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Making Sense of Fats and Oils

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Hi

thought this article might be of interest to everyone.

 

Laura :-)

 

 

_

 

Making Sense of Fats and Oils

by Brenda Davis, R.D.

 

For healthy vegetarians, cutting down too much on wholesome, high-fat

plant foods poses several problems.

 

QUESTION: What are the best fats and oils for vegetarians and vegans,

and is it always better to follow a low fat diet?

 

BRENDA DAVIS: Let's begin with the question of low fat diets always

being better.

 

Very low fat diets have been popular among vegetarians because of

their proven effectiveness in treating severe coronary artery

disease. People often assume that such diets would therefore be the

best choice for all vegetarians. But what's best for healthy

vegetarians, particularly growing vegetarian children, can be quite

different from what's best for people with serious chronic disease.

It's important to realize that the adverse effects of excessive fat

are consistently linked with animal fats and processed fats and oils

containing trans fatty acids. The unprocessed fats and oils of whole

plant foods have quite a different effect on health. Many studies

have demonstrated that the fat in nuts, seeds, avocados, olives and

other plant foods is actually protective. When people get most of

their fat from these sources, they can consume relatively high

amounts without adverse effects. In contrast, people who get most of

their fat from animal foods and processed products tend to be at risk

even at moderate fat intakes. They really do need to cut down on

these potentially damaging fats and oils.

For healthy vegetarians, cutting down too much on wholesome, high-fat

plant foods poses several problems:

 

Very low-fat diets may provide excessive bulk and insufficient

calories, particularly for infants, children, and people with very

high energy requirements, like athletes or labourers.

Very low fat diets often contain inadequate amounts of essential

fatty acids, especially the omega-3 fatty acids (discussed below).

Insufficient fat can compromise absorption of fat-soluble vitamins

(A, D, E, and K), minerals (including iron, zinc, manganese, and

calcium), and healthful phytochemicals (like the lycopene in tomato

products).

People on very low fat diets often become " fat phobic. " They assume

all high fat foods are bad and that all low fat foods are good. This

often leads them to choose foods that are actually " nutritional

washouts " (packaged fat-free cookies, cakes, and chips, for example)

while obsessively avoiding higher-fat plant foods that are very

nutritious, like avocados, olives, nuts, seeds, and tofu.

 

Very low fat diets can cause a drop in HDL-cholesterol ( " good

cholesterol " ) and a rise in triglycerides (another potentially

damaging blood fat, like LDL-cholesterol), actually increasing your

risk for cardiovascular disease. However, this is not normally a

problem unless you replace the fat with refined carbohydrates, like

sugar and white flour products.

So, how much fat should you eat?

I'd suggest something in the range of 15 to 30 percent of calories.

But remember, the quality of the fat is at least as important as the

quantity.

 

That brings us to part two of your question:

 

What are the best fats and oils for vegetarians?

 

Without a doubt the answer is whole plant foods, like nuts, seeds,

avocados, olives, and soybeans. These foods are packaged by nature to

protect their fats and oils from damaging light, heat, and oxygen.

They also carry valuable vitamins, minerals, phytochemicals, plant

sterols, essential fatty acids, and fibre

As I've already suggested, the fats in these foods are actually good

for us.

 

That's right: we need fat. It provides energy, insulation,

and " padding, " not just for our posteriors but to protect internal

organs. We need fat to absorb many vitamins, minerals and

phytochemicals. Certain fats are required for healthy cell membranes

and to maintain cell integrity, permeability, shape, and flexibility.

These fats also are critical for the development and functioning of

the brain and nervous system. Finally, they are the building blocks

for hormone-like substances called eicosanoids that regulate many

organ systems.

 

These special fats are known as essential fatty acids (EFA), because

they are as essential for our survival as vitamins and oxygen.

 

How do we ensure that we eat good fats?

 

Begin by reducing your intake of foods rich in saturated fats,

cholesterol, and trans fatty acids.

 

Unless you use large amounts of tropical plant oils (coconut, palm,

and palm kernel oil), vegan diets are generally low in saturated fat.

They're always free of cholesterol.

 

On the other hand, lacto- and lacto-ovo vegetarian diets have the

potential to be high in saturated fat and cholesterol if you eat a

lot of eggs or full-fat dairy products.

 

There is considerable controversy about tropical oils. In less

affluent parts of the world where the indigenous diet is plant-based

and coconuts and other high saturated-fat plant foods are staples,

the rates of chronic disease are relatively low. By contrast,

tropical oils are scarce in most North American diets, yet chronic

disease rates are high. Research suggests that – when consumed in

moderation as part of a high fibre, cholesterol-free, plant-based

diet – coconut and other saturated fat-rich plant foods do not

increase cholesterol levels or heart attacks.

 

So it's unnecessary for vegans or vegetarians to completely eliminate

these foods from their diets. The small amount of saturated fat

coming from whole plant foods may in fact be of benefit for vegans.

These are very stable fats with a low risk of being damaged and made

dangerous to your health by oxidation, in contrast to the unstable

polyunsaturated fats that are generally very high in vegan diets.

 

What about cholesterol? Since it's found only in animal foods, this

potential artery clogger is rarely a problem in vegetarian diets,

unless you eat a lot of eggs and high fat dairy products.

