Vegetable Fat as Medicine

Vegetable fats have been recommended for better health since the mid-1960s when we were asked to replace butter with margarine, and lard with corn and safflower oil in order to lower our cholesterol and reduce our risk of dying of heart disease. By the mid-1970s researchers had discovered margarine raises cholesterol even more than butter, and even though vegetable oils might reduce our risk of heart disease they would greatly increase our risk of cancer, and make us fat.

Now, in the 1990s leading health experts are advising us to liberally use olive oil, a monounsaturated fat, and the polyunsaturated omega-3 fats, like fish and flaxseed oils. These oils are touted as miracle tonics able to relieve suffering from arthritis to cancer. Have we finally got the right message on the use of oils? The truth is there can be some benefits, but like the margarine and corn oils recommended with impunity in the past, these oils also have serious drawbacks.
Essential Fats

Only plants can create two types of polyunsaturated fats called essential fatty acids (FE) known as omega-3 and omega-6 fats (w-3 and w-6 fats). They are considered essential because we cannot make either so both must be present in our foods. All other fatty acids can be synthesized by man from any excess of dietary energy. However, just because other fatty acids are considered unessential because we can make them does not mean they are unimportant. For example, arachidonic acid, derived from linoleic acid, is the major precursor for those very important and powerful hormones, known as eicosanoids.

Linoleic acid is the most common kind of w-6 fat consumed by people. Another w-6 fat often talked about is gamma linolenic acid. Alpha linolenic acid is the most common w-3 fat consumed. Eicosapentaenoic acid is an w-3 fat made from alpha linolenic acid and found in large concentrations in fish oils. Linoleic acid is found mainly in vegetable seed oils, and the main dietary source of alpha linolenic acid is leaves and some seeds.
There are three important functions of EFA:

    The most important is as part of phospholipids in all animal cellular membranes–a deficiency of EFA results in the formation of faulty membranes.
    A second is the transport and oxidation of cholesterol; as a result EFA tend to lower plasma cholesterol.
    A third function is as precursors of tiny, but powerful hormones, known as eicosanoids (prostaglandins, leukotrienes, and thromboxanes), which are only formed from EFA.

EFA Deficiency

Deficiency of EFA in experimental animals causes lesions mainly attributable to faulty cellular membranes, such as sudden failure of growth, scaliness of the skin, increased water loss by a change of skin permeability, impaired fertility, kidney abnormalities, increased susceptibility to infection, and weaknesses in the cardiovascular system. In man, pure deficiency of EFA has been studied mostly in persons fed intravenously. However, sensitive tests have found deficiencies in elderly patients, people with fat malabsorption diseases, and after serious accidents or burns. EFA deficiency does not occur in people following low-fat diets, because these diets are high in vegetable foods, rich in EFA.

Through the intake of large amounts of animal products, hydrogenation of vegetable oils, milling, and selection of w-3 poor foods, we have been systematically depleting our intake of EFA. A relative deficiency is also caused by large intakes of saturated animal fats and synthetic trans fats (as found in margarine and shortenings) common in Western diets. This deficiency of EFA plays an important part in the causation of atherosclerosis, coronary thrombosis, multiple sclerosis, complications of diabetes mellitus, hypertension, and certain forms of cancer.
EFA Requirements

Feeding diets containing as little as 0.1 to 0.5% of the calories as linoleic acid is sufficient to correct all signs of essential fatty acid deficiency. However, for optimal health higher intakes are recommended. Various factors affect the dietary requirement of EFA. Animal experiments and epidemiological studies lead to a recommendation that the intake of w-6 linoleic acid should be decreased to as low as 2-4 % of the calories and that of w-3 fats be increased to levels higher than w-6 linoleic acid for the prevention of chronic diseases prevailing in the industrialized countries (Proc Soc Exp Biol Med 200:174, 1992).

Since plants synthesize these fats they are the original and obvious source of all EFA. If animals, say fish, have significant amounts of EFA in their tissues it is because they ate plants, like algae, which originally made the EFA. Natural oils contain combinations of varying amounts of both w-6 and w-3 fats, as well as several saturated and monounsaturated fats. Essential fatty acids are found in significant amounts in various plants:

Linoleic: Safflower, sunflower, hemp seed, soybeans, walnuts, pumpkin, sesame, flax.
Alpha linolenic: Flax, hemp, canola (rapeseed), soybeans, walnuts, green leafy vegetables, purslane, perilla.
Gamma linolenic: Borage, black currant seed, primrose.
Eicosapentaenoic: Cold water marine fish.
The Benefits of EFA:

Heart Disease:
There is evidence that EFA in the diet, especially of the w-3 variety, protects against atherosclerosis and its related thrombotic complications, such as a heart attack (Eicosanoids 1989;2(2):69-99). Mechanisms probably involve the eicosanoids and a decrease in the tendency of platelets to adhere together, a decrease in blood viscosity, and a decrease in fibrinogen with a resulting decrease in tendency for a blood clot (thrombus) in the heart artery to form (Am J Clin Nutr 54:438, 1991). After feeding alpha linolenic acid the arteries of obese subjects have become more compliant (elastic), which indicates a decreased risk of a heart attack (Aterioscler Thromb Vasc Biol 17:1163, 1997). However, there are other factors EFA change that may increase the tendency for heart trouble, as you will learn below.

