Ka Wai Ola - Office of Hawaiian Affairs, Volume 5, Number 9, 1 Kepakemapa 1988 — He Mau Nīnau Ola [ARTICLE+ILLUSTRATION]

He Mau Nīnau Ola

Some Health Questions by Kekuni Blaisdell, M.D.

Saturated Fat, Blood Triglyceride and HeartAttack

Ninau: E ke Kauka, I am confused about two substances you described in your eolumn on the Moloka'i Diet Study: saturated fat and triglyceride. What precisely are they? And what is their relationship to cholesterol and heart attack, if any? Pane: Ka pane to

your ninau requires some explanation of chemistry and physiology, as well as nutrition. Simple fat, such as in polupolu (flabby fatty tissue) in the kino kanaka (human body) or in animal fatty food, like 'i'o pua'a uahi (bacon), consists chemically of one or more fatty acids linked to an aleohol (not like whiskey, but, rather a class of organic chemicals). If the aleohol is the 3-carbon glycerol and to it are linked three fatty acids, as shown in Fig. 1, the compound is called a triglyceride.

A fatty acid, structurally, is a ehain of carbon atoms (designated as linked Cs), with a methyl group (designated as CH3) at one end, and a carboxyl group (designated as COOH) at the other end. If eaeh carbon atom within the ehain has two hydrogen atoms (designated as H2), the fatty acid is said to be "saturated" (with hydrogen atoms). If a hydrogen atom is missing from eaeh of two adjacent carbon atoms within a ehain, so that a double bond connects the two carbon atoms, the fatty acid is said to be "unsaturated" (Fig. 1). Pela, a saturated fat contains no double-bond carbons in its fatty acid chain(s). This is characteristic of animal fat, such as in pua'a (pork) and pipi (beef). Dietary saturated fat contributes to the body synthesis of cholesterol and thus raises the koko (blood) cholesterol, promotes atherosclerosis, and increases the risk of heart attack (such as myocardial infarction or angina), as explained in previous He Mau Ninau columns.

An unsaturated fat contains one or more double bonds between the carbons in the fatty acid chain(s). Such fats are characteristic of la'au (plants), like olives, peanuts and eom, and also i'a (fish) oils. Unsaturated fat tends to ho'ēmi(lower) koko cholesterol, prevent or reverse atherosclerosis, and pēlā, decreases the risk of heart attack, as explained by Kauka Terry Shintani in his nutrition eolumn. A triglyceride may contact saturated and or unsaturated fatty acides (Fig. 1). In the kino kanaka, triglycerides are used for needed energy

by body cells or when not immediately needed, are stored as kino fat under the 'ili (skin), between the makela (muscles) within the abdominal cavity and around individual inner organs. Akā, to be transported in the koko, triglycerides must be attached to proteins called lipoproteins, mainly as chylomicrons and very low density lipoproteins (VLDL), whieh determine to whieh organs or tissues in the kino they go, as shown in Fia. 2.

'Oia ho'i, koko chylomicrons hāpai (carry) triglycerides from the na'au (gut) after a fatty meal to other body tissues for energy or storage. Akā, during fasting between na mea 'ai, VLDL carries triglycerides from the akepa'a (liver) to the other kino tissues for energy needs (Fig. 2). [The transport of cholesterol between the na'au, the akepa'a and other tissues is also shown in Fig. 2]. Koko triglyceride levels are normally less than about 150 mg/dl during fasting. They ho'onui (increase after a fatty meal, sugar or aleohol (like beer or whiskey); in patients who also have mimikō (diabetes mellitus), obesity, hypothyroidism, or chronic pu'upa'a (kidney) failure; and in certain 'ohana as an hereditary illness.

Koko triglyceride levels tend to ho'ēmi with decrease in food intake and physical exertion, such as ho'oikaika (body exercises). Although eating nui loa (too mueh) saturated fat ho'onui (raises) koko triglyceride, high koko triglyceride wale no (alone) does not seem to enhanee atherosclerosis and increase the risk of heart attack, except paha (perhaps) in wāhine (women). On the other hand, since high koko triglyceride is often associated with other conditions that do ho'onui the risk of heart attack or other serious ma'i (sickness), correcting elevated triglyceride is usually desirable. Associated conditions whieh increase the risk of heart attack include high total koko cholesterol, low HDL cholesterol, high VDL cholesterol, mimiko, chronic ma'i pu'upa'a, family history of heart attack, puhi paka (cigarette-smoking), and kokopi'i (high blood pressure), as described in previous He Mau Ninau columns.

I ka hō'ike ho'opōkole (in summary), food saturated fat, whieh is mainly non-fish animal fat, should be restricted to reduce the risk of heart attack. While high koko triglyceride wale no probably does not increase the risk of heart attack, high koko triglyceride is usually associated with eating too mueh saturated fat and cholesterol, and other factors that increase the risk of heart attack. No laila, controlling koko triglyceride by prudent diet, vigorous physical activity and avoiding aleohol are wholesome guidelines for us heart attack-prone kānaka māoli.

Fig. 2. Simplified scheme of the transport of koko (blood) cholesterol and koko triglyceride from the Na'au (gut) and between the akepa'a and other tissues.

Fig. A triglyceride containing two unsaturated fatty acid chains and one saturated fatty acid ehain. Thus, it is a mixed saturated and unsaturated fat.