Commonly occurring unsaturated fatty acids are linoleic acid (in ground nut oil) and linolenic acid (sun flower oil).  Thus people started to take these vegetable oils with reduced usage of coconut oil.  Within the last 50 years, per capita consumption of coconut oil in Kerala has been reduced to one-third.  But during the same period in the same population, the incidence of myocardial infarction has increased to three folds.  This fact alone is enough to disprove the anti-propaganda against coconut oil.

It may be stressed that all saturated fats are not harmful.  Now we know that saturated fatty acids in coconut oil are of the medium chain variety.  Nearly 55 % of the fatty acids in coconut oil are lauric acid (12 carbon atoms) and 20% myristic acid (14 carbon atoms), both medium chain fatty acids.  On the other hand, the fats that cause heart disease are saturated long chain fatty acids with 16 or 18 carbon atoms in their structure. 

The earliest pathologic lesion of atherosclerosis is the fatty streak, which may progress to lipid accumulation and the migration and proliferation of smooth muscle cells. Thus a fibrous plaque is formed.  Activated platelets and macrophages will further contribute to vascular inflammation and later, thrombosis at these sites. Then a fibrous cap is formed that overlies a core of lipid-laden foam cells. Growth of the fibrous plaque results in vascular remodeling, progressive luminal narrowing, blood-flow abnormalities, and compromised oxygen supply to the heart muscle.

Hypertension is an important risk factor for the development of atherosclerosis, atherosclerotic cardiovascular disease and stroke. Diabetes mellitus is commonly associated with hyperlipidemia, hypertension, abnormalities of coagulation, platelet adhesion, atherosclerosis and myocardial infarction.  Good control of diabetes may also reduce the risk of complications of CAD.  Smoking has been identified as a major and modifiable risk factor for atherosclerosis and is associated with an increased relative risk of dying from vascular disease.

Prevention of atherosclerosis
People who are physically active are less likely to develop coronary artery disease and high blood pressure. Exercise that promotes endurance (aerobic exercise such as brisk walking, cycling, and jogging) or muscle strength (resistance training with free weights or weight machines) helps prevent coronary artery disease.

Convincing evidences are available to show that lowering serum cholesterol reduces the risk of subsequent coronary heart disease and overall mortality.  The primary treatments of hypercholesterolemia are diet and exercise.  This includes restriction of calorie intake; reduction in intake of saturated fats and avoidance of cholesterol-containing food stuff. Limiting the amount of fat to no more than 25 to 30% of daily calories is recommended. The type of fat consumed is important. It is better to take saturated (coconut oil), mono unsaturated (Gingelly oil) and poly unsaturated (sunflower oil) in 1:1:1 ratio. A diet containing mono-unsaturated or omega-3 fats will reduce the incidence of atherosclerosis. Eating fruits and vegetables daily will also decrease the risk of coronary artery disease.

Avoid Trans  Fatty  Acids  (TFA)
Poly unsaturated fatty acids (PUFA) seen in vegetable oils are said to reduce cholesterol level in blood.  However, when such oils are heated, there is a probability of them to become Trans fatty acids (with double bonds having trans configuration).  Trans fatty acids (TFA) are also formed during the partial hydrogenation of vegetable oils.  TFA are found to be more atherogenic than saturated fatty acids.   TFA decreases HDL (good cholesterol) and increases LDL (bad cholesterol) levels.  Hence Federal Drug Agency (FDA) in USA stipulates that TFA content of food items be given on the labels. Reducing the intake of TFA to 2-7 g/day is now strongly advised. 

PUFA, in excess, may be harmful
Poly unsaturated fatty acids (PUFA, present in vegetable oils such as sunflower oil) can definitely reduce cholesterol level in blood. But there should be moderation. The diet should contain correct type and quantity.  Very high intake of omega-6 oils will cause lowering of HDL, elevation of plasma triglycerides, and will promote platelet aggregation. Vegetable oils (such as sunflower oil), containing PUFA are rich in omega-6 variety; while ghee and butter are low in omega-6.
Normal Indian diet consisting of cereals, pulses and vegetables provides “invisible oils”, which contains about 10 g of PUFA / day (out of which about 2 g is omega-3 and the rest 8 g is omega-6). Further intake of omega-6 oils is unnecessary and may be harmful.  The optimal ratio for omega-6 to omega-3 in diet is 4:1.  In an average Indian diet, this is about 30:1.  In sunflower oil, this value is 160:1, and therefore, unnecessary addition of such vegetable oils will further deteriorate the condition.  Coconut oil, although contains saturated fatty acids, the omega ratio is 3:1, and therefore superior to sunflower oil in this respect.

Coconut oil and body weight
Overweight is an important health problem in developed countries  and it is becoming so in India too.  Overweight increases the risk for osteoarthritis, on diabetes, heart disease, stroke and early death.  The usual advice given to overweight individual is to reduce food intake, particularly fat intake.  However, on such a diet, the person will feel hungry and feel depressed.  In such circumstances they stop the dieting and end up in rebound weight gaining. 

