The Fats of Life Revealed
Nutrition News @ 2006 VOL XXX, NO.10
Fats are essential to life.
Siri Khalsa, Editor in Chief
Lisa Wade Devine, Associate Editor
How does fat keep you together?
How can only 2 fats make a difference?
What 7 ways can cholesterol improve your health?
What does fish have to do with it?
Are you one of the 80% of Americans who are deficient in necessary fats?
Haven't you always been interested in the fats of life? Well, now is the time to learn more....
Today, most of us are aware that we need to eat fats. In spite of this, fat remains the most misunderstood of foods. Much of the information we hear about them sounds contradictory and even confusing. Many of us wonder, "What's the real skinny on fats?"
Which fats are good for us? Which should we stay away from or avoid altogether? What are lipids? What are triglycerides? Eicosanoids? How do these relate to cholesterol, HDL, LDL, and VLDL?
What are fatty acids? What do you know about saturated, monounsaturated, and polyunsaturated fats? What is the significance of omega-3? Of omega-6? And what about all of those other acronyms we hear: EFAs, ALA, LA, GLA, CLA, EPA and DHA? How do all these fit into the big fat picture?
Fats and fatlike substances are called lipids. Their unique characteristic is that they are not soluble in water. We are interested in three major types of lipids: triglycerides, phospholipids, and cholesterol. Found in every cell, lipids are integrally involved in cell membrane structure, blood and tissue structure, enzyme reactions, and the synthesis and use of certain hormones, including the hormone-like eicosanoids (cell-to-cell communicators).
Triglycerides make up the substance we commonly call "fat". Fat comprises 95% of the lipids in foods. In our bodies, they support and cushion the internal organs and serve as insulation against body heat loss. However, their principal use is as an energy source for metabolism.1
Any excess calories we eat - from any foods - are converted to triglycerides and stored as body fat. This fat provides reserve fuel. On the other hand, too much in reserve (triglycerides over 200 mg/dl) indicates high blood fat and is considered a heart disease risk factor.
Phospholipids are the second class of lipid in our discussion. Many kinds exist in the body, especially the brain. Lecithin is a familiar phospholipid. Found in the cells, it is part of the fat digestion process. It is an emulsifying agent, making it possible for fats and water/blood to mix.
The third major lipid is cholesterol. Cholesterol is essential to life. As with triglycerides, it is too much that creates health problems. Found in all body tissues, cholesterol is particularly concentrated in the liver, blood, and brain. (For example, 3 oz of muscle contain about 75 mg of cholesterol while 3 oz of brain tissue contain over 35 times that amount.) Cholesterol helps make up the cell membranes and nerve fibers, bile, the sex and adrenal hormones, and vitamin D. The liver normally produces between 500 and 1000 mg of cholesterol every day whether or not we eat cholesterol-laden foods.
Triglycerides, phospholipids, and cholesterol interact with protein to form lipoproteins. Lipoproteins are the L in HDL, LDL, and VLDL. These acronyms represent tiny packages of fat wrapped in protein. This cleverly allows the lipids to travel in the water-based bloodstream. These terms are universally recognized as parts of cholesterol measures. HDL refers to "the good" high density lipoprotein; LDL, to "the bad" low density lipoprotein; and VLDL, very low density to "the ugly". Actually, it's unfortunate that these acronyms have become labeled as good and bad. In truth, all of them are imperative to healthy body functioning. Again, it is imbalance that causes problems.
Regarding LDLs: Once they are broken down in the liver, the resulting protein and cholesterol particles are absorbed and used to make bile, sex hormones, and other compounds. Diets high in saturated fat impede this process, leaving some LDLs in the bloodstream. These loose LDLs (and VLDLs) can be oxidized in the blood vessels. The resulting rancid gunk builds up as plaque. Ultimately, plaque narrows the arteries, again increasing heart disease risk.2
Fats consist of molecules called fatty acids. They are made up of carbon, hydrogen, and oxygen. The configuration (shape) of the molecule determines whether a fat is saturated, monounsaturated, or polyunsaturated. This also determines the melting temperature and the stability of the fat. All fats are a mixture of these fatty acids.
Saturated fats include butter, coconut oil, palm oil, and lard. They are normally solid at room temperature. This is because each carbon atom is attached to as many hydrogen atoms as it can carry. Thus, the molecule is saturated. As you look at the figure, you see that the structure is "straight". This allows the molecules to stack on top of each other like logs. This stable structure results in a high melting point.
Now notice that the unsaturated fatty acid figure contains double lines at the bend. These represent double bonds - spaces where there is no hydrogen atom. Thus, they are not saturated. Mono-unsaturated fatty acids like the figure have only one double bond while poly-unsaturated fatty acids have more than one. They bend at each double bond. This prevents stacking and results in a less stable, liquid fat. Some (like fish and flax seed oils) have so many double bonds they even remain liquid at freezing temperatures. It is this very instability that makes them available for our body to use.
