Calorie Restriction, PUFA, and Aging

Also see:
Protect the Mitochondria
PUFA Accumulation & Aging
Unsaturated Fats and Longevity
Anti-Inflammatory Omega -9 Mead Acid (Eicosapentaenoic acid)
Protective “Essential Fatty Acid Deficiency”
“Curing” a High Metabolic Rate with Unsaturated Fats
Fat Deficient Animals – Activity of Cytochrome Oxidase
Dietary PUFA Reflect in Human Subcutaneous Fat Tissue
Toxicity of Stored PUFA
PUFA, Development, and Allergy Incidence
PUFA, Aging, Cytochrome Oxidase, and Cardiolipin

Quotes by Ray Peat, PhD:
“Calorie-restricted animals (on a diet of normal composition) have a lower degree of fat unsaturation in their mitochondria as they age, preserving the relatively more saturated fats of youth.”

“In this culture that repeatedly makes such claims of essentiality, the growing number of reports of biological superiority of “deficient” animals suggests that nutritional research may be near the point at which it can resume the line of study begun by Northrup, Osborne, Mendel, Drummond, Bernstein, Elias, and others, that was interrupted for 60 years by industrial interests that promoted antiscientific opinions.

For example, in 1914 F.P. Rous showed that limiting food intake reduced the incidence of cancer, and then in 1915 and 1917, Osborne and Mendel showed that food restriction extended the fertility and longevity of female rats. The association between estrogen and cancer had become known during this time, and vitamin E, which was originally known as the fertility vitamin, was soon recognized to have antiestrogenic properties, as well as to prevent the deadly effects of excessive polyunsaturated fats in the diet. My endocrinology professor, A.S. Soderwall, who had found that excess estrogen prevented (or interrupted) pregnancy, demonstrated that increased vitamin E extended fertility in aging female rodents.

By the time I began my research, it seemed clear that it had been the reduction of PUFA in the diet which, like the addition of vitamin E, had prevented sterility in the calorie restriction experiments, and that those treatments had limited the effects of estrogen in the aging organisms.”

“Caloric restriction does extend the life span of many species, but it generally preserves the high metabolic rate of youth, so that at a given age the calorie-restricted animal has a higher rate of oxygen consumption per gram of body weight than the unrestricted eaters”

Mech Ageing Dev. 2005 Sep;126(9):1003-10.
Membrane alteration as a basis of aging and the protective effects of calorie restriction.
Yu BP.
As has been experimentally determined, oxidative modification to biological systems can be extensive, although the identification and stochiometric relation of the reactive species that cause these alterations have not been fully elucidated. In this review, arguments are presented to support the notion that the combined effects of membrane lipid peroxidation and its by-products, reactive aldehydes are likely responsible for membrane-associated functional declines during aging. As evidence for a systemic response to overall oxidative stress, the molecular inflammation hypothesis of aging is discussed by considering that the activation of inflammatory genes act as a bridge linking normal aging to pathological processes.

The phospholipids of mitochondria and microsomes become more unsaturated with aging (Laganiere and Yu, 1993, Lee, et al., 1999). -Ray Peat, PhD

Gerontology. 1993;39(1):7-18.
Modulation of membrane phospholipid fatty acid composition by age and food restriction.
Laganiere S, Yu BP.
Phospholipids from liver mitochondrial and microsomal membrane preparations were analyzed to further assess the effects of age and lifelong calorie restriction on membrane lipid composition. Results showed that the major phospholipid classes, phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylinositol and cardiolipin did not vary significantly with age or diet. The fatty acid composition of the phospholipids was determined in PC and PE and ages of 6, 12 and 24 months. The data revealed characteristic patterns of age-related changes in ad libitum (AL) fed rats: membrane levels of long-chain polyunsaturated fatty acids, 22:4 and 22:5, increased progressively, while membrane linoleic acid (18:2) decreased steadily with age. Levels of 18:2 fell by approximately 40%, and 22:5 content almost doubled making the peroxidizability index increase with age. In addition, levels of 16:1 and 18:1 decreased significantly with age, indicating a possible change in delta 9-desaturase activity coefficient. Food restriction resulted in a significant increase in levels of essential fatty acids while attenuating levels of 22:4, 22:5, 22:6 and peroxidizability. We concluded that the membrane-stabilizing action of long-term calorie restriction relates to the selective modification of membrane long-chain polyunsaturated fatty acids during aging.