Arthritis:
Eicosanoids produced by EFA and their derivatives cause suppression of the immune system which has been found to be particularly beneficial to people suffering from inflammatory arthritis, like rheumatoid arthritis. Thirty-seven patients with rheumatoid arthritis and active synovitis were treated with 1.4 g/d gamma linolenic acid in borage seed oil or cotton seed oil (placebo). Gamma linolenic acid reduced the number of tender joints by 36% and swollen joint count by 28%. Patients given a placebo showed no change or showed worsening of disease. (Ann Intern Med 119:867, 1993 ). Other studies have shown similar benefits from gamma linolenic acid (Arthritis Rheum 39:1808, 1996). Treatment with alpha linolenic acid, however, has not been shown to help victims of rheumatoid arthritis (Rheumatology International 14:231, 1995).

Diabetic Neuropathy:
People with diabetes often develop pain, numbness, and burning in their feet after years of disease. This condition, known as diabetic neuropathy, has benefited from gamma linolenic acid therapy. For example, 111 patients with mild diabetic neuropathy were given a dose of gamma linolenic acid of 480 mg/day. The change over one year was more favorable than the change with placebo. Treatment was more effective in relatively well-controlled rather than in poorly-controlled diabetic patients. (Diabetes Care 16:8, 1993).
Questionable Benefits EFA

Research has suggested EFA to benefit many other conditions, however, when put to the test by well-designed studies (double-blind, placebo-controlled) their effectiveness has failed to be confirmed. Placebo-controlled trials of EFA supplementation in atopic dermatitis, which avoided the methodological and analytical problems of previous studies, found no effect of EFA supplementation in atopic dermatitis (Lancet 341:1557, 1993; Clin Exp Dermatol 19:127, 1994). Evening primrose oil and fish oil in the treatment of psoriasis was studied in thirty-seven patients in a double-blind parallel trial and no significant improvement in clinical severity of psoriasis was seen (Clin Exp Dermatol 1994 19:127, 1994).

In a randomized, double-blind, crossover trial 27 women diagnosed with PMS were treated with EFA and placebo, and treatment did not reduce premenstrual symptoms (Obstet Gynecol 81:93, 1993).

EFA treatment has been claimed to benefit many other problems, including migraines (Cephalalgia 17:127 1997), Alzheimer’s disease (Med Hypotheses 39:123, 1992), and tardive dyskinesia (Psychiatry Res 27:313, 1989). However, properly designed studies have yet to be done to confirm or refute the claimed benefits.
Too Much of a Good Thing

Olive oil and omega-3 fatty acids have been promoted to prevent and treat diseases, however, supplementation with large doses of these pharmacologically active substances in the wrong setting can do harm.
Greater Risks of Heart Disease:

Most people have assumed olive oil to be protective against heart disease because of the low incidence of heart disease in Mediterranean countries and that EFA also prevent heart disease. However, research indicates otherwise. A study on humans conducted by David Blankenhorn, M.D., and his associates compared the effects of different types of fats on the growth of atherosclerotic lesions inside the coronary arteries of people by studying the results of angiograms taken one year apart (JAMA 263:1646, 1990). The study demonstrated that all three types of fat–saturated animal fat, monounsaturated (olive oil), and polyunsaturated (EFA)–were associated with a significant increase in new atherosclerotic lesions. Most importantly, the growth of these lesions did not stop when polyunsaturated fats of the w-6 type (linoleic acid) and monounsaturated fats (olive oil) were substituted for saturated fats. Only by decreasing all fat intake–including poly- and monounsaturated fats–did the lesions stop growing.

Dietary polyunsaturated fats (EFA), both the w-3 and w-6 types, are incorporated into human atherosclerotic plaques; thereby promoting damage to the arteries and the progression of atherosclerosis (Lancet 344:1195, 1994). In part, this is because these oils are easily oxidized, forming free radicals that damage the arteries. Most research indicates w-6 type EFA are much more damaging to the arteries than w-3 type EFA (Am J Clin Nutr 49:301, 1989).

A recent study in African green monkeys found when saturated fat was replaced with monounsaturated fat (olive oil), the olive provided no protection from atherosclerosis (Aterioscler Thromb Vasc Biol 15:2101, 1995).

Furthermore, high-fat meals, in contrast to low-fat meals, can cause considerable increases in plasma triglycerides and plasma levels of blood coagulation factors which lead to a blood clot or thrombosis in the heart artery. One of the most important clotting factors predicting the risk of a heart attack is factor VII. The five fats tested–rapeseed oil (canola), olive oil, sunflower oil, palm oil, and butter–showed similar increases in triglycerides and clotting factor VII after eating. According to the authors, “These findings indicate that high-fat meals may be prothrombotic (causing a blood clot leading to a heart attack), irrespective of their fatty acid composition.” (Aterioscler Thromb Vasc Biol 17:2904, 1997).

