Cholesterol and triglycerides
are endogenously manufactured by the body and are also greatly obtained from
fatty foods and oils. When
the blood levels of cholesterol becomes too high, the risk of developing heart disease
Once made by the liver, cholesterol and
triglycerides move into the bloodstream to reach various organs and tissues in
the body. However, they cannot enter the bloodstream by themselves. They have
to be carried in conjugation with certain proteins. The resulting
compound is then known as a lipoprotein.
HDL - the Bad and Good Cholesterol
Lipoproteins are of various types. LDL stands for "low density lipoprotein," and
carries cholesterol to various tissues. When the LDL cholesterol levels are too high in the blood, the LDL
lipoprotein tends to stick to the lining of the blood vessels and consequently stimulates
An elevated LDL
cholesterol level is a major risk factor for heart ailments and is therefore
addressed as "bad"
HDL, or high density lipoprotein removes
excess cholesterol from the tissues.
So the cholesterol present in HDL is to a large extent
the excess cholesterol that has been removed from cells and blood vessel walls,
and is being transported back to the liver for processing. The higher the HDL cholesterol, presumably,
more cholesterol is being scavenged from the cells and blood vessels where it
might otherwise cause damage. It is the "good" cholesterol. In most people, the majority of the cholesterol in the blood
is packaged as LDL, and only a small proportion is present as HDL.
Cholesterol rich foods
(organ meat especially brain,
butter, ghee, egg yolk, chicken with skin, prawns and shrimps),
saturated fats (meat, poultry skin, coconut, palm oil,
full cream dairy products, ghee, margarine, butter, cream and mayonnaise)
and trans fats (found in cookies, biscuits, cakes, fried
snacks and wafers)
should be consumed with some discretion and in moderation. These
dietary fats raise cholesterol levels, clog arteries, and increase the risk for
All the excess calories consumed, whether
from fats or carbohydrates, if not utilized, ultimately get converted to
triglycerides and get stored in tissues.
Elevated levels of triglycerides in the blood have
also been found to be associated with an increased risk of cardiovascular
Exercise & Reduction of Cholesterol & Heart Disease
In view of
this, George A Kelly and colleagues conducted a study with the aim to assess
the combined effects of aerobic
exercise and a prudent diet on lipid and lipoprotein concentrations in adults
. The study results has been published in the journal BMC
The study included nine electronic databases,
cross-referencing, and expert review of randomized
controlled trials involving interventions of more than 4 weeks in adults.
The results showed statistically significant
Total cholesterol: HDL cholesterol and
There was no significant decrease in the HDL
The study suggests that the combined effect of both,
a prudent diet and regular aerobic exercise, is efficacious for reducing the
levels of total cholesterol, LDL cholesterol and triglycerides. By 'prudent' diet, the authors
mean 'a diet in which saturated/trans fat intake is less than approximately 10
percent of total calories and cholesterol is less than 300 mg/day and/or fiber
intake is 25 g/day or more in women and 35 g/day or more in men'.
These findings appear to be important from a practical
perspective, especially in relation to the prevention of coronary heart
a disease with an annual
estimated incidence rate of more than 1.4 million people in the United States.
account that every 1 percent reduction in total cholesterol levels results in
approximately 2 percent reduction in the rate of CHD, this study found that aerobic exercise along with a
prudent diet would result in 15 percent reduction in the rate of CHD.
decrease in the total cholesterol and high density lipoprotein cholesterol
(HDL-C) ratio with this module, translates into approximately 21 percent in the
CHD risk. The reduction in low density lipoprotein cholesterol (LDL-C) is
equivalent to 7 percent in the 12-year incidence of CHD.
According to the
study, findings support the current recommendations regarding the use of
aerobic exercise and a prudent diet as a first line strategy for maintaining
optimal concentrations of lipids and lipoproteins in adults. If optimal levels cannot be attained, aerobic
exercise and diet are still recommended with the possible addition of fibrates
or niacin for increasing HDL-C and/or a statin for improving all other lipid
and lipoprotein concentrations, especially LDL-C.
In addition, a
statistically significant increase in VO2max in ml.kg-1.min-1 was also
observed. This finding is not surprising given that weight loss and increase in
cardio respiratory fitness is a common change that occurs as a result of
Undoubtedly, adopting a few precautionary changes in the diet and
lifestyle such as
Avoiding saturated and trans fats,
Eating plenty of fruits and vegetables,
Following a regular exercise regime,
Controlling blood sugar and blood pressure
can go a long way in preventing increase of cholesterol and many related
of Aerobic Exercise and a Prudent Diet for Improving Selected Lipids and
Lipoproteins in Adults: A Meta-Analysis of Randomized Controlled Trials; George
A Kelly et al; BMC Medicine 2011