". . . coconut oil enhances kidney function . . . because it supplies myristic acid, the 14-carbon saturated fatty acid."
Saturated Fats and the Kidneys
Posted on September 30, 2000 by Mary Enig, PhD • 1 Comment
One of the body’s most important organs is the kidney.
Properly functioning kidneys are essential for maintaining proper blood volume
and composition; for filtering and excreting or saving various chemical
metabolites; and for helping to maintain proper blood pressure. Hypertension
(high blood pressure) is known to result from improperly functioning kidneys.
Research carried out during the last few years indicates that both saturated
fat and cholesterol play important roles in maintaining kidney function, as do
the omega-3 fatty acids.
The kidneys need stable fats both for their cushioning and
as their energy source. We know that the kidney fat normally has a higher
concentration of the important saturated fatty acids than are found in any of
the other fat depots. These saturated fatty acids are myristic acid (the
14-carbon saturate), palmitic acid (the 16-carbon saturate), and stearic acid
(the 18-carbon saturate). When we consume various polyunsaturated fatty acids
in large amounts, they are incorporated into kidney tissues, usually at the
expense of oleic acid, because the normal high level of saturated fatty acids
in the kidney fat does not change.1
A species of rat known to be prone to strokes and to
spontaneously develop hypertension (high blood pressure) has been used to
evaluate effects of different lipids such as plant sterols or cholesterol, and
also fatty acids such as omega-3 or omega-6 fatty acids in the finely tuned
functions of the kidney. These animals are very sensitive to dietary cholesterol
manipulations and a deficiency of cholesterol in their membranes makes their
membranes weak and fragile. When plant sterols found in vegetable oils are
substituted for cholesterol in their diets, these animals have a shortened life
span.2Also,
these animals are reported to need a proper omega-6 to omega-3 ratio in the
kidney phospholipids. It was further reported that feeding oils high in omega-6
fatty acids without omega-3 fatty acids resulted in renal injury, and that
feeding oils rich in the omega-3 fatty acids such as fish oil, perilla oil, and
flaxseed oil prolonged the survival time of this animal.3
The omega-3 fatty acids are recognized as being important,
and the conversion of the flax oil-type omega-3 fatty acid (alpha-linolenic
acid) to the fish oil-type omega-3 fatty acids (EPA and DHA) is enhanced when
the diet contains saturated fat such as coconut oil. This conversion is
hindered when there is extra omega-6 oils in the diet.4 Injury
to the kidney from immune dysfunction (IgA nephropathy) responds to omega-3
fats (both flax oil-type omega-3 and fish oil-type omega-3).5 As
noted, adding the saturated fats, especially coconut oil, improves the body’s
use of omega-3 fatty acids.
Another reason that coconut oil enhances kidney function is
because it supplies myristic acid, the 14-carbon saturated fatty acid.6 Myristic
acid is involved in the signalling from cell membrane receptors through G
proteins and their attachment to membranes. These signalling proteins require a
lipid such as myristic acid to be added to one end of the protein, a process
called myristolation.7
Thus, the fats that we recommend for general good health,
namely various saturated animal fats and tropical oils, along with a supplement
of flax oil, are also specifically helpful for kidney function. Products
containing high omega-6 oils and trans fatty acids should be avoided.
REFERENCES
1. Suarez et al, Lipids
1996;31:345; Taugbol and Saarem, Acta Vet Scand 1995;36:93
2. Ratnayake, et al, J
Nutrition 2000;130:1166
3. Miyazaki et al, Biochim
Biophys Acta 2000;1483:101
4. Gerster, Int J Vitam
Nutr Res 1998;68:159
5. Kelley, ISSFAL,
2000;7:6
6. Monserrat et al, Res
Exp Med (Berl) 2000;199:195
7. Busconi and Denker, Biochem
J 1997;328:23
This article appeared in Wise Traditions in Food,
Farming and the Healing Arts, the quarterly magazine of the Weston A. Price
Foundation, Fall 2000.
