Lecture 15

Question 1

What are minerals and trace elements?

Answer 1

Essential, non-organic elements that DO NOT PROVIDE ENERGY. Required in small amounts

Question 2

If minerals/trace elements are low in the body, what happens?

Answer 2

Symptoms of deficiency may appear

Question 3

What is a mineral?

Answer 3

An element found in the body in a quantity of >5grams e.g. Na/K/Ca

Question 4

What is a trace element?

Answer 4

An element found in the body in a quantity of <5grams e.g. Fe/I/Zn

Question 5

What is the composition of sodium in the diet?

Answer 5

10% is inherent = naturally occurring in food
15% is discretionary = at consumers discretion to add more
75% is salt added during food processing

Question 6

What did the NZ Total Diet Study show?

Answer 6

• Didn’t look at discretionary sodium
• Saw a decrease in intake from the 80’s
• > food companies slowly decreasing amount of salt in packaged foods

Question 7

From the NZ Total Diet Study, what was the highest source of sodium?

Answer 7

Grain

Question 8

Describe sodium absorption

Answer 8

• Well absorbed, but not regulated

- Plasma levels controlled by the kidney

Question 9

What % of sodium is excreted in the urine?

Answer 9

> 90%

Question 10

Is sodium deficiency common?

Answer 10

No it is rare from the diet, can become depleted from losses (sweat, diarrhoea, vomiting)

Question 11

What happens to the kidneys with age?

Answer 11

The capacity to excrete sodium declines with age

Question 12

At what age does GFR start to decline?

Answer 12

30

Question 13

What is GFR at by age 80?

Answer 13

40%

Question 14

What does the decrease in GFR mean for blood pressure?

Answer 14

A smaller increase in salt intake can cause increased BP

Question 15

What is hypertension?

Answer 15

A disease where someone has higher than normal BP

Question 16

What is the effect of hypertension?

Answer 16

Can damage blood vessels which increases risk of heart and renal disease

Question 17

Describe the DASH1 diet

Answer 17

• Used an RCT with three conditions
  1. Control (typical diet)
  2. Fruit and vegetables
  3. F/V + low fat dairy products

Question 18

What were the results of the DASH1 diet?

Answer 18

• Sodium intake across the groups was very similar

- After 8 weeks, a decrease in BP was seen for both intervention diets

Question 19

Describe the DASH2 diet

Answer 19

• Another RCT with 2 conditions
  1. Control diet
  2. DASH diet

Question 20

What were the findings of the DASH2 diet?

Answer 20

• Regardless of Na+ levels, in both types of DASH diet results ALWAYS showed a decrease in blood pressure compared to the standard diet
• When you decrease Na+ in the diet, BP decreases
• When combining DASH with less sodium, this has the best effect

Question 21

What was the overall conclusion from the DASH2 diet?

Answer 21

Fruit and vege, calcium, and reduced sodium has the best effect at decreasing blood pressure