Fruit, Vegetables & Potatoes: Health and Safety Aspects

Fruit, vegetables & potatoes (3): Health and safety aspects Ronan Gormley UCD Institute of Food & Health, Dublin 4, Ireland [email protected] ‘Eat colour’ and superfruits and make sure to get your 5-a-day (400-600g) - - - SuperValu...

Fruit, vegetables & potatoes (3): Health and safety aspects Ronan Gormley UCD Institute of Food & Health, Dublin 4, Ireland [email protected] ‘Eat colour’ and superfruits and make sure to get your 5-a-day (400-600g) - - - SuperValu - Swords Outline of presentation - - - FVP as suppliers of mainstream nutrients FVP as suppliers of other nutrients Antioxidants & free radicals FVP and gut health FVP and cardiovascular health FVP and cancer FVP and obesity/diabetes Microbiological safety of FVP Residues & contaminants in FVP  Plant-based diets could save ‘billions in healthcare costs A recent study examined the health & economic of 2 plant-based eating patterns: (a) a diet based on a daily proportion of soya foods and (b) a Mediterranean-style diet. The researchers concluded that savings would rise as high as €8.5bn if 10% of the UK population incorporated soya products into their daily diets Journal of Nutrition 2017 ‘Mainstream’ nutrients from FVP Carbohydrates (+ starch in potatoes) Proteins Fats Vitamins Minerals: K (fruit), Ca, Mg, P, Fe (spinach), Cu, Zn, S, Se + others Potatoes enriched with selenium (an antioxidant) ‘ACE’ vitamins: ‘traditional’ benefits Vitamin A (ß-carotene  retinol) negates: Night blindness Corneal ulceration Mucous membrane damage Vitamin C Negates scurvy Aids wound healing & the immune sytem Cold prevention? (‘Linus Pauling’) Vitamin E Aids cell metabolism Prevents a range of degenerative disorders  ‘ACE’ vitamins: ‘new’ benefits (~15years) ACE vitamins act a potent antioxidants and protect the body against free radical damage ACE vitamins are readily oxidised and act as free radical scavengers and chain breakers (i.e. free-radical quenchers) Free radicals are very unstable molecules (they contain an unpaired electron) and cause oxidative damage to cell membranes & DNA; this can lead to inflammatory diseases including certain forms of cancer and also to CHD Our bodies produce millions of free radicals every day and these need ‘quenching’; ACE vitamins assist in this process. The hydroxyl radical (OH) is particularly reactive  Provitamin A/ß-carotene content of selected F&V + other foods Fruit/vegetable µg Retinol equivalent/100g Carrots 2000 Leafy vegetables 685 Sweet potatoes 670 Fresh apricots 250 Tomatoes 100 Bananas 30 Oranges/juice 8 Other sources Cod-liver oil 23000 Liver (sheep) 17000 Butter 830 Cheese 320 Eggs 140 Availability of nutrients (to the body) http://apc.ucc.ie Only a proportion of a nutrient may be absorbable (e) and only part of this may be absorbed (d) ed = the proportion of the ingested nutrient flowing to the tissues; the maximal value is regarded as availability e = dietary component and depends on: the form in which the nutrient is present the digestibility of the matrix containing the nutrient the constituents affecting the proportion which remains available d = the consumer component, i.e. the genetically determined efficiency of the absorptive process Irish Times, Dec 31, 2013 ß-Carotene absorption vs fat/oil content of the diet [*The subjects (african boys) had low fat diet] Diet* supplemented Absorption with: efficiency (%) Carrots 5 Carrots + olive oil 25 Carotene in olive oil 45 ß-carotene is a fat soluble vitamin It is stable to cooking/canning It may become more available after heating, e.g. in boiled carrots  Good sources of vitamin C (cooked*) Fruit/vegetable Vitamin C (mg/100g) Blackcurrants 200 Parsley 150 VC is water soluble and highly Green peppers 100 available. It is easily lost on cooking, e.g. in potato during Broccoli tops 100 boiling (↓35%), warm-holding Strawberries 60 (60ºC/1h:↓20%), mashed Kiwi fruit 60 & chilled (3ºC/4d;↓70%) Cauli/cabbage/spinach 55 (20)* Oranges 50 Microwaving gives double the Peas 25 (15)* retention compared to boiling Potatoes - old 14 (10)* or steaming. Potatoes - new 30 (15)*  Vitamin E (tocopherols) Comprises 8 fat-soluble, heat stable compounds with biological activity of α-tocopherol Major antioxidants both in-situ and as additives; prevent oxidation of lipids (fats) in cell membranes; also reduce oxidation in foods Wheatgerm oil (133)** and vegetable oils (25- 50) the main sources, also extra virgin oil (24- 34) {refined olive oil = 2.2} **Units: tocopherols (mg/100g)  Vitamin D (calciferol) (IU µg) Fat soluble vitamin which ‘needs sunshine to shine’[VD3 (cholcalciferol) is the biologically active form found in our bodies and in animals. Sunlight on our skin converts cholesterol into VD3] VD3 is twice as effective at raising VD levels in the body than VD2 (ergocalciferol) Deficiency leads to poor bone development, rickets and osteoporosis Fatty fish, eggs & cheese are good VD sources UV light during growing ↑↑ vit D2 content of mushrooms (UCD trial) Evidence that Vitamin D supplementation could reduce risk of influenza and COVID-19 infections and deaths: Nutrients 2020, 12, 988 + Irish Times October 5, 2020 Vitamin D3 or oral vitamin D is converted to 25(OH)D in the liver & then to 1,25(OH)2D (calcitriol), in the kidneys or other organs as needed. Most of vitamin D’s effect arises from calcitriol entering the nuclear vitamin D receptor, a DNA binding protein ? 