Since w-3 EFA cause a variety of changes that both decrease and increase the risk of a heart attack, the overall impact of consuming these as free oils will have to be determined by future experiments. Undoubtedly, the w-6 varieties are artery damaging. Most likely, the heart benefits of a Mediterranean diet are due to it being a nearly vegetarian diet. The Mediterranean diet is good in spite of the olive oil (Am J Clin Nutr 61:1321S, 1995).
Higher Cholesterol and More Diabetes from Fish Oils:

Much attention has recently been paid to the possible benefits of increasing the intake of eicosapentaenoic acid (EPA) by consuming fish oil. However, this can have adverse effects such as raising LDL “bad” cholesterol levels in patients with already high cholesterol and causing a deterioration in glucose tolerance, in other words, making diabetes worse. (Prostaglandins Leukot Essent Fatty Acids 44:127, 1991). In one recent study of feeding w-6 alpha linolenic acid to obese subjects insulin sensitivity and HDL “good” cholesterol diminished, and the amount of oxidized LDL “bad” cholesterol increased (Aterioscler Thromb Vasc Biol 17:1163, 1997). In most other studies, however, oils high in alpha linolenic acid have little effect on cholesterol and triglycerides (Am J Clin Nutr 65:1645, 1997).
Increased Risk of Bleeding:

As mentioned, one of the benefits of EFA is to decrease the risk of a heart attack by decreasing the tendency for a blood clot to form by “thinning” the blood. Alpha linolenic acid is much more effective at decreasing the tendency of platelets to stick together than linoleic acid (Euro J Clin Nutr 49:169, 1995. However, when you decrease the clotting tendency of the blood you also increase the bleeding time and the risk of a fatal bleed after an accident or death during a hemmorhagic stroke. (Rheumatology International 14:231, 1995).
Nutritional Imbalances:

When a large amount of one type of nutrient is given then it displaces the metabolism of other similar type nutrients. For example, high doses of eicosapentaenoic (fish oil) given to westerners also lower levels of dihomogammalinolenic acid (DGLA), a substance with a wide range of desirable cardiovascular and anti-inflammatory actions. (Prostaglandins Leukot Essent Fatty Acids 44:127, 1991). Proper balance is more likely the closer the source of EFA is to its natural origin–plant foods.
Immune System Suppression:

EFA of both the w-3 and w-6 types inhibit our immune system–especially human lymphocyte cell-mediated and the production and activity of immune substances (Immunology 92:166, 1997). This includes suppression of natural killer cells, the production of immune substances known as cytokines (interleukin-1 (IL-1), IL-2, tumor necrosis factor-alpha (TNF-alpha) and also interferon-gamma production. These immune functions are important for defending ourselves from viruses, bacteria, and parasites, and cancer cells.
Obesity:

Body fat represents that saved “metabolic dollar” for the day when food becomes unavailable (which hasn’t happened lately). Vegetable fats, including olive oil and EFA are as easily stored as fat from cows, pigs, and chickens. When 54 obese women in a Mediterranean country were studied, they were found to be following a diet low in carbohydrates (35% of the calories) and high in fats (43% of the calories). And 55% of the total of these fats came from olive oil (Horm Metab Res 27:499, 1995).

It has been suggested that certain kinds of EFA might help people lose weight. However, a 12 week, double-blind evaluation of evening primrose oil as an antiobesity agent on 100 women found no significant difference in the weight loss achieved by those taking primrose oil compared with placebo (Int J Obes 7:549, 1983).
Cancer:

Hundreds of studies since 1930 have been done on the effects of dietary fat on cancer occurrence in experimental animals. Both animal and vegetable fats have been shown to increase the risk of animals developing and dying of cancer (Cancer Res 52:2040, 1992). The risk of spread (metastasis) is also increased with greater fat intake. Most of the effects occur during the promotion stage rather than at the time of initiation of the cancer (when it begins).

Linoleic acid found in large amounts in corn and safflower oils is the strongest promoter of cancers of all the fatty acids. Olive, fish, flaxseed and other w-3 essential fatty acids have been shown to inhibit the growth of cancers in animals when fed as pure fatty acids. However, after the addition of small amounts of linoleic acid (like corn oil) they lose some or all of their ability to block tumor growth (Am J Clin Nutr 66:1523S, 1997). Therefore, it appears that a small amount of linoleic acid must be present for a fat to be cancer promoting. Of course, this small amount of linoleic acid will be in all natural human diets.

