omega-3 fatty acids, may interact with certain medications such as blood thinners, leading to an increased risk of bleeding. This risk can potentially rise if PUFAs are consumed in excessive amounts.

Section Summary

It’s crucial to maintain a balanced ratio of omega-6 to omega-3 PUFAs and to consider overall calorie intake when consuming these fats. As with all nutrients, it’s important to consume Polyunsaturated Fatty Acids in moderation as part of a varied and balanced diet.

Consequences of Insufficient PUFA Intake

Polyunsaturated fatty acids (PUFAs), including both omega-3 and omega-6 fatty acids, are essential nutrients, meaning they are necessary for health and must be obtained through the diet.

Here are some potential consequences of insufficient PUFA intake:

Poor Skin Health: Omega-3 and omega-6 fatty acids are essential for maintaining healthy skin. Deficiency can lead to symptoms like dry and flaky skin.
Eye Health: The omega-3 fatty acid DHA is a key component of the retina in the eye. A deficiency can contribute to vision problems.
Impaired Brain Function: Omega-3 fatty acids are vital for brain health and cognitive function. Deficiency, especially in DHA, can negatively impact cognitive performance and may increase the risk of neurodegenerative disorders.
Mental Health Issues: Some studies suggest that low levels of omega-3 fatty acids are associated with an increased risk of several mental disorders, including depression and anxiety.
Heart Disease: Both omega-3 and omega-6 fatty acids play crucial roles in heart health. Insufficient intake can increase the risk of heart disease.
Poor Growth and Development in Infants and Children: Omega-3 fatty acids, particularly DHA, are crucial for the growth and development of the brain and nervous system in infants and children. Insufficient intake can lead to developmental problems.
Increased Inflammation: Omega-3 fatty acids are known for their anti-inflammatory properties. Insufficient intake, particularly in relation to omega-6 intake, can result in an increased inflammatory response.
Reduced Immune Function: Polyunsaturated Fatty Acids play a role in immune function, and deficiency can result in an impaired immune response.

Section Summary

To avoid these potential health issues, it’s important to ensure sufficient intake of both omega-3 and omega-6 Polyunsaturated Fatty Acids in the diet.

The specific recommended intake can vary depending on age, sex, and overall health, so it’s advisable to seek personalized guidance from a healthcare professional or dietitian.

Where to Find PUFAs in Your Diet?

Omega-3 Fatty Acids

PUFAs are found in various foods. Some of the best sources of omega-3 fatty acids are fatty fish like salmon, mackerel, sardines, flaxseeds, chia seeds, and walnuts.

Omega-6 Fatty Acids

On the other hand, omega-6 fatty acids are abundant in plant-based oils, such as sunflower, safflower, soybean, and corn oils, and many nuts and seeds.

Wrapping Up: PUFAs’ Role in Health and Weight

Polyunsaturated fatty acids are a vital component of a healthy diet, playing significant roles in numerous bodily functions.

They can impact weight regulation and have notable implications for heart and brain health.

Balancing PUFA intake, and ensuring adequate consumption without overindulging, is key to harnessing their benefits for health.

Sources for Further Reading

Calder PC. (2018). Very long-chain n-3 fatty acids and human health: fact, fiction and the future. Proc Nutr Soc, 77(1), 52-72.
Harris WS, et al. (2009). Omega-6 fatty acids and risk for cardiovascular disease: a science advisory from the American Heart Association Nutrition Subcommittee of the Council on Nutrition, Physical Activity, and Metabolism; Council on Cardiovascular Nursing; and Council on Epidemiology and Prevention. Circulation, 119(6), 902-7.
Simopoulos AP. (2006). Evolutionary aspects of diet, the omega-6/omega-3 ratio and genetic variation: nutritional implications for chronic diseases. Biomed Pharmacother, 60(9), 502-7.
Wu JHY, et al. (2017). Circulating Omega-6 Polyunsaturated Fatty Acids and Total and Cause-Specific Mortality: The Cardiovascular Health Study. Circulation, 130(15), 1245-1253.
WHO. (2008). Interim Summary of Conclusions and Dietary Recommendations on Total Fat & Fatty Acids. From the Joint FAO/WHO Expert Consultation on Fats and Fatty Acids in Human Nutrition, 10-14 November 2008, WHO, Geneva.
Merino, D. M., Johnston, H., Clarke, S., Roke, K., Nielsen, D., Badawi, A., … & Mutch, D. M. (2011). Polymorphisms in FADS1 and FADS2 alter desaturase activity in young Caucasian and Asian adults. Molecular genetics and metabolism, 103(2), 171-178.
Lai, C. Q., Corella, D., Demissie, S., Cupples, L. A., Adiconis, X., Zhu, Y., … & Ordovas, J. M. (2006). Dietary intake of n-6 fatty acids modulates effect of apolipoprotein A5 gene on plasma fasting triglycerides, remnant lipoprotein concentrations, and lipoprotein particle size: the Framingham Heart Study. Circulation, 113(17), 2062-2070.
Flavell, D. M., Pineda Torra, I., Jamshidi, Y., Evans, D., Diamond, J. R., Elkeles, R. S., … & Staels, B. (2000). Variation in the PPARα gene is associated with altered function in vitro and plasma lipid concentrations in Type II diabetic subjects. Diabetologia, 43(5), 673-680.
Yamauchi, T., Kamon, J., Waki, H., Terauchi, Y., Kubota, N., Hara, K., … & Ueki, K. (2001). The fat-derived hormone adiponectin reverses insulin resistance associated with both lipoatrophy and obesity. Nature medicine, 7(8), 941-946.
Baier, L. J., Sacchettini, J. C., Knowler, W. C., Eads, J., Paolisso, G., Tataranni, P. A., … & Bogardus, C. (1995). An amino acid substitution in the human intestinal fatty acid binding protein is associated with increased fatty acid binding, increased fat oxidation, and insulin resistance. Journal of Clinical Investigation, 95(3), 1281-1287.
Wittrup, H. H., Tybjaerg-Hansen, A., & Nordestgaard, B. G. (1999). Lipoprotein lipase mutations, plasma lipids and lipoproteins, and risk of ischemic heart disease. A meta-analysis. Circulation, 99(22), 2901-2907.