I often hear this comment: "I have a normal cholesterol panel. So I have low risk for heart disease, right?"
While there's a germ of truth in the statement, there are many exceptions. Having "normal" cholesterol values is far from a guarantee that you won't drop over at your daughter's wedding or find yourself lying on a gurney at your nearest profit-center-for-health, aka hospital, heading for the cath lab.
Statistically, large populations do indeed show fewer heart attacks at the lower end of the curve for low total and LDL cholesterol and the higher end of HDL. But that's on a population basis. When applied to a specific individual, population observations can fall apart. Heart attack can occur at the low risk end of the curve; no heart attack can occur at the high risk end of the curve.
First of all, to me a "normal" lipid panel is not adhering to the lax notion of "normal" specified in the lab's "reference range" drawn from population observations. Most labs, for instance, specify that an HDL cholesterol of 40 mg/dl or more and triglycerides of 150 mg/dl or less are in the normal ranges. However, heart disease can readily occur with normal values of, say, an HDL of 48 mg/dl and triglycerides of 125 mg/dl, both of which allow substantial small oxidation-prone LDL particles to develop. So "normal" may not be ideal or desirable. Look at any study comparing people with heart disease vs. those without, for instance: Typical HDLs in people with heart attacks are around 46 mg/dl, while HDLs in people without heart attacks typically average 48 mg/dl--there is nearly perfect overlap in the distribution curves.
There are also causes for heart disease that are not revealed by the lipid values. Lipoprotein(a), or Lp(a), is among the most important exceptions: You can have a heart attack, stroke, three stents or bypass surgery at age 40 even with spectacular lipid values if you have this genetically-determined condition. And it's not rare, since 11% of the population express it. How about people with the apo E2 genetic variation? These people tend to have normal fasting cholesterol values (if they have only one copy of E2, not two) but have extravagant abnormalities after they eat that contribute to risk. You won't know this from a standard cholesterol panel.
Vitamin D deficiency can be suggested by low HDL and omega-3 fatty acid deficiency suggested by higher triglycerides, but deficiencies of both can exist in severe degrees even with reasonably favorable ranges for both lipid values. Despite the recent inane comments by the Institute of Medicine committee, from what I've witnessed from replacing vitamin D to achieve serum 25-hydroxy vitamin D levels of 60-70 ng/ml, vitamin D deficiency is among the most powerful and correctable causes of heart disease I've ever seen. And, while greater quantities of omega-3 fatty acids from fish oil are associated with lower triglycerides, they are even better at reducing postprandial phenomena, i.e., the after-eating flood of lipoproteins like VLDL and chylomicron remnants, that underlie formation of much atherosclerotic plaque--but not revealed by fasting lipids.
I view standard cholesterol panels as the 1963 version of heart disease prediction. We've come a long way since then and we now have far better tools for prediction of heart attack. Yet the majority of physicians and the public still follow the outdated notion that a cholesterol panel is sufficient to predict your heart's future. Nostalgic, quaint perhaps, but as outdated as transistor radios and prime time acts on the Ed Sullivan show.
The notion of genetic modification of foods and livestock is a contentious issue. The purposeful insertion or deletion of a gene into a plant or animal's genome to yield specific traits, such as herbicide resistance, nutritional composition, or size, prompted the Codex Alimentarius Commission, an international effort to regulate the safety of foods, to issue guidelines concerning genetically-modified foods.
The committee is aware of the concept of unintended effects, i.e., effects that were not part of the original gene insertion or deletion design. In their report, last updated in 2009, they state that:
Unintended effects can result from the random insertion of DNA sequences into the plant genome, which may cause disruption or silencing of existing genes, activation of silent genes, or modifications in the expression of existing genes. Unintended effects may also result in the formation of new or changed patterns of metabolites. For example, the expression of enzymes at high levels may give rise to secondary biochemical effects or changes in the regulation of metabolic pathways and/or altered levels of metabolites.
They make the point that food crops generated using techniques without genetic modification are released into the food supply without safety testing:
New varieties of corn, soybean, potatoes and other common food plants are evaluated by breeders for agronomic and phenotypic characteristics, but generally, foods derived from such new plant varieties are not subjected to the rigorous and extensive food safety testing procedures, including studies in animals, that are typical of chemicals, such as food additives or pesticide residues, that may be present in food.
In other words, conventional plant breeding techniques, such as hybridization, backcrossing, and introgression, practices that include crossing parental plants with their progeny over and over again or crossing a plant with an unrelated plant, yield unique plants that are not subject to any regulation. This means that unintended effects that arise are often not identified or tested. Plant geneticists know that, when one plant is crossed with another, approximately 5% of the genes in the offspring are unique to that plant and not present in either parent. It means that offspring may express new characteristics, such as unique gliadin or gluten proteins in wheat, not expressed in either parent and with new immunological potential in consuming humans.