The reason some studies have shown olive oil to be cancer promoting and others have not is probably because of the varying amounts of linoleic acid in commercially available olive oils. There appears to be some balance between w-3 and w-6 fatty acids that is ideal for tumor inhibition, unfortunately that ratio varies with different experimental models. Because all of the types of fatty acids have been found to be cancer promoting under some circumstances, prudence would dictate that all fats, regardless of who labels them “good fats,” be kept to a minimum in your diet.
Heating Oil:

The heating of oil can produce cancer-causing byproducts. The lung cancer incidence in Chinese women is among the highest in the world, but tobacco smoking accounts for only a minority of the cancers. Chinese women are exposed to indoor air pollution from wok cooking. Cancer causing chemicals from heating cooking oils are dispersed into the air. In a recent experiment several cooking oils and EFA were heated in a wok to boiling (J Natl Cancer Inst 87:836, 1995). The oils tested were unrefined Chinese rapeseed, refined U.S. rapeseed (known as canola), Chinese soybean, and Chinese peanut, in addition to linolenic, linoleic, and erucic fatty acids. Cancer causing substances such as 1,3-butadiene, benzene, acrolein, formaldehyde, and other related compounds were detected, with emissions tending to be highest for unrefined Chinese rapeseed oil and lowest for peanut oil. Among the individual fatty acids tested, heated linolenic acid produced the greatest quantities of cancer causing substances (1,3-butadiene, benzene, and acrolein). Condensates from heated linolenic acid, but not linoleic or erucic acid, were found to be highly cancer causing.
What to Do?

The safest and healthiest way to get your EFA is in their natural packages of starches, vegetables, and fruits. Here they are found in the correct amounts in protected environments surrounded by vitamins, minerals, fibers, antioxidants, and other phytochemicals to make them balanced nutrition. If you desire higher concentrations than are present in these foods then you will want to include more nuts, seeds, and soybean products in your diet. Remember, these are high fat foods and can contribute to obesity. Research suggests that there may be a connection between frequent nut consumption and a reduced incidence of coronary heart disease (Nutr Rev 54:241, 1996).

Flaxseed (as a whole seed) is one of the richest sources of alpha linolenic acid and is also a good source of soluble fiber. Consumption of 50g (1 2/3 ounces) of raw, ground flaxseeds has been shown to increase the amount of w-3 EFA in the blood and tissues and to lower the cholesterol by 9% and LDL “bad” cholesterol by 18% (Br J Nutr 69:443, 1993). Blood sugar was also decreased. Even though the benefits of EFA as oils on cancer growth are questionable, the lignans present in flaxseed seem to have an antitumor effect when fed at the early stages of cancer promotion (Nutr Cancer 26:159, 1996). Plant foods are the only source of phytoestrogens, like isoflavones, coumestans, and lignans, that are believed to be beneficial for many problems, including menopausal symptoms, osteoporosis, cancer, and heart disease (Annu Rev Nutr 17:353, 1997).

Flaxseed is also an excellent laxative. The number of bowel movements per week is found to increase by 30% with the addition of 50g of flaxseed daily. The seeds can be added to hot or cold grain cereals and consumed whole. Uncle Sam cold cereal and Prairie Sun Hot Cereal sold in the natural foods store have flaxseed. Or it can be ground in a coffee grinder and applied to almost any dish. About 5 tablespoons of ground flaxseed daily should have a positive effect. A mixture of ground nuts, seeds and vegetables, called “The Missing Link,” is sold in many natural food stores or can be ordered by calling (800) 446-2110. Refrigerate oils and ground seeds because they oxidize easily and become rancid.

For treating some conditions, such as rheumatoid arthritis or diabetic neuropathy, you may want to try oils high in gamma linolenic acid, such as primrose oil. The doses used are ½ to 1 ½ grams a day of gamma linolenic acid. This free oil is no longer to be thought of as a food–it is a medication used to treat symptoms of a disease with both positive and negative effects.
More on Omega-3 Fats in Vegan Diets
By Ginny Messina on November 19, 2010 in Uncategorized
Based on some emails I received about my blog post from November 17, I realize that there is a little bit of confusion about the different types of omega-3 fats. I want to clear that up so that readers can make the best informed decision about meeting needs for these compounds.
There are two different type of omega-3 fats in foods. We definitely need one of these and may need the other.
Alpha-linolenic acid (ALA) is a short-chain omega-3 fatty acid that is an essential nutrient. We absolutely need to have some in our diet. It’s provided by just a few plant foods but requirements are so small that it’s easy to get enough. You can meet your entire needs for the day by consuming a teaspoon of flaxseed oil or a tablespoon of canola oil or 3 to 4 walnut halves.
DHA and EPA are the long-chain omega-3 fats that are found in fish oils. Although there is a little bit of EPA in sea vegetables, vegans generally don’t consume these fats at all. While DHA and EPA are not considered essential nutrients (there is no RDA for them), they are linked to some health benefits including reduced risk for heart disease. Low levels of DHA may raise risk for depression and, in older people, cognitive decline.
Even though vegans don’t consume these fats, we do have some in our blood because the body can make DHA and EPA from the essential fat ALA. The problem is that it takes a lot of ALA–maybe more than is actually healthy–and the conversion doesn’t seem to be very efficient. There is some evidence, including the findings from the EPIC-Norfolk study I wrote about, that the conversion is more efficient in vegetarians than in meat-eaters. But even so, vegetarians’ blood levels of EPA and DHA are generally lower than those of people who consume fish.
So, everyone needs to consume some source of ALA no matter what; it’s an essential nutrient. Even if you are taking DHA supplements, you still need ALA in your diet because it has its own set of functions.
And consuming ALA from flaxseed or hemp oil or other foods does not necessarily mean that you’ll end up with optimal DHA levels. Taking DHA supplements from algae is effective in raising levels of both DHA and EPA in the blood (some of the DHA converts back to EPA). But whether or not vegetarians benefit from those higher levels isn’t known.
If you want to know everything in the world about omega-3 fats in vegetarian diets, I recommend the section covering this topic on 
 
Taking Omega-3/DHA Pills? Must-listen Interview (AUDIO)

07/21/13

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Be sure to listen to this interview if you take DHA/Omega 3 supplements or are considering doing so. Also read Dr. Fuhrman's description below of the dangerous trial-and-error method of discovering supplements thought to be helpful can turn out to be quite harmful.