 

Trans fatty acids are another story. The product primarily of

hydrogenation (the food technology process of changing liquid oils

into solid fats), the main sources of these harmful fats are:

 

shortening

hydrogenated commercially prepared foods, like crackers, cookies,

cakes, pastries, potato chips, frozen convenience foods (just about

any commercial snack food)

and, of course, any food that lists " hydrogenated " or " partially-

hydrogenated " vegetable oil on the label.

Also, beware of fast food establishments: they generally use

hydrogenated oils for deep-frying.

Because trans fatty acids increase the risk of degenerative diseases,

they should be avoided.

 

Now for the healthy fats.

 

One of the biggest problems with fat in the vegetarian diet (and many

nonvegetarian diets too) is that we get a poor balance of essential

fatty acids.

 

There are two essential fatty acids:

 

Linoleic acid, from the omega-6 family, which can be converted and

elongated in our bodies to two very important long-chain fatty acids

named GLA (gamma-linolenic acid) and AA (arachidonic acid).

Similarly, alpha-linolenic acid, from the omega-3 family, which can

be converted and elongated to two other very important long-chain

fatty acids: DHA (docosahexaenoic acid) and EPA (eicosapentaenoic

acid).

Most people get too much of the omega-6 fatty acids in their diet and

not enough of the omega-3s. This imbalance may result in poor brain

development and reduced visual acuity in infants. In people of any

age, it may also contribute to chronic diseases, immune/inflammatory

disorders, and psychological disorders too.

Linoleic acid is found mainly in seed oils (like sunflower,

safflower, sesame, and grape), corn oil, soy, and grains. Alpha-

linolenic acid is found mainly in flax seeds, hemp seeds, greens,

canola oil, walnuts, and soy.

 

Few plant foods contain the long-chain fatty acids, which are most

commonly found in fish (omega-3s – namely EPA and DHA) and meat

(omega-6s – namely AA). Algae and seaweed are the only exception.

They contain long-chain omega-3s, but generally in very small

amounts.

 

Thus, vegans (but not necessarilly vegetarians, see below) get almost

all their long-chain fatty acids from internal conversion of the

short-chain EFA. Unfortunately, this conversion is very limited for

omega-3 fatty acids: only about 4-10% of alpha-linolenic acid is

converted into EPA, and just 2-5% becomes DHA. Worse, high intakes of

omega-6 fatty acids can competitively block this conversion by up to

50%.

 

Fortunately, to optimize your essential fatty acid balance there are

several things you can do:

 

Limit your use of linoleic-acid-rich oils (see above).

Select foods rich in monounsaturated fat as your primary fat source:

nuts and nut oils, olives and olive oil (extra virgin is best),

canola oil (preferably organic), and avocados.

Include a good source of alpha-linolenic acid in your diet every day.

We need about 2 to 3 grams. You can get this much from:

 

1 tsp. flax oil

1/4 cup walnuts

2 Tbsp. soy oil

1 Tbsp. hemp oil

20 cups dark greens

1 cup soybeans

1 Tbsp. ground flaxseeds

4 tsp. canola oil

12 ounces firm tofu

 

 

Consider getting a direct source of EPA and DHA, especially if you're

pregnant or lactating.

For lacto-ovo vegetarians, omega-3 rich eggs are a reasonable source

of DHA.

For vegans, microalgae-based supplements are the best option. While

seaweeds themselves contain some EPA, they are so low in fat you'd

have to eat enormous (and potentially unhealthful) amounts to make

any significant contribution to omega-3 intake.

There are two companies that market vegetarian DHA. NuTru sells " O-

Mega-Zen3 " with 300 mg of DHA per capsule, and Seroyal of Toronto

sells a 100 mg capsule, but only through licensed health

practitioners. Martek and OmegaTech also sell microalgae-based DHA,

but their capsules are made of nonvegetarian gelatin. A reasonable

daily intake of DHA would be 100-300 mg. Use 200-300 mg during

pregnancy and lactation.

To ensure the highest quality of fat in your diet, remember to use

fresh, whole plant foods.

Whenever possible, choose mechanically-pressed, unrefined oils.

 

Store nuts, seeds and oils in a cool, dry place in airtight

containers away from direct sunlight. When properly stored, unshelled

nuts and whole seeds last up to a year. Shelled nuts and ground seeds

can be stored in the refrigerator for up to four months or in an

airtight container in the freezer for up to one year. Ground

flaxseeds are more unstable due to their high omega-3 content. They

are best stored in the freezer after grinding. Nut halves keep better

than pieces as they are less exposed to light and oxygen.

 

While refined oils last many months in the pantry, fresh-pressed oils

(other than olive oil) go rancid much more quickly and need to be

refrigerated and used within two months (flax oil is best used up

within six weeks). Olive oil lasts longer than other fresh-pressed

oils and can be stored in the pantry for up to three to four months.

 

Finally, oils are easily damaged by heat, especially those containing

omega-3 fatty acids. But those like olive oil, organic canola oil,

and high oleic sunflower or safflower oil that contain mostly

monounsaturated fats are more stable when heated and are your best

choice for cooking and baking. So is nonhydrogenated margarine

(casein-free, if you're vegan).

 

With just a little bit of care, a vegetarian diet can be a source of

fats and oils that add savour to your meals and health to your years.

Brenda Davis, R. D.

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