Almonds
Lower Cholesterol Despite Fat Content
Further
evidence to suggest that almonds could benefit our health hit the
press this week as scientists in Canada report that almonds
significantly lowered bad cholesterol levels in a study of people with
high cholesterol.
A
study was done in order to determine if, and at what level of
consumption, almonds could help reduce heart disease risk by lowering
high cholesterol.
Previous
research has suggested that nut consumption could reduce the risk of
coronary heart disease. However eating more nuts increases calories,
and therefore is generally not recommended for people who need to
restrict calories.
For
the study 27 high cholesterol patients (15 men and 12 postmenopausal
women, average age 64) completed the three-phase study. Their average
total cholesterol level was 260 milligrams per decilitre (mg/dL) at
baseline.
Three
one-month diets were undertaken. For one month each participant ate a
full dose of almonds (average 74 grams), which represented a little
less than one quarter of their total daily caloric intake. For one
month they took a half dose of almonds (average 37 grams) –
described as a 'handful' of almonds. In the last month, they ate a
low-saturated fat, wholewheat muffin as a daily snack.
The
muffin snack served as the control diet because it had about the same
amount of calories, protein and saturated and polyunsaturated fats,
explained lead author David Jenkins, director at the Clinical
Nutrition and Risk Factor Modification Center, St. Michael's Hospital,
Toronto. The only difference being that the monounsaturated fat was
swapped for the starch in the muffin, he said.
Researchers
measured cholesterol levels, blood pressure and weight in the
subjects. They found that patients reduced the low-density lipoprotein
(LDL – bad cholesterol) by an average of 4.4 per cent with the half
portion of almonds and 9.4 per cent with the full portion.
"We
were quite impressed,"
said Jenkins. "If you look at the ratio of LDL to HDL
(high-density lipoprotein, the good cholesterol), the reduction was
7.8 per cent for the half dose and 12 per cent for the full dose by
the fourth week. That ratio is very important in assessing
cardiovascular risk."
The
patients' cholesterol levels did not significantly drop after the
muffin phase.
Jenkins
said that practitioners should encourage patients to eat almonds as
part of a healthy balanced diet as long as they are natural or "dry
roasted" without added oils or salts.
Nuts
do not have cholesterol and are a good source of protein, according to
the American Heart Association. However, the association stresses that
the potential benefits of nuts may be negated if they are added rather
than substituted for other foods in the diet. While nuts and seeds
tend to be very high in fat and calories, most of the fat is
polyunsaturated or monounsaturated (eg. almonds, pecans, walnuts).
Jenkins
added that nuts, including almonds, walnuts, pecans, peanuts,
macadamia and pistachios, have been shown to lower blood cholesterol.
He maintained that the combination of monounsaturates with some
polyunsaturates in nuts is an ideal combination of fats and that
although there is not enough research to say that all nuts are equal
in their health value, almonds have particularly well researched
profiles.
"This
study suggests that replacing carbohydrates with monounsaturated fat
– within the context of a diet that is low in saturated, trans-fat
and cholesterol – favourably affects cholesterol levels and
cardiovascular risk,"
said Alice Lichtenstein, vice-chairman of the American Heart
Association nutrition committee.
Full
findings are published in the latest issue of Circulation: Journal of
the American Heart Association.