The talk is below is a link to a recent 11-minute interview with the lead researcher on the new DHA study that showed those with higher blood levels of DHA had a whopping 70% higher risk of aggressive prostate cancer.

This fellow has been at this research for 25 years. If you are taking or considering DHA supplements, from fish oil or the vegan kind, you should definitely take note. It appears that excess DHA above what you consume may crowd out other nutrients and set the stage for serious, lethal disease. Here is the interview:

http://www.sciencefriday.com/playlist/#play/segment/9172

The interview has some bad news not only for taking Omega 3 pills, but for a variety of other supplements. Bottom line: supplement at your own risk, and the risk is considerable.

You should also check out this letter from some of the biggest hitters in Cancer Prevention, published in the British Journal of Nutrition, late last year. In it, the researchers very seriously call into question the idea of supplementing with these DHA/EPA fish oil type supplements, and that increasing food or supplements that raise blood levels of DHA can not be seen as uniformly safe -- there are risks to trying to raise your DHA levels. See:

http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=8735103

I also want to bring attention to an interesting piece by Dr. Joel Fuhrman about the hazards of supplements and how theories about supplements may sound reasonable at first -- but often they turn out to be wrong and have deadly consequences for those who took the supplements.

Disclaimer: As a vegan for 18 years and veg for 23, I personally only take B-12 and otherwise stay away from the supplement aisle.

In the excerpt below from his site, Dr. Fhurman talks about beta-cartone (Vitamin A). The story he tells is a story which is increasingly showing up for a number of other vitamins and supplements. Something that may be found to be low in the blood of unhealthy people -- when you try to raise that level in a healthy person with a pill, generally it doesn't promote health but in more and more cases it can actually promote cancer the subject would not otherwise have gotten if they hadn't taken the pills.

Quoting from Dr. Fuhrman:

"Why did researchers think that beta-carotene (Vitamin A) had such a powerful anti-cancer effect? They had found that populations with high levels of beta-carotene in their bloodstream had exceedingly low rates of cancer. Recently, it was discovered that the reason these people were protected against cancer was because of hundreds of carotenoids and phytochemicals in the fruits and vegetables they were consuming. It wasn't that beta-carotene alone was responsible for the benefit; it was merely that it had served as a flag or marker for those populations with a high fruit and vegetable intake. Unfortunately, many scientists confused the flag for the ship.

"In Finnish trials, those using beta-carotene supplements failed to prevent lung cancer, and there was actually an increase in cancer in those who took the supplement. 2 This study was halted when the physician researchers discovered the death rate from lung cancer was 28 percent higher among participants who had taken the high amounts of beta-carotene and vitamin A. Furthermore, the death rate from heart disease was 17 percent higher in those who had taken the supplements compared to those just given a placebo. 3 Another recent study showed similar results, correlating beta-carotene supplementation with an increased occurrence of prostate cancer.

"As a result of these European studies, as well as similar studies conducted here in the United States, 4 articles in the Journal of the National Cancer Institute, 5 the Lancet, 6 and the New England Journal of Medicine all advise people to stop taking beta-carotene supplements.

"How have supplement manufacturers responded? As a result of these studies, I expected many manufacturers to drop beta-carotene from their vitamins and substitute plant-derived carotenoids, but it never happened."

- - - end of excerpt from http://www.diseaseproof.com/archives/supplements-dr-fuhrman-discusses-vitamins-and-supplements.html

This is the same progression for recent studies on DHA/omega 3. The most common form is from fish oil, which experts are now advising people to avoid or minimize. But just like Vitamin A, sellers of DHA pills show no signs of slowing down or dropping a potentially problematic substance. Some vegan supplement sellers say it is probably the fish origin, and not the higher DHA levels, that is causing the cancer. But there is currently no research to back that up, so you have to take it on faith.

If you are vegan and believe you have "low" DHA/omega 3 levels, are you actually at any increased risk of disease? Studies of people eating the SAD with low DHA levels may have increased risks of some chronic illnesses if they have low DHA. But what about people who have switched to a plant-based diet?

