Wow!

In a culinary way, This is definitely enough to inspire kind thoughts of filet mignon, foie gras, and creme brulee. Periodically over the past decade, researchers, including those engaged in a massive study known in the health biz as "MR. FIT" (Multiple Risk Factor Intervention Trial), announced that low-cholesterol levels...the aim of "heart-healthy" eating...are linked in men to an increased risk of suicide, homicide, accidents, and other violent deaths. Even some doctors began to wonder if they should stop prescribing cholesterol-lowering medications.

But the Senior Medical Director of the Cholesterol Center of Jewish Hospital in Cincinnati, Dr. Charles Glueck, has never taken the findings at "face value". He doesn't see a direct "cause-effect" relationship between low cholesterol and violent death. He beefs that MR. FIT failed to examine critical variables that may predispose those who are violent to low cholesterol levels--namely, depression, often exacerbated by drug and/or alcohol abuse, all of which often lead to malnutrition. The generally poor nutritional status of certain depressed people deprives them of food components required for normal mood states, Glueck explains.

In fact, Glueck finds that high cholesterol levels are not only bad for the heart, they're dreadful for the brain. High blood levels of cholesterol, and especially of a related saturated blood fat known as triglyceride, are strongly correlated, in both adults and children, with the incidence of affective disorders, including depression, manic depression, and schizoaffective disorder, as well as with hostility and aggression. Most fats in food are composed of triglycerides, which are broken down to various fatty acids. "We have shown that in patients with high triglycerides who were in a depressive state, the more you lower the triglycerides, the more you alleviate the depression."

In a dramatic 1994 study, Glueck and colleagues demonstrated that hypertriglyceridemia, together with high total cholesterol and low HDL or "good" cholesterol, were the sole causative factors in mild to serious depression he detected in patients referred for treatment of severe familial hypertriglyceridemia.

None of the patients--fourteen men and nine women--were receiving psychiatric care. But when he administered a standard test for depressive symptoms, Glueck found that a substantial 39 percent of them had mild to severe depression.

For the next 54 weeks, they ate a diet very low in fat (10 to 15 percent fat as a proportion of total calories) and they also took a triglyceride-lowering medication.  As the triglyceride levels fell, depressive symptoms abated.  Did you know that after 54 weeks, 91 percent of those patients were rated normal. The largest reduction in triglycerides and depression occurred in the first six weeks of treatment.

There's a 'Sludge' Factor

What is the "blood fat-depression" connection?  In a word, 'viscosity'. A high triglyceride level increases blood sludginess, says Glueck. It's harder for blood to transport sufficient oxygen to brain cells. Under such conditions, mini brain lesions and blood clots may form. Those affected may exhibit symptoms of so-called organic brain syndrome, among them depression and hostility.  Lowering triglyceride levels normalizes serum viscosity and reverses cerebral oxygen deficiency.

Other investigators have also observed a "positive correlation" between triglyceride values, hostile acts, and a domineering attitude. In addition, lowering triglyceride levels improves scores on dementia screening tests in elderly patients. On top of that, there are regimens such as the Pritikin diet, which is aimed at lowering triglycerides and cholesterol, that  also reduce depression and hostility, which suggests that cholesterol-lowering medications are not the main mood-altering factor.

It's pretty obvious that not all psychological or psychiatric disorders are attributable to triglycerides and saturated fats, notes Glueck. But this guy's research suggests that high blood-fat levels can be the sole cause of depression in some cases, and that they may exacerbate mental problems due to other causes.  Glueck recommends consequently that anyone with a psychiatric problem or may be suffering from depression should have his or her cholesterol and triglyceride levels tested.

Fats and Smarts

A diet high in saturated fat not only can make you depressed and downright antisocial, it can also impair general mental performance.  So will a diet high in total fat and one that is deficient in essential fatty acids (EFAs).  I grew up thinking that Indiana Kitchen Bacon was "Nature's Perfect Food."

Once dietary fats are broken down into fatty acids, the body uses them for myriad purposes.  They go into all hormones. They are critical to body metabolism.  They're also a constituent of the outer membrane of every cell in the body...including those in the brain.  Of the numerous fatty acids the body uses, two are called "essential" because they cannot be manufactured in the body...they must be supplied by daily diet. These are linoleic acid, or n-6, and linolenic acid, or n-3; both are super-unsaturated fats. (You need only about a tablespoon of EFAs daily.)

N-3 fatty acids--popularly called omega-3s--are known to be particularly crucial for proper development of the human brain, both before birth and in infancy it is through the lipid-rich cell membrane of neurons that all nerve signals must pass. In addition, as learning and memory forge new connections between nerve cells, new membranes are formed to sheath them. All brain cell membranes continuously need to refresh themselves with a new supply of fatty acids. Preliminary research suggests that EFAs--particularly n-3s--are best suited for optimal brain function.

In a key animal study soon to be published, Carol E. Greenwood, Ph.D., and colleagues fed rats various amounts and types of fat for a three-month period and then measured their performance on memory tests. Fat content ranged from 40 percent of calories--approximating that of the average American--to 10 percent of calories. Rats fed the high-fat diet that was highest in saturated fat (from lard) performed the worst. Those on the diet lowest in saturated and total fat did the best.

While consuming too much saturated fat and too much fat overall, many North Americans may not be consuming anywhere near enough n-3 fatty acids for optimum brain health, notes Greenwood, associate professor of nutritional sciences at the University of Toronto. The polyunsaturated vegetable oils touted as healthful for the heart and so widely used in cooking and in prepared foods--corn, safflower, and sunflower oils--have almost no n-3s. Instead they are loaded with n-6s. Unless balanced with a large amount of n-3s, n-6s are associated with abnormalities of immune function, inflammation, and even cancer. Greenwood suggests using canola (rapeseed), soy, and walnut oils, which have ample n-3s in a healthful ratio to n-6s.

In a recent study at Oregon Health Sciences University, a team led by William Connor, M.D., fed infant rhesus monkeys a diet containing adequate amounts of fat but the fat was supplied in one of two forms--soybean oil, rich in n-3s, or safflower oil, deficient in n-3s. The EFA-deficient monkeys grew well, but their visual development was impaired; acuity was 50 percent of normal.  In addition, notes Connor, professor of medicine, the n-3-deprived infants "seemed to pace back and forth purposelessly," suggesting a neurological defect.  Autopsy showed numerous abnormalities in brain neurons, Connor reports.