Nutrition: “Planetary-diet” could lead to poor health

Impact of sustainable diets on micronutrient intakes and status: outcomes of the MyPlanetDiet randomized controlled trial – ScienceDirect

Those eating a recommended “planetary-diet” (dramatic reduction of meat), even when counseled by experts, ended up with sharp drops in nutrients including a -36% drop in B-12.

Results

There were differential changes in intakes in the intervention arm compared to controls for GHGE (-22%), energy (-8%), retinol (-25%), thiamin (-11%), riboflavin (-16%), niacin (-16%), calcium (-16%), zinc (-13%), potassium (-10%), selenium (-15%), and iodine (-26%), vitamins B₆ (-12%), B₁₂ (-36%), C (-23%), D (-28%) and K₁ (30%) (P_interaction < 0.05). These were consistent following energy adjustment for retinol, riboflavin, niacin, calcium, iodine and vitamins B₁₂ and K_1. The prevalence of inadequate intakes of riboflavin, vitamins B₆ and B₁₂, calcium and zinc increased considerably, and at endpoint, there was a higher prevalence of inadequate intakes in the intervention arm for riboflavin, vitamins B₆, B₁₂ and C, calcium, zinc and selenium, than controls. Iron, iodine, vitamins A, D, E, C, and K₁ status did not change.

They then conclude, after finding drops in key nutrients:

Conclusions

A diet based on sustainable dietary principles lowered dietary GHGE and several MNs, despite provision of daily servings of dairy, three weekly servings of animal protein and two servings of fish. These findings show that MNs should be considered in developing environmentally protective diets.

Their diet requires a spreadsheet to follow.

Table 1. Overview of dietary guidelines in the MyPlanetDiet trial intervention arm based on sustainable healthy diet principles¹ and the control arm based on healthy eating guidelines²

Food Group	Intervention arm3	Control arm
Animal Protein (Beef, lamb, poultry, pork, eggs)	3 x servings/ week (140 – 160 g) Including a maximum of 1 serving of beef or lamb (140 g)	≤500 g of red meat (beef, lamb, pork)/ week Avoid processed meat
Plant Protein	1 serving of legumes /day (125-150 g) 1 serving of nuts and seeds/ day (25-35 g) ≤2 meat alternatives/ week (100-150 g)	No recommendation
Fish	2 servings/ week (100-140 g each) Include one oily fish, sustainably sourced	2 servings/ week (100 g) Choose oily
Dairy	1.5 – 2.5 servings/ day Serving = 125 mL milk, 125 g yogurt, 25 g cheese; Maximum 1 serving of cheese/ day	3 servings/ day (low fat) Serving: 200 mL milk, 125 g yogurt, 25 g cheese
Fruits and Vegetables	5 – 6 servings/ day (100 g) 2-3 servings of fruit 3 servings of vegetables including: ≥1 dark green ≥1 red/orange vegetable	5 servings/ day (80 g) 1 serving of citrus fruit ≤1 servings from juice or smoothies (150 mL)
Grains and starches	4-7 servings/ day according to energy requirement Serving: 2 slices of bread, 2 medium potatoes, 1 cup of cereal or cooked pasta, rice, or noodles Choose wholegrains where possible (>2 servings/ day) Limit potatoes to ≤ 2-3 servings/ week	≥50

While intakes among controls increased, vitamin D, thiamin, B₁₂, calcium, potassium, selenium and iodine decreased in the intervention arm, with a net difference between the arms as follows: vitamin D (-28%; 95% CI: -42, -10), thiamin (-11%; 95% CI: -18, -3), B₁₂ (-36%; 95% CI: -45, -25), calcium (-16%; 95% CI: -23, -8), potassium (-10%; 95% CI: -15, -4), selenium (-15%; 95% CI: -23, -6), and iodine (-26%; 95% CI: -35, -15). 

Supplemental Fig. 1 focuses on the MNs with a higher prevalence of inadequate intakes in the intervention arm at endpoint: participants consumed less riboflavin, vitamins B₆ and B₁₂, calcium, zinc and selenium from “milk & yogurt” (P = 0.004) and “ruminant meats” (P = 0.004); and with the exception of vitamin B₁₂, more from “legumes, soy & alternatives” (P = 0.004), “vegetables” (P ≤ 0.01) and “nuts & seeds” (P = 0.004), compared to controls.

Even with experts advising study participants – they still saw drops in important macro nutrients, including B-12:

However, despite individualized dietary counselling, we observed lower intakes of several key MNs in the intervention arm relative to controls, which were consistent following energy adjustment, including retinol, riboflavin, vitamin B₁₂, calcium and iodine.

After this finding:

The impact of a more restrictive dietary intervention, with lower amounts of meat, fish and dairy foods, is likely to limit the supply of these MNs still further, particularly vitamin B₁₂,

Only one other dietary intervention has assessed the impact of a more sustainable diet: a 12-week dose-response RCT from Finland which investigated the impact of consuming plant-proteins at 30%, 50% and 70% of total protein 24, 72. Compared to the 30% group, representing typical plant-protein intakes, Pellinen and colleagues reported significantly lower intakes of vitamin B₁₂ and D, iodine, zinc and calcium, with higher proportions of plant-protein, in alignment with our findings in the intervention arm. The Finnish team reported lower status of vitamin B₁₂ and iodine at 70% plant-protein, and no differences in iron, folate or vitamin D status between arms 24, 72

 With a one-third reduction in dietary GHGE, the MyPlanetDiet resulted in higher intakes of vitamin K₁ and lower intakes of key MNs including riboflavin, calcium, iodine and vitamin B_12, which persisted after adjusting for energy intake. Corresponding increases in the prevalence of inadequate intakes of riboflavin, calcium, zinc, selenium and vitamins B₆, and B₁₂ are concerning. These reductions occurred despite an allowance of three weekly servings of animal protein and two of fish, as well as daily servings of dairy

They then conclude:

Conclusions

A diet based on sustainable dietary principles lowered dietary GHGE and several MNs, despite provision of daily servings of dairy, three weekly servings of animal protein and two servings of fish. These findings show that MNs should be considered in developing environmentally protective diets.

They then end with a conclusion that “macro nutrients should be considered in developing environmentally protective diets“.

How about developing healthy diets that will not lead to health problems and possibly fatalities?

For those lacking classic heart disease risk factors, vitamin B deficiencies become a major risk factor for heart disease and heart attack – and may triple the risk of a heart attack.

See The Accidental Vegetarian – Coldstreams, for what happened to me due to vitamin B-12 deficiency.