nutrition over the life course

45
Nutrition over the life cycle Gianluca Tognon www.gianlucatognon.com

Upload: gianluca-tognon

Post on 27-Jun-2015

431 views

Category:

Health & Medicine


0 download

DESCRIPTION

My lecture at the course in lifecourse epidemiology, describing nutrition topics along the lifespan.

TRANSCRIPT

Page 1: Nutrition over the life course

Nutrition over the life cycle

Gianluca Tognonwww.gianlucatognon.com

Page 2: Nutrition over the life course

The lifecourse modelCritical period model

Critical period influences with later modifiers of their effects

Accumulation of risks with correlated results (one adverse or protective experience brings to another adverse or protective experience)

Accumulation of risks with independent and uncorrelated results

Page 3: Nutrition over the life course

24h dietary recall

Food frequency questionnaire

Diet history

Food records

Dietary assessment methods

Page 4: Nutrition over the life course

LIFECOURSE TOPICS IN NUTRITION

Breastfeeding Food contaminants

Children and adolescents Diet and cancer

Diet and the elderlyDiet and

cardiovascular disease

Go to the conclusions

Page 5: Nutrition over the life course

Breastfeeding

Which are the WHO recommendations for breastfeeding?

And for complementary foods/weaning?

Page 6: Nutrition over the life course

WHO Recommendations for breastfeeding

Exclusive breastfeeding is recommended up to 6 months of age, with continued breastfeeding along with appropriate complementary foods up to two years of age or beyond

Breastfeeding should begin within one hour of birth

Breastfeeding should be "on demand", as often as the child wants day and night

Bottles or pacifiers should be avoided

Page 7: Nutrition over the life course

Guidelines for complementary foods and weaning (WHO)

Start to give complementary foods at 4-6 months

7-12 months: continue breast-feeding as often as the baby wants. Give the child complementary food regularly, about 3-5 times per day

Do not give glucose drinks, sodas, and soft drinks, and avoid giving spicy foods to the baby

When the baby is already taken to eating, give mixes of complementary food

Continue to breast-feed the child up to 2 years and beyond

Page 8: Nutrition over the life course

breastfeeding should not be decreased when starting on solids

food should be given with a spoon or cup, not in a bottle

food should be clean, safe and locally available

ample time is needed for young children to learn to eat solid foods

Page 9: Nutrition over the life course

Breast milk substitutesAn international code to regulate the marketing of breast-milk substitutes was adopted in 1981. It calls for:

All formula labels and information to state the benefits of breastfeeding and the health risks of substitutes

No promotion of breast-milk substitutes

No free samples of substitutes to be given to pregnant women, mothers or their families

No distribution of free or subsidized substitutes to health workers or facilities

Back to the questions

Page 10: Nutrition over the life course

Children and adolescents

Malnutrition and undernutrition affect childhood health in a very serious way. These two terms are often used interchangeably, but do they really mean the same?

Which are possible causes and consequences of these conditions?

Page 11: Nutrition over the life course

Malnutrition and Undernutrition Malnutrition: A physical condition in which

people experience either nutrition deficiencies (undernutrition) or an excess of certain nutrients (overnutrition)

Undernutrition: The physical condition resulting from deficiencies in one or several macro- and micronutrients. It impairs growth, pregnancy, lactation, physical work, cognitive function, and disease resistance and recovery

Page 12: Nutrition over the life course

UndernutritionUndernutrition encompasses:

Stunting: low height for age

Wasting: low weight for age

Deficiencies of vitamins and minerals

Page 13: Nutrition over the life course
Page 14: Nutrition over the life course

Causes of undernutrition: biological & environmental

Maternal malnutrition before and/or during pregnancy (underweight newborn)

Infectious diseases (diarrheal disease, measles, AIDS, tuberculosis and others)

Overcrowded and/or unsanitary living conditions (which increase the likelihood of infections)

Agricultural patterns, droughts, floods, wars and forced migrations

Page 15: Nutrition over the life course

Social and economic causes

Poverty

Low/No education

Inadequate weaning practices (withdrawal of breastmilk or inadequate nutrient composition)

Social problems (child abuse, maternal deprivation, abandonment of the elderly, alcoholism, drug addiction)

Cultural and social practices (food taboos, food and diet fads)

Page 16: Nutrition over the life course

Consequences of chronic hunger

Most undernourished people do not starve to death, they die because their health has been compromised by dehydration from infections that cause diarrhea

