Sunday, February 19, 2012

Paleo vs DGA


New Food Groups
(NFG)
Australian Dietary Guidelines - Good
(DGA+)
Australian Dietary Guidelines - Bad
(DGA-)
6 Servings of Vegetables and Legumes/Beans
75g Spinach
75g Tomato
75g Carrot
75g Cos Lettuce
150g Snap Beans (2 Serves)
75g Spinach
75g Tomato
75g Carrot
75g Cos Lettuce
75g Chickpeas
75g Lentils
150g Potato (2 Serves)
150g Corn (2 Serves)
75g Chickpeas
75g Lentils
2 Servings of Fruit
150g Apple
150g Banana
150g Apple
150g Banana
60g Raisins (2 Serves)
6 Servings of Grain (Cereal) Foods, Mostly Wholegrain
150g Potato
150g Sweet Potato

120g Wholegrain Wheat Flour/Wheat Durum (4 Serves)
60g Brown Rice (2 Serves)
90g Wholegrain Wheat Flour/Wheat Durum (3 Serves)
30g White Flour
60g White Rice (2 Serves)
3 Servings of Lean Meat, Poultry, Fish, Eggs, Legumes/Beans and Nuts/Seeds
200g Lamb Chops (2 Serves)
115g Salmon
115g Salmon
75g Kidney Beans
30g Almonds
75g Kidney Beans
60g Almonds (2 Serves)
2.5 Servings of Milk, Yogurt, Cheese and/or Alternatives (Mostly Reduced Fat)
300g 5 Eggs (2.5 Serves)
(+ Vitamin D)

120g Ricotta Cheese
100g Yogurt (0.5 Serves)
250mL Milk
120g Ricotta Cheese
100g Yogurt (0.5 Serves)
250mL Milk

Vegetables and Legumes/Beans: The vegetables are kept constant between the NFG and DGA+.  The point of difference is that DGA+ recommends mature legumes, while NFG doesn’t recommend mature legumes but considers immature legumes to be similar to non-starchy vegetables.  Seeing as corn is considered a starchy vegetable by the guidelines, despite it being a nutritionally inferior grain, I gave it to DGA-, along with mature legumes and potato.

Fruit: Fruit is kept constant between the NFG and DGA+.  125mL of fruit juice is considered a serve of fruit by the guidelines.  I didn’t have data for fruit juice so I used the least nutrient dense fruit as a proxy for the low nutrient density of juice in the DGA- diet.  (Just as dairy is reduced to calcium, fruit is reduced to vitamin C).

Grain (Cereal) Foods, Mostly Wholegrain: The DGA+ has all wholegrains.  NFG places other foods in this category and suggests starchy vegetables are preferable to seed foods due to their lower toxicity.  So NFG has 3 serves of potato and 3 serves of sweet potato.  Each serve is 50g.  DGA- has 3 wholegrain serves and 3 refined grain serves.  The 4 serves of wheat reflects the high consumption of wheat.

Lean Meat, Poultry, Fish, Eggs, Legumes/Beans and Nuts/Seeds: The guidelines suggest legumes, nuts and seeds are alternatives to meat and eggs, so I replaced meat and eggs with seed foods in the DGA diets.

Milk, Yogurt, Cheese and/or Alternatives (Mostly Reduced Fat): NFG suggests alternatives to dairy can be other animal foods as well as vitamin D.  The alternative was eggs.

The differences between the guidelines and NFG are:

NFG
Guidelines
Immature Legumes
Mature Legumes
Starchy Vegetables
Grains
Meat
Mature Legumes, Nuts and Seeds
Eggs
Dairy

To compare them, I'm using my nutrient database

At the end of this NFG came to 1,632 calories, DGA+ came to 2,499 calories and DGA- came to 2,550 calories (this is without added fats/oils and extras).  So I adjusted the nutrient intakes of the diets as if there were 2000 calories.  Here are the results for the micronutrients.  The data is the % of the NRV.


NFG
DGA+
DGA-
Calcium
60
*102
98
Iron
*310
277
294
Magnesium
104
*162
144
Phosphorus
195
*227
204
Potassium
*149
130
114
Sodium
*112
46
33
Zinc
116
*117
110
Copper
135
158
*182
Manganese
71
*167
139
Selenium
*243
206
152
Vitamin C
*278
132
70
Vitamin B1
120
*192
158
Vitamin B2
*267
152
146
Vitamin B3
*205
150
95
Vitamin B5
*212
135
116
Vitamin B6
*361
238
154
Vitamin B9
175
*306
252
Choline
*209
45
32
Vitamin B12
*604
202
77
Vitamin A
*400
139
20
Vitamin E
*137
130
136
Vitamin D
*151
6
6
Vitamin K1
*848
556
33



What’s evident from calcium is that it is very difficult to meet the RDI for calcium without dairy.  As I pointed out in the response to section 2.5, the RDI for calcium should depend on vitamin D blood level of the individual.  An ideal vitamin D blood level of roughly 90 µmol/l decreases the calcium needed to 606 grams, the amount needed may be lower still if the RDI for calcium was set to compensate for widespread low vitamin D in Australia and in the context of a low phytic acid diet, which NFG is.  Seeing as NFG also promotes healthy vitamin D levels, calcium should not be an issue for it.  Among women and sedentary men, who can’t eat 2,000 calories they won’t even be able to meet the RDI for calcium with dairy.