The double bonds also determine the omega designation of the fatty acid. There are omega-3, -6, -7, and -9 designations of edible oils. For example, olive, canola, and macadamia nut oils are all omega-9 mono-unsaturated fatty acids. Their double bond occurs in the ninth place after 8 saturated bonds.
Why Eat Fat?
Since our bodies make fat out of any excess calories we consume, why do we need to eat any fat at all? There are some fatty acids that our bodies need but can't make. Instead we must supply them through our diets. These are called essential fatty acids or EFAs. All essential fatty acids are polyunsaturated.
Until very recently, fatty acid researchers believed there were only two EFAs: alpha- linolenic acid (ALA) and linoleic acid (LA). Alpha-linoleic is an omega-3 fatty acid while linoleic acid is an omega-6. For a long time, it was believed that these two would metabolize into six further fatty acids needed to sustain health. Omega-3 fatty acid research has brought this assumption into question. At this time, the complexity and complementarity of omega-3 and omega-6 fatty acids is not fully understood.
Some things haven't changed. It is known that the EFAs have a regulatory effect on the body's fatty acid metabolism. Directly connected with this is their role in the synthesis of eicosanoids. These hormone-like substances are produced at the cellular level and include prostaglandins and leukotrienes. In general, they participate in immune processes and vision, help form cell membranes, and are important in the regulation of multiple bodily functions, including:
- inflammation, pain, and swelling
- pressure in the eye, joints, or blood vessels
- secretion and viscosity of mucus
- nerve transmission
- steroid production and hormone synthesis
- smooth muscle and autonomic reflexes
- water retention
- blood clotting ability
- allergic response
- rheumatoid arthritis
Failure to grow, severe dermatitis, inability to heal wounds, and inappropriate loss of water through the skin are all classic symptoms of EFA deficiency. Multiple sclerosis is also associated with fatty acid impairment. Furthermore, the major degenerative diseases, heart disease, stroke, cancer, and arthritis all demonstrate a major disruption in fat metabolism.
CLA, the Fat Buster
Conjugated linoleic acid is produced by cows and other grazing farm animals from linoleic acid in the grass they eat. (We get it if the meat, whole milk, and full-fat dairy products we eat come from grass-grazed animals.) Hundreds of studies (most in animals) have shown CLA's potential benefit in cancer, diabetes, and cardiac therapies.
However, human studies have focused on CLA's special properties for weight control. In 2000, a study of 80 overweight people found those who took CLA while dieting and then regained the weight, put it back as 50% muscle and 50% fat. Regained weight of those not on the CLA consisted of the expected 75% fat and 25% muscle. This study determined that CLA helps convert fat to lean muscle, one of the body's best metabolizers.
CLA is also reported to reduce inflammatory signals from fat cells. In addition, it maintains insulin receptor sensitivity which decreases blood sugar and insulin levels. The recommendation for CLA is 3-6 grams daily. This is 6-12 500 mg caps in divided doses, taken before meals.
Not Enough Fat?
As a nation, we are not eating enough healthy fats. It is estimated that as many as 80% of us are deficient in the essential fatty acids, particularly omega-3. This fat is derived from oily deep water fish, wild game, and flax, hemp, and perilla seed oils.
We have the lowest consumption of omega-3s in the world and the highest consumption of omega -6. Omega-6 is in all vegetable oil, grains, and even beans. (Some people are deficient in omega-6. See GLA sidebar on the back page.) Again, we are talking about balance. Researchers suggest a ratio of 1:4 omega-3 fats to omega-6. Instead, we may be taking in these fats at a ratio as high as 1:40!!!
An overabundance of omega-6 has an inflammatory effect on the body, plus it interferes with the body's ability to use omega-3. This potentially serious situation is thought to account for the growing prevalence of heart attacks, cancer, diabetes, asthma, lupus, schizophrenia, accelerated aging, ADHD (attention deficit/hyperactivity disorder), Alzheimer's disease, metabolic syndrome, obesity, and depression.3
An important thing to know about omega-3 oils is that the body needs the conversion of ALA into EPA and DHA to reap all its benefits. EPA and DHA are the beneficial fatty acids from fish, wild game, and microalgae. The body's conversion of ALA from flax, perilla, and hemp seed oils is not efficient. Because of the importance of DHA to brain and eye development and to health throughout life, one current debate centers around declaring DHA to be an essential fatty acid.
Let's take a look at one omega 3 highlight: the ability to prevent depression. The relationship of DHA and EPA to depression has been revealed in several studies worldwide. Researchers theorize that the human brain is adapted to the Paleolithic diet which contained foods in a 1:1 omega relationship. Dr. Joseph R. Hibbeln of the National Institutes of Health, has discovered that omega-3 may influence the functionality of serotonin (the happiness neurotransmitter).
