Lecture 23: Primary Preventions - smoking, alcohol and food Flashcards
what are the lifestyle factors recommended to reduce CVD?
- diet
- weight management
- physical activity
- smoking cessation
how does smoking relate to CVD?
should already know this from the cancer module
- but smoking cigarettes is an important risk factor for CVD as well as cancer.
what is a ‘heart healthy’ diet?
the Heart Foundation has a guideline for people to refer to.
suggests to:
- eat mostly fruits and vegetables
- eat some breads, cereals, grains and starchy vegetables (wholegrain and high-fibre)
- eat some fish, meat, chicken, legumes, eggs
- some milk, yogurt, cheese
- less oils nuts
- cut back on junk, takeaways, sugary, salty and fatty food and drink
- the Harvard healthy plate has similar guidelines
what does this show?
a study that shows that dietary factors are important!
- number of deaths and age-standardised mortality rate attributable to individual dietary risks at the global and SDI level in 2017
- dietary risk factors are just as important as smoking risk factors for non-communicable diseases
- the top of the graph shows that diets high in sodium but low in whole grains, fruits, nuts, seeds and vegetables contribute most to mortality and CVD events
- interesting to note that low-middle income countries have less regulation of transfats in their food and as a result experience more diet-related mortality compared to higher income countries who do regulate trans fats.
what are the fatty acids in our diet?
- saturated fatty acid
- trans-fatty acid
- monosaturated fatty acid
- polyunsaturated fatty acid
what are saturated fatty acids? (SAFA)
animal fats:
- butter, full fat milk and dairy foods, fat on meat, skin on chicken. Also, palm oil and coconot oil
what are trans-fatty acids? (TFA)
- partially hydrogenated vegetable oils; processed foods like pastries, cakes, biscuits
what are monounsaturated fatty acids? (MUFA)
- olive oil, avocado, peanute, canola, ricebran oil, nuts
- important component of mediterranean diet
what are polyunsaturated fatty acids? (PUFA)
- sunflower oil, safflower oil, soybean oil, polyunsaturated margarines
- fish oils (omega-3 fatty acids)
what does this show?
- the 7 countries study
- close examination of dietary patterns in these countries with different rates of coronary artery disease mortaliy
- looked at the proportion of calorie intake from each type of fat
Kyushu (japan) had a total fat intake of 9% (3% each fat)
while countries like Finland had 39% total fat (22% saturated, 14% monounsaturated, 3% polyunsaturated)
what does this show?
linear relationship between the proportion of saturated fat and serum cholesterol
what does this show?
linear relationship between serum cholesterol and CHD mortality
- first suggestion that saturated fat was risk of CHD
what were the findings of the cochrane study?
there were 15 randomised control trials with 15,000 participants
found that cutting down on saturated fat had a 17% reduction in the risk of combined CV events, but had a limited impact on the risk of dying
- health benefits came from replacing saturated fat with polyunsaturated fat or starchy food
- no difference in men and women
what does this show?
this is a dose-response analysis
- found evidence of a cutpoint at 9% energy from saturated fat
- if you eat below 9% it a benefit for CV events and mortality
- most dietary guidelines recommend less than 10% energy from saturated fats
what is important to consider when replacing fats in your diet?
you need to substitue it with something healthy!!
- Reducing fat became a marketing ploy
- Unhealthy foods said they were low fat (e.g. marshmallows)
- Replacing saturated fat from healthy source of food with unhealthy food is not a good idea. Cutting down on things, you need to be careful with what you replace it with
what were the findings of the nurses health study and health professionals study?
if you replace saturated fats with trans fats or carbohydrates from refined starches or added sugars, there was an increased risk of coronary heart disease, but replacing SFAs with MUFAs, PUFAs or carbohydrates from whole grains had a decreased risk
- so don’t elimate fat out of diet completely
what does this show?
once you have above 10% sugar intake, there is an associated increased risk of CVD mortality
what does this show?
low systolic blood pressure is associated with a decreased sodium
- average of -5.4mmHg
(hypertension people)
what does this show?
people with a normal BP (non-hypertension) had a lower SBP with decreased sodium (-2.4mmHg) - smaller reduction than hypertension people
the overall effect:
- lower SBP associated with decreased sodium -4.2mmHg
what is the link between sodium intake and CVD events?
reduction in risk of CVD events with decreased sodium RR 0.80 (95%CI- 0.64,0.99) = 0.04
what is interesting about alcohol and CVD?
- the J shaped curve!
- this graph shows that more wine consumption = less mortality by IHD per 1000 men
- “french paradox” - low mortality by IHD despite most wine consumption
- is it something to do with confounding?
what does this show?
20g/day or less alcohol intake shows a decreased relative risk of coronary heart disease
- after 20g/day the risk starts to increase (j shaped curve)
what does this show?
- gender effect:
women have higher risk of coronary heart disease due to alcohol consumption.