40ng VD/ml blood = significantly reduced risk Kenny (TCD) recommends 400IU VD/d =10micrograms of VD 1 microgram = (10-6g)  Good sources of folic acid Lentils Frozen peas Asparagus Raw egg Spinach Various grains Deficiency is associated with neural tube defects (spina bifida) It is also important for the production of healthy red blood cells Many foods are fortified with folic acid Other nutrients & non-nutrients from F&V Cell wall material (dietary fibre) Cellulose Hemicellulose (gums, mucilages) Pectin Lignin Antioxidants Other bioactives  The future is fibre according to Tate & Lyle NUTRAingredients.com; December 2018 European consumers of all ages & from all regions want to increase their fibre intake but motivation/reasons differ with age. Younger consumers seek fibre for weight management benefits whereas older consumers seek digestive health, satiety & a lowering of glycaemic response HEALTH CLAIMS >3g/100g or >1.5g/100kcal = source of fibre >6g/100g or >3g/100kcal = high fibre  Dietary fibre (DF) content of selected F&V Fruit/vegetable DF (%) Raspberries 7.4 Bananas 3.4 Apples 2.2 Functions of F&V DF: Strawberries 2.2 Reduces gut transit time Oranges 2.0 May act as a prebiotic Peas 5.2 May reduce cholesterol Carrots 2.9 May aid diabetic control Cabbage 2.5 Lettuce 1.5 DF/d > 25g Wholemeal bread 8.5 White bread 2.7  FV & gut health Dietary fibre from FV will decrease gut transit time thereby decreasing the residence time of ‘damage-causing agents’ Dietary fibre from FV may act as a prebiotic thereby stimulating the profileration of in-gut beneficial bacteria FV bioactives (including antioxidants) may combat inflammation in the gut thereby preventing the onset/development of certain cancers Antioxidants – currently a hot topic!! Most are coloured–hence ‘eat colour’ Anthocyanins (red & blue berries) Carotene (carrots) Lycopene (tomatoes) Flavonoids (many F&V) Polyacetylenes (carrots) Other Antioxidants are thought to have a major role in combating inflammatory diseases (CHD & certain cancers) by reducing the level of mucous membrane & tissue damage. Protective may be direct OR indirect, i.e., (stimulates immune system)  ARP (1/IC50) of apples ± skin Roessle et al., 0.8 AFRC study 2007 0.7 0.6 0.5 Granny 0.4 Braeburn 0.3 Golden 0.2 0.1 0 + Skin -Skin  FV & cardiovascular health Many fruits reduce serum cholesterol in humans and raise the high density lipoprotein (good) fraction. Fruit pectin is the likely active agent. See apple example ---- Some vegetables, e.g. peas, also reduce serum cholesterol. Saponins in the peas are the likely active agents. See example ----  2 apples/day reduce serum cholesterol levels (mmol) in humans Mechanism = bile acid excretion? 6.1 6 5.9 5.8 5.7 Apple group No apple group 5.6 5.5 5.4 2 apples/day 5.3 78 volunteers wk6 39 pairs Gormley et al 1978  30g of freeze-dried peas/day reduce serum cholesterol levels (mmol) in humans Peas (30g/day) 6.4 56 volunteers 6.3 28 pairs 6.2 C. Flakes (40g/d) 6.1 6 Peas group Corn flakes group 5.9 5.8 5.7 Mechanism = 5.6 saponins are the wk 6 active agents? Gormley et al 1979  FV and cancer F&V are linked to cancer prevention via their antioxidant content and other bioactives (phytochemicals), e.g. lycopene and prostate cancer Brassicas (esp. broccoli & B. sprouts) are called ‘cancer busters’ based on their content of glucosinolates - - these produce isothiocyanates which can (i) act in a protective capacity or (ii) cause cancerous cells to self-destruct. Indoles & organic sulphur compounds are also important Onions & garlic are protective via allium compounds FV may also be beneficial in that they may displace other foods in the diet; some of these may be linked with possible cancer initiation & development, e.g charred meats The word ‘linked’ is very important as most of the evidence is epidemiological rather than based on satisfactory clinical human trials  FV and obesity Obesity is reaching epidemic proportions in many developed countries with consequent negative implications for health Obesity has a number of causes including: Energy kcal/g Consuming too many calories Consuming ‘unpackaged’ calories Carbo = 3.75 Consuming the wrong type of foods Protein = 4 Insufficient exercise Alcohol = 7 Genetic predisposition Fat = 9 FV can help combat obesity in a number of ways including: By displacing more calorific foods in the diet (satiety effect) By providing ‘packaged’ (slow release) calories By helping control late-maturity-onset diabetes Natural complexity—whole foods (Grimme, H., Humboldt University, Berlin) Key nutrients are retained Nutrients are in a cell matrix Nutrients are diluted  (BEWARE OF OVERLOAD!) Slow release of nutrients is likely = (release & use!!) Nutrients may be in a more absorbable form?, e.g. hydrogen bonded?  