Undernutrition reduces mental and physical development in children and makes people susceptible to potentially fatal infections

Consequences of unrelieved hunger include stunted growth, poor learning, extreme weakness, clinical signs of protein-energy malnutrition (PEM), increased susceptibility to disease, loss of the ability to stand or walk, premature death

Page 17: Nutrition over the life course

Undernutrition in early life and risk of obesity and T2D in adulthood

Disturbed growth due to undernutrition during fetal life, infancy or childhood results in early metabolic adaptations

These adaptations may be beneficial for short-term survival, but can increase the risk of chronic diseases, including obesity and T2D in the long term

The combination of low birth weight and rapid childhood growth has been associated with increased central fat deposition and insuline resistance

Page 18: Nutrition over the life course
Page 19: Nutrition over the life course

Back to the questions

Page 20: Nutrition over the life course

Diet and the elderly

What is sarcopenia?

Which dietary factors are important in its management?

Page 21: Nutrition over the life course

SarcopeniaAge-related loss of muscle mass,

strength and performance

The decline in skeletal muscle mass with aging is attributed to a disruption in the regulation of skeletal muscle protein turnover (synthesis/turnover)

The major factors considered to be involved include inflammation, hormonal changes, neurological factors, physical inactivity and inadequate nutritional intake (vitamin D and protein intake)

Page 22: Nutrition over the life course

Poor muscle strength is a major public health concern in older persons because it predisposes to poorer function and greater risk of falls, disability, and death

Several chronic conditions such as stroke, diabetes mellitus, arthritis, coronary heart disease, and chronic obstructive pulmonary disease seems to be associated with steeper strength decline and low handgrip strength

Page 23: Nutrition over the life course
Page 24: Nutrition over the life course

22-year follow-up data

Determinants of muscular strength decline:physically strenuous work and

becoming physically sedentaryexcess body weight smokingcardiovascular disease,

hypertension, diabetes mellitus, asthma in midlife

pronounced weight loss chronic bronchitis

Page 25: Nutrition over the life course

Dietary proteins It has been suggested that 25-30 g of

dietary protein per meal is required to allow an appropriate stimulation of postprandial muscle protein synthesis

Dietary protein intake should be overall equal to 1.2-1.5 g/kg/day to attenuate muscle loss compared to the recommended intake of at least 0.8 g/kg/day

Dietary protein supplementation might be a possible strategy

Page 26: Nutrition over the life course

Vitamin D The reduction in endogenous

vitamin D synthesis together with low vitamin D intakes result in a high prevalence of vitamin D deficiency among elderly people

Low vitamin D has been associated with poor muscle mass and impaired physical performance in the elderly

The activation of the vitamin D receptor in skeletal muscle tissue seems to stimulate muscle protein synthesis, preventing atrophy

Another mechanism is the regulation of calcium pumps and therefore, calcium concentration and muscle contraction performance

7-Dehydrocholesterol

Back to the questions

Page 27: Nutrition over the life course

Food contaminants

What’s an endocrine disruptor?

Can you name at least two endocrine disruptors that can be found in food?

Why are they interesting issue for life course epidemiology?

Page 28: Nutrition over the life course

Endocrine disruptors

Endocrine disruptors are chemicals that may interfere with the body’s

endocrine system and produce adverse developmental, reproductive,

neurological, and immune effects in both humans and wildlife

DioxinsPCBs

Brominated flame retardants

Polyflorinated compounds (e.g. teflon)

Bisphenol A

Page 29: Nutrition over the life course

Old and new acquaintances

Old acquaintances: Dioxins (ED, carcinogenic and teratogenic) PCBs (109 congeners, interfere with thyroid hormones,

toxicity evaluated with TEF and TEQ) PAHs (combustion products which are carcinogenic

metabolites)

New acquaintances: Perfluoroctans (ED and carcinogenic contained in cleaning

products, food containers, cardboard, photographic films, shampoos, toothpastes, lubricants for bicycles, garden tools, Teflon, Goretex, pesticides)

Flame retardants (very common, ED; contain bromine, many are produce dioxins or by incineration)

Phenols (ED; contained in plastic products, degreasing solutions, paints, plastics, pesticides).

