Balanced fatty acid intake crucial for heart wellness

Cardiovascular disease has been a major contributor of morbidity and mortality across the globe ever since the industrial and agricultural revolution changed our dietary habits, with the inclusion of affordable cereals and oils in our daily diet.

The proportion of beneficial versus harmful fatty acids changed and resulted in the progression of incidence of cardiovascular diseases including hypertension, coronary heart diseases, insulin resistance, hyperinsulinemia and obesity. In last few decades, research focused on studying the role of essential fatty acids on prevention of cardiovascular diseases, especially poly or monounsaturated fatty acids.

It is widely accepted that the excess consumption of saturated fats increases low-density lipoprotein (LDL), whereas monounsaturated (MUFAs) and polyunsaturated fatty acids (PUFAs) do not. Consequently, a moderate fat diet in which unsaturated fatty acids replace saturated fatty acids and carbohydrates is found to lower LDL; compared with a low-fat diet with disproportionate fatty acids, a moderate-fat diet with balanced fatty acid composition has been found to lower triglycerides and increase high density lipoprotein (HDL), which could be considered as cardio-protective.

Classification of fatty acids
Therefore, it is to be understood that each type of fatty acid contributes uniquely to health and cardiovascular function, and an appropriate balance is essential for preventing disease and promoting overall wellness. Fatty acids can be broadly classified into saturated fatty acids (SFAs), MUFAs and PUFAs.

SFAs are fatty acids that have no double bonds between the carbon atoms and are typically solid at room temperature. These are mainly found in animal fats and some tropical oils. While the excessive intake of SFAs has been studied to cause elevation in LDL levels, not all SFAs have the same detrimental impact on heart health. For example, medium-chain saturated fats found in coconut oil and palm oil may have a more neutral effect on cholesterol levels. Therefore, it is moderation in SFA consumption, rather than complete avoidance, which is recommended.

MUFAs are fatty acids which have one double bond in their structure and are usually liquid at room temperature. They are known to be present in olive oil, avocados, and nuts. These fatty acids are known to reduce LDL levels while maintaining HDL levels, which is supposedly beneficial for heart health. Diets rich in MUFAs, such as the Mediterranean diet which is rich in fruits, vegetables, whole nuts and fish, have been associated with a lower risk of cardiovascular diseases.

PUFAs are fatty acids which contain more than one double bond and are liquid at room temperature. These are mainly found in fish, flaxseeds, and vegetable oils. These constitute mainly omega-3 and omega 6 fatty acids, which play a crucial role in reducing inflammation by their anti-inflammatory properties thus lowering triglyceride levels, LDL and promoting an increase in HDL when consumed in balanced proportions with healthy lifestyle, which includes moderate oil consumption, a balanced diet and regular exercise.

Role of oils in diet
The role of various oils in our diet have been studied with respect to heart health. Ideally, A heart healthy oil should be cholesterol and trans fats free, low in saturated fats, high in MUFA and PUFA, should have an ideal N-6 to N-3 ratio (< 4:1) and high smoking points. Studies have highlighted that it is not one particular oil which is harmful or beneficial for heart health, it is the practice of using repeatedly heated cooking oil to reduce the cost of food preparation which leads to production of new functional groups due to thermal oxidation of oils and may be potentially hazardous to cardiovascular health. The benefits of vegetable oil can be deteriorated by repeated heating that leads to lipid oxidation.

Although the guidelines recommend diets rich in fruits, vegetables, whole grains, nuts, and legumes; moderate in low-fat dairy and seafood; and low in processed meats, sugar-
sweetened beverages, refined grains, and sodium. A few examples out of the countless factors that influence people to consume a low-quality diet are a lack of knowledge, a lack of availability, high cost, time scarcity, social and cultural norms, the marketing of poor-quality foods, and palatability.

Governments should enact policies that will reach all levels of society and create a food environment wherein healthy foods are accessible, affordable, and desirable. Even health professionals have a duty to promote a sustainable pattern of healthy eating rather than simply focusing on high quality, selectively affordable food products for cardiovascular disease prevention for both healthy individuals and those at higher risk

A recent study from the University of Florida highlighted the quantity to be consumed as it studied the effects of extra virgin olive oil in diet. The participants consumed two different diets for four weeks which had whole foods, plant based vegan diet with quantity difference in the consumption of extra virgin olive oil. It was observed that when people consumed the diet with less extra virgin olive oil and then suddenly shifted to the other diet with more olive oil content, their LDL levels spiked. It was also observed that glucose levels, total cholesterol, and HDL cholesterol increased with the increase in the consumption of extra virgin olive oil.

Palm oil
Several oils which have been under scrutiny for being good or bad for heart health include coconut oil, canola oil, palm oil, sunflower oil, soybean oil and several others. Palm oil is one of the most commonly used cooking oils in the world and has enormous nutritional benefits for the whole body including the heart.

Palm oil is obtained from the fruit of the oil palm, which is cultivated in tropic region across the world. The fleshy mesocarp of the fruit is the source of palm oil and the seed is the source of kernel palm oil. It has almost a balanced percentage of saturated and unsaturated fatty acids. While palmitic acid (44%), stearic acid (5%) and myristic acid (1%) for the saturated fatty acid content, oleic acid (39%) and linolenic acid (11%) for the mono and polyunsaturated content of palm oil. This healthy mix of saturated and unsaturated fatty acids also gives it the semi-solid consistency at room temperature making it convenient ingredient to be used as spread for various food products.

Recent studies published in 2023 and 2018 show that a diet rich in foods containing carotenoids, including beta carotene, can be helpful in maintaining heart health when consumed in mild to moderate amounts.

The mesocarp of oil palm is red in colour due to the presence of beta-carotene, which is the precursor of vitamin A, an antioxidant. Palm oil also contains vitamin E precursors called tocotrienols, which also act as antioxidants in preventing inflammation and neuronal degeneration in the body. Another study published in 2020 highlighted a decrease in the overall levels of triglycerides and an increase in HDL (good cholesterol) when tocotrienols are increased in a diet or are given as supplements.

Palm oil has a high smoke point and is considered one of the ideal oils for cooking at high temperatures. Its calorific value is also in coordination with other oils providing approximately 9 kcal of energy for each gram consumed. It serves as a potential source of energy when prolonged times of fasting are imminent or to provide satiety during meals. On the other hand, extra virgin olive oil, walnut oil, pumpkin seed oil, even while having the same energy content, have low smoke point and are not ideal for cooking. They are best sprinkled over salads and might not constitute or suffice the daily dietary need of the oil content.

A meta-analysis of studies also showed that, when palm oil is used to replace trans-fat in diet, it has can cause a slight reduction of LDL (bad cholesterol) in the body, leading to a lowering in the incidence of cardiovascular disease.

Some reports suggest that excessive consumption of any oil, whether it’s olive oil, soy, ghee or any other edible oil, can be harmful for the heart as it causes increased levels of triglyceride and cholesterol. But the key element here is in excessive consumption. Small to moderate amounts of any oil, including oils which have saturated and unsaturated fatty acids, have their own benefits to health, including heart health and maintaining healthy tissues and skin and providing much needed energy in our lives.