Coconut oil has an advantage in these types of settings.  Overweight person taking coconut oil, containing medium chain fatty acids, gradually over the months lose weight effortlessly (Geliebter  1980; Baba 1982; Bach and Babayan 1982). Replacing long chain fatty acids with medium chain fatty acids results in a decrease in body weight and a reduction in fat deposition (Bray  1980; Geliebter 1983; Hasihim and Tantibhedyangkul  1987).  Coconut-oil-enriched diet was found to be effective in producing a decrease in fat stores (Portillo et al 1998).  Cleary et al (1999) found that the safflower oil-fed animals had more fat cells than the coconut oil-fed.

Our idea is that when you take fat, you will gain weight.  In this context, it may be a paradoxical finding that overweight person taking coconut oil is losing weight.  The explanation is the following: Long chain fats will almost always go into fat stores; this will eventually make the person overweight and will cause dyslipidemia.  However, as explained previously, the medium chain fatty acids will be immediately utilised for energy purposes, and will not be deposited in the body. Since coconut oil will speed up metabolism and body will actually be burning more calories in a day.  This will help to reduce weight (Hill et al  1989).

Lipid profile in persons consuming coconut oil
Continuing these previous observations by other research workers, at Amrita Institute of Medical Sciences, Kochi, we have analysed serum from persons, consuming coconut oil or sunflower oil.  70 normal, healthy subjects were taken as controls and 70 subjects with Type 2 diabetes were recruited in patient group. Each group was further subdivided into two subgroups of 35 subjects each, consuming coconut oil and sunflower oil respectively as cooking medium.  Samples of blood were collected and analyzed for serum total cholesterol, triacylglycerols, and cholesterol in lipoprotein fractions. Trigycerides, LDL and VLDL cholesterol levels were high in the diabetic subjects compared to the controls. Though lipid profile parameters and oxidative stress parameters were high in Type 2 diabetic subjects compared to controls, no pronounced changes for these parameters were observed between the subgroups (coconut oil vs. sunflower oil) (Sabitha et al 2009).

This study was extended to analyse serum from 302 normal healthy persons, out of which 152 were consuming coconut oil and 150 were using sunflower oil for the past 2 years or more.  There was no statistically significant difference in the cholesterol, HDL or LDL levels in coconut oil consuming population versus sunflower oil consuming population.  Thus plasma fatty acid composition reflected no changes with dietary fat source.  Lauric acid, the principal fatty acid of coconut oil was found in low concentrations among subjects of both groups. Higher intake of coconut oil did not cause any significant increase in the concentration of lauric acid in blood among coconut oil consumers. 

Lipid profile in coconut oil consumers with disease
At Amrita Institute of Medical Sciences, Kochi ,lipid profile was analysed in 76 coronary artery disease patients, out of which 41 were used to take coconut oil and 35 were used to take sunflower oil.  There was no statistically significant difference in the cholesterol, HDL or LDL levels in coconut oil consuming patients versus sunflower oil consuming patients.  Plasma fatty acid composition reflected no changes with dietary fat source.

Coconut oil and lipid Oxidative stress
Free radicals generated by oxidative stress are the cause for many chronic diseases such as coronary artery disease, ageing process etc.  At Amrita Institute of Medical Sciences, the effect of diets containing coconut oil or sunflower oil on oxidative stress and lipid peroxidation was studied in rabbits maintained for 6 months. Serum lipid values did not show significant variation between animals fed coconut oil or sunflower oil Lipid peroxidation was found to be higher in sunflower oil fed rabbits, compared to controls or coconut oil fed rabbits.  Coconut oil intake did not cause hyper cholesterolemia or oxidative stress in rabbits (Sabitha et al, 2010). 

Fatty acid composition of atheromatous plaques
In another study conducted at Amrita Institute of Medical Sciences, 71 samples of plaques (from diseased coronary arteries) were analysed.  Out of these patients, 48 persons were using coconut oil and 23 persons were using sunflower oil routinely.  Fatty acids were extracted by chloroform and then analysed by HPLC (high performance liquid chromatography). Surprisingly, the fatty acid content of the plaque did not show any difference between coconut oil consumers versus sunflower oil consumers.  In both coconut oil consumers and sunflower oil consumers, the major substances present in the plaques were saturated fatty acids; palmitic acid (46%) and stearic acid (33%) of total lipids. The concentrations of unsaturated fatty acids and medium chain fatty acids were low. Lauric acid (fatty acid present in coconut oil) was only 3.5% of the total content of plaques in both coconut oil consumers and sunflower oil consumers.

The general advice given by physicians against the use of coconut oil needs re-evaluation. This mis-information arose, when long chain saturated fatty acids (LCSFA) were shown to increase cholesterol level. Since coconut oil also contains satu­rated fatty acids, people equated them with LCSFA. Now it is known that coconut oil contains medium chain fatty acids (MCFA). Metabolisms of LCFA and MCFA are drastically different. Coconut oil, within normal limits, neither decrease nor increase cholesterol levels.  The advantages of coconut oil are that it  does not affect serum cholesterol (neutral); it produces very little free radicals, as opposed to other oils (beneficial); it is rapidly absorbed, rapidly oxidized and is not deposited (beneficial) and it helps in resisting invading micro-organisms.