The US-with the lowest consumption of omega-3s in the world-also has one of the highest depression rates. Depression among adults has tripled in the last 10 years. Estimates are that 5-10% of adults have major depressive episodes each year. Diagnosed depression occurs in about 2% of children and 4% to 8% of adolescents.
Eat Fat, Lose Weight
In 1988, Ann Louise Gittleman, PhD, launched a one woman crusade to turn Americans away from their fat-free bender. In Beyond Pritikin, she introduced readers to the importance of essential fatty acids and their effects on health and weight loss.4 Now "good" fats are routinely recommended in weight loss diets.
Recently Nicholas Perricone, MD, outlined how omega-3s aid weight-control by:
- Influencing key anti-obesity genetic switches that govern both inflammation and conversion of food to body fat.
- Reducing inflammation that promotes weight gain.
- Enabling burning of dietary fats by transporting fatty acids into the mitochondria of our cells for burning as fuel.
- Enhancing "fuel efficiency" (metabolism) and improving fatty acid balance.
- Improving blood sugar control by increasing insulin sensitivity.
- Stimulating the secretion of leptin, a peptide hormone that is produced by fat cells.5
Unless you eat a lot of deep water fish or game meats, we recommend an omega-3 supplement in the form of pharmaceutical grade fish oils. This guarantees your intake of both DHA and EPA. Take about 3-6 grams daily. If you are a vegetarian, you will want to take flax, hemp, or perilla seed oil, about a tablespoon a day or 12 grams. ALA is very valuable in dispersing saturated fats.
FYI: Dr. Ohhira (the Japanese probiotic specialist) has developed a new vegetarian essential fatty acid formula. It contains eight oils, including flax, perilla, and borage. They occur in a ratio of 4:1:1 (omega-3:-6:-9). The label recommendation is 1-3 capsules per meal.
Essential fatty acids need vitamins A, B3, B6, C, E, and the minerals magnesium and zinc to function. As always, we recommend taking a daily multiple vitamin-mineral formula.
In a recent study of depressed children given fish oils (Nemets, et al), researchers found that seven of ten showed that depression ratings had been reduced by 50% or more within eight weeks. The dose was 500 mg 2x/d of a 2: 1 mixture of EPA and DHA. A similar study was completed previously with adults. Their dose was double the children's.
GLA: Missing Fatty Acid?
For the body to use linoleic acid (omega-6) to produce eicosanoids, it must first become gammalinolenic acid, GLA. This fatty acid is found in mothers' milk and borage and evening primrose seeds. Under certain conditions, our bodies do not have the ability to perform this process. In this case, the end result is an omega-6 fatty acid deficiency. Infancy, aging, diabetes, eczema and psoriasis, viral infections, stress, and trans fats in the diet all interfere with our ability to produce this fatty acid. This indicates a need to supplement it.
A combination of GLA and omega-3 fatty acids have demonstrated the ability to lower inflammatory activity by up to 65% within four weeks. These essential fatty acids can also suppress C-reactive protein and fibrinogen levels, two heart risk factors.
- Gittleman, AL. (2002). The Fat Flush Plan. McGraw-Hill, New York.
- Khalsa, SD. (September 2004). Nutrition News: Fats & Oils.
- Khalsa, SD. (March 2004). Nutrition News: On Fire!
- Khalsa, SD. (April 1999). Nutrition News: Fish & Flax.
- FDA Announces Qualified Health Claims for Omega-3 Fatty Acids. Retrieved on September 10, 2006 from http://www.fda.gov/bbs/topics/news/2004/NEWOI115.html
- Introduction to fatty acids. Retrieved on October 23, 2006 from http://www.fatsoflife.com/pufa/intro_1asp.
- Nemets H, et al. Omega-3 treatment of childhood depression: a controlled, double-blind pilot study. American Journal of Psychiatry 2006; 163: 1098-1100. [Pub Med]
- Perricone, N. (2005). The Perricone Weight Loss Program. Retrieved on September 17, 2006 from http://lef.org.
- The Medical BioChem Page. Retrieved on October 20, 2006 from httpllwebindstate.edu/thcme/mwking/home/html.
1A simple definition of metabolism is the process of building the body's molecular structures from nutrients (anabolism) and breaking the down for energy production (catabolism).
2Supplement note: Because of its fat-related antioxidant properties, 400-800 IU of vitamin E daily can protect against the oxidation of these cholesterol particles.
3Even though the FDA says these fatty acids are not essential to the diet, they allow a qualified health claim for reduced risk of coronary heart disease (CHD) on conventional foods that contain eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) omega-3 fatty acids.
4Dr. Gittleman is currently helping thousands of people to reach and maintain their weight goals with her original "Fat Flush Plan". Visit her website: www.annlouise.com.
5Leptin functions within the hypothalamus to suppress appetite and burn fat stored in adipose tissue (fat cells). For an in depth discussion of manipulating leptin for weight loss, read Nutrition News "Eating Fitness".