Should you trust the RDA?

Are we really eating a healthy balanced diet?

Experts who claim that we can get all the nutrients we need from our diet always use the caveat 'a healthy balanced diet'. But how do we really know if our diet is providing all the nutrients we need?

Fruit and vegetables are one of the most important sources of many vitamins and minerals. But while 90% of UK adults say they are aware of the recommendation to eat 5-a-day, less than a third (27%) of adults reach this target (1). 

Quick Definitions!

• Recommended Dietary Allowance (RDA): an estimation of how much of a nutrient you need, based on your age, sex, and pregnancy status.
• Adequate Intake (AI): how much of a nutrient you need to avoid an obvious deficiency disease.
• Tolerable Upper Limit (UL): how much of a nutrient you can safely take without overdose.

1. The numbers are for preventing deficiency

The numbers in the RDA report are designed to prevent obvious deficiency, not to achieve optimal health.

So if you follow their recommendation for Vitamin D, you won’t get rickets; if you follow the recommendation for Vitamin B1, you won’t get beriberi.

It’s definitely better not to have these diseases than to have them (obviously), but just the fact that you don’t have rickets or beriberi doesn’t make you healthy.

Nutrients can play a crucial role in helping to reduce the risk of a whole host of conditions like certain types of cancer, dementia and heart disease.

So how can you tell how much of a nutrient you really need? One way is via a DNA test, as variations on our DNA affect the absorption and uptake of vitamins and minerals.

In general terms, there’s reasonably solid evidence that the RDA for Vitamin C, Vitamin D, and iodine might be too low.

2. Declining soil quality

Some experts believe that intensive farming, which uses artificial fertilisers to encourage plants to grow bigger and faster, means that fruit and vegetable are far less nutritious now than they were 60 years ago.

A paper published in the Journal Hort Science in 2009 (2) suggested that the nutrition content of some fruit and veg may have dropped by as much as 40% in the last 70 years.

Another report published by UK nutritionist Dr David Thomas found that levels of iron, copper and calcium in vegetables had decreased by up to 76% since 1940. His research revealed that in vegetables, levels of magnesium had dropped by 25%, calcium and copper by 75%, in fruit iron had dropped by 25% and copper by 20% (3).

As a result, you would need to:

• Eat three apples or oranges to get the same iron content as one in 1940.
• Eat four carrots today to get the same amount of magnesium found in one in 1940.

Even if our fruit and veg do contain plenty of vitamins, how many of them are still there by the time the food gets to your plate?

Your shopping habits, as well as the way you prepare and cook fruit and vegetables can also lead to a significant decline in the levels of vitamins and minerals.

A study published in the Journal of Food Chemistry found that broccoli could lose up to 70% of its vitamin C and beta-carotene and 50% of its antioxidant activity in the time it takes to get from the farm to your plate (4).

If vegetables are boiled in a large amount of water, vitamins C and B are leaked into the cooking water and up to 50% can be lost.

Therefore, be sure to roast or steam your vegetables whenever possible. 

3 Ways To Up Your Nutrient Intake

1. Stick to seasonal produce

If you can eat local and/or seasonal fruit and vegetables, they won’t have travelled as far and should still contain healthy nutrient levels.

2. Don’t forget about frozen

Freezing fruits and vegetables almost as soon as they are picked helps preserve their nutrient content. Adding some frozen veg to a casserole or berries to your NGX smoothie can help increase your vitamin and mineral intake.

3. Take a multivitamin and mineral supplement

Plug any gaps by taking a full-spectrum multivitamin. The long-range nutrient study found that sodium, potassium, magnesium, calcium, iron and copper were all significantly lacking in our fruit and vegetables, so any supplement should include these essential minerals. Hint hint: BodyFuel contains all of these and much, much more 😉

Sources

(1) http://www.telegraph.co.uk/news/2017/03/30/just-one-four-adults-eating-five-day-nhs-reveals/

(2) https://journals.ashs.org/hortsci/view/journals/hortsci/44/1/article-p15.xml

(3) https://www.rejuvenation-science.com/research-news/calcium-magnesium/n-calcium-depletion 

(4) https://www.emerald.com/insight/content/doi/10.1108/NFS-11-2012-0123/full/html