Dr. James Maryanski, the FDA's Biotechnology Coordinator, stated during Congressional testimony in 1999 that:
The new gene splicing techniques are being used to achieve many of the same goals and improvements that plant breeders have sought through conventional methods. Today's techniques are different from their predecessors in two significant ways. First, they can be used with greater precision and allow for more complete characterization and, therefore, greater predictability about the qualities of the new variety. These techniques give scientists the ability to isolate genes and to introduce new traits into foods without simultaneously introducing many other undesirable traits, as may occur with traditional breeding. [Emphasis mine.]
Efforts by the Codex Alimentarius and FDA are meant to control the introduction and specify safety testing procedures for genetically modified foods. But both organizations have publicly stated that there is another larger problem that has not been addressed that predates genetic modification. In other words, conventional methods like hybridization techniques, the crossing of different strains of a crop or crossing two dissimilar plants (e.g., wheat with a wild grass) have been practiced for decades before genetic modification became possible. And it is still going on.
In other words, the potential hazards of hybridization, often taken to extremes, have essentially been ignored. Hybridized plants are introduced into the food supply with no question of human safety. While hybridization can yield what appear to be benign foods, such as the tangelo, a hybrid of tangerines and grapefruit, it can also yield plants containing extensive unintended effects. It means that unique immunological sequences can be generated. It might be a unique gliadin sequence in wheat or a unique lectin sequence in beans. None are tested prior to selling to humans. So the world frets over the potential dangers of genetic modification while, all along, the much larger hazard of hybridization techniques have been--and still are--going on.
Imagine we applied the hybridization techniques applied by plant geneticists to humans, mating an uncle with his niece, then having the uncle mate again with the offspring, repeating it over and over until some trait was fully expressed. Such extensive inbreeding was practiced in the 19th century German village of Dilsberg, what Mark Twain described as "a thriving and diligent idiot factory."
Dietary fats, from olive oil to cocoa butter to beef tallow, are made of triglycerides.
Triglycerides are simply three ("tri-") fatty acids attached to a glycerol backbone. Glycerol is a simple 3-carbon molecule that readily binds fatty acids. Fatty acids, of course, can be saturated, polyunsaturated, and monounsaturated.
Once ingested, the action of the pancreatic enzyme, pancreatic lipase, along with bile acids secreted by the gallbladder, remove triglycerides from glycerol. Triglycerides pass through the intestinal wall and are "repackaged" into large complex triglyceride-rich (about 90% triglycerides) molecules called chylomicrons, which then pass into the lymphatic system, then to the bloodstream. The liver takes up chylomicrons, removes triglycerides which are then repackaged into triglyceride-rich very low-density lipoproteins (VLDL).
So eating triglycerides increases blood levels of triglycerides, repackaged as chylomicrons and VLDL.
Many physicians are frightened of dietary triglycerides, i.e, fats, for fear it will increase blood levels of triglycerides. It's true: Consuming triglycerides does indeed increase blood levels of triglycerides--but only a little bit. Following a fat-rich meal of, say, a 3-egg omelet with 2 tablespoons of olive oil and 2 oz whole milk mozzarella cheese (total 55 grams triglycerides), blood triglycerides will increase modestly. A typical response would be an increase from 60 mg/dl to 80 mg/dl--an increase, but quite small.
Counterintuitively, it's the foods that convert to triglycerides in the liver that send triglycerides up, not 20 mg/dl, but 200, 400, or 1000 mg/dl or more. What foods convert to triglycerides in the liver? Carbohydrates.
After swallowing a piece of multigrain bread, for instance, carbohydrates are released by salivary and gastric amylase, yielding glucose molecules. Glucose is rapidly absorbed through the intestinal tract and into the liver. The liver is magnificently efficient at storing carbohydrate calories by converting them to the body's principal currency of energy, triglycerides, via the process of de novo lipogenesis, the alchemy of converting glucose into triglycerides for storage. The effect is not immediate; it may require many hours for the liver to do its thing, increasing blood triglycerides many hours after the carbohydrate meal.
This explains why people who follow low-fat diets typically have high triglyceride levels--despite limited ingestion of triglycerides. When I cut my calories from fat to 10% or less--a very strict low-fat diet--my triglycerides are 350 mg/dl. When I slash my carbohydrates to 40-50 grams per day but ingest unlimited triglycerides like olive oil, raw nuts, whole milk cheese, fish oil and fish, etc., my triglycerides are 50 mg/dl.
Don't be afraid of triglycerides. But be very careful with the foods that convert to triglycerides: carbohydrates.