Free Radic Biol Med. 1999 Feb;26(3-4):260-5.
Modulation of cardiac mitochondrial membrane fluidity by age and calorie intake.
Lee J, Yu BP, Herlihy JT.
The aim of the present study was to determine the effects of dietary restriction (DR) on the age-related changes in membrane fluidity, fatty acid composition and free radical damage of mitochondrial membranes obtained from the rat left ventricle. Mitochondrial membrane preparations were obtained from the left ventricles of 6- and 24-month-old, male, Fischer 344 rats that were allowed to eat throughout their life either ad lib (Group A) or only 60% of the amount consumed by the ad lib fed group (Group B). Our results show that the membrane fluidity of the 24 month Group A hearts was less than that of the 6 month group A hearts. No differences in membrane fluidity were observed between the 6 and 24 month DR groups. The fatty acid composition of the mitochondrial membranes of the two ad lib fed groups differed: the long-chain polyunsaturated 22:4 fatty acid was higher in the older group, although linoleic acid (18:2) was lower. DR eliminated the differences. No statistically significant difference in the overall polyunsaturated fatty acid content was noted. However, the peroxidizability index was higher in the membranes of the 24 month Group A hearts but not in the 24 month Group B hearts. Finally, the degree of lipid damage, as assessed in vitro by the induced production of reactive oxygen species, was elevated in the 24 month Group A hearts. No difference was observed between the young and old DR groups. Considered together, these results suggest that DR maintains the integrity of the cardiac mitochondrial membrane fluidity by minimizing membrane damage through modulation of membrane fatty acid profile.

Biochem Biophys Res Commun. 1987 Jun 30;145(3):1185-91.
Anti-lipoperoxidation action of food restriction.
Laganiere S, Yu BP.
Chronic food restriction inhibited the age-related increase of malondialdehyde production and lipid hydroperoxides in liver mitochondrial and microsomal membranes of ad libitum fed Fischer 344 rats. The anti-lipoperoxidation action of food restriction could not be attributable to the changes in membrane lipid content nor vitamin E status. Restricting calories modified membrane fatty acid composition by increasing linoleic acid and decreasing docosapentaenoic acid content in both membranes. The significance of the fatty acid modification was discussed in terms of anti-lipoperoxidation and membrane fluidity.

Aging Clin Exp Res. 2004 Dec;16(6):425-31.
Effects of dietary restriction on age-related changes in the phospholipid fatty acid composition of various rat tissues.
Tamburini I, Quartacci MF, Izzo R, Bergamini E.
Polyunsaturated fatty acids (PUFAs) are essential components of the cell lipid bilayer and are involved in membrane fluidity and normal functioning, but they are vulnerable to free radical attack. Given the role of oxidative stress in the aging process, age-related changes in phospholipid fatty acid (PLFA) composition in rat liver, kidney and heart were assessed in 3-, 12- and 24-month-old rats fed either ad libitum but only every other day, or daily but only 60% of the quantity normally consumed by age-matched controls.
Lipids were extracted and phospholipids (PLs) were separated using the solid phase extraction technique, then transesterified and assayed by gas-liquid chromatography.
Saturated fatty acids (FAs) did not change significantly with age; mono- and bi-unsaturated FAs decreased in the liver and heart, and the ratio of the former to the latter increased in the liver, kidney and heart. PUFAs increased in the liver and heart. As regards individual FAs, 20:1(n-9) decreased in all organs, 14:1 and 18:1(n-7) increased in the kidney and heart, 18:1(n-9) increased in the kidney, 20:2(n-6), 18:2(n-6) and 22:5(n-3) decreased in the liver and heart, 20:3(n-6) decreased in the kidney and increased in the heart. The most abundant PUFAs, 20:4(n-6) and 22:6(n-3), either remained the same or increased with age. The N-9 family increased in the kidney, the N-7 family increased in the kidney and heart, the N-6 family decreased in all three organs, and the N-3 family increased in the liver and kidney. Dietary restriction (DR) significantly counteracted most of these changes, but changes in some FAs [20:2(n-6) in the heart] were magnified by DR and may not be age-related.
Most age-related changes (that occurred in the rat liver, kidney and heart and were counteracted by the two different types of DR) may be involved in the mechanism of aging.

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