Seed foods are rich in phosphorus as an important building block towards the metal chelator, phytic acid.  80% of the phosphorus in seed foods may be bound up in undigestable phytic acid, so it is not absorbed.  The two DGA diets contain many seed foods and get much of their phosphorus this way.  However if the measurement was which diet has the most bioavailable phosphorus NFG will likely be ahead of the DGA diets.

Even though NFG is richer in sodium it does not matter because salt (sodium chloride) is so easy to come by.  I won’t include sodium when comparing these diets.

It’s odd that DGA+ had slightly more zinc than NFG, even though NFG was richer in animal foods, which are good sources of zinc.  Once again if zinc bioavailability is taken into account NFG will be ahead of DGA+.

“Zinc found in animal products, crustaceans and molluscs is more readily absorbed than zinc found in plant foods. In contrast, legumes and unrefined cereals contain phytates that reduce zinc absorption.” [1]

NFG seems low in manganese, but the opposite could be true – that the NRV is too high.  The NRV for manganese is an AI based on the median intake of the Australian population.  As Australians eat a plant based diet and plants are the main source of manganese, Australians therefore consume a fair bit of it.  To compare this with other recommendations, the USDA AI for manganese is only 2.3 for men and 1.8 mg for women [2].  Both Australian and US recommendations were AI and based on the median population intake.  Seeing as the two country’s diets are similar it might have something to do with the concentration of manganese in soils.  I’m using data from the USDA, so data from Australian food might show higher levels.  The amount of manganese in NFG doesn’t seem to be an issue.

The low intake of choline in both DGA diets is due to our high requirement for choline.  Without eggs, organ meats or a fair bit of muscle meat it’s very difficult to meet this requirement for choline.  Most Australians are stuck in the unscientific dietary cholesterol and saturated fat phobia, meaning the average Australian won’t consume choline rich foods and runs the risk of choline deficiency.  The Australian and USDA AI for choline are the same and are based on what is needed to prevent liver damage rather than median intakes [3].  This is an issue for the dietary guidelines.

Vitamin D is a little out of place as we should be getting most of it from the sun.  I am going to include it because the recommended AI is far too low and fear mongering to keep us out of the sun is responsible for the low vitamin D in Australia.

The worse quality DGA diet (DGA-) was low is a few other nutrients.  Vitamin C was low, but I was too lazy to include orange juice as fruit serves (which was the plan) and that would have made it adequate.  Vitamin B3 (niacin) and B12 was low, which is what you would expect from a diet without meat.  Vitamin A was low because of the lack of carrots, sweet potato, eggs, liver, other vegetables, etc.  A diet of white foods such as grains, potatoes and reduced fat, grain-fed dairy (because vitamin A is fat soluble) may be lacking in some nutrients such as vitamin A.  K1 was low because of the lack of non-starchy vegetables especially the green leaves.  The DGA- diet had no long chain omega 3 because it didn’t include fish and had very little quality animal fats from meat or eggs.

NFG was a better source of 14 out of the 22 nutrients when compared with the DGA diets, which has 8 out of 22.  On average NFG was 37% higher in nutrients than DGA+ and 97% higher in nutrients than DGA-.  I’m now going to adjust for vitamin D and consider calcium to be a non-significant difference, hand over phosphorus and zinc to NFG due to superior bioavailability and consider vitamin E to be a non-significant difference.  Now NFG is a better source of 15 out of the 22 nutrients, 2 are tied and DGA has 5 out of 22.

There are other factors in favour of NFG.  There are fewer problematic dietary lectins, such as those found in grains and legumes, which damage the intestinal lining, increase intestinal permeability and decrease nutrient absorption.  I’m using USDA data for grain-fed animals, which could be improved nutritionally if they were grass-fed.  NFG allows consumption of liver, arguably the most nutrient dense food.

Overall NFG is better than the current recommendations both on paper and even more so when other factors are considered.  That being said current recommendations have an adequate nutrient content except in choline, which can lead to liver damage.  At the very least the guidelines should aim to increase choline intake by recommending eggs, organ meats and more muscle meat.

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