Cardiovascular Journal of Africa: Vol 25 No 6 (November/December 2014)

48 / 66

CARDIOVASCULAR JOURNAL OF AFRICA • Volume 25, No 6, November/December 2014 298 AFRICA
Review Article
Lifestyle and diet
Lionel H Opie
Abstract
Currently, there is widespread interest in many different diets.
The best-known diets include the New Atkins diet in the USA,
the Dukan diet in France, and in South Africa the Noakes
diet. Two different approaches have emerged, one focusing on
a life-long healthy lifestyle and the other emphasising weight
loss. These are in fact complementary aims, as will be reviewed
and reconciled. Furthermore, besides the dietary approach,
there is a valid case for added drug therapy for selected lipid
disorders with the use statins. In addition, new drugs are
emerging that in the future might eventually considerably
reduce the negative health impact of coronary artery disease.
Keywords: diet, cardiovascular risk, Noakes diet, Banting diet,
Mediterranean diet
Submitted 9/10/14, 16/10/14
Cardiovasc J Afr 2014; 25: 298–301
DOI: 10.5830/CVJA-2014-063
Lifestyle is life-long
Life-style is life-long in its health implications.1 Although diet is
only one of the five components of a healthy lifestyle,2 diet has
recently come to the fore.3 When considering overall health, the
most important are non-smoking and regular exercise, followed
by body weight and diet, in order of importance (Table 1).
These proposals are based on a series of important studies on
over 100 000 US health professionals over 10 to 25 years, which
defined the contribution to health of four major lifestyle factors,
only one of which is diet (Table 1).2,4,5
While there are many diets to choose from, the majority
focusing on weight loss, few diets have had scientifically solid
outcome studies to prove that the diet in question actually
improves health and increases life span. An exception is the
Mediterranean diet, so called because of the very low incidence
of heart attacks observed by Ancel Keys in the Mediterranean
islands of Corfu and Crete, thus leading to the concept that the
Mediterranean diet is an ideal diet,1,6,7 also protecting against
heart failure.8
Palaeolithic, the oldest diet
What is the paleolithic diet? Mankind evolved over hundreds of
millions of years, therefore the paleolithic diet must have been the
standard diet that also evolved over that time. Studies on the teeth
of the paleolithic man, as found in East Africa (also in its congener
from South Africa), showed that the dental bones and teeth had
adapted to process large quantities of low-quality vegetation
rather than hard objects.9 The paleolithic diet is now recognised as
a nutritional pattern based on the ancient diet of wild plants and
animals that our ancestors consumed over 10 000 years ago.
In the Kitava dietary study on isolated tribes in Papua, New
Guinea, who even recently ate a pre-Westernised diet of 55 to
65% animal foods and 35 to 45% plant foods, these societies had
no incidence of stroke, heart disease, diabetes or hypertension. 10
The diet consisted mainly of fish, grass-fed pasture-raised meats,
vegetables, fruits, roots, spices and nuts. There was no restriction
on calories or on the foods to be cooked.
Although the Mediterranean diet overlaps with the
palaeolithic diet in terms of fibre, antioxidants, saturated fat
and mono-unsaturated fat, the paleolithic diet improved glucose
tolerance more than did the Mediterranean diet.10 Furthermore,
this diet is more food satiating than a Mediterranean-like diet in
persons with ischaemic heart disease.11 Therefore the paleolithic
diet both preceded the Mediterranean diet and was apparently
better, so it may be that ‘the simpler, the better’.
Diet and lipids
Moving on in history, it was the early Cape Town studies that
made the link between fat in the diet and blood cholesterol
values. Nearly 60 years ago, Professors John Brock and Brian
Bronte-Stuart from Groote Schuur and the University of Cape
Hatter Institute for Cardiovascular Research in Africa,
Groote Schuur Hospital and Medical School, University of
Cape Town, Cape Town, South Africa
Lionel H Opie, MD, FRCP,
Table 1. The ‘big-five’ components of the healthy lifestyle, with
contributions of the various components to give protection
from risk of death, with and the proposed mechanisms of
action. Note that the missing 21% is probably stress related.
From Opie,1 page 33.
Lifestyle: ‘big five’
Reduced
all-cause
death
risk (%) Mechanism
Non-smoking 28 Protects arteries
Exercise 30 min or
more daily
17 Slows the heart rate, lowers BP
Ideal weight 14 Less toxic chemicals released from fat
cells
Ideal diet 13 High unsaturated fatty acids, high
vegetables and fruit, low red meat
Modest alcohol 7 Red wine preferred, contains melatonin
All five 79 Remaining 21% may be stress related