Heaton, K.W. 1978. Fibre, satiety & insulin-a new approach to overnutrition & obesity. In: Dietary fibre: current developments of importance to health. Proc 3rd Kellogg Nutrition Symposium, Newman Publishing, London,141-149 Apple juice 60g Apple puree 60g Serum Apple slices 60g insulin 1h 2h 3h  CONTROLLING DIABETES 3 x 5g portions/d of apple fibre reduce blood glucose (mmol/L) in 12 humans with type 2 diabetes 10 9.5 9 8.5 8 7.5 7 wk 0 wk 1 wk 2 wk 3 wk 4 Mayne et al 1982  Boiled potato: many nutrients + resistant starch Starch is a slow-release form of energy as the grains are contained in cells and the chains have then to be broken down by enzyme action and only then the released sugar is absorbed. Resistant starch passes through the small intestine but is fermented in the large intestine Starch content and properties affect flouriness Starch grains are almost visible to the naked eye & are seen as a ‘milkiness’ during potato peeling. Extracted starch is a white powder like wheat flour Potato starch is a glucose polymer (‘chain’) comprised of amylose (linear =3k glucose molecules) & amylopectin (branched = 2mio glucose molecules) Effect of multiple cooking-cooling on the formation of resistant starch (% of DM) in boiled diced potatoes Cook-cool1 Storage temperature2 4ºC 20ºC Once 12.8 12.1 Twice 17.5 14.1 Three times 23.2 18.2 1 Cook 8 min/blast cool 8 min 2 All samples stored for 24h prior to analysis RS ↑ therefore DF ↑ Has ‘DF’ potential for cold potato salad  Vegetarianism, veganuary and health Many vegetarians consume dairy products & eggs; vegans do not Vegetarians: 30% less CHD in men; 20% less in women Vegetarians : lower body mass, cholesterol and blood pressure Vegetarians : Good diet; dairy products + eggs supply essential nutrients Vegans: Less good diet & must consume a wide range of whole grain foods in order to obtain essential nutrients Many researchers say that vegetarians have a similar lifespan to carnivores BUT - - - - - RECENT LANCET ARTICLE (2019) Vegetarians have a significantly lower mortality rates reveals new (U.California) study - - - (Orlich et al., 2013. JAMA Internal Medicine) Study followed the death rates of 73,308 people (adventists) over a six year period The adjusted hazard ratio for all-cause mortality in all vegetarians was 12% lower than non-vegetarians and for males following a vegan diet the lowering was 28% Epidemiological evidence shows that vegetarians typically have lower blood pressure, lower LDL cholesterol, a lower BMI, and lower fasting blood glucose WHY vegetarians typically have better health outcomes remains the subject of intense debate  Food Navigator January 2014 NESTLE: ‘Garden Gourmet’ range of 12 meat-free products based on plant protein Food Navigator, June 2018  Plant-based seafood brand TUNO hits the shelves Food Navigator, 6 November 2018 North Carolina-based ‘Natural Foods’ have launched a canned plant-based seafood (TUNO) made from non-GMO soy flour Tuna is a heavily overfished valuable species and ‘Natural Foods’ recognise that wild fish are not an endless resource TUNO is in line with consumers’ growing interest in sustainability & the need for companies to implement programmes to improve the environment Irish Times, 14 November 2018 - - - - product made from wheat and soya CAGR = compound annual growth rate APAC = Asia Pacific Vertical farming = sustainable solution to food insecurity? 7.5bn 2019 Shorter supply chains = urban growing 8.5bn 2030 Delivering quality and efficiency Higher start-up and energy costs than conventional agriculture 9.7bn 2050  Safety aspects of F&V Safety may, potentially, be compromised by one or more of the following: Fertilisers Pesticides Natural toxicants Microorganisms Additives  Fertilisers NPK + minerals + trace elements Excessive application causes environmental problems, especially in water, but usually has little impact on produce composition. However, nitrate is an exception, especially in leafy produce such as lettuce and spinach  Pesticides & agrochemicals Insecticides Fungicides Herbicides Sprout inhibitors Other There are strict protocols for the application of agrochemicals embracing amounts, frequency of application, withdrawal periods before harvest and other safeguards Pesticides & MRLs (maximum residue level) MRL = maximum concentration of pesticide residue likely to occur in fruit & vegetables after the use of pesticides according to Good Agricultural Practice MRLs are primarily trading standards & are typically