Well actually this question was looked at in a study in 2009:

A review of "DHA status in vegetarians" noted that "Dietary analyses show that vegan diets are devoid of DHA and vegetarian diets that included dairy food and eggs only provide about 0.02 g DHA/d." It went through all of the presumptive problems in bioconversion, and the resulting low levels of DHA observed in body fluids of average veg(etari)ans, but still concluded that: "There is no evidence of adverse effects on health or cognitive function with lower DHA intake in vegetarians. " It also stated, "In the absence of convincing evidence for the deleterious effects resulting from the lack of DHA from the diet of vegetarians, it must be concluded that needs for omega-3 fatty acids can be met by dietary ALA. "

Sanders TA. DHA status of vegetarians. Prostaglandins Leukot Essent Fatty Acids. 2009 Aug-Sep;81(2-3):137-41. Epub 2009 Jun 4. Review. PubMed PMID: 19500961.
---

Most important, there have been zero studies showing that supplementing with DHA -- whether from fish oil or vegan sources -- confers any actual health benefit, or that raising your blood levels of DHA through supplementation does anything actually health-promoting. Again, I am talking about research, not hyperbole, puffery or conjecture.

So if there's no proven benefit, but it is shown an elevated DHA may seriously increase your cancer risk, why would anyone do it?

Perhaps a low DHA level in people eating a SAD is simply a flag for something bigger, as Dr. Fuhrman noted a low beta-cartone level turned out to be. More likely, if you are eating a healthy diet like Fuhrman and McDougall teach, you simply don't need to obsess about your omega-3's to the point of taking expensive supplements. To repeat: the study above notes that expected low levels of omega-3's in the blood of vegetarians and vegans didn't actually translate to any health problems in the real world.

In any event, all of this is probably why experts like Neal Barnard MD (expert on Alzheimer's), John McDougall MD, Caldwell Esselstyn MD, Jeff Novick MS RD and others are opposed to DHA pills and many other supplements. Don't be scaremongered into doing something potentially risky, without at least some research to back up potential benefits against known risks of any pills you may take. 

Low Vitamin D: One Sign of Sunlight Deficiency

A low vitamin D level found in the blood is one sign of sunlight deficiency, just like high blood cholesterol is one sign of eating too much meat and cheese.  A far-reaching campaign has been launched by doctors, health organizations, supplement companies, and pharmaceutical industries to fix the problem of sunlight deficiency with pills.  Take vitamin D pills and the internal levels of this vitamin will increase, but 5 of 9 studies have shown no reduction in the risk of suffering from a fracture and 9 of 10 studies have shown no decrease in the most serious bone break—hip fractures.1   In addition, no reduction in deaths has been found with supplementation.1  Any hope for benefit is limited to people with severe deficiency (levels below 25 nmol/L).*  These pills cost money and the patient becomes dependent on one more drug.  This profile is analogous to taking “statin” cholesterol-lowering medications: the cholesterol plummets, but the risk of heart attacks in otherwise healthy people remains unchanged and some people are harmed by the medication’s side effects.2  Any hope of benefit is limited to those at very high risk of heart disease.2 Neither medication should have been unleashed on the public as a tonic for better health, yet both have been.1,2

Exposure of the body to sunshine reduces the risk of cancer and heart disease, but the use of vitamin D supplements may increase the risk of both diseases.  Scientific research has shown that supplements raise the vitamin D levels in a man’s blood, and increase his risk of prostate cancer.3  Vitamin D supplements given to women increase their  “bad” LDL-cholesterol by 4.1%, and reduce their HDL/LDL ratio by 10.5%—changes in both risk factors reflect an increased risk for heart attack and stroke.4

Sunshine never causes a toxic overproduction of vitamin D in the body.  However, like all other drugs, toxicity has been reported with the consumption of vitamin D supplements as pills and fortified foods, like cow’s milk.5 The first sign of toxicity is excess calcium appears in the urine (hypercalcuria) and then blood levels of calcium rise (hypercalcemia).   Hypercalcemia over time results in bone loss, kidney stones, and calcification of organs, like the heart and kidneys.

Like proper food, sunshine is essential for life. But, wait a minute!  Aren’t people supposed to stay out of the sun?

Consequences of “The No Sun Campaign”

For the past half century people have been warned to stay out of the sun—wear protective clothing and use sunscreens to reduce premature aging of the skin and prevent skin cancers.  The irritating effects of the sun’s energy may also cause pterygia (superficial blood vessel tissue on the whites of the eye) and reactivation of viral infections, such as lip herpes.  There is no question overexposure should be avoided.  But, have we gone too far with sun avoidance?  I, along with the vast majority of the informed scientific community, believe so.

The best recognized consequence of sunlight deficiency is the bone-deforming children’s disease known as rickets. This condition is corrected by sunshine and/or vitamin supplements. A similarly-caused softening of the bone materials in adults, accompanied by the loss of minerals, is called osteomalacia.  In most cases, sunlight deficiency causes no symptoms, but it can present as diffuse muscle and bone pain, and weakness, which can be misdiagnosed as fibromyalgia.6

Sunshine Deficiency May Also Contribute To:

Increased risk of cancer

Poorer cancer survival

Type-1 diabetes

Decrease in insulin’s responsiveness

Multiple Sclerosis

Osteoporosis

Decline in periodontal attachment (loose teeth)

Cardiovascular disease

The proposed benefits of sunlight overlap with those of diet and exercise.  Traditionally, people living closer to the equator who are exposed to more sunlight also eat more plant foods; whereas those living at higher latitudes eat more meat and dairy products.  Most exercise takes place outdoors (or at least it did until the recent popularity of health-clubs).  Therefore, in general, more exercise also means more sunshine.  In practical terms, separating the benefits of sunshine, a plant-food based diet, and moderate exercise is pointless mental gymnastics.  A health-conscious person will choose all three.

