EAT FOR HEALTH Australian Dietary Guidelines

EAT FOR HEALTH – AusTRALiAn diETARy guidELinEs

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Guideline 2

Cancer

No recent studies investigating the association of consumption of nuts and seeds with cancer were identified.

legumes/beans

Few studies on legumes/bean foods, other than soy foods, were identified in the literature review to inform the

review of these dietary guidelines. For the evidence regarding legumes/beans, see Evidence Report, Section 7.

2.4.3 How consuming lean meats and poultry, fish, eggs, tofu, nuts and seeds,

and legumes/beans may improve health outcomes

This is such a broad and diverse group of foods that a variety of possible mechanisms may influence the effects

of their consumption.

Smoked, salted and chemically preserved foods have properties that may be responsible for increased health

risks. Endogenous formation of N-nitroso compounds has been suggested as a possible link between red meat

and colorectal cancer555,556 or that inflammatory effects of haem iron may be relevant^557 and further research is

occurring. As with other areas of diet and disease risk, an individual’s dietary pattern may be more relevant than

a direct effect from a single component.558,559

It has been suggested that components of meat such as saturated fats, or other dietary and lifestyle factors

associated with meat intake, may be relevant factors for further study. Previous evidence related to the amount of

saturated fat in red meat and increased risk of cardiovascular disease may not be relevant for lean Australian meats.

The protective effect of fish consumption on cardiovascular disease is thought to be mediated through the

influence of specific nutrients such as omega-3 lCPuFAs. These essential fatty acids exert their physiological

effect by altering cell membrane composition, fluidity, receptors and membrane-bound enzymes, gene expression

and eicosanoid production (see Section 3.1.1).

Nut consumption provides benefits by enhancing anti-inflammatory processes^560 and lowering serum cholesterol

possibly due to the presence of phytosterols, which reduce cholesterol re-absorption,^561 and/or the effects of

shifting dietary fat quality, notably replacing saturated with unsaturated fat. Nut consumption is also associated

with increased levels of adiponectin, which has anti-inflammatory and anti-atherogenic properties.^562 Early work

suggests that the delivery of components such as tocopherols and phenolic acids may help to reduce lipid

peroxidation and oxidative DNA damage, and there is some indication that walnuts with a relatively high content

of the amino acid l-arginine may have an effect on vasodilation through nitrous oxide pathways.^560 Other nuts

are also significant sources of arginine. Proposed mechanisms for effects on weight control include increased

satiety, increased faecal fat excretion, increased thermogenesis^563 and increased fat oxidation.^564

2.4.4 Practical considerations: enjoy lean meats and poultry, fish, eggs, tofu,

nuts and seeds, and legumes/beans

The most recent dietary survey data for adults in Australia showed that daily mean consumption of meat,

poultry and game was 200g for men and 120g for women.^45 Adult men and women daily consumed 99g

and 54g of lean red meat respectively.^45

The recommended consumption of lean meats and poultry, fish, eggs, tofu, nuts and seeds and legume/beans

for children and adults is one to three serves a day depending on age and sex (see Tables 2.11 and 2.12).

During pregnancy, three to four serves a day are recommended to provide additional iron and zinc.

To enhance dietary variety and reduce some of the health risks associated with consuming meat, up to a

maximum of 455g per week (one serve [65 g] per day) of lean meats is recommended for Australian adults.^9

The companion resources provide more detailed information on the recommended number of serves and

serve sizes of lean meats, poultry, fish, eggs, nuts and seeds and legumes/beans required for different

population groups. Discussion of dietary patterns and the environment is included in Appendix G.