Phthalates (ED, some are carcinogenic, their use is becoming less frequent, classically in PVC and in the films)

Page 30: Nutrition over the life course

Mother and child

Back to the questions

Endocrine disruptors accumulates in the human (and animal) body fat tissue over the entire life

Unfortunately, one of the mechanisms through which the body eliminates chemicals is breastfeeding

However, breastfeeding is discouraged only in women who have been exposed to chemical exposure

Exposure during gestation of certain compounds (e.g. PCBs) can affect thyroid hormones and thus, nervous system’s development

Page 31: Nutrition over the life course

Diet and cancerSome years ago, the WCRF released

an expert report about diet and cancer. Can you remember at least some of the recommendation made by WCRF?

What do you know about antioxidants? Are they really so important and why?

Page 32: Nutrition over the life course
Page 33: Nutrition over the life course
Page 34: Nutrition over the life course
Page 35: Nutrition over the life course

The concentration of antioxidants from food reaches very low levels in the organism (much lower than glutathione)

Not all oxidative processes happening inside the body are necessarily negative

Bioactive substances in fruit and vegetables might work through mechanisms other than protection from oxidation and at low concentrations: no need to use supplements and supplemented foods!

Page 36: Nutrition over the life course

INCREASED RISK DECREASED RISK

Oral cavity, pharynx, larynx

Alcoholic beveragesNon-starchy vegetables and carotenoid-rich foods

Esophagus Alcoholic beveragesNon-starchy vegetables, Fruit, carotenoid and vitamin C-rich fruit

Stomach Salt, Salted foods Non-starchy vegetables, garlic and fruit

Colon-rectus

Red meat, processed meats Alcoholic drinks (men)

Fiber-rich foods, Milk, Calcium, Garlic

Alcoholic beverages (women)

Breastpre-menopause

Alcoholic beverages Breastfeeding

Breastpost-menopause

Alcoholic beverages

Prostate High-calcium diets Licopene and selenium-containing foods

Modified from: WCRF 2007Convincing reduction

Convincing increase

Probable reduction

Probable increase

Page 37: Nutrition over the life course

INCREASED RISK DECREASED RISK

LungArsenic in drinking water, beta-carotene supplements

Fruit, carotenoid-rich foods

LiverAflatoxins

Alcoholic beverages

PANCREAS Folate-rich foods

Skin Arsenic in drinking water

Back to the questionsConvincing reduction

Convincing increase

Probable reduction

Probable increase

Page 38: Nutrition over the life course

Diet and cardiovascular diseases

Are obese at an increased risk of mortality compared to normal weight people?

What are trans fatty acids? Why they are dangerous?

How would you define a ”Mediterranean diet pattern”?

Page 39: Nutrition over the life course

Physiology. The health risk of obesity--better metrics imperative. Science 2013, 341, 856.

Page 40: Nutrition over the life course

Trans fatty acids

Natural TFAs constitutes a small portion of the human diet and mostly come from dairy products

The intake of TFAs has increased since the advent of fat hydrogenation (e.g. margarines)

In natural isomers the double bond is generally at C11 (e.g. vaccenic acid), while in technologically-produced ones it is generally between C4 or C10

The most common TFA in partially hydrogenated vegetable oils is the elaidic acid (trans-18:1 n9/∆9), a trans isomer of the oleic acid

Page 41: Nutrition over the life course

The Mediterranean dietary pattern

• One of the most cited examples of dietary pattern, repeatedly shown to be positively associated with a good health

• The first evidence of the beneficial effects of the Mediterranean diet came years ago from the Seven Country Study (Keys, 1980)

Page 42: Nutrition over the life course

Mediterranean diet, health and

longevityThe Mediterranean diet was first considered

protective against coronary heart diseases (de Lorgeril et al., 1999)

In other studies, beneficial effects on total mortality reduction have been discovered

(Trichopoulou et al., 2005)

Two recent literature meta-analyses showed that the Mediterranean diet is associated with a better

health status overall (Sofi et al., 2008 & 2010)

Page 43: Nutrition over the life course

The general features of this pattern are a high or moderately high intake of: cereals (that in the past were largely

unrefined) olive oil (or in general higher unsaturated

than saturated fat intake) fruit, vegetables and legumes nuts and seeds fish alcoholic beverages, but mostly red wine,

generally during meals

And a low or moderately low intake of dairy products meat and meat products

Highintakes

Mediterrean diet score

Low intake

s

Back to the questions

Page 44: Nutrition over the life course

Final considerations

Page 45: Nutrition over the life course

Thank you!

Gianluca Tognonwww.gianlucatognon.com