Sunlight as Therapy

Sunshine costs nothing and is effortless.   Drawings in ancient cave dwellings indicate that people understood the importance of the sun for health, as well as warmth.  During World War I sunlight therapy was used to heal soldiers’ wounds; and in the years that followed, hospitals and clinics were built for treating tuberculosis with sunshine.7  This phototherapy, also know as heliotherapy, was also prescribed during these times to treat chronic diseases, such as ulcers, leukemia, arthritis, gout, and diabetes.8

Recognized Medical Uses of Sunlight:9-19

Systemic:

        Rickets

        Osteomalacia

        Psoriasis

        Hypertension

        High pulse rate

        Low HDL-cholesterol

        Neonatal jaundice

        Pruritis

Psychological:

        Premenstrual syndrome

        Sleep disorders

        Jet-lag

        Insomnia

        Adult attention-deficit/hyperactivity disorder

        Mental depression (Seasonal Affective Disorder)

Skin:

        Acne

        Alopecia

        Atopic dermatitis

        Contact dermatitis

        Cutaneous T-cell lymphoma

        Disseminated granuloma annulare

        Localized scleroderma

        Urticaria pigmentosa

        Pityriasis lichenoides

        Pityriasis rosea

        Pityriasis rubra pilaris

        Pruritis

        Urticaria pigmentosum

        Vitiligo

Ultraviolet light of the sun’s spectrum has been used for centuries and is now standard medical therapy, most commonly prescribed for the debilitating skin condition psoriasis, and for chronic depression.  Alone or in combination with medications, like vitamin D and Psoralen, ultraviolet-emitting artificial lightings clear the skin of psoriasis and relieve associated arthritis.   Life-threatening depression, called seasonal affective disorder, is successfully treated by exposing patients to additional ultraviolet light by using “light boxes.”  The benefits of light therapy are temporary, stopping when the treatment is discontinued.  Please note: the use of natural sunlight has been found to be superior to the use of light produced by artificial sources in both psoriasis and depression.14,15

Sunlight and Cancer Prevention

Excess sunlight is a recognized carcinogen, resulting in precancerous actinic keratosis and squamous and basal cell skin cancers.  More than 1.5 million skin cancers are diagnosed annually in the US.  Fortunately, these cancers are easy to detect, are almost never fatal, and are effectively removed by simple therapies, such Aldara cream, liquid nitrogen freezing, and laser treatments.

In 1936, Dr. Peller reported that among US Navy Personnel, those with frequent skin cancers seemed to possess immunity to more serious internal cancers, such as those of the breast, colon, and prostate.20 Consequently, he recommended deliberate induction of (non-melanoma) skin cancers as a “vaccination” against life-threatening cancers.  It is unlikely that skin cancer provides direct immunity to other cancers. Rather, the sunlight itself makes the body healthier and more cancer resistant. 

Worldwide, the incidence of serious cancers, such as those of the breast, colon, and prostate, occur less commonly in geographic latitudes where sun exposure is greater.  Another intriguing finding is that increased exposure to sunshine improves survival for people who already have cancer, including, those of the breast, colon, prostate, and lung, and melanoma and lymphoma.21-24

Vitamin D Is Only One Part of the Story

Rather than focusing on non-profit, self-administered, non-toxic, highly-effective sunlight, the money-making spotlight of the medical, research, and pharmaceutical industries has been on vitamin D pills. (Similar to the way that dietary diseases, such as type-2 diabetes and heart disease, are treated—drug-therapy is the only game in town.)  Apart from vitamin D synthesis there are a number of known ways that sunlight can affect a person’s health.  Some of the discovered mechanisms involve the direct alterations of the immune system, locally and systemically; modulation of other hormones, like melatonin, calcitonin, and melanocyte stimulating hormone; and changing the number and function of cells present in the skin.8,9 Sunlight also establishes circadian rhythms.  Undoubtedly, many important mechanisms for the benefit of natural sunlight remain to be discovered.

Vitamin D Is Really “Hormone D”

Vitamin D is known as the “sunshine vitamin,” because it is made by the action of sunlight on the skin.   Plant-derived sterols found in the skin are converted by ultraviolet sunlight into vitamin D.  Two further steps occur in the liver and kidney in order to finalize the production of the physiologically active form of vitamin D.  Its name comes from the fact that it was discovered after vitamins A, B, and C.   Under usual circumstances, vitamin D is not a vitamin, defined as an organic substance which must be obtained in small amounts from the diet for growth and health.  Rather, this substance is a hormone made within the body. This hormone has the rare property of being formed by ultraviolet light rather than by an enzyme, and should not be regarded as a nutrient. In real life, approximately 90% of the vitamin D that people use is formed within the skin through the action of sunlight—only 10% comes from diet and/or supplements.20

The need for sun precautions these days is because populations have migrated from their natural environments.  Light-skinned people vacation and live in places closer to the equator than their ancestors did—now the direct sunlight exposure is too intense for their fair skin-type.  Dark skinned people now live in low-sunlight latitudes, wear cover-up clothing, and work all day inside; causing sunlight deficiency. The epidemic of obesity in people of all skin tones has added to the problem. Because vitamin D is fat soluble, excess body fat will pull vitamin D out of circulation thus contributing to deficiency.25

Sunlight is Quick and Efficient

Most of the benefits of sunlight, like vitamin D production, occur within the first 20 minutes of exposure.1    Applying sunscreen will increase the time requirement for exposure—but is almost never the cause of vitamin D deficiency.1

Exposing the body in a bathing suit to enough sun to make the skin just begin to turn red (one minimal erythema dose) is equivalent to ingesting 250 µg of vitamin D orally.20 (Recommended oral doses are 50 to 100 µg daily. For conversion purposes: 1 µg equals 40 IU.) Exposing the face, arms, and hands of a light-skinned person to 5 minutes of sun at noon two or three times a week at a latitude of Boston, MA in the spring, summer, or fall will cause the body to produce sufficient vitamin D to meet all of its needs.20  This time limit is skin-pigment-dependent. Asian-Indians may require 3 times, and Blacks may require 10 times as much exposure, as Whites under the same sunlight conditions.  During wintertime, people must rely on their fat stores.

Vitamin D is a fat soluble vitamin that is stored for long periods of time mainly in the liver and the fatty tissues.  When a person is completely deprived of sunlight, such as occurs with people on submarine missions or people living in extreme northern and southern latitudes, more than 2 months must pass before half of the vitamin D is depleted from the fat stores.26 A sufficiency of vitamin D throughout the year depends upon how much sunshine a person is exposed to on his or her summer vacation—summertime synthesized D being released from body fat throughout the winter months.27

People who already have sun damaged areas of skin, such as on their arms or face, should keep these surfaces protected.  Rather they should expose only undamaged areas, like their chest, back, abdomen and legs in order to collect the benefits of sunshine.

Food and Supplement Sources of Vitamin D

People following the typical Western diet and taking over-the-counter supplements consume less than 25 µg daily.  Sufficient levels of oral vitamin D intake would require at least 50 µg daily. Therefore, without sunlight exposure, the amount of vitamin D in the diet and over-the-counter supplements is typically insufficient to produce optimal levels.26

Fish, including salmon, eel, pike, tuna, cod, and herring, have the highest amounts of vitamin D in their tissues (averaging 8 µg per 3.5 ounce serving).  This means eating 20 ounces of fish daily to meet needs—which would also mean eating about 900 calories of fish fat and protein.  Farmed salmon has only 25% of the vitamin D of wild salmon.28  Egg yolk, beef liver, and a few plant foods, like wild mushrooms, have very small amounts of vitamin D.  Eight ounces of fortified cow’s milk or orange juice contains 2.5 µg of added vitamin D. Some cereals and breads are fortified with vitamin D.  A one-a-day vitamin may contain 10 µg and over-the counter high potency supplements may contain 25 to 50 µg. Prescription vitamin D supplements are made from a much more potent form of vitamin D, with a greater risk of toxicity.

The expected consequences of eating foods high in calories, fat, and cholesterol like fish, eggs, beef liver, and milk would be obesity, type-2 diabetes, and even heart disease.  Therefore, relying on foods for vitamin D runs the very real risk of making a person sick. Plus, non-white people who use lactose-containing dairy products can expect diarrhea, stomach cramps and gas, due to lactose intolerance.

Should Healthy People Take Supplements?

No, otherwise healthy people who can expose themselves to life-giving sunshine should not bother with supplements. In addition to missing many valuable benefits of sunlight, taking supplements leads to the delusion that “the problem is solved;” like when people take high blood pressure, cholesterol and diabetic pills; they think they are cured.

However, many people are unable or unwilling to get outdoors.  Lack of information on the importance of sunlight and the unwillingness to leave their offices and homes will cause many otherwise healthy people to get inadequate sunlight.  The elderly and infirm confined to nursing homes, long-term care facilities, and homes are at high risk of developing deficiencies.  Living above latitudes of 35 degrees—New York, London, Moscow, as well as living under sunlight-blocking air pollution increases the risk of vitamin D deficiency, especially in the winter months and for darker-skinned people.

In the above instances, daily supplementation with 50 to 100 µg of over-the-counter vitamin D will correct the vitamin D blood level; which is good, but will not solve the real problem of sunlight deficiency.

* Circulating levels of an inactive stable form of vitamin D (25-OH vit D) measured in the blood is an accepted indicator of vitamin D status.  Normal in various laboratories is considered 20 to 150 nmol/L.  When the lower threshold of normal is set to 25 nmol/L then 12.2% of US African-American women are deficient; when the lower limit is 50 nmol/L then 42